WorldWideScience

Sample records for adi internal gears

  1. Effect of tooth profile modification on wear in internal gears

    Science.gov (United States)

    Tunalioglu, M. S.; Tuc, B.

    2018-05-01

    Internal gears are often used in the automotive industry when two gears are required to rotate in the same direction. Tooth shapes, slippage speeds at the beginning and end of meshing are different according to the external gears. Manufacturing of internal gears is more difficult than external gears. Thus, it is necessary to determine the working conditions and wear behavior of internal gears carefully. The profile modification method in terms of strength and surface tension of the gear mechanism are performed in order to increase the load-carrying capability. In this study, profile modification method was performed in the internal gears to reduce the wear on the teeth. For this purpose, the wear of the internal gears was theoretically investigated by adapting the Archard wear equation to the internal gears. Closed circuit power circulation system was designed and manufactured to experimentally investigate the wear in internal gears. With this system, wear tests of gears made of St 50 material without profile modification and different profile modifications were made and the results were compared. Experimental study was performed in the same loading and cycle time conditions to validate the theoretical results and it was seen that the results are compatible. According to the experimental results, it is seen that in the internal gears, when profile modification done the wear is decreased in the teeth tip region.

  2. Expanding Internationally: OCLC Gears Up.

    Science.gov (United States)

    Chepesiuk, Ron

    1997-01-01

    Describes the Online Computer Library Center (OCLC) efforts in China, Germany, Canada, Scotland, Jamaica and Brazil. Discusses FirstSearch, an end-user reference service, and WorldCat, a bibliographic database. Highlights international projects developing increased OCLC online availability, database loading software, CD-ROM cataloging,…

  3. A method for gear fatigue life prediction considering the internal flow field of the gear pump

    Science.gov (United States)

    Shen, Haidong; Li, Zhiqiang; Qi, Lele; Qiao, Liang

    2018-01-01

    Gear pump is the most widely used volume type hydraulic pump, and it is the main power source of the hydraulic system. Its performance is influenced by many factors, such as working environment, maintenance, fluid pressure and so on. It is different from the gear transmission system, the internal flow field of gear pump has a greater impact on the gear life, therefore it needs to consider the internal hydraulic system when predicting the gear fatigue life. In this paper, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposing the prediction method based on the virtual simulation. The method use CFD (Computational fluid dynamics) software to analyze pressure distribution of internal flow field of the gear pump, and constructed the unidirectional flow-solid coupling model of gear to acquire the contact stress of tooth surface on Ansys workbench software. Finally, employing nominal stress method and Miner cumulative damage theory to calculated the gear contact fatigue life based on modified material P-S-N curve. Engineering practice show that the method is feasible and efficient.

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: ADI INTERNATIONAL INC. ADI PILOT TEST UNIT NO. 2002-09 WITH MEDIA G2®; PHASE II

    Science.gov (United States)

    Verification testing of the ADI International Inc. Unit No. 2002-09 with MEDIA G2® arsenic adsorption media filter system was conducted at the Hilltown Township Water and Sewer Authority (HTWSA) Well Station No. 1 in Sellersville, Pennsylvania from October 8, 2003 through May 28,...

  5. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  6. Multi-stage internal gear/turbine fuel pump

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Eugen; Raney, Michael Raymond

    2004-07-06

    A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.

  7. Gearing.

    Science.gov (United States)

    1985-12-01

    trichloroethyl phosphite and a phosphate ester containing a pentachlorphenyl radical. Most of the Asperity heights phosphorous compounds in gear oils...108) found that phosphorous compounds chemisorption. These boundary films can be thinner than ( 1 0 u ts n 0.025 pm (I in ) or several microinches thick...Pinion 1 .. dibutylxanthic acid disulfide. Ŗ %- Lead soaps have been used in lubricants for many 02 years. They resist the wiping and sliding action in

  8. Application of x-ray method for measuring internal stress in the gear teeth surface layer

    International Nuclear Information System (INIS)

    Zaborowski, T.

    1996-01-01

    This paper presents the methodics of the internal stress measurements concerning cylindrical gear teeth of involute profile. There are the method selected, relation between stress and strain presented and conditions of investigation discussed in the study, including preparation of samples for investigation and conditions of the strain measurement. Exemplifying results of stress measurements for teeth of gears made of 4OH steel are shown. Suitability of the developed investigation method is indicated

  9. On optimization of internal/external spur gears tooth bending strength

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2014-01-01

    level at the tooth root. As with most machine elements the design/geometry is defined in standards (ISO). The present work focuses on changing the tooth root design of both external and internal gears, in order to improve the stress concentration factor. The design changes made are compliant...

  10. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  11. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  12. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  13. Adie's syndrome: some new observations.

    Science.gov (United States)

    Thompson, H S

    1977-01-01

    Adie's syndrome is a disease of unknown etiology. We known where the damage is, and which nerves are involved. We even know something of how the nerves react after the damage is done, but we don't known what causes the primary injury. The first step in working a jigsaw puzzle is to getall of the pieces right side up and take a good look at them. Some of the jigsaw pieces handled in this paper are listed below. Some of them are new observations; many of them are old concepts, partly modified and partly made secure by new facts. 1. Not all "tonic pupils" are due to "Adie's syndrome"; some are due to local injury and some to a generalized peripheral neuropathy (Table II). 2. All patients should have serologic tests for shyphilis. In this series one in six had positive serology. 3. The incidence of Adie's syndrome in Iowa in the early 1970's was approximately 4.7 per 100,000 population per year. 4. The prevalence of Adie's syndrome, therefore, was approximately 2 per 1000. 5. The mean age of onset of Adie's syndrome was about 32.2 years (Figure 1A). 6. The sex ratio was 2.6 females to each male. 7. Right eyes and left eyes were involved at approximately the same rate (Figure 2). 8. The incidence of second eye involvement in unilateral cases was about 4% per year during the first decade of the disease (Figure 18). 9. If this rate of second eye involvement (4% per year) persists during subsequent decades, then most Adie's pupils will eventually become bilateral. 10. The incidence of Adie's syndrome in a largely caucasian patient group is independent of iris color (Figure 4). 11. Only 10% of patients with Adie's syndrome had completely normal muscle stretch reflexes. 12. The muscle stretch reflexes in the arms were just as frequently imparied as those in th elegs, but the degree of impariment tended to be more severe in the ankles and triceps. 13. When there was any light reaction remaining in an Adie's pupil, a segmental paralysis of the sphincter muscle could be seen

  14. Design of Gear Churning Power Loss Measurement Device

    OpenAIRE

    Wang Bin; Zhou Ya Jie; Wang Ping

    2017-01-01

    To explore the impacts of gear churning power losses, a research was conducted to achieve the internal causes of power losses of churning gear by designing a gear churning power losses measurement device. The gear churning power losses could be influenced by different gear modules, the number of teeth and the axial position of gear. Finally, the impacts of gear churning power losses were discussed by comparing experimental data and theoretical data.

  15. A superconducting magnetic gear

    International Nuclear Information System (INIS)

    Campbell, A M

    2016-01-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844–46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further. (paper)

  16. Stability of BDF-ADI Discretizations

    KAUST Repository

    Felí cio dos Reis, Joã o Miguel

    2017-01-01

    We present new results on absolute stability for BDF-ADI (Backward differentiation formula Alternating Direction Implicit) methods applied to a linear advection and diffusion equations. Unconditional absolute stability of the BDF2-ADI method is proven for advection and diffusion separately, as well as to the BDF3-ADI method for the purely-diffusive case. Conditional absolute stability of the BDF4-ADI is also proven for the purely-diffusive case, and stability regions for BDF3-ADI and BDF4- ADI are given in terms of the PDE coefficients and numerical parameters. Lastly, numerical experiments are presented to support the theoretical results and conjectures. These experiments also suggest future work.

  17. Stability of BDF-ADI Discretizations

    KAUST Repository

    Felício dos Reis, João Miguel

    2017-08-17

    We present new results on absolute stability for BDF-ADI (Backward differentiation formula Alternating Direction Implicit) methods applied to a linear advection and diffusion equations. Unconditional absolute stability of the BDF2-ADI method is proven for advection and diffusion separately, as well as to the BDF3-ADI method for the purely-diffusive case. Conditional absolute stability of the BDF4-ADI is also proven for the purely-diffusive case, and stability regions for BDF3-ADI and BDF4- ADI are given in terms of the PDE coefficients and numerical parameters. Lastly, numerical experiments are presented to support the theoretical results and conjectures. These experiments also suggest future work.

  18. Reduction of image-based ADI-to-AEI overlay inconsistency with improved algorithm

    Science.gov (United States)

    Chen, Yen-Liang; Lin, Shu-Hong; Chen, Kai-Hsiung; Ke, Chih-Ming; Gau, Tsai-Sheng

    2013-04-01

    In image-based overlay (IBO) measurement, the measurement quality of various measurement spectra can be judged by quality indicators and also the ADI-to-AEI similarity to determine the optimum light spectrum. However we found some IBO measured results showing erroneous indication of wafer expansion from the difference between the ADI and the AEI maps, even after their measurement spectra were optimized. To reduce this inconsistency, an improved image calculation algorithm is proposed in this paper. Different gray levels composed of inner- and outer-box contours are extracted to calculate their ADI overlay errors. The symmetry of intensity distribution at the thresholds dictated by a range of gray levels is used to determine the particular gray level that can minimize the ADI-to-AEI overlay inconsistency. After this improvement, the ADI is more similar to AEI with less expansion difference. The same wafer was also checked by the diffraction-based overlay (DBO) tool to verify that there is no physical wafer expansion. When there is actual wafer expansion induced by large internal stress, both the IBO and the DBO measurements indicate similar expansion results. The scanning white-light interference microscope was used to check the variation of wafer warpage during the ADI and AEI stages. It predicts a similar trend with the overlay difference map, confirming the internal stress.

  19. Modern gear production

    CERN Document Server

    Watson, H J

    1970-01-01

    Modern Gear Production focuses on the processes and methods in gear making. The book first gives information on the history of gear making and types of gears. Topics such as the classification of gears based on the disposition of their shafts; shafts lying in the same plane with axes intersecting; and shafts lying in parallel planes but with axes inclined to one another are then discussed. The text describes gear groups, tooth forms, and gear materials. Heat treatment of steels, casehardening, nitriding, induction hardening, sulfinuzing, and flame hardening are explained. The book takes a look

  20. Kinematic geometry of gearing

    CERN Document Server

    Dooner, David B

    2012-01-01

    Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat

  1. Gear Tooth Root Stresses of a Very Heavily Loaded Gear Pair-Case Study: Orbiter Body Flap Actuator Pinion and Ring Gear

    Science.gov (United States)

    Krantz, Timothy L.; Handschuh, Robert F.

    2015-01-01

    The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.

  2. Gear bearing drive

    Science.gov (United States)

    Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor); Weinberg, Brian (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  3. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  4. Estimating Gear Teeth Stiffness

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffness’s of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact length is constant....

  5. AERODYNAMIC IMPROVEMENT OF KhADI 33 RACING CAR RADIATOR COMPARTMENT

    Directory of Open Access Journals (Sweden)

    A. Avershyn

    2011-01-01

    Full Text Available Aerodynamic characteristics of radiator compartment of KhADI 33 racing car on the basis of the decision of the interfaced problem of internal and external aerodynamics are numerically investigated. The rational variant of radiator compartment which is characterized by high throughput and low level of non-uniformity of speed field at the input is offered.

  6. Microadditions of boron and vanadium in ADI

    Directory of Open Access Journals (Sweden)

    Rzychoń T.

    2007-01-01

    Full Text Available In the second part of the study, describing the role of vanadium and boron microadditions in the process of structure formation in heavy-walled castings made from ADI, the results of own investigations were presented. Within this study two series of melts of the ductile iron were made, introducing microadditions of the above mentioned elements to both unalloyed ductile iron and the ductile iron containing high levels of nickel and copper (the composition typical of ADI. Melts were conducted with iron-nickel-magnesium master alloy. Thermal analysis of the solidification process of the cast keel blocks was conducted, the heat treatment of the alloys was carried out, and then the effect of the introduced additions of boron and vanadium on the hardenability of the investigated cast iron was examined and evaluated.

  7. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  8. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  9. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun; (4...

  10. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp...

  11. Prediction of Microstructure in ADI Castings

    Directory of Open Access Journals (Sweden)

    Guzik E.

    2016-12-01

    Full Text Available Tests were carried out on samples of low-alloy ductile iron with additions of Ni, Cu and Mo, subjected to austempering heat treatment. The samples were austenitized at 850, 900 and 950 °C, and then austempered at T = 210, 240, 270, 300 and 330 °C. The ausferritizing treatment was carried out in a salt bath for the time τ = 2 - 8 hours. Additionally, tests and studies covered samples subjected to the ausferritizing treatment at 270 °C with the time of holding castings in a bath from 2 to 24 hours. Evaluation covered the results of the ADI microstructure examinations and hardness measurements. The ADI matrix morphology was identified counting the average number of ausferrite plates and measuring their width and spacing. The regression equations HB = f (τ, T and τ = f (HB, T were derived to establish the, so-called, “process window”, allowing obtaining a priori the required microstructure of ADI and, consequently, the required mechanical properties, mainly hardness, shaping the functional properties of castings, abrasion wear resistance – in particular.

  12. Landing Gear Door Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  13. Process and Performance Outcomes of a Nontraditional Postbaccalaureate PharmD Program Geared Toward Internationally Trained Pharmacists.

    Science.gov (United States)

    Prabhu, Sunil; Chung, Eunice; Le, Quang A; Nguyen, Megan; Robinson, Daniel

    2015-10-25

    Established in 2003, the fully accredited international postbaccalaureate doctor of pharmacy (IPBP) program has attracted internationally trained pharmacists from approximately 25 countries and 6 continents, mostly residents of the United States, to attain the doctor of pharmacy (PharmD) degree at the Western University of Health Sciences. While recent trends in the IPBP applicant pool have shown a decline from its peak numbers in 2009 (222 applicants) for the 20 available seats each year, the quality of students remains high. Benchmark measures assessed for this group of students include the internal assessment entrance examination, admissions scores, academic assessments from didactic blocks, and scores on the North American Pharmacy Licensure Examination (NAPLEX), all of which indicate this quality. Moreover, graduates from the program not only consistently demonstrate excellence in the pharmacy curriculum and board examinations, but also go on to establish themselves as competent practitioners and educators. While the long-term future of the program is unknown, the status of the program and its graduates provides ample evidence of its value and ensures its continued success going forward.

  14. Gearing Up for Mountain Biking.

    Science.gov (United States)

    Jahnke, Thomas; Hamson, Mike

    1999-01-01

    Examines the gear system of a mountain bike to discover any redundancy in the many gear settings available to the cyclist. Suggests a best strategy for changing up through the gears on a typical 21-gear system and an adjustment to the available gears that would result in a smoother change. (Author/ASK)

  15. Controlled pump with internal toothed gears during four-quadrant operation. Velocity- and position control of a hydraulic handling device; Geregelte Innenzahnradpumpe im Mehrquadrantenbetrieb. Geschwindigkeits- und Positionsregelung eines hydraulischen Handlinggeraetes

    Energy Technology Data Exchange (ETDEWEB)

    Dahmann, P. [Fachhochschule Aachen (Germany). FB Luft- und Raumfahrttechnik; Hagemeister, W. [IGH, Essen (Germany); Nagel, G.; Exner, P. [Voith Turbo, Heidenheim (Germany)

    2006-07-01

    The drive of a handling device (weight 3t) is realized by an hydrocylinder, which is directly connected with the pressure side of a pump with internal toothed gears. The drive speed is generated by a frequency controlled electric motor. As a result for frequency-controlled drive can be noted less noise formation, less heat generation, an energy efficienct operation as a simple control- and regulation possibilities for position and velocities. (GL)

  16. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2013-01-01

    Full Text Available A method to simulate residual stress field of planetary gear is proposed. In this method, the finite element model of planetary gear is established and divided to tooth zone and profile zone, whose different temperature field is set. The gear's residual stress simulation is realized by the thermal compression stress generated by the temperature difference. Based on the simulation, the finite element model of planetary gear train is established, the dynamic meshing process is simulated, and influence of residual stress on equivalent stress of addendum, pitch circle, and dedendum of internal and external meshing planetary gear tooth profile is analyzed, according to non-linear contact theory, thermodynamic theory, and finite element theory. The results show that the equivalent stresses of planetary gear at both meshing and nonmeshing surface are significantly and differently reduced by residual stress. The study benefits fatigue cracking analysis and dynamic optimization design of planetary gear train.

  17. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  18. Low alloy steel versus ADI – differences and similarities

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2009-01-01

    Full Text Available The results of comparison between the microstructure of selected bainitic low alloy steel and austempered ductile iron ADI are presented. The aim of the comparison was to find out differences and similarities existing in these iron carbon commercial alloys. In this paper our own results on ADI structure and literature data were used. It follows from discussion presented here that both microstructure and properties of ADI are very close that which are observed in low alloy carbon steel. Moreover, we suggest that there is no so doubt to treat ADI mechanical properties as steel containing nodular inclusions of graphite.

  19. Fiscal 1999 technical achievement report. Research and development project on prompt-effect international standards creation (Standardization of test and evaluation of superhigh-precision toothed gear); 1999 nendo shinki sangyo ikusei sokkogata kokusai hyojun kaihatsu jigyo seika hokokusho. Choseimitsu haguruma no seidono shiken hyoka hoho no hyojunka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In ISO1328 that covers specifications on precision of toothed gears, gears are graded according to the magnitude of error, but there is no system established for guaranteeing measured error values for accuracy. Activities are conducted for realizing such a guarantee, for establishing methods for testing and evaluating gear precision measuring devices, and for working out international standards for them. It is decided that the current status be investigated and then a concrete method be proposed as an international standard centering about gear precision measuring digital devices which will stay important in the future. A digital measuring device enhanced in precision is constructed by way of trial, and then it is proved that the newly fabricated device works effectively in the calibration of gear precision measuring devices in general use. Thanks to this process, basic data are collected about the measurement of gear precision using a gear precision measuring digital device, and this enables the preparation of a draft of criteria for international standardization. (NEDO)

  20. Rigid MATLAB drivetrain model of a 500 kW wind turbine for predicting maximum gear tooth stresses in a planetary gearbox using multibody gear constraints

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

    2014-01-01

    multiple planetary gears are not taken into account. Finite Element Method (FEM) calculations show that when the wind turbine runs close to the maximum wind speed, the maximum gear tooth stress is in the range of 500–700 MPa, which is considered to be realistic using a “worst-case” method. The presented...... for not only transferring torque but also for calculating the gear tooth and internal body reaction forces. The method is appropriate for predicting gear tooth stresses without considering all the complexity of gear tooth geometries. This means that, e.g. gear tooth load-sharing and load-distribution among...

  1. Cold deformation of ADI castings: Martensitic transformation

    International Nuclear Information System (INIS)

    Navea, Lilian R; Mannheim, Rodolfo M; Garin, Jorge L

    2004-01-01

    Research and applications in austempered ductile iron (ADI castings) have recently undergone noticeable progress in the industrialized world, becoming a highly competitive engineering material. The notable properties of these castings derive from their austenitic matrix stabilized by carbon, a thermally stable austenite during the austenizing process but possibly turning into martensite when undergoing plastic deformation. This work aims to study the changing structure of an ADI casting caused by one directional cold lamination. The samples that were studied were obtained from two nodular castings, one without alloying and the other alloyed with Cu, Ni and Mo. The samples were austenized in the first stage of the austempering process at 910 o C for 80 min. Then in the second stage the unalloyed samples were austempered at 410 o C for 10 min and the alloyed samples for 120 min. After the thermal treatment, the test pieces were deformed 0% to 25% by cold lamination. The quantification of the phases was performed using x-ray diffraction and the metallographic study using optic and Scanning Electronic Microscopy. The results show that the martensitic phase obtained by deformation is a very fine structure that evolves into a thicker one when the deformation of the samples increases (CW)

  2. Modeling an internal gear pump

    Science.gov (United States)

    Chen, Zongbin; Xu, Rongwu; He, Lin; Liao, Jian

    2018-05-01

    Considering the nature and characteristics of construction waste piles, this paper analyzed the factors affecting the stability of the slope of construction waste piles, and established the system of the assessment indexes for the slope failure risks of construction waste piles. Based on the basic principles and methods of fuzzy mathematics, the factor set and the remark set were established. The membership grade of continuous factor indexes is determined using the "ridge row distribution" function, while that for the discrete factor indexes was determined by the Delphi Method. For the weight of factors, the subjective weight was determined by the Analytic Hierarchy Process (AHP) and objective weight by the entropy weight method. And the distance function was introduced to determine the combination coefficient. This paper established a fuzzy comprehensive assessment model of slope failure risks of construction waste piles, and assessed pile slopes in the two dimensions of hazard and vulnerability. The root mean square of the hazard assessment result and vulnerability assessment result was the final assessment result. The paper then used a certain construction waste pile slope as the example for analysis, assessed the risks of the four stages of a landfill, verified the assessment model and analyzed the slope's failure risks and preventive measures against a slide.

  3. Austempered ductile iron (ADI) for railroad wheels : final report.

    Science.gov (United States)

    2017-01-31

    The purpose of this project is to investigate the potential for austempered ductile iron (ADI) to be used as an alternative material for the production of rail wheels, which are currently cast or forged steel which is commonly heat treated. ADI has s...

  4. A Generalized Dynamic Model of Geared System: Establishment and Application

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2011-12-01

    Full Text Available In order to make the dynamic characteristic simulation of the ordinary and planetary gears drive more accurate and more efficient , a generalized dynamic model of geared system is established including internal and external mesh gears in this paper. It is used to build a mathematical model, which achieves the auto judgment of the gear mesh state. We do not need to concern about active or passive gears any more, and the complicated power flow analysis can be avoided. With the numerical integration computation, the axis orbits diagram and dynamic gear mesh force characteristic are acquired and the results show that the dynamic response of translational displacement is greater when contacting line direction change is considered, and with the quickly change of direction of contacting line, the amplitude of mesh force would be increased, which easily causes the damage to the gear tooth. Moreover, compared with ordinary gear, dynamic responses of planetary gear would be affected greater by the gear backlash. Simulation results show the effectiveness of the generalized dynamic model and the mathematical model.

  5. Communication: Molecular gears

    Energy Technology Data Exchange (ETDEWEB)

    Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)

    2016-09-07

    The {sup 1}H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  6. The cycloid Permanent Magnetic Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank T.

    2008-01-01

    This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model...... regarding torque density. The results were promising as compared to other high-performance magnetic-gear designs. A test model was constructed to verify the analytical model....

  7. Research of HCR Gearing Properties from Warm Scuffing Damage Point of View

    Directory of Open Access Journals (Sweden)

    Kuzmanović Siniša

    2014-12-01

    Full Text Available The issue of design and dimensioning of HCR gearing, particularly of the gearings with an internal engagement, it nowadays, especially in the design of hybrid cars drives, highly topical. This kind of gearing has many advantages in operation, but at the same time it is more complicated in stage of its design and load capacity calculation. Authors in this contribution present some results of temperature scuffing research of internal and external HCR gearing. There are given the equations for calculation of warm scuffing resistance of both external and internal HCR gearing derived according to the integral temperature criterion.

  8. Unique microstructure and excellent mechanical properties of ADI

    Directory of Open Access Journals (Sweden)

    Jincheng Liu

    2006-11-01

    Full Text Available Amongst the cast iron family, ADI has a unique microstructure and an excellent, optimised combination of mechanical properties. The main microstructure of ADI is ausferrite, which is a mixture ofextremely fine acicular ferrite and stable, high carbon austenite. There are two types of austenite in ADI:(1 the coarser and more equiaxed blocks of austenite between non-parallel acicular structures, which exist mainly in the last solidified area, and (2 the thin films of ustenite between the individual ferriteplatelets in the acicular structure. It is this unique microstructure, which gives ADI its excellent static and dynamic properties, and good low temperature impact toughness. The effect of microstructure on the mechanical properties is explained in more detail by examining the microstructure at the atomic scale. Considering the nanometer grain sizes, the unique microstructure, the excellent mechanical properties,good castability, (which enables near net shape components to be produced economically and in large volumes, and the fact that it can be 100% recycled, it is not overemphasized to call ADI a high-tech,nanometer and “green” material. ADI still has the potential to be further improved and its production and the number of applications for ADI will continue to grow, driven by the resultant cost savings over alternative materials.

  9. LHC preparations change gear

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    After the formal approval by CERN Council in December (January, page 1) of the LHC protonproton collider for CERN's 27- kilometre LEP tunnel, preparations for the new machine change gear. Lyndon Evans becomes LHC Project Leader, and CERN's internal structure will soon be reorganized to take account of the project becoming a definite commitment. On the experimental side, the full Technical Proposals for the big general purpose ATLAS and CMS detectors were aired at a major meeting of the LHC Committee at CERN in January. These Technical Proposals are impressive documents each of some several hundred pages. (Summaries of the detector designs will appear in forthcoming issues of the CERN Courier.) The ALICE heavy ion experiment is not far behind, and plans for other LHC experiments are being developed. Playing an important role in this groundwork has been the Detector Research and Development Committee (DRDC), founded in 1990 to foster detector development for the LHC experimental programme and structured along the lines of a traditional CERN Experiments Committee. Established under the Director Generalship of Carlo Rubbia and initially steered by Research Director Walter Hoogland, the DRDC has done sterling work in blazing a trail for LHC experiments. Acknowledging that the challenge of LHC experimentation needs technological breakthroughs as well as specific detector subsystems, DRDC proposals have covered a wide front, covering readout electronics and computing as well as detector technology. Its first Chairman was Enzo larocci, succeeded in 1993 by Michal Turala. DRDC's role was to evaluate proposals, and make recommendations to CERN's Research Board for approval and resource allocation, not an easy task when the LHC project itself had yet to be formally approved. Over the years, a comprehensive portfolio of detector development has been built up, much of which has either led to specific LHC detector subsystems for traditional detector tasks

  10. The changes of ADI structure during high temperature annealing

    OpenAIRE

    A. Krzyńska; M. Kaczorowski

    2010-01-01

    The results of structure investigations of ADI during it was annealing at elevated temperature are presented. Ductile iron austempered at temperature 325oC was then isothermally annealed 360 minutes at temperature 400, 450, 500 and 550oC. The structure investigations showed that annealing at these temperatures caused substantial structure changes and thus essential hardness decrease, which is most useful property of ADI from point of view its practical application. Degradation advance of the ...

  11. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...

  12. 49 CFR 230.89 - Reverse gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse gear...

  13. analysis of gear milling at vari gear milling at various gear milling

    African Journals Online (AJOL)

    eobe

    2 DEPARTMENT OF INDUSTRIAL AND ... conventional machine tools, cutter tool wear, .... speed, and tool wear on case-hardened gear is also .... study. The gear cutter is mounted on the spindle. Spindle speeds and feed rates are essential ...

  14. Torsional vibration signal analysis as a diagnostic tool for planetary gear fault detection

    Science.gov (United States)

    Xue, Song; Howard, Ian

    2018-02-01

    This paper aims to investigate the effectiveness of using the torsional vibration signal as a diagnostic tool for planetary gearbox faults detection. The traditional approach for condition monitoring of the planetary gear uses a stationary transducer mounted on the ring gear casing to measure all the vibration data when the planet gears pass by with the rotation of the carrier arm. However, the time variant vibration transfer paths between the stationary transducer and the rotating planet gear modulate the resultant vibration spectra and make it complex. Torsional vibration signals are theoretically free from this modulation effect and therefore, it is expected to be much easier and more effective to diagnose planetary gear faults using the fault diagnostic information extracted from the torsional vibration. In this paper, a 20 degree of freedom planetary gear lumped-parameter model was developed to obtain the gear dynamic response. In the model, the gear mesh stiffness variations are the main internal vibration generation mechanism and the finite element models were developed for calculation of the sun-planet and ring-planet gear mesh stiffnesses. Gear faults on different components were created in the finite element models to calculate the resultant gear mesh stiffnesses, which were incorporated into the planetary gear model later on to obtain the faulted vibration signal. Some advanced signal processing techniques were utilized to analyses the fault diagnostic results from the torsional vibration. It was found that the planetary gear torsional vibration not only successfully detected the gear fault, but also had the potential to indicate the location of the gear fault. As a result, the planetary gear torsional vibration can be considered an effective alternative approach for planetary gear condition monitoring.

  15. Three new models for evaluation of standard involute spur gear mesh stiffness

    Science.gov (United States)

    Liang, Xihui; Zhang, Hongsheng; Zuo, Ming J.; Qin, Yong

    2018-02-01

    Time-varying mesh stiffness is one of the main internal excitation sources of gear dynamics. Accurate evaluation of gear mesh stiffness is crucial for gear dynamic analysis. This study is devoted to developing new models for spur gear mesh stiffness evaluation. Three models are proposed. The proposed model 1 can give very accurate mesh stiffness result but the gear bore surface must be assumed to be rigid. Enlighted by the proposed model 1, our research discovers that the angular deflection pattern of the gear bore surface of a pair of meshing gears under a constant torque basically follows a cosine curve. Based on this finding, two other models are proposed. The proposed model 2 evaluates gear mesh stiffness by using angular deflections at different circumferential angles of an end surface circle of the gear bore. The proposed model 3 requires using only the angular deflection at an arbitrary circumferential angle of an end surface circle of the gear bore but this model can only be used for a gear with the same tooth profile among all teeth. The proposed models are accurate in gear mesh stiffness evaluation and easy to use. Finite element analysis is used to validate the accuracy of the proposed models.

  16. Energy efficiency improvement by gear shifting optimization

    Directory of Open Access Journals (Sweden)

    Blagojevic Ivan A.

    2013-01-01

    Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.

  17. A Numerical Instability in an ADI Algorithm for Gyrokinetics

    International Nuclear Information System (INIS)

    Belli, E.A.; Hammett, G.W.

    2004-01-01

    We explore the implementation of an Alternating Direction Implicit (ADI) algorithm for a gyrokinetic plasma problem and its resulting numerical stability properties. This algorithm, which uses a standard ADI scheme to divide the field solve from the particle distribution function advance, has previously been found to work well for certain plasma kinetic problems involving one spatial and two velocity dimensions, including collisions and an electric field. However, for the gyrokinetic problem we find a severe stability restriction on the time step. Furthermore, we find that this numerical instability limitation also affects some other algorithms, such as a partially implicit Adams-Bashforth algorithm, where the parallel motion operator v parallel ∂/∂z is treated implicitly and the field terms are treated with an Adams-Bashforth explicit scheme. Fully explicit algorithms applied to all terms can be better at long wavelengths than these ADI or partially implicit algorithms

  18. Određivanje krutosti planetarnog prenosnika / Determination of gear mesh stiffness in planetary gearing

    Directory of Open Access Journals (Sweden)

    Vojislav Batinić

    2008-04-01

    Full Text Available Kontaktna krutost zubaca jedan je od glavnih generatora unutrašnjih dinamičkih sila u spregama zupčanika planetarnih prenosnika. Neophodan je pri opisivanju dinamičkog ponašanja planetarnih prenosnika, tj. pri postavljanju jednačina dinamičke ravnoteže. U radu je prikazan metodološki pristup analitičkom i eksperimentalnom određivanju krutosti posmatranog planetarnog prenosnika. / Gear mesh stiffness in planetary gearing is one of the main generators of internal dynamic forces. It is necessary in describing dynamic behavior of planetary trains, i.e. in defining their equations of dynamic balance. This paper presents a methodological approach to experimental and analytical calculation of stiffness in planetary gearing.

  19. Gear ratting noise reduction of diesel engine; Diesel engine no gear hauchi soon teigen

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, S; Miura, Y [Hino Motors, Ltd., Tokyo (Japan)

    1997-10-01

    Gear raffling noise of diesel engine at idling condition is required to reduce for keeping quiet environment and comfort of driver and passengers on track and bus. Decrease of gear backlash is generally adopted for reducing gear rattling noise. On the other hand, it has been found that newly devised measurement of gear teeth speed and gear meshing error has clarified phenomena of gear rattling between the crankshaft gear and the camshaft gear of the diesel engine. And it has been also found that gear ratting noise is reduced by changing meshing between the crankshaft gear and the camshaft gear. 2 refs., 10 figs.

  20. 46 CFR 28.885 - Cargo gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire rope...

  1. Double Helical Gear Performance Results in High Speed Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  2. High Pressure Angle Gears: Comparison to Typical Gear Designs

    Science.gov (United States)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  3. The comparative studies of ADI versus Hadfield cast steel wear resistance

    Directory of Open Access Journals (Sweden)

    Mieczysław Kaczorowski

    2011-04-01

    Full Text Available The results of comparative studies of wear resistance of ADI versus high manganese Hadfield cast steel are presented. For evaluation ofwear resistance three type of ADI were chosen. Two of them were of moderate strength ADI with 800 and 1000MPa tensile strength whilethe third was 1400MPa tensile strength ADI. The specimens were cut from ADI test YII type casting poured and heat treated in Institute ofFoundry in Krakow. The pin on disc method was used for wear resistance experiment. The specimens had a shape of 40mm long rod withdiameter 6mm. The load and speed were 100N and 0,54m/s respectively. It was concluded that the wear resistance of ADI is comparablewith high manganese cast steel and in case of low tensile grade ADI and is even better for high strength ADI than Hadfield steel.

  4. Design and construction of permanent magnetic gears

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif

    /l]. Measurement from this gear has resulted in a measured total torque density of 23 [Nm/l]. Mechanical versions of this gear type are found with total torque density in the 16 to 31 [Nm/l] range. The third and last gear technology that is investigated is a gear that reminds of a planetary gear. Research shows......This thesis deals with design and development of permanent magnetic gears. The goal of this thesis is to develop knowledge and calculation software for magnetic gears. They use strong NdFeB permanent magnets and a new magnetic gear technology, which will be a serious alternative to classical...... mechanical gears. The new magnetic gear will have a high torque density1 relationship –high efficiency and are maintenance free. In this project was manufactured two test gears which is tested and verified with models developed in this project. Present technological status for magnetic gears is introduced...

  5. Tensile properties of ADI material in water and gaseous environments

    Energy Technology Data Exchange (ETDEWEB)

    Rajnovic, Dragan, E-mail: draganr@uns.ac.rs [Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovića 6, 21000 Novi Sad (Serbia); Balos, Sebastian; Sidjanin, Leposava [Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovića 6, 21000 Novi Sad (Serbia); Eric Cekic, Olivera [Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade (Serbia); Grbovic Novakovic, Jasmina [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade (Serbia)

    2015-03-15

    Austempered ductile iron (ADI) is an advanced type of heat treated ductile iron, having comparable mechanical properties as forged steels. However, it was found that in contact with water the mechanical properties of austempered ductile irons decrease, especially their ductility. Despite considerable scientific attention, the cause of this phenomenon remains unclear. Some authors suggested that hydrogen or small atom chemisorption causes the weakening of the surface atomic bonds. To get additional reliable data of that phenomenon, in this paper, two different types of austempered ductile irons were tensile tested in various environments, such as: argon, helium, hydrogen gas and water. It was found that only the hydrogen gas and water gave a statistically significant decrease in mechanical properties, i.e. cause embrittlement. Furthermore, the fracture surface analysis revealed that the morphology of the embrittled zone near the specimen surface shares similarities to the fatigue micro-containing striation-like lines, which indicates that the morphology of the brittle zone may be caused by cyclic local-chemisorption, micro-embrittlement and local-fracture. - Highlights: • In contact with water and other liquids the ADI suddenly exhibits embrittlement. • The embrittlement is more pronounced in water than in the gaseous hydrogen. • The hydrogen chemisorption into ADI surface causes the formation of a brittle zone. • The ADI austempered at lower temperatures (300 °C) is more resistant to embrittlement.

  6. NEW TECHNIQUES FOR HIGH-CONTRAST IMAGING WITH ADI: THE ACORNS-ADI SEEDS DATA REDUCTION PIPELINE

    International Nuclear Information System (INIS)

    Brandt, Timothy D.; Turner, Edwin L.; McElwain, Michael W.; Grady, C. A.; Abe, L.; Brandner, W.; Feldt, M.; Henning, T.; Carson, J.; Egner, S.; Golota, T.; Guyon, O.; Hayano, Y.; Hayashi, S.; Ishii, M.; Goto, M.; Hashimoto, J.; Hayashi, M.; Iye, M.; Hodapp, K. W.

    2013-01-01

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the SEEDS survey. We implement several new algorithms, including a method to register saturated images, a trimmed mean for combining an image sequence that reduces noise by up to ∼20%, and a robust and computationally fast method to compute the sensitivity of a high-contrast observation everywhere on the field of view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is written in python. It is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI requires minimal modification to reduce data from instruments other than HiCIAO. It is freely available for download at www.github.com/t-brandt/acorns-adi under a Berkeley Software Distribution (BSD) license.

  7. Development of Airport Noise Mapping using Matlab Software (Case Study: Adi Soemarmo Airport - Boyolali, Indonesia)

    Science.gov (United States)

    Andarani, Pertiwi; Setiyo Huboyo, Haryono; Setyanti, Diny; Budiawan, Wiwik

    2018-02-01

    Noise is considered as one of the main environmental impact of Adi Soemarmo International Airport (ASIA), the second largest airport in Central Java Province, Indonesia. In order to manage the noise of airport, airport noise mapping is necessary. However, a model that requires simple input but still reliable was not available in ASIA. Therefore, the objective of this study are to develop model using Matlab software, to verify its reliability by measuring actual noise exposure, and to analyze the area of noise levels‥ The model was developed based on interpolation or extrapolation of identified Noise-Power-Distance (NPD) data. In accordance with Indonesian Government Ordinance No.40/2012, the noise metric used is WECPNL (Weighted Equivalent Continuous Perceived Noise Level). Based on this model simulation, there are residence area in the region of noise level II (1.912 km2) and III (1.16 km2) and 18 school buildings in the area of noise levels I, II, and III. These land-uses are actually prohibited unless noise insulation is equipped. The model using Matlab in the case of Adi Soemarmo International Airport is valid based on comparison of the field measurement (6 sampling points). However, it is important to validate the model again once the case study (the airport) is changed.

  8. Analysis of justification for applying two gear sets within the universal gear reducers

    OpenAIRE

    Rackov Milan; Kuzmanović Siniša; Knežević Ivan; Čavić Maja; Penčić Marko

    2017-01-01

    In the area of universal gear reducers, standard does not prescribe relations between load capacity, gear ratios and axis heights. Therefore, larger load capacity of some gear reducers manufacturers has advantage for lower gear ratio and, vice versa, smaller load capacity of the gearbox achieves higher values of gear ratio. However, there are some manufacturers who produce gear reducers with smaller or larger load capacity for higher or lower gear ratio, within the same axis height. This pape...

  9. Interlocking Molecular Gear Chains Built on Surfaces.

    Science.gov (United States)

    Zhao, Rundong; Qi, Fei; Zhao, Yan-Ling; Hermann, Klaus E; Zhang, Rui-Qin; Van Hove, Michel A

    2018-05-17

    Periodic chains of molecular gears in which molecules couple with each other and rotate on surfaces have been previously explored by us theoretically using ab initio simulation tools. On the basis of the knowledge and experience gained about the interactions between neighboring molecular gears, we here explore the transmission of rotational motion and energy over larger distances, namely, through a longer chain of gear-like passive "slave" molecules. Such microscopic gears exhibit quite different behaviors compared to rigid cogwheels in the macroscopic world due to their structural flexibility affecting intermolecular interaction. Here, we investigate the capabilities of such gear chains and reveal the mechanisms of the transmission process in terms of both quantum-level density functional theory (DFT) and simple classical mechanics. We find that the transmission of rotation along gear chains depends strongly on the gear-gear distance: short distances can cause tilting of gears and even irregular "creep-then-jump" (or "stick-slip") motion or expulsion of gears; long gear-gear distances cause weak coupling between gears, slipping and skipping. More importantly, for transmission of rotation at intermediate gear-gear distances, our modeling clearly exhibits the relative roles of several important factors: flexibility of gear arms, axles, and supports, as well as resulting rotational delays, slippages, and thermal and other effects. These studies therefore allow better informed design of future molecular machine components involving motors, gears, axles, etc.

  10. Gear Tooth Wear Detection Algorithm

    Science.gov (United States)

    Delgado, Irebert R.

    2015-01-01

    Vibration-based condition indicators continue to be developed for Health Usage Monitoring of rotorcraft gearboxes. Testing performed at NASA Glenn Research Center have shown correlations between specific condition indicators and specific types of gear wear. To speed up the detection and analysis of gear teeth, an image detection program based on the Viola-Jones algorithm was trained to automatically detect spiral bevel gear wear pitting. The detector was tested using a training set of gear wear pictures and a blind set of gear wear pictures. The detector accuracy for the training set was 75 percent while the accuracy for the blind set was 15 percent. Further improvements on the accuracy of the detector are required but preliminary results have shown its ability to automatically detect gear tooth wear. The trained detector would be used to quickly evaluate a set of gear or pinion pictures for pits, spalls, or abrasive wear. The results could then be used to correlate with vibration or oil debris data. In general, the program could be retrained to detect features of interest from pictures of a component taken over a period of time.

  11. Development in Geared Turbofan Aeroengine

    Science.gov (United States)

    Mohd Tobi, A. L.; Ismail, A. E.

    2016-05-01

    This paper looks into the implementation of epicyclic gear system to the aeroengine in order to increase the efficiency of the engine. The improvement made is in the direction of improving fuel consumption, reduction in pollutant gasses and perceived noise. Introduction of epicyclic gear system is capable to achieve bypass ratio of up to 15:1 with the benefits of weight and noise reduction. Radical new aircraft designs and engine installation are being studied to overcome some of the challenges associated with the future geared turbofan and open-rotor engine.

  12. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: PHASE 1-ADI PILOT TEST UNIT NO. 2002-09 WITH MEDIA G2®

    Science.gov (United States)

    Integrity verification testing of the ADI International Inc. Pilot Test Unit No. 2002-09 with MEDIA G2® arsenic adsorption media filter system was conducted at the Hilltown Township Water and Sewer Authority (HTWSA) Well Station No. 1 in Sellersville, Pennsylvania from October 8...

  13. Analysis of 'ADI' welding, with Fe-Ni electrodes

    International Nuclear Information System (INIS)

    Aguera, Francisco R; Ansaldi, Andrea; Reynoso, Alejandro; Fierro, Victor; Alvarez Villar, Nelson; Aquino, Daniel; Ayllon, Eduardo S

    2008-01-01

    This work analyzes the results of ADI, welded with consumable electrodes that deposit an alloy of 50%Fe and 50%Ni. The iron and nickel properties and the microstructures resulting from the alloying used in the support material are studied, and the current phase diagrams and their predecessors are reviewed for this purpose. The mechanical properties of the base materials and the support material were determined. The microhardness of specially prepared test pieces was measured in the base material, the mixed zone and the zone affected by heat. The results of these determinations were linked to the previously identified microstructural components. The base materials and the support material were characterized, for which Charpy, HRB, and metallography traction tests were prepared. The tests show the possibilities of welding the ADI, with 50% nickel electrodes, as well as the difficulties with the technique used and the limitations in the results obtained to date

  14. 29 CFR 1918.54 - Rigging gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees from...

  15. 50 CFR 648.84 - Gear-marking requirements and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear-marking requirements and gear... Management Measures for the NE Multispecies and Monkfish Fisheries § 648.84 Gear-marking requirements and gear restrictions. (a) Bottom-tending fixed gear, including, but not limited to, gillnets and longlines...

  16. Modelling the Meshing of Cycloidal Gears

    Directory of Open Access Journals (Sweden)

    Nachimowicz Jerzy

    2016-06-01

    Full Text Available Cycloidal drives belong to the group of planetary gear drives. The article presents the process of modelling a cycloidal gear. The full profile of the planetary gear is determined from the following parameters: ratio of the drive, eccentricity value, the equidistant (ring gear roller radius, epicycloid reduction ratio, roller placement diameter in the ring gear. Joong-Ho Shin’s and Soon-Man Kwon’s article (Shin and Know, 2006 was used to determine the profile outline of the cycloidal planetary gear lobes. The result was a scatter chart with smooth lines and markers, presenting the full outline of the cycloidal gear.

  17. Translation and validation of Autism Diagnostic Interview-Revised (ADI-R for autism diagnosis in Brazil

    Directory of Open Access Journals (Sweden)

    Michele M. Becker

    2012-03-01

    Full Text Available OBJECTIVE: To translate into Brazilian Portuguese the Autism Diagnostic Interview-Revised (ADI-R, an extremely useful diagnostic tool in autism. METHODS: A case-control study was done to validate the ADI-R. After being translated, the interview was applied in a sample of 20 patients with autism and 20 patients with intellectual disability without autism, in order to obtain the initial psychometric properties. RESULTS: The internal consistency was high, with a of Crombach of 0.967. The validity of criterion had sensitivity and specificity of 100%, having as a gold standard the DSM-IV diagnostic criteria. The interview had high discriminant validity, with higher scores in the group of patients with autism, as well as high interobserver consistency, with median kappa of 0.824. CONCLUSION: The final version of ADI-R had satisfactory psychometric characteristics, indicating good preliminary validation properties. The instrument needs to be applied in bigger samples in other areas of the country.

  18. Clinical Validity of the ADI-R in a US-Based Latino Population

    Science.gov (United States)

    Vanegas, Sandra B.; Magaña, Sandra; Morales, Miguel; McNamara, Ellyn

    2016-01-01

    The Autism Diagnostic Interview-Revised (ADI-R) has been validated as a tool to aid in the diagnosis of Autism; however, given the growing diversity in the United States, the ADI-R must be validated for different languages and cultures. This study evaluates the validity of the ADI-R in a US-based Latino, Spanish-speaking population of 50 children…

  19. Theory of gearing kinematics, geometry, and synthesis

    CERN Document Server

    Radzevich, Stephen P

    2012-01-01

    The first book of its kind, Theory of Gearing: Kinematics, Geometry, and Synthesis systematically develops a scientific theory of gearing that makes it possible to synthesize novel gears with the desired performance. Written by a leading gearing expert who holds more than 200 patents, it presents a modern methodology for gear design. The proposed theory is based on a key postulate: all the design parameters for an optimal gear pair for a particular application can be derived from (a) a given configuration of the rotation vectors of the driving and driven shafts and (b) the power transmitted by

  20. Advanced Face Gear Surface Durability Evaluations

    Science.gov (United States)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  1. The factors influencing microstructure and mechanical properties of ADI

    Directory of Open Access Journals (Sweden)

    A. Vaško

    2009-01-01

    Full Text Available The paper deals with the influence of different conditions of isothermal heat treatment on microstructure and mechanical properties of austempered ductile iron (ADI. Different temperature of isothermal transformation of austenite and different holding time at this temperature were used for heat treatment of specimens. The microstructure of specimens after casting and after heat treatment was evaluated by STN EN ISO 945 and by image analysis (using Lucia software. Mechanical properties were evaluated by the tensile test, the Rockwell hardness test and fatigue tests.

  2. Advanced theories of hypoid gears

    CERN Document Server

    Wang, Xudong

    2013-01-01

    In order to develop more efficient types of gears, further investigation into the theories of engagement is necessary. Up until now most of the research work on the theories of engagement has been carried out separately on different groups, and based on individual types of profiles. This book aims at developing some universal theories, which can not only be used for all types of gears, but can also be utilized in other fields such as sculptured surfaces. The book has four characteristics: the investigations are concentrated on mismatched tooth surfaces; all the problems are dealt with from a

  3. Induction Hardening of External Gear

    Science.gov (United States)

    Bukanin, V. A.; Ivanov, A. N.; Zenkov, A. E.; Vologdin, V. V.; Vologdin, V. V., Jr.

    2018-03-01

    Problems and solution of gear induction hardening are described. Main attention is paid to the parameters of heating and cooling systems. ELTA 7.0 program has been used to obtain the required electrical parameters of inductor, power sources, resonant circuits, as well as to choose the quenching media. Comparison of experimental and calculated results of investigation is provided. In order to compare advantages and disadvantages of single- and dual-frequency heating processes, many variants of these technologies were simulated. The predicted structure and hardness of steel gears are obtained by use of the ELTA data base taken into account the Continuous Cooling Transformation diagrams.

  4. Unilateral maxillary molar distalization with zygoma-gear appliance.

    Science.gov (United States)

    Kilkis, Dogan; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin

    2012-08-01

    The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  5. Computer simulation of gear tooth manufacturing processes

    Science.gov (United States)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  6. GEAR UP Aspirations Project Evaluation

    Science.gov (United States)

    Trimble, Brad A.

    2013-01-01

    The purpose of this study was to conduct a formative evaluation of the first two years of the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) Aspirations Project (Aspirations) using a Context, Input, Process, and Product (CIPP) model so as to gain an in-depth understanding of the project during the middle school…

  7. Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry

    African Journals Online (AJOL)

    Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry was studied as a function of the microstructure developed by austempering at 380 and 300°C for different exposure time in the slurry. The corrosion rates of the ADI balls immersed in the iron ore slurry was determined using weight loss method.

  8. New Siemens applications for designing bevel gears

    Science.gov (United States)

    Goanta, A. M.; Dumitrache, P.

    2017-08-01

    The current situation in the design of gearings is different from software to software and in some cases requires specialized settings with or without additional costs. There are two ways of generating evolving tooting: one is based on the designer’s solid knowledge of geometry and gearing and the other is based on a series of automation subprograms for 3D modelling of gears. The first method is a general one, applicable to all design software that is based on generating a curve evolving specific to a tooth flank, continued with the construction of the symmetrical flank, the pattern multiplication of circular type around the center of the gear and finally generation of the three-dimensional characteristic of each individual tooth. The second method is much faster and requires only general knowledge about the gear but sufficiently advanced to allow permanent dialogue with the subprogram for generating cone gears. Absolute novelty items are brought about by the new NX design applications that lead to getting gears with curved teeth. In conclusion the paper shows how different variants of bevel gears are generated using various subprograms or performance settings, installed over the SIEMENS NX. An essential component of the paper is highlighting generation capacity of gears and gearing intended for predefined types of gear cutting machines such as those for Gleason and Oerlikon teeth.

  9. Helicopter time-domain electromagnetic numerical simulation based on Leapfrog ADI-FDTD

    Science.gov (United States)

    Guan, S.; Ji, Y.; Li, D.; Wu, Y.; Wang, A.

    2017-12-01

    We present a three-dimension (3D) Alternative Direction Implicit Finite-Difference Time-Domain (Leapfrog ADI-FDTD) method for the simulation of helicopter time-domain electromagnetic (HTEM) detection. This method is different from the traditional explicit FDTD, or ADI-FDTD. Comparing with the explicit FDTD, leapfrog ADI-FDTD algorithm is no longer limited by Courant-Friedrichs-Lewy(CFL) condition. Thus, the time step is longer. Comparing with the ADI-FDTD, we reduce the equations from 12 to 6 and .the Leapfrog ADI-FDTD method will be easier for the general simulation. First, we determine initial conditions which are adopted from the existing method presented by Wang and Tripp(1993). Second, we derive Maxwell equation using a new finite difference equation by Leapfrog ADI-FDTD method. The purpose is to eliminate sub-time step and retain unconditional stability characteristics. Third, we add the convolution perfectly matched layer (CPML) absorbing boundary condition into the leapfrog ADI-FDTD simulation and study the absorbing effect of different parameters. Different absorbing parameters will affect the absorbing ability. We find the suitable parameters after many numerical experiments. Fourth, We compare the response with the 1-Dnumerical result method for a homogeneous half-space to verify the correctness of our algorithm.When the model contains 107*107*53 grid points, the conductivity is 0.05S/m. The results show that Leapfrog ADI-FDTD need less simulation time and computer storage space, compared with ADI-FDTD. The calculation speed decreases nearly four times, memory occupation decreases about 32.53%. Thus, this algorithm is more efficient than the conventional ADI-FDTD method for HTEM detection, and is more precise than that of explicit FDTD in the late time.

  10. Investigation on wear characteristic of biopolymer gear

    Science.gov (United States)

    Ghazali, Wafiuddin Bin Md; Daing Idris, Daing Mohamad Nafiz Bin; Sofian, Azizul Helmi Bin; Basrawi, Mohamad Firdaus bin; Khalil Ibrahim, Thamir

    2017-10-01

    Polymer is widely used in many mechanical components such as gear. With the world going to a more green and sustainable environment, polymers which are bio based are being recognized as a replacement for conventional polymers based on fossil fuel. The use of biopolymer in mechanical components especially gear have not been fully explored yet. This research focuses on biopolymer for spur gear and whether the conventional method to investigate wear characteristic is applicable. The spur gears are produced by injection moulding and tested on several speeds using a custom test equipment. The wear formation such as tooth fracture, tooth deformation, debris and weight loss was observed on the biopolymer spur gear. It was noted that the biopolymer gear wear mechanism was similar with other type of polymer spur gears. It also undergoes stages of wear which are; running in, linear and rapid. It can be said that the wear mechanism of biopolymer spur gear is comparable to fossil fuel based polymer spur gear, thus it can be considered to replace polymer gears in suitable applications.

  11. Automatic Classification of the Sub-Techniques (Gears Used in Cross-Country Ski Skating Employing a Mobile Phone

    Directory of Open Access Journals (Sweden)

    Thomas Stöggl

    2014-10-01

    Full Text Available The purpose of the current study was to develop and validate an automatic algorithm for classification of cross-country (XC ski-skating gears (G using Smartphone accelerometer data. Eleven XC skiers (seven men, four women with regional-to-international levels of performance carried out roller skiing trials on a treadmill using fixed gears (G2left, G2right, G3, G4left, G4right and a 950-m trial using different speeds and inclines, applying gears and sides as they normally would. Gear classification by the Smartphone (on the chest and based on video recordings were compared. Formachine-learning, a collective database was compared to individual data. The Smartphone application identified the trials with fixed gears correctly in all cases. In the 950-m trial, participants executed 140 ± 22 cycles as assessed by video analysis, with the automatic Smartphone application giving a similar value. Based on collective data, gears were identified correctly 86.0% ± 8.9% of the time, a value that rose to 90.3% ± 4.1% (P < 0.01 with machine learning from individual data. Classification was most often incorrect during transition between gears, especially to or from G3. Identification was most often correct for skiers who made relatively few transitions between gears. The accuracy of the automatic procedure for identifying G2left, G2right, G3, G4left and G4right was 96%, 90%, 81%, 88% and 94%, respectively. The algorithm identified gears correctly 100% of the time when a single gear was used and 90% of the time when different gears were employed during a variable protocol. This algorithm could be improved with respect to identification of transitions between gears or the side employed within a given gear.

  12. Automatic Classification of the Sub-Techniques (Gears) Used in Cross-Country Ski Skating Employing a Mobile Phone

    Science.gov (United States)

    Stöggl, Thomas; Holst, Anders; Jonasson, Arndt; Andersson, Erik; Wunsch, Tobias; Norström, Christer; Holmberg, Hans-Christer

    2014-01-01

    The purpose of the current study was to develop and validate an automatic algorithm for classification of cross-country (XC) ski-skating gears (G) using Smartphone accelerometer data. Eleven XC skiers (seven men, four women) with regional-to-international levels of performance carried out roller skiing trials on a treadmill using fixed gears (G2left, G2right, G3, G4left, G4right) and a 950-m trial using different speeds and inclines, applying gears and sides as they normally would. Gear classification by the Smartphone (on the chest) and based on video recordings were compared. Formachine-learning, a collective database was compared to individual data. The Smartphone application identified the trials with fixed gears correctly in all cases. In the 950-m trial, participants executed 140 ± 22 cycles as assessed by video analysis, with the automatic Smartphone application giving a similar value. Based on collective data, gears were identified correctly 86.0% ± 8.9% of the time, a value that rose to 90.3% ± 4.1% (P < 0.01) with machine learning from individual data. Classification was most often incorrect during transition between gears, especially to or from G3. Identification was most often correct for skiers who made relatively few transitions between gears. The accuracy of the automatic procedure for identifying G2left, G2right, G3, G4left and G4right was 96%, 90%, 81%, 88% and 94%, respectively. The algorithm identified gears correctly 100% of the time when a single gear was used and 90% of the time when different gears were employed during a variable protocol. This algorithm could be improved with respect to identification of transitions between gears or the side employed within a given gear. PMID:25365459

  13. Reduction of belt CVT gear noise by gear train modification. Optimize vibration characteristics of gear train; Belt CVT no gear noise teigen gijutsu. Gear train shindo tokusei no saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Arimatsu, M; Kawakami, T [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    With the reduction of vehicle noise, the requirements for an efficient method to reduce transmission gear noise have become stronger yearly. So far efforts to reduce gear noise have generally focused on ways of improving the gears themselves. In addition to these traditional methods, it proved very beneficial to us to optimize the gear train structure. Nissan has just released the new Belt CVT for 2.0L Front wheel drive vehicles. We have been analyzing vibration of the gear train by using a finite element model since the early development stage, and we could achieve the quiet gears effectively. 2 refs., 9 figs.

  14. Gear failure of a PHWR refuelling machine

    International Nuclear Information System (INIS)

    Iorio, A.F.; Crespi, J.C.

    1986-01-01

    After ten year service in Atucha Nuclear Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to transmit motion to the inlet-outlet heavy-water valve of that machine. Visual examination of the gear device revealed an absence of lubricant and several gear teeth were broken off at the root. The gear motion was transmitted from a speed-reducing device with controlled adjustable times in order to produce a right fitness of the valve closure. The main cause of gear failure was due to misalignment produced during assembly or in-service operation. It is suggested to control periodically the level of oil lubricant. (orig./IHOE) [de

  15. Lubrication and cooling for high speed gears

    Science.gov (United States)

    Townsend, D. P.

    1985-01-01

    The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

  16. 29 CFR 1919.19 - Gear requiring welding.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly heat...

  17. 50 CFR 697.23 - Restricted gear areas.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Restricted gear areas. 697.23 Section 697... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed...) Restricted Gear Area I—(1) Duration—(i) Mobile Gear. From October 1 through June 15 of each fishing year, no...

  18. A Circularly Arranged Sextuple Triptycene Gear Molecule.

    Science.gov (United States)

    Ube, Hitoshi; Yamada, Ryo; Ishida, Jun-Ichi; Sato, Hiroyasu; Shiro, Motoo; Shionoya, Mitsuhiko

    2017-11-22

    Herein we report the synthesis of a circularly arranged sextuple triptycene gear molecule, hexakis(10-dodecyloxy-9-triptycyl)ethynylbenzene, via the trimerization of the corresponding triyne with a cobalt catalyst. The six triptycene gears are closely engaged with each other as confirmed by single crystal X-ray structure analysis, and their motion in solution was established by NMR spectroscopy. Notably, when one bulky RuCp* complex was attached to one triptycene gear, the whole movement of the six gears was highly restricted via their mechanical engagement. Development of such a multigear molecule would provide a structural basis for molecular motion transmission systems with a switching function.

  19. Linear dynamic coupling in geared rotor systems

    Science.gov (United States)

    David, J. W.; Mitchell, L. D.

    1986-01-01

    The effects of high frequency oscillations caused by the gear mesh, on components of a geared system that can be modeled as rigid discs are analyzed using linear dynamic coupling terms. The coupled, nonlinear equations of motion for a disc attached to a rotating shaft are presented. The results of a trial problem analysis show that the inclusion of the linear dynamic coupling terms can produce significant changes in the predicted response of geared rotor systems, and that the produced sideband responses are greater than the unbalanced response. The method is useful in designing gear drives for heavy-lift helicopters, industrial speed reducers, naval propulsion systems, and heavy off-road equipment.

  20. Load Sharing Behavior of Star Gearing Reducer for Geared Turbofan Engine

    Science.gov (United States)

    Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo

    2017-07-01

    Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.

  1. Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry

    African Journals Online (AJOL)

    ADI austempered at higher temperature showed better corrosion resistance than the ..... temperature and time on corrosion behaviour of ductile iron in chloride and acidic ... iron ore in ball mills, Transactions of the Indian Institute of Metals, Vol.

  2. ADI as a preconditioning for solving the convection-diffusion equation

    International Nuclear Information System (INIS)

    Chin, R.C.Y.; Manteuffel, T.A.; De Pillis, J.

    1984-01-01

    The authors examine a splitting of the operator obtained from a steady convection-diffusion equation with variable coefficients in which the convection term dominates. The operator is split into a dominant and subdominant parts consistent with the inherent directional property of the partial differential equation. The equations involving the dominant parts should be easily solved. The authors accelerate the convergence of this splitting or the outer iteration by a Chebyshev semi-iterative method. When the dominant part has constant coefficients, it can be easily solved using alternating direction implicit (ADI) methods. This is called the inner iteration. The optimal parameters for a stationary two-parameter ADI method are obtained when the eigenvalues become complex. This corresponds to either the horizontal or the vertical half-grid Reynolds number larger than unity. The Chebyshev semi-iterative method is used to accelerate the convergence of the inner ADI iteration. A two-fold increase in speed is obtained when the ADI iteration matrix has real eigenvalues, and the increase is less significant when the eigenvalues are complex. If either the horizontal or the vertical half-grid Reynolds number is equal to one, the spectral radius of the optimal ADI iterative matrix is zero. However, a high degree of nilpotency impairs rapid convergence. This problem is removed by introducing a more implicit iterative method called ADI/Gauss-Seidel (ADI/GS). ADI/GS resolves the nilpotency and, thus, converges more rapidly for half-grid Reynolds number near 1. Finally, these methods are compared with several well-known schemes on test problems. 23 references, 5 figures

  3. Test of the Angle Detecting Inclined Sensor (ADIS) Technique for Measuring Space Radiation

    Science.gov (United States)

    Connell, J. J.; Lopate, C.; McLaughlin, K. R.

    2009-12-01

    In February 2008 we exposed an Angle Detecting Inclined Sensor (ADIS) prototype to beams of 150 MeV/u 78Kr and fragments at the National Superconducting Cyclotron Laboratory's (NSCL) Coupled Cyclotron Facility (CCF). ADIS is a highly innovative and uniquely simple detector configuration used to determine the angles of incidence of heavy ions in energetic charged particle instruments. Corrections for angle of incidence are required for good charge and mass separation. An ADIS instrument is under development to fly on the GOES-R series of weather satellites. The prototype tested consisted of three ADIS detectors, two of which were inclined at an angle to the telescope axis, forming the initial detectors in a five-detector telescope stack. By comparing the signals from the ADIS detectors, the angle of incidence may be determined and a pathlength correction applied to charge and mass determinations. Thus, ADIS replaces complex position sensing detectors with a system of simple, reliable and robust Si detectors. Accelerator data were taken at multiple angles to both primary and secondary beams with a spread of energies. This test instrument represents an improvement over the previous ADIS prototype in that it used oval inclined detectors and a much lower-mass support structure, thus reducing the number of events passing through dead material. These data show a charge peak resolution of 0.18 ± 0.01 e at Br (Z = 35), excellent for such a simple instrument. We will present the results of this test. The ADIS instrument development project was partially funded by NASA under the Living With a Star (LWS) Targeted Research and Technology program (grant NAG5-12493).

  4. Dispersion Analysis of the ADI-FDTD and S-FDTD Methods

    OpenAIRE

    KUŞAF, Mehmet; ÖZTOPRAK, Abdullah Y.

    2014-01-01

    Numerical dispersion performances of ADI-FDTD and S-FDTD methods have been compared. It has been shown that for time steps below the stability limits of the S-FDTD method it has much better dispersion performance compared with the ADI-FDTD method and that the S-FDTD method can be usefully employed for space increments in the order of l/25 to l/50.

  5. The Dilemma of Derelict Gear.

    Science.gov (United States)

    Scheld, A M; Bilkovic, D M; Havens, K J

    2016-01-21

    Every year, millions of pots and traps are lost in crustacean fisheries around the world. Derelict fishing gear has been found to produce several harmful environmental and ecological effects, however socioeconomic consequences have been investigated less frequently. We analyze the economic effects of a substantial derelict pot removal program in the largest estuary of the United States, the Chesapeake Bay. By combining spatially resolved data on derelict pot removals with commercial blue crab (Callinectes sapidus) harvests and effort, we show that removing 34,408 derelict pots led to significant gains in gear efficiency and an additional 13,504 MT in harvest valued at US $21.3 million--a 27% increase above that which would have occurred without removals. Model results are extended to a global analysis where it is seen that US $831 million in landings could be recovered annually by removing less than 10% of the derelict pots and traps from major crustacean fisheries. An unfortunate common pool externality, the degradation of marine environments is detrimental not only to marine organisms and biota, but also to those individuals and communities whose livelihoods and culture depend on profitable and sustainable marine resource use.

  6. Involute Spur Gear Template Development by Parametric Technique ...

    African Journals Online (AJOL)

    Nekky Umera

    cylindrical coordinate systems to create the involute curve profile. Since spur gear ... Template gear development using parametric method means that the dimensions control the ... and rapid prototyping of interlocking gears. Excel is a common ...

  7. VARIABLE MESH STIFFNESS OF SPUR GEAR TEETH USING ...

    African Journals Online (AJOL)

    gear engagement. A gear mesh kinematic simulation ... model is appropnate for VMS of a spur gear tooth. The assumptions for ... This process has been continued until one complete tooth meshing cycle is ..... Element Method. Using MATLAB,.

  8. Surface contact fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-06-01

    Full Text Available Surface contact fatigue is the most common cause of gear failure. It results in damage to contacting surfaces which can significantly reduce the load-carrying capacity of components, and may ultimately lead to complete failure of a gear. Three types...

  9. Shimmy of Aircraft Main Landing Gears

    NARCIS (Netherlands)

    Besselink, I.J.M.

    2000-01-01

    The landing gear is an important aircraft system, which has to meet many different design requirements. It is a highly loaded structure, which is designed for minimum weight. Shimmy is a dynamic instability of the landing gear, which is caused by the interaction of the dynamic behaviour of the

  10. Tooth bending fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1996-09-01

    Full Text Available . It results in progressive damage to gear teeth and ultimately leads to complete failure of the gear. The characteristics of this failure mode are discussed in detail and a number of actual case studies are presented which show the occurrence of this failure...

  11. Analysis of Dynamic Behavior of Multiple-Stage Planetary Gear Train Used in Wind Driven Generator

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2014-01-01

    Full Text Available A dynamic model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind driven generator to analyze the influence of revolution speed and mesh error on dynamic load sharing characteristic based on the lumped parameter theory. Dynamic equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind driven generator.

  12. Experimental Investigations of Noise Control in Planetary Gear Set by Phasing

    Directory of Open Access Journals (Sweden)

    S. H. Gawande

    2014-01-01

    Full Text Available Now a days reduction of gear noise and resulting vibrations has received much attention of the researchers. The internal excitation caused by the variation in tooth mesh stiffness is a key factor in causing vibration. Therefore to reduce gear noise and vibrations several techniques have been proposed in recent years. In this research the experimental work is carried out to study the effect of planet phasing on noise and subsequent resulting vibrations of Nylon-6 planetary gear drive. For this purpose experimental set-up was built and trials were conducted for two different arrangements (i.e., with phasing and without phasing and it is observed that the noise level and resulting vibrations were reduced by planet phasing arrangement. So from the experimental results it is observed that by applying the meshing phase difference one can reduce planetary gear set noise and vibrations.

  13. Engagement of Metal Debris into Gear Mesh

    Science.gov (United States)

    handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  14. VTVL concept optimisation of the landing gear

    Directory of Open Access Journals (Sweden)

    Camelia Elena MUNTEANU

    2017-03-01

    Full Text Available Vertical takeoff, vertical landing (VTVL is a subject of international interest at the moment thanks to the successful recovery of the Blue Origin vehicle. Aggressive weight targets with a short development time in the aerospace and space industry clearly need an integration of advanced computer aided structural optimization methods. Topological optimization is used from the concept phase of a design process development in order to obtain a fundamental design approach. The aim of the article is to determine the principal directions for distribution of the material for a VTVL landing gear within the specified volume in order to obtain the initial design approach. To achieve the maximum performance within the studied component, the result is then refined from a manufacturability point of view. The use of such methods notably reduces the development iterations between the design and stress departments. Thus, the overall time is reduced which translates into a lower overall cost and shorter time development from the concept to the final product.

  15. 50 CFR 622.46 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 622.46... Management Measures § 622.46 Prevention of gear conflicts. (a) No person may knowingly place in the Gulf EEZ any article, including fishing gear, that interferes with fishing or obstructs or damages fishing gear...

  16. 46 CFR 108.641 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary steering...

  17. 14 CFR 25.1515 - Landing gear speeds.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear, as...

  18. 50 CFR 654.25 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 654.25... Measures § 654.25 Prevention of gear conflicts. (a) No person may knowingly place in the management area any article, including fishing gear, that interferes with fishing or obstructs or damages fishing gear...

  19. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall be...

  20. 50 CFR 640.22 - Gear and diving restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear and diving restrictions. 640.22... ATLANTIC Management Measures § 640.22 Gear and diving restrictions. (a) Prohibited gear and methods. (1) A spiny lobster may not be taken in the EEZ with a spear, hook, or similar device, or gear containing such...

  1. 29 CFR 1919.31 - Proof tests-loose gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear (whether...

  2. 46 CFR 58.25-20 - Piping for steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Piping for steering gear. 58.25-20 Section 58.25-20... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must... the hydraulic system can be readily recharged from within the steering-gear compartment and must be...

  3. DESIGN FOR A BI-PLANETARY GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    Józef DREWNIAK

    2016-06-01

    Full Text Available The article presents the design for a bi-planetary gear train. The project description is supplemented with calculations of kinematics, statics and meshing efficiency of the gear wheels included in the gear train. Excluded are calculations of strength and geometry of gears, shaft and rolling bearing, since they are similar to classical calculations for planetary gears. An assembly drawing in 2D and assembly drawings in 3D of the designed bi-planetary gear train are also shown. This gear train will form the main element of the research in hand.

  4. 50 CFR 654.22 - Gear restrictions.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Management Measures § 654.22 Gear... retaining chamber. (6) A plastic or wire trap must have a degradable panel. (i) A plastic trap will be...

  5. Sea Turtle Human/Gear Interactions Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories is responsible for new gear development and testing to reduce bycatch and incidental interactions of...

  6. Gulf of Mexico Shrimp Permit Gear Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set contains annual vessel gear characterization of permit holders shrimp vessel. Data includes net type, TED type, BRD type, etc.

  7. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  8. 3000-HP Roller Gear Transmission Development Program. Volume 3. Roller Gear Manufacture

    Science.gov (United States)

    1975-07-01

    power is fed through the ramp roller clutch type free- wheel units to spur gears which mesh with the combining spur gear whose centerline is common...when the engine tends to turn faster than the main rotor shaft. It is in the free- wheel mode when the main rotor shaft tends to turn faster than the...gears are cut progrind at this time. Check face runout on each end of largo gears. Not to exceed .002" TIR 30 EBW one end 40 EBW opposite end

  9. Tooth contact analysis of spur gears. Part 2-Analysis of modified gears

    Directory of Open Access Journals (Sweden)

    Pop Nicolae

    2017-01-01

    Full Text Available The misalignment between gears axes or direction deviations of teeth leads accentuate the edge effect, Modified spur gears which localize the initial bearing contact by proper modifications of the lead profile are used to avoid the development of the edge effect. A semi-analytical method was involved to find the contact area, pressures distribution and depth stresses states for the standard gears and gears with modified lead profile. The lead modifications concerned the crowning of the flank surface and the end relieving of the tooth flanks, both being applied to the pinion teeth only.

  10. High Speed Gear Sized and Configured to Reduce Windage Loss

    Science.gov (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  11. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  12. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

    1998-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  13. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

    1999-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  14. Efeito da adição de goma tara e carragena em iogurte firme desnatado

    OpenAIRE

    Camila Lie Hatanaka

    2009-01-01

    Resumo: Atualmente a adição de hidrocolóides é um recurso utilizado em produtos lácteos para modificar a textura ou evitar defeitos como a sinérese. Hidrocolóides são utilizados como agentes espessantes, gelificantes e estabilizantes, e podem apresentar características sinérgicas quando utilizados em conjunto. O objetivo deste trabalho foi avaliar o efeito da adição de goma tara e carragena sobre a sinérese do iogurte firme desnatado. Os iogurtes foram fabricados com leite desnatado reconstit...

  15. Systems and Methods for Implementing Bulk Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Wilcox, Brian (Inventor)

    2016-01-01

    Bulk metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a strain wave gear includes: a wave generator; a flexspline that itself includes a first set of gear teeth; and a circular spline that itself includes a second set of gear teeth; where at least one of the wave generator, the flexspline, and the circular spline, includes a bulk metallic glass-based material.

  16. 78 FR 68817 - Proposed Information Collection; Comment Request; Northeast Region Gear Identification

    Science.gov (United States)

    2013-11-15

    ... gear type being used to help prevent gear conflicts. II. Method of Collection No information is... certain types of fishing gear mark the gear with specified information. The gear marking requirements... for marking several strings of a given gear type, or may use multiple different gear types that...

  17. Research on the Problem of Spur Gear Teeth Contact in the Car Gear Box

    Directory of Open Access Journals (Sweden)

    Viktor Skrickij

    2011-04-01

    Full Text Available The article presents research on the problem of two gear contact in the car gearbox. Contact stiffness is evaluated for the whole period of mesh. Also, contact stresses are evaluated in the contact place. The presented method can be used for calculating spur gear.Article in Lithuanian

  18. Application of Face-Gear Drives in Helicopter Transmissions

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  19. Classifying Autism Spectrum Disorders by ADI-R: Subtypes or Severity Gradient?

    Science.gov (United States)

    Cholemkery, Hannah; Medda, Juliane; Lempp, Thomas; Freitag, Christine M.

    2016-01-01

    To reduce phenotypic heterogeneity of Autism spectrum disorders (ASD) and add to the current diagnostic discussion this study aimed at identifying clinically meaningful ASD subgroups. Cluster analyses were used to describe empirically derived groups based on the Autism Diagnostic Interview-revised (ADI-R) in a large sample of n = 463 individuals…

  20. Influence of intercritical austempering on the microstructure and mechanical properties of austempered ductile cast iron (ADI)

    International Nuclear Information System (INIS)

    Panneerselvam, Saranya; Putatunda, Susil K.; Gundlach, Richard; Boileau, James

    2017-01-01

    The focus of this investigation was to examine the influence of intercritical austempering process on the microstructure and mechanical properties of low-alloyed austempered ductile cast iron (ADI). The investigation also examined the influence of intercritical austempering process on the plane strain fracture toughness of the material. The effect of both austenitization and austempering temperature on the microstructure and mechanical properties was examined. The microstructural analysis was carried out using optical microscopy, scanning electron microscopy and X-ray diffraction. The test results indicate that by intercritical austempering it is possible to produce proeutectoid ferrite in the matrix microstructure. Lower austenitizing temperature produces more proeutectoid ferrite in the matrix. Furthermore, the yield, tensile strength and the fracture toughness of the ADI decreases with decrease in austenitizing temperature. A considerable increase in ductility was observed in the samples with higher proeutectoid ferrite content. The fracture surfaces of the ADI samples revealed that dimple ductile fracture produced higher fracture toughness of 60±5 MPa√m in this intercritically austempered ADI.

  1. Influence of intercritical austempering on the microstructure and mechanical properties of austempered ductile cast iron (ADI)

    Energy Technology Data Exchange (ETDEWEB)

    Panneerselvam, Saranya [Wayne State University, Detroit, MI (United States); Putatunda, Susil K., E-mail: sputa@eng.wayne.edu [Wayne State University, Detroit, MI (United States); Gundlach, Richard [Element Materials Technology, MI (United States); Boileau, James [Ford Motor Company, Dearborn, MI (United States)

    2017-05-10

    The focus of this investigation was to examine the influence of intercritical austempering process on the microstructure and mechanical properties of low-alloyed austempered ductile cast iron (ADI). The investigation also examined the influence of intercritical austempering process on the plane strain fracture toughness of the material. The effect of both austenitization and austempering temperature on the microstructure and mechanical properties was examined. The microstructural analysis was carried out using optical microscopy, scanning electron microscopy and X-ray diffraction. The test results indicate that by intercritical austempering it is possible to produce proeutectoid ferrite in the matrix microstructure. Lower austenitizing temperature produces more proeutectoid ferrite in the matrix. Furthermore, the yield, tensile strength and the fracture toughness of the ADI decreases with decrease in austenitizing temperature. A considerable increase in ductility was observed in the samples with higher proeutectoid ferrite content. The fracture surfaces of the ADI samples revealed that dimple ductile fracture produced higher fracture toughness of 60±5 MPa√m in this intercritically austempered ADI.

  2. A Computational Investigation of Gear Windage

    Science.gov (United States)

    Hill, Matthew J.; Kunz, Robert F.

    2012-01-01

    A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear windage loss, including the physics of loss mitigation strategies, and to propose and evaluate new approaches for minimizing loss. Absolute and relative frame CFD simulation, overset gridding, multiphase flow analysis, and sub-layer resolved turbulence modeling were brought to bear in achieving these goals. Several spur gear geometries were studied for which experimental data are available. Various shrouding configurations and free-spinning (no shroud) cases were studied. Comparisons are made with experimental data from the open literature, and data recently obtained in the NASA Glenn Research Center Gear Windage Test Facility. The results show good agreement with experiment. Interrogation of the validative and exploratory CFD results have led, for the first time, to a detailed understanding of the physical mechanisms of gear windage loss, and have led to newly proposed mitigation strategies whose effectiveness is computationally explored.

  3. Vibration characteristics of two-stage planetary transmission system with thin-walled ring gear on elastic supports

    Science.gov (United States)

    Li, JianYing; Hu, QingChun; Zong, ChangFu; Zhu, TianJun; Zhang, ZeXing

    2018-03-01

    A dual-clutch and dual-speed planetary gears mechanism of a hybrid car coupled-system is taken as research subject, in which the ring gear of planet set II is a thin-walled structure and the clutch friction plates of planet set II are used as its elastic supports. Based on the lumped parameter-rigid elastic coupled dynamic model of two-stage planetary transmission system with thin-walled ring gear on elastic supports, the motion differential equations are established and the dynamic responses are solved by the Runge-Kutta method considering each stage internal and external time-varying mesh stiffness. The vibration displacements of each stage ring gear have been affected differently in time-domain, the translational vibration displacement of the ring gear of planet set I are obviously more than the torsional vibration displacement, but it is opposite for the ring gear of planet set II; The translational and torsional vibration responses of each stage ring gear arrive the peak in low-frequency. The analysis results of this paper can enrich the theoretical research of multistage planetary transmission and provide guidance for dynamic design.

  4. DETERMINATION OF TRANSMISSION GEAR RATIO IN MECHANICAL PART OF TRACTOR ELECTRO-MECHANICAL TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Ch. I. Zhdanovich

    2016-01-01

    Full Text Available A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provision of nominal operational mode of the electric motor for all tractor operations where it is working for a long period of time; provision of minimum possible number of gears; complete realization of internal combustion engine power on the tractor wheels at limit operational mode of the electric motor. As a characteristic of the asynchronous electric motor with variable-frequency control contains various portions which can be used either completely or partially due to operating conditions, the gear number is determined in the process of transmission gear ration finding but not prior to this. A wheel torque of the tractor with electro-mechanical transmission can be limited according to the following factors: grip of wheel with supporting surface; maximum power of an internal combustion engine which can be transferred to the wheels and a torque which is developed by a propulsion electric motor. It is not proposed to exceed nominal operational mode of the propulsion electric motor for all the operations of the tractor if it is working for a long period of time because in the case of significant excess of the nominal operational mode of the asynchronous electric motor its rather long operation leads to low efficiency and high losses in power, large heat liberation and consequently requires to develop more complicated system for electric motor cooling. An excess of nominal electric motor torque can be justified for short-term operational modes because in this case

  5. D Modelling with the Samsung Gear 360

    Science.gov (United States)

    Barazzetti, L.; Previtali, M.; Roncoroni, F.

    2017-02-01

    The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing) have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images) in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.

  6. MODELING THE DOUBLE WORM-FACE GEARS

    Directory of Open Access Journals (Sweden)

    BOLOŞ Codruţa

    2015-06-01

    Full Text Available The worm-face gear family, invented 60 years ago, contains in its structure several variants which have the following defining elements: tapered worm, reverse tapered worm and cylindrical worm. This type of gear can be realized with a single wheel and also in engagement with the second embodiment of the front worm wheels. This paper presents the matrix - vectorial mathematical model of the double worm-face gear with cylindrical worm and a graphical modeling which is based on the specific geometrical characteristics accomplished by means of the Autodesk Inventor 3D modeling program. The applicability of the study, considering the solutions which it suggests, aims to create opportunities for the use of modern rapid prototyping and analysis of stress FEM technique.

  7. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    Science.gov (United States)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  8. Vibration behavior optimization of planetary gear sets

    Directory of Open Access Journals (Sweden)

    Farshad Shakeri Aski

    2014-12-01

    Full Text Available This paper presents a global optimization method focused on planetary gear vibration reduction by means of tip relief profile modifications. A nonlinear dynamic model is used to study the vibration behavior. In order to investigate the optimal radius and amplitude, Brute Force method optimization is used. One approach in optimization is straightforward and requires considerable computation power: brute force methods try to calculate all possible solutions and decide afterwards which one is the best. Results show the influence of optimal profile on planetary gear vibrations.

  9. Power Consumption Optimization in Tooth Gears Processing

    Science.gov (United States)

    Kanatnikov, N.; Harlamov, G.; Kanatnikova, P.; Pashmentova, A.

    2018-01-01

    The paper reviews the issue of optimization of technological process of tooth gears production of the power consumption criteria. The authors dwell on the indices used for cutting process estimation by the consumed energy criteria and their applicability in the analysis of the toothed wheel production process. The inventors proposed a method for optimization of power consumptions based on the spatial modeling of cutting pattern. The article is aimed at solving the problem of effective source management in order to achieve economical and ecological effect during the mechanical processing of toothed gears. The research was supported by Russian Science Foundation (project No. 17-79-10316).

  10. Simulation and analysis of hot forging process for industrial locking gear elevators

    Science.gov (United States)

    Maarefdoust, M.; Kadkhodayan, M.

    2010-06-01

    In this paper hot forging process for industrial locking gear elevators is simulated and analyzed. An increase in demand of industrial locking gear elevators with better quality and lower price caused the machining process to be replaced by hot forging process. Production of industrial locking gear elevators by means of hot forging process is affected by many parameters such as billet temperature, geometry of die and geometry of pre-formatted billet. In this study the influences of billet temperature on effective plastic strain, radius of die corners on internal stress of billet and thickness of flash on required force of press are investigated by means of computer simulation. Three-dimensional modeling of initial material and die are performed by Solid Edge, while simulation and analysis of forging are performed by Super Forge. Based on the computer simulation the required dies are designed and the workpieces are formed. Comparison of simulation results with experimental data demonstrates great compatibility.

  11. Improving bending stress in spur gears using asymmetric gears and shape optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2010-01-01

    Bending stress plays a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape. The bending stress is indirectly related to shape changes made to the cutting tool. This work shows that the bending...... stress can be reduced significantly by using asymmetric gear teeth and by shape optimizing the gear through changes made to the tool geometry. However, to obtain the largest possible stress reduction a custom tool must be designed depending on the number of teeth, but the stress reductions found...

  12. Tooth contact analysis of spur gears. Part 1-SAM analysis of standard gears

    Directory of Open Access Journals (Sweden)

    Creţu Spiridon

    2017-01-01

    Full Text Available The involute gears are sensitive to the misalignment of their axes which determines transmission errors and perturbations of pressures distributions along the tooth flank. The concentrated contacts in gears are no longer as Hertz type. A semi-analytical method was developed to find the contact area, pressures distribution and depth stresses state. The matrix of initial separations is found analytically for standard and non-standard spur gears. The presence of misalignment as well as the flank crowning and flank end relief are included in the numerical analysis process.

  13. Induction of arginosuccinate synthetase (ASS) expression affects the antiproliferative activity of arginine deiminase (ADI) in melanoma cells.

    Science.gov (United States)

    Manca, Antonella; Sini, Maria Cristina; Izzo, Francesco; Ascierto, Paolo A; Tatangelo, Fabiana; Botti, Gerardo; Gentilcore, Giusy; Capone, Marilena; Mozzillo, Nicola; Rozzo, Carla; Cossu, Antonio; Tanda, Francesco; Palmieri, Giuseppe

    2011-06-01

    Arginine deiminase (ADI), an arginine-degrading enzyme, has been used in the treatment of tumours sensitive to arginine deprivation, such as malignant melanoma (MM) and hepatocellular carcinoma (HCC). Endogenous production of arginine is mainly dependent on activity of ornithine transcarbamylase (OTC) and argininosuccinate synthetase (ASS) enzymes. We evaluated the effect of ADI treatment on OTC and ASS expression in a series of melanoma cell lines. Twenty-five primary melanoma cell lines and normal fibroblasts as controls underwent cell proliferation assays and Western blot analyses in the presence or absence of ADI. Tissue sections from primary MMs (N = 20) and HCCs (N = 20) were investigated by immunohistochemistry for ASS expression. Overall, 21/25 (84%) MM cell lines presented a cell growth inhibition by ADI treatment; none of them presented constitutive detectable levels of the ASS protein. However, 7/21 (33%) ADI-sensitive melanoma cell lines presented markedly increased expression levels of the ASS protein following ADI treatment, with a significantly higher IC50 median value. Growth was not inhibited and the IC50 was not reached among the remaining 4/25 (16%) MM cell lines; all of them showed constitutive ASS expression. The OTC protein was found expressed in all melanoma cell lines before and after the ADI treatment. Lack of ASS immunostaining was observed in all analyzed in vivo specimens. Our findings suggest that response to ADI treatment in melanoma is significantly correlated with the ability of cells to express ASS either constitutively at basal level (inducing drug resistance) or after the treatment (reducing sensitivity to ADI).

  14. Gear Fault Diagnosis Based on BP Neural Network

    Science.gov (United States)

    Huang, Yongsheng; Huang, Ruoshi

    2018-03-01

    Gear transmission is more complex, widely used in machinery fields, which form of fault has some nonlinear characteristics. This paper uses BP neural network to train the gear of four typical failure modes, and achieves satisfactory results. Tested by using test data, test results have an agreement with the actual results. The results show that the BP neural network can effectively solve the complex state of gear fault in the gear fault diagnosis.

  15. 50 CFR 622.31 - Prohibited gear and methods.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prohibited gear and methods. 622.31... Management Measures § 622.31 Prohibited gear and methods. In addition to the prohibited gear/methods specified in this section, see §§ 622.33, 622.34, and 622.35 for seasonal/area prohibited gear/methods and...

  16. Mathematical Modelling of Involute Spur Gears Manufactured by Rack Cutter

    Directory of Open Access Journals (Sweden)

    Tufan Gürkan YILMAZ

    2016-05-01

    Full Text Available In this study, mathematical modelling of asymmetric involute spur gears was situated in by Litvin approach. In this context, firstly, mathematical expressions of rack cutter which manufacture asymmetric involute spur gear, then mathematical expression of asymmetric involute spur gear were obtained by using differential geometry, coordinate transformation and gear theory. Mathematical expressions were modelled in MATLAB and output files including points of involute spur gear’s teeth were designed automatically thanks to macros.

  17. Characteristics of Reduction Gear in Electric Agricultural Vehicle

    Science.gov (United States)

    Choi, W. S.; Pratama, P. S.; Supeno, D.; Jeong, S. W.; Byun, J. Y.; Woo, J. H.; Lee, E. S.; Park, C. S.

    2018-03-01

    In electric agricultural machine a reduction gear is needed to convert the high speed rotation motion generated by DC motor to lower speed rotation motion used by the vehicle. The reduction gear consists of several spur gears. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modelling and simulation of spur gears in DC motor reduction gear is important to predict the actual motion behaviour. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress. The stress may not attain their maximum values at the same point of contact fatigue. These types of failure can be minimized by analysis of the problem during the design stage and creating proper tooth surface profile with proper manufacturing methods. To improve its life expectation in this study modal and stress analysis of reduction gear is simulated using ANSYS workbench based on finite element method (FEM). The modal analysis was done to understand reduction gear deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on reduction gear to simulate the gear teeth bending stress and contact stress behaviour.

  18. Gear cutting tools fundamentals of design and computation

    CERN Document Server

    Radzevich, Stephen P

    2010-01-01

    Presents the DG/K-based method of surface generation, a novel and practical mathematical method for designing gear cutting tools with optimal parameters. This book proposes a scientific classification for the various kinds of the gear machining meshes, discussing optimal designs of gear cutting tools.

  19. Intelligent Test Mechanism Design of Worn Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. The measure equations transformations were made on involute straight gear. Original polar coordinate equations were transformed into rectangular coordinate equations. Big gear abrasion measure principle was introduced. Detection principle diagram was given. Detection route realization method was introduced. OADM12 laser sensor was selected. Detection on big gear abrasion area was realized by detection mechanism. Tested data of unworn gear and worn gear were led in designed calculation program written by Visual Basic language. Big gear abrasion quantity can be obtained. It provides a feasible method for intelligent test and intelligent repair welding on worn big gear.

  20. Electrostatic microactuators with integrated gear linkages for mechanical power transmission

    NARCIS (Netherlands)

    Legtenberg, R.; Legtenberg, Rob; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    1996-01-01

    In this paper a surface micromachining process is presented which has been used to fabricate electrostatic microactuators that are interconnected with each other and linked to other movable microstructures by integrated gear linkages. The gear linkages consist of rotational and linear gear

  1. 50 CFR 635.21 - Gear operation and deployment restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear operation and deployment restrictions....21 Gear operation and deployment restrictions. Link to an amendment published at 75 FR 57701, Sept. 22, 2010. The green-stick gear authorization requirements under paragraphs (c)(2)(v)(A), (c)(2)(v)(B...

  2. 46 CFR 182.610 - Main steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all service...

  3. Gear shift map design methodology for automotive transmissions

    NARCIS (Netherlands)

    Ngo, Viet Dac; Hofman, Theo; Steinbuch, Maarten; Serrarens, Alex

    In this paper, a design methodology is developed to condtruct the gear shift map for the automotive transmissions used in conventional and hybrid electric vehicles. The methodology utilizes an optimal gear shift strategy to derive the optimal gear shift patterns over a wide range of driving

  4. 46 CFR 167.65-25 - Steering gear tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means of...

  5. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other...

  6. 46 CFR 61.20-1 - Steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of Inspections...

  7. Evaluation Of Vibration-Monitoring Gear-Diagnostic System

    Science.gov (United States)

    Townsend, Dennis P.; Zakrajsek, James J.

    1995-01-01

    Report describes experimental evaluation of commercial electronic system designed to monitor vibration signal from accelerometer on gear-box to detect vibrations indicative of damage to gears. System includes signal-conditioning subsystem and personal computer in which analog-to-digital converter installed. Results show system fairly effective in detecting surface fatigue pits on spur-gear teeth.

  8. Analysis of landing gear noise during approach

    NARCIS (Netherlands)

    Merino Martinez, R.; Snellen, M.; Simons, D.G.

    2016-01-01

    Airframe noise is becoming increasingly important during approach, even reaching higher noise levels than the engines in some cases. More people are a_ected due to low ight altitudes and _xed tra_c routing associated with typical approaches. For most air- craft types, the landing gear system is a

  9. Stuck in gear: age-related loss of variable gearing in skeletal muscle.

    Science.gov (United States)

    Holt, Natalie C; Danos, Nicole; Roberts, Thomas J; Azizi, Emanuel

    2016-04-01

    Skeletal muscles power a broad diversity of animal movements, despite only being able to produce high forces over a limited range of velocities. Pennate muscles use a range of gear ratios, the ratio of muscle shortening velocity to fiber shortening velocity, to partially circumvent these force-velocity constraints. Muscles operate with a high gear ratio at low forces; fibers rotate to greater angles of pennation, enhancing velocity but compromising force. At higher forces, muscles operate with a lower gear ratio; fibers rotate little so limiting muscle shortening velocity, but helping to preserve force. This ability to shift gears is thought to be due to the interplay of contractile force and connective tissue constraints. In order to test this hypothesis, gear ratios were determined in the medial gastrocnemius muscles of both healthy young rats, and old rats where the interaction between contractile and connective tissue properties was assumed to be disrupted. Muscle fiber and aponeurosis stiffness increased with age (PGear ratio decreased with increasing force in young (Pgearing is lost in old muscle. These findings support the hypothesis that variable gearing results from the interaction between contractile and connective tissues and suggest novel explanations for the decline in muscle performance with age. © 2016. Published by The Company of Biologists Ltd.

  10. A Rare Case in the Emergency Department: Holmes-Adie Syndrome

    Directory of Open Access Journals (Sweden)

    Sahin COLAK

    2015-03-01

    Full Text Available SUMMARY: Holmes-Adie syndrome (HAS is a rare syndrome characterized by tonic pupil and the absence of deep tendon reflexes. HAS was first described in 1931 and is usually idiopathic, with incidences reported to be 4-7 per 100,000. Although tonic pupil is usually unilateral, it can also be bilateral. Enlarged and irregular pupil is usually noticed by the patient. Light reflex is weak or unresponsive. Another characteristic of HAS is the absence of deep tendon reflexes, and unilateral involvement is more common. This case report emphasizes that HAS should be considered in the differential diagnosis of patients presenting to the emergency department with anisocoria, and the dilute pilocarpine test can be used in diagnosis. Key words: Emergency department, Holmes-Adie syndrome, pilocarpine

  11. Recent Advances in the Analysis of Spiral Bevel Gears

    Science.gov (United States)

    Handschuh, Robert F.

    1997-01-01

    A review of recent progress for the analysis of spiral bevel gears will be described. The foundation of this work relies on the description of the gear geometry of face-milled spiral bevel gears via the approach developed by Litvin. This methodology was extended by combining the basic gear design data with the manufactured surfaces using a differential geometry approach, and provides the data necessary for assembling three-dimensional finite element models. The finite element models have been utilized to conduct thermal and structural analysis of the gear system. Examples of the methods developed for thermal and structural/contact analysis are presented.

  12. Technologies for the marking of fishing gear to identify gear components entangled on marine animals and to reduce abandoned, lost or otherwise discarded fishing gear.

    Science.gov (United States)

    He, Pingguo; Suuronen, Petri

    2018-04-01

    Fishing gears are marked to establish and inform origin, ownership and position. More recently, fishing gears are marked to aid in capacity control, reduce marine litter due to abandoned, lost or otherwise discarded fishing gear (ALDFG) and assist in its recovery, and to combat illegal, unreported and unregulated (IUU) fishing. Traditionally, physical marking, inscription, writing, color, shape, and tags have been used for ownership and capacity purposes. Buoys, lights, flags, and radar reflectors are used for marking of position. More recently, electronic devices have been installed on marker buoys to enable easier relocation of the gear by owner vessels. This paper reviews gear marking technologies with focus on coded wire tags, radio frequency identification tags, Automatic Identification Systems, advanced electronic buoys for pelagic longlines and fish aggregating devices, and re-location technology if the gear becomes lost. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Perfectly matched layers in a divergence preserving ADI scheme for electromagnetics

    International Nuclear Information System (INIS)

    Kraus, C.; Adelmann, A.; Arbenz, P.

    2012-01-01

    For numerical simulations of highly relativistic and transversely accelerated charged particles including radiation fast algorithms are needed. While the radiation in particle accelerators has wavelengths in the order of 100 μm the computational domain has dimensions roughly five orders of magnitude larger resulting in very large mesh sizes. The particles are confined to a small area of this domain only. To resolve the smallest scales close to the particles subgrids are envisioned. For reasons of stability the alternating direction implicit (ADI) scheme by Smithe et al. [D.N. Smithe, J.R. Cary, J.A. Carlsson, Divergence preservation in the ADI algorithms for electromagnetics, J. Comput. Phys. 228 (2009) 7289-7299] for Maxwell equations has been adopted. At the boundary of the domain absorbing boundary conditions have to be employed to prevent reflection of the radiation. In this paper we show how the divergence preserving ADI scheme has to be formulated in perfectly matched layers (PML) and compare the performance in several scenarios.

  14. Construction of novel Saccharomyces cerevisiae strains for bioethanol active dry yeast (ADY) production.

    Science.gov (United States)

    Zheng, Daoqiong; Zhang, Ke; Gao, Kehui; Liu, Zewei; Zhang, Xing; Li, Ou; Sun, Jianguo; Zhang, Xiaoyang; Du, Fengguang; Sun, Peiyong; Qu, Aimin; Wu, Xuechang

    2013-01-01

    The application of active dry yeast (ADY) in bioethanol production simplifies operation processes and reduces the risk of bacterial contamination. In the present study, we constructed a novel ADY strain with improved stress tolerance and ethanol fermentation performances under stressful conditions. The industrial Saccharomyces cerevisiae strain ZTW1 showed excellent properties and thus subjected to a modified whole-genome shuffling (WGS) process to improve its ethanol titer, proliferation capability, and multiple stress tolerance for ADY production. The best-performing mutant, Z3-86, was obtained after three rounds of WGS, producing 4.4% more ethanol and retaining 2.15-fold higher viability than ZTW1 after drying. Proteomics and physiological analyses indicated that the altered expression patterns of genes involved in protein metabolism, plasma membrane composition, trehalose metabolism, and oxidative responses contribute to the trait improvement of Z3-86. This work not only successfully developed a novel S. cerevisiae mutant for application in commercial bioethanol production, but also enriched the current understanding of how WGS improves the complex traits of microbes.

  15. Construction of novel Saccharomyces cerevisiae strains for bioethanol active dry yeast (ADY production.

    Directory of Open Access Journals (Sweden)

    Daoqiong Zheng

    Full Text Available The application of active dry yeast (ADY in bioethanol production simplifies operation processes and reduces the risk of bacterial contamination. In the present study, we constructed a novel ADY strain with improved stress tolerance and ethanol fermentation performances under stressful conditions. The industrial Saccharomyces cerevisiae strain ZTW1 showed excellent properties and thus subjected to a modified whole-genome shuffling (WGS process to improve its ethanol titer, proliferation capability, and multiple stress tolerance for ADY production. The best-performing mutant, Z3-86, was obtained after three rounds of WGS, producing 4.4% more ethanol and retaining 2.15-fold higher viability than ZTW1 after drying. Proteomics and physiological analyses indicated that the altered expression patterns of genes involved in protein metabolism, plasma membrane composition, trehalose metabolism, and oxidative responses contribute to the trait improvement of Z3-86. This work not only successfully developed a novel S. cerevisiae mutant for application in commercial bioethanol production, but also enriched the current understanding of how WGS improves the complex traits of microbes.

  16. OBSERVATION OF FATIGUE CRACK PATHS IN NODULAR CAST IRON AND ADI MICROSTRUCTURES

    Directory of Open Access Journals (Sweden)

    Lukáš Bubenko

    2009-07-01

    Full Text Available When speaking about quality of construction materials, fatigue crack propagation resistance is one of the most important considered properties. That is essentially influenced by character of matrix. Here presented contribution deals with the fatigue crack propagation mode through the matrix of as-cast nodular cast iron (NCI and austempered ductile iron (ADI, whereas influence of microstructure has been considered and discussed. Experimental materials used in presented contribution were pearlitc-ferritic NCI and heat treated ADI 800. Pearlitic-ferritic NCI was used as the base for ADI production. Experiments were performed on mini round compact tension (RCT specimens using an Amsler vibrophore. Fatigue crack paths in both materials were investigated and compared. Light microscopy was used to analyze the microstructure, crack initiation and propagation within broken specimens. In both tested materials fatigue cracks always initiated at graphite-matrix interface, while graphite nodules remained generally unbroken, eventually only surface of nodules was damaged. Though, comparing two materials with different microstructures, the diversity of fatigue crack propagation modes at high deltaK and low deltaK was observed.

  17. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  18. Efficiency of fishing gears in the river Halda, Chittagong, Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Arshad-Ul-Alam

    2015-12-01

    Full Text Available To determine the catch efficiency of fishing gears, catch per unit effort (CPUEdata were collected for two years during January 2007 to December 2008 from the river Halda. Analyses were done to examine the variation of CPUE among gears, studied sections, months and years. The mean CPUE for pooled data of all gears was 2.247±0.265 kg.gear-1day-1 and 2.697±0.355 kg.gear-1day-1 for 2007 and 2008 respectively. Among eight gear categories, bag nets yielded the highest CPUE during 2007 (5.957±0.704 kg.gear-1day-1 and seine nets during 2008 (7.288±1.477 kg.gear-1day-1. Among 31 gear types, small meshed bag nets yielded the highest CPUE (18.065±6.660 and 15.69±4.479 kg.gear-1day-1 during 2007 and 2008 respectively. CPUE was highest during March-April and September-November periods. Analysis of variance showed significant difference among catch rates of different fishing gears. The CPUE differed significantly among different months for net fence, gill net, cast net and scoop net during 2007; and for seine net, net fence, bag net and cast net during 2008.

  19. Power loss analysis in altered tooth-sum spur gearing

    Directory of Open Access Journals (Sweden)

    Sachidananda H. K.

    2018-01-01

    Full Text Available The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing.

  20. Investigation of Sideband Index Response to Prototype Gear Tooth Damage

    Science.gov (United States)

    Dempsey, Paula J.

    2013-01-01

    The objective of this analysis was to evaluate the ability of gear condition indicators (CI) to detect contact fatigue damage on spiral bevel gear teeth. Tests were performed in the NASA Glenn Spiral Bevel Gear Fatigue Rig on eight prototype gear sets (pinion/gear). Damage was initiated and progressed on the gear and pinion teeth. Vibration data was measured during damage progression at varying torque values while varying damage modes to the gear teeth were observed and documented with inspection photos. Sideband indexes (SI) and root mean square (RMS) CIs were calculated from the time synchronous averaged vibration data. Results found that both CIs respond differently to varying torque levels, damage levels and damage modes

  1. Modeling of automotive driveline system for reducing gear rattles

    Science.gov (United States)

    Shangguan, Wen-Bin; Liu, Xue-Lai; Yin, Yuming; Rakheja, Subhash

    2018-03-01

    A nonlinear torsional model for a driveline system with 4 degrees of freedom is proposed for studying gear rattle if a car is at idle. The time-varying meshing stiffness of geared teeth, gear backlash, and the damping from oil film are included in the model. The dynamic responses of the driveline system, such as clutch angular displacement, meshing force and relative displacement between geared teeth, are calculated using the presented model. The influences of stiffness and damping of a clutch on gear rattle of geared teeth in a generic transmission are investigated. Based on the calculation and analysis results, a design guideline to select clutch's stiffness and damping is developed to reduce gear rattle for a car at idle. Taking a generic driveline system of a passenger car as an example, the developed method is experimentally validated by comparing the baseline clutch and revised clutch, in terms of the measured noise inside engine compartment and cab and vibrations at transmission housing.

  2. Bevel gear driver and method having torque limit selection

    Science.gov (United States)

    Cook, Joseph S., Jr.

    1994-08-01

    This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior

  3. Global Analysis of a Planetary Gear Train

    Directory of Open Access Journals (Sweden)

    Tongjie Li

    2014-01-01

    Full Text Available By using the Poincaré-like cell-to-cell mapping method and shooting method, the global characteristics of a planetary gear train are studied based on the torsional vibration model with errors of transmission, time-varying meshing stiffness, and multiple gear backlashes. The study results reveal that the planetary with a certain set of parameters has four coexisting periodic orbits, which are P-1, P-2, P-4, and P-8, respectively. P-1 and P-2 motions are not of long-term stability, P-8 motion is of local stability, and P-4 motion is of global stability. Shooting method does not have the capacity of searching coexisting periodic orbits in a global scope, and it is easy to omit some periodic orbits which are far away from the main gropes of periodic orbits.

  4. Geared Topological Metamaterials with Tunable Mechanical Stability

    Directory of Open Access Journals (Sweden)

    Anne S. Meeussen

    2016-11-01

    Full Text Available The classification of materials into insulators and conductors has been shaken up by the discovery of topological insulators that conduct robustly at the edge but not in the bulk. In mechanics, designating a material as insulating or conducting amounts to asking if it is rigid or floppy. Although mechanical structures that display topological floppy modes have been proposed, they are all vulnerable to global collapse. Here, we design and build mechanical metamaterials that are stable and yet capable of harboring protected edge and bulk modes, analogous to those in electronic topological insulators and Weyl semimetals. To do so, we exploit gear assemblies that, unlike point masses connected by springs, incorporate both translational and rotational degrees of freedom. Global structural stability is achieved by eliminating geometrical frustration of collective gear rotations extending through the assembly. The topological robustness of the mechanical modes makes them appealing across scales from engineered macrostructures to networks of toothed microrotors of potential use in micromachines.

  5. Electrohydraulic drive system with planetary superposed gears

    Energy Technology Data Exchange (ETDEWEB)

    Graetz, A.; Klimek, K.H.; Welz, H.

    1989-01-01

    To prevent drive problems in ploughs the drives must be designed in such a way as to compensate for asymmetries. If electromechanical drives are replaced by an electrohydraulic drive system with superposed planetary gears and hydrostatic torque reaction supports the following advantages occur: load-free acceleration, load equalisation between main and auxiliary drive, overload protection, and reduction of systems vibrations. 2 figs., 2 tabs.

  6. Generating Cycloidal Gears for 3D Printing

    OpenAIRE

    Daniels, Sunny

    2016-01-01

    (Shortened version of abstract in article itself) This article describes an algorithm for producing, for any desired resolution and any desired numbers of wheel and pinion teeth, polygonal approximations to the shapes of a pair of cycloidal gears that mesh correctly. An Octave implementation of the algorithm, mostly written in 2014, is included. The Octave implementation contains a (crude, but evidently adequate, at least for reasonable numbers of wheel and pinion teeth) solution of the probl...

  7. Assistance Dogs: Historic Patterns and Roles of Dogs Placed by ADI or IGDF Accredited Facilities and by Non-Accredited U.S. Facilities.

    Science.gov (United States)

    Walther, Sandra; Yamamoto, Mariko; Thigpen, Abigail Paige; Garcia, Anaissa; Willits, Neil H; Hart, Lynette A

    2017-01-01

    Dogs' roles to support people with disabilities are increasing. Existing U.S. laws and regulations pertaining to the use of dogs for people with disabilities are only minimally enforced. Pushback legislation against some aspects of uses of assistance dogs currently is being passed or proposed in several states. Further, the U.S. Department of the Army and the Veterans' Administration support only dogs trained by an Assistance Dogs International (ADI) or International Guide Dog Federation (IGDF) accredited facility. Lacking a mandatory national process for screening the selection, training, and placement of assistance dogs with persons who have disabilities, the U.S. offers a creative but confusing opportunity for people to train their own dogs for any disability. While no U.S. surveillance system monitors assistance dogs, other countries generally have a legislated or regulatory process for approving assistance dogs or a cultural convention for obtaining dogs from accredited facilities. We conducted an online survey investigating current demographics of assistance dogs placed in 2013 and 2014 with persons who have disabilities, by facilities worldwide that are associated with ADI or IGDF and by some non-accredited U.S. facilities. Placement data from ADI and IGDF facilities revealed that in most countries aside from the U.S., guide dogs were by far the main type of assistance dog placed. In the U.S., there were about equal numbers of mobility and guide dogs placed, including many placed by large older facilities, along with smaller numbers of other types of assistance dogs. In non-accredited U.S. facilities, psychiatric dogs accounted for most placements. Dogs for families with an autistic child were increasing in all regions around the world. Of dog breeds placed, accredited facilities usually mentioned Labrador Retrievers and Golden Retrievers, and sometimes, German Shepherd Dogs. The facilities bred their dogs in-house, or acquired them from certain breeders

  8. DESIGN IMPROVEMENT OF THE LOCOMOTIVE RUNNING GEARS

    Directory of Open Access Journals (Sweden)

    S. V. Myamlin

    2013-09-01

    Full Text Available Purpose. To determine the dynamic qualities of the mainline freight locomotives characterizing the safe motion in tangent and curved track sections at all operational speeds, one needs a whole set of studies, which includes a selection of the design scheme, development of the corresponding mathematical model of the locomotive spatial fluctuations, construction of the computer calculation program, conducting of the theoretical and then experimental studies of the new designs. In this case, one should compare the results with existing designs. One of the necessary conditions for the qualitative improvement of the traction rolling stock is to define the parameters of its running gears. Among the issues related to this problem, an important place is occupied by the task of determining the locomotive dynamic properties on the stage of projection, taking into account the selected technical solutions in the running gear design. Methodology. The mathematical modeling studies are carried out by the numerical integration method of the dynamic loading for the mainline locomotive using the software package «Dynamics of Rail Vehicles » («DYNRAIL». Findings. As a result of research for the improvement of locomotive running gear design it can be seen that the creation of the modern locomotive requires from engineers and scientists the realization of scientific and technical solutions. The solutions enhancing design speed with simultaneous improvement of the traction, braking and dynamic qualities to provide a simple and reliable design, especially the running gear, reducing the costs for maintenance and repair, low initial cost and operating costs for the whole service life, high traction force when starting, which is as close as possible to the ultimate force of adhesion, the ability to work in multiple traction mode and sufficient design speed. Practical Value. The generalization of theoretical, scientific and methodological, experimental studies aimed

  9. Face Gear Technology for Aerospace Power Transmission Progresses

    Science.gov (United States)

    2005-01-01

    The use of face gears in an advanced rotorcraft transmission design was first proposed by the McDonnell Douglas Helicopter Company during their contracted effort with the U.S. Army under the Advanced Rotorcraft Transmission (ART) program. Face gears would be used to turn the corner between the horizontal gas turbine engine and the vertical output rotor shaft--a function currently done by spiral bevel gears. This novel gearing arrangement would substantially lower the drive system weight partly because a face gear mesh would be used to split the input power between two output gears. However, the use of face gears and their ability to operate successfully at the speeds and loads required for an aerospace environment was unknown. Therefore a proof-of-concept phase with an existing test stand at the NASA Lewis Research Center was pursued. Hardware was designed that could be tested in Lewis' Spiral Bevel Gear Test Rig. The initial testing indicated that the face gear mesh was a feasible design that could be used at high speeds and load. Surface pitting fatigue was the typical failure mode, and that could lead to tooth fracture. An interim project was conducted to see if slight modifications to the gear tooth geometry or an alternative heat treating process could overcome the surface fatigue problems. From the initial and interim tests, it was apparent that for the surface fatigue problems to be overcome the manufacturing process used for this component would have to be developed to the level used for spiral bevel gears. The current state of the art for face gear manufacturing required using less than optimal gear materials and manufacturing techniques because the surface of the tooth form does not receive final finishing after heat treatment as it does for spiral bevel gears. This resulted in less than desirable surface hardness and manufacturing tolerances. An Advanced Research and Projects Agency (ARPA) Technology Reinvestment Project has been funded to investigate

  10. External gear pumps operating with non-Newtonian fluids: Modelling and experimental validation

    Science.gov (United States)

    Rituraj, Fnu; Vacca, Andrea

    2018-06-01

    External Gear Pumps are used in various industries to pump non-Newtonian viscoelastic fluids like plastics, paints, inks, etc. For both design and analysis purposes, it is often a matter of interest to understand the features of the displacing action realized by meshing of the gears and the description of the behavior of the leakages for this kind of pumps. However, very limited work can be found in literature about methodologies suitable to model such phenomena. This article describes the technique of modelling external gear pumps that operate with non-Newtonian fluids. In particular, it explains how the displacing action of the unit can be modelled using a lumped parameter approach which involves dividing fluid domain into several control volumes and internal flow connections. This work is built upon the HYGESim simulation tool, conceived by the authors' research team in the last decade, which is for the first time extended for the simulation of non-Newtonian fluids. The article also describes several comparisons between simulation results and experimental data obtained from numerous experiments performed for validation of the presented methodology. Finally, operation of external gear pump with fluids having different viscosity characteristics is discussed.

  11. Dynamic characteristics of motor-gear system under load saltations and voltage transients

    Science.gov (United States)

    Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

    2018-02-01

    In this paper, a dynamic model of a motor-gear system is proposed. The model combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system. The external excitations including voltage transients and load saltations, as well as the internal excitations such as spatial effects, magnetic circuits topology and material nonlinearity in the motor, and time-varying mesh stiffness and damping in the planetary gear system are considered in the proposed model. Then, the simulation results are compared with those predicted by the electromechanical model containing a dynamic motor model with constant inductances. The comparison showed that the electromechanical system model with the PNM motor model yields more reasonable results than the electromechanical system model with the lumped-parameter electric machine. It is observed that electromechanical coupling effect can induce additional and severe gear vibrations. In addition, the external conditions, especially the voltage transients, will dramatically affect the dynamic characteristics of the electromechanical system. Finally, some suggestions are offered based on this analysis for improving the performance and reliability of the electromechanical system.

  12. Influence of material and gear parameters on the safety of gearing in metallurgical industry

    Directory of Open Access Journals (Sweden)

    S. Medvecká - Beňová

    2015-01-01

    Full Text Available This paper deals with the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load. Steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500 - 650 HBW are used. As a final heat treatment are used surface hardening, cementation and hardening, nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. Results are presented for dual-ratio gearbox with spur gears from operation of an integrated steel company.

  13. Magnet-Sleeve-Sealed Mini Trochoidal-Gear Pump Prototype with Polymer Composite Gear

    Directory of Open Access Journals (Sweden)

    Pedro Javier Gamez-Montero

    2017-09-01

    Full Text Available The trochoidal-gear technology has been growing in groundbreaking fields. Forthcoming applications are demanding to this technology a step forward in the conceiving stage of positive displacement machines. The compendium of the qualities and the inherent characteristics of trochoidal-gear technology, especially towards the gerotor pump, together with scale/size factor and magnetic-driven transmission has led to the idea of a magnet-sleeve-sealed variable flow mini trochoidal-gear pump. From its original concept, to the last phase of the design development, the proof of concept, this new product will intend to overcome problems such as noise, vibration, maintenance, materials, and dimensions. The paper aims to show the technological path followed from the concept, design, and model, to the manufacture of the first prototype, where the theoretical and numerical approaches are not always directly reflected in the prototype performance results. Early in the design process, from a standard-commercial sintered metal mini trochoidal-gear unit, fundamental characteristics and dimensional limitations have been evaluated becoming the strategic parameters that led to its configuration. The main technical challenge to confront is being sealed with non-exterior driveshaft, ensuring that the whole interior is filled and wetted with working fluid and helping the hydrodynamic film formation, the pumping effect, and the heat dissipation. Subsequently, the mini pump architecture, embodiment, methodology, materials, and manufacture are presented. The trend of applications of polymer composite materials and their benefits wanted to be examined with this new mini pump prototype, and a pure polyoxymethylene mini trochoidal-gear set has been designed and manufactured. Finally, both the sintered and the polymer trochoidal-gear units have been experimentally tested in an in-house full-instrumented mini test bench. Although the main goal of the presented work is the

  14. Nonlinear dynamics modelling of multistage micro-planetary gear transmission

    Directory of Open Access Journals (Sweden)

    Li Jianying

    2018-01-01

    Full Text Available The transmission structure of a 2K-H multistage micro-planetary gear transmission reducer is described in detail, and three assumptions are supposed in dynamic modelling. On basis of these assumptions, a three stages 2K-H micro-planetary gear transmission dynamic model is established, in which the relative displacement each meshing gear pairs can be obtained after including the comprehensive transmission error. According to gear kinematics, the friction arms between the sun gear, the ring gear and the nth planet are also obtained, and the friction coefficient in the mixed elastohydrodynamic lubrication is considered, the transmission system motion differential equations are obtained, including above factors and the time-varying meshing stiffness, damping and backlash, inter-stage coupling stiffness, it can be provided an theoretical foundation for further analysing the parameter sensitivity, dynamic stability and designing.

  15. Prediction of potential failures in hydraulic gear pumps

    Directory of Open Access Journals (Sweden)

    E. Lisowski

    2010-07-01

    Full Text Available Hydraulic gear pumps are used in many machines and devices. In hydraulic systems of machines gear pumps are main component ofsupply unit or perform auxiliary function. Gear pumps opposite to vane pumps are less complicated. They consists of such components as:housing, gear wheels, bearings, shaft, seal for rotation motion which are not very sensitive for damage and that is why they are using veryoften. However, gear pumps are break down from time to time. Usually damage of pump cause shutting down of machines and devices.One of the way for identifying potential failures and foreseeing their effects is a quality method. On the basis of these methods apreventing action might be undertaken before failure appear. In this paper potential failures and damages of a gear pump were presented bythe usage of matrix FMEA analysis.

  16. Economic method for helical gear flank surface characterisation

    Science.gov (United States)

    Koulin, G.; Reavie, T.; Frazer, R. C.; Shaw, B. A.

    2018-03-01

    Typically the quality of a gear pair is assessed based on simplified geometric tolerances which do not always correlate with functional performance. In order to identify and quantify functional performance based parameters, further development of the gear measurement approach is required. Methodology for interpolation of the full active helical gear flank surface, from sparse line measurements, is presented. The method seeks to identify the minimum number of line measurements required to sufficiently characterise an active gear flank. In the form ground gear example presented, a single helix and three profile line measurements was considered to be acceptable. The resulting surfaces can be used to simulate the meshing engagement of a gear pair and therefore provide insight into functional performance based parameters. Therefore the assessment of the quality can be based on the predicted performance in the context of an application.

  17. Prediction of Landing Gear Noise Reduction and Comparison to Measurements

    Science.gov (United States)

    Lopes, Leonard V.

    2010-01-01

    Noise continues to be an ongoing problem for existing aircraft in flight and is projected to be a concern for next generation designs. During landing, when the engines are operating at reduced power, the noise from the airframe, of which landing gear noise is an important part, is equal to the engine noise. There are several methods of predicting landing gear noise, but none have been applied to predict the change in noise due to a change in landing gear design. The current effort uses the Landing Gear Model and Acoustic Prediction (LGMAP) code, developed at The Pennsylvania State University to predict the noise from landing gear. These predictions include the influence of noise reduction concepts on the landing gear noise. LGMAP is compared to wind tunnel experiments of a 6.3%-scale Boeing 777 main gear performed in the Quiet Flow Facility (QFF) at NASA Langley. The geometries tested in the QFF include the landing gear with and without a toboggan fairing and the door. It is shown that LGMAP is able to predict the noise directives and spectra from the model-scale test for the baseline configuration as accurately as current gear prediction methods. However, LGMAP is also able to predict the difference in noise caused by the toboggan fairing and by removing the landing gear door. LGMAP is also compared to far-field ground-based flush-mounted microphone measurements from the 2005 Quiet Technology Demonstrator 2 (QTD 2) flight test. These comparisons include a Boeing 777-300ER with and without a toboggan fairing that demonstrate that LGMAP can be applied to full-scale flyover measurements. LGMAP predictions of the noise generated by the nose gear on the main gear measurements are also shown.

  18. Alternating Direction Implicit (ADI) schemes for a PDE-based image osmosis model

    Science.gov (United States)

    Calatroni, L.; Estatico, C.; Garibaldi, N.; Parisotto, S.

    2017-10-01

    We consider Alternating Direction Implicit (ADI) splitting schemes to compute efficiently the numerical solution of the PDE osmosis model considered by Weickert et al. in [10] for several imaging applications. The discretised scheme is shown to preserve analogous properties to the continuous model. The dimensional splitting strategy traduces numerically into the solution of simple tridiagonal systems for which standard matrix factorisation techniques can be used to improve upon the performance of classical implicit methods, even for large time steps. Applications to the shadow removal problem are presented.

  19. New generation methods for spur, helical, and spiral-bevel gears

    Science.gov (United States)

    Litvin, F. L.; Tsung, W.-J.; Coy, J. J.; Handschuh, R. F.; Tsay, C.-B. P.

    1987-01-01

    New methods for generating spur, helical, and spiral-bevel gears are proposed. These methods provide the gears with conjugate gear tooth surfaces, localized bearing contact, and reduced sensitivity to gear misalignment. Computer programs have been developed for simulating gear meshing and bearing contact.

  20. Diagnostics of power transmissions system with tooth gear

    Directory of Open Access Journals (Sweden)

    Grzegorz WOJNAR

    2008-01-01

    Full Text Available This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and gear shafts at different speeds and gear loads. Results were analyzed and compared but in this paper is presented only selected examples. This paper shows that on the basis of the transverse vibration speed of transmission gear shafts, it is possible to detect defects at an earlier stage than on the basis of the housing vibration accelerations. In the case of measuring gear shaft vibration velocity, the way of the signal generated by the defect of a gear wheel (or bearing is shortened as well as the influence of composed transmittance of the bearing-gear housing system is eliminated. WV time-frequency analysis and complex continuous wavelet transformations were used for detection. The authors introduced a measure of local tooth damage, which was proportional to the size of damage. The results of research presented in this paperconfirmed that the defect's measure is very sensitive to the development of teeth faults.

  1. Turbine Engine with Differential Gear Driven Fan and Compressor

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)

    2013-01-01

    A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

  2. The theory and practice of worm gear drives

    CERN Document Server

    Dudás, Ilés

    2005-01-01

    Worm gears are special gears that resemble screws, and can be used to drive other gears. Worm gears, enable two non-touching shafts in a machine to mesh (join) together. This publication, unique in that it combines both theoretical and practical design aspects, including the latest results of research and development, provides detailed treatment of the theory and production of worm drives, as well as the overarching subject of production geometry of helicoidal surfaces.Included are mathematical models for a number of practical applications; a description of dressing equipment r

  3. Offset Compound Gear Inline Two-Speed Drive

    Science.gov (United States)

    Stevens, Mark A. (Inventor); Handschuh, Robert F. (Inventor); Lewicki, David G. (Inventor)

    2014-01-01

    A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

  4. Gear-shaft linkage, especially for nuclear reactor coolant pumps

    International Nuclear Information System (INIS)

    Delaunois, T.; Lefevre, R.

    1990-01-01

    The pump comprises: - inlet and outlet channels for the pumped fluid - a rotating shaft - a gear wheel mounted on the shaft by an axial locking nut which can support the axial hydraulic force - a thermal barrier above the gear wheel. A hydrostatic bearing fitted to the exterior surround of the gear wheel, the gear shaft linkage is made by at least a centering and locating device having a cylindrical span and an axial stop and another independent device which can take up the torque [fr

  5. EEG POLISOMNOGRAFIJA KAO ZNAČAJNA DIJAGNOSTIČKA I PROGNOSTIČKA METODA ZA PROCJENU OŠTEĆENJA MOZGA U NOVOROĐENČADI I DOJENČADI

    OpenAIRE

    Paškov Dugandžija, Gordana

    2008-01-01

    EEG polisomnografija je značajna metoda za dijagnozu i prognozu oštećenja mozga u nedonošene i donošene novorođenčadi i dojenčadi. Sadrži slijedeće elemente: EEG(elektroencefalografija), EOG( elektrookulografija) , EMG( elektromiografija), EKG (elektrokardiografija), respiracija i video monitoriranje. Primjenjujemo polisomnografsku montažu. To je specifično modificiran način postavljanja elektroda. Koristimo posrebrene pločaste elektrode sa 1 metar savitljivim silikonskim odvodima u šest razl...

  6. Interactions of two co-propagating laser beams in underdense plasmas using a generalized Peaceman-Rachford ADI form

    International Nuclear Information System (INIS)

    Mahdy, A.I.

    2005-12-01

    A generalized Peaceman-Rachford (P-R) ADI form based on the regularized finite difference scheme is employed in order to study the interactions of two co-propagating laser beams in underdense plasmas. A numerical algorithm using the P-R ADI form is constructed for solution of coupled 2D time-dependent non-linear Schroedinger equations for quasineutral plasmas in paraxial approximation. The ability of the form to solve the equations is discussed, and its performance in simulating phenomena associated with the interactions in the presence of pondermotive nonlinearity and relativistic nonlinearity is examined. It is shown that the generalized P-R ADI form can accurately solve the coupled NLS equations. With simulation results, the form is shown to be suitable to simulate the interactions of two co-propagating laser beams with underdense plasma, and it can successively simulate the associated phenomena at varying conditions. (author)

  7. Improving fishing effort descriptors: Modelling engine power and gear-size relations of five European trawl fleets

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Rihan, Dominic; Graham, Norman

    2011-01-01

    Based on information from an international inventory of gears currently deployed by trawlers in five European countries, the relationship between vessel engine power and trawl size is quantified for different trawl types, trawling techniques and target species. Using multiplicative modelling it i...

  8. Adi Quala: application of solar photovoltaic generation in rural medical centres.

    Science.gov (United States)

    Allen, P; Welstead, J

    1994-01-01

    Adi Quala is an Eritrean agricultural town of 14,000 people, and is situated about 70 km south of the capital, Asmara and 30 km from the border with Tigray, Ethiopia. On good days electricity was received from Asmara between 0600 h and 2300 h with nothing available outside these hours. These conditions meant the electricity supply had been a constant problem for the Adi Quala hospital which caters for about 50,000 people with 21 staff. It was for this reason that it was chosen for the first solar system, which provides all essential requirements completely independently from the grid connection. This will in turn enable the hospital to increase the range and reliability of services on offer. Three weeks after the arrival of the equipment the elders were able to have a guided tour of their new local facilities. This included 2kW of photovoltaic panels (installed on the roof), batteries and control equipment powering a range of hospital equipment used in the Mother and Child Health Centre, delivery room, wards, dispensary, clinic and laboratory. Their enormous appreciation was very moving and well articulated in an afternoon of music, speeches and feasting. Eritrea's first solar powered hospital was welcomed into capable hands. The pilot project was successfully installed and commissioned in February 1992, and has performed well to date.

  9. Influence of the surface roughness on the fatigue properties in ausferritic ductile irons (ADI

    Directory of Open Access Journals (Sweden)

    Svenningsson Roger

    2014-06-01

    Full Text Available Heat treatment of cast ductile iron (DI to ausferritic ductile iron (ADI is known to increase fatigue properties. However, the surface roughness of the cast material is also of significant importance. In this investigation, test rods with seven different surface qualities were cast from the same melt i.e. with same chemical composition. The surfaces of the test rods were varied by a number of parameters; grain size of the moulding sand, coated or non-coated mould surfaces, as-cast or machined and polished, shot peened or not. In addition, a reference material in conventional DI was cast and tested. All eight series were subjected to high-cycle fatigue bending tests. The results show that surface defects, such as micro porosity and minor inclusions drastically decrease the fatigue properties. For some ADI materials the stress amplitude limit was actually lower compared to the non-heat treated DI. The machined, polished and shot-peened material demonstrated the best fatigue properties, which is as expected.

  10. Sensitivity study with respect to direction of ADI method during re-flooding in AHWR

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M.; Mukhopadhyay, D. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Div.; Ghosh, A.K. [Bhabha Atomic Research Centre, Mumbai (India). Raja Ramanna Fellow; Kumar, R. [Indian Institute of Technology, Roorkee (India)

    2015-05-15

    The Advanced Heavy water Reactor (AHWR) is a natural circulation vertical pressure tube type boiling light water cooled and heavy water moderated reactor. As the AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations, bottom re-flooding still remain open as another option. Radial direction injection of emergency core cooling leads to rewetting of AHWR fuel cluster in circumferential direction. A 3D fuel pin model has been developed by using Finite Difference Method (FDM) of transient heat conduction equation. Alternating Direction Implicit technique of Finite Difference Method (FDM) has been used for discretisation of numerical equation in different time step at different direction. Sensitivity numerical study with respect to direction of ADI method has been carried out to optimize the time step during the transient as well as steady state and is found that it is insensitivity with direction of solution. Further, to assess influence of circumferential rewetting vis-a-vis axial rewetting. Both the analyses are carried out with same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that for radial jet, the circumferential conduction is significant and overall the fuel temperature falls in the quench plane with the initiation of quenching event. The paper discusses the sensitivity study with respect to direction of ADI solution and comparison of numerical results for circumferential and axial rewetting for single pin.

  11. Fishing gear-related injury in California marine wildlife.

    Science.gov (United States)

    Dau, Brynie Kaplan; Gilardi, Kirsten V K; Gulland, Frances M; Higgins, Ali; Holcomb, Jay B; Leger, Judy St; Ziccardi, Michael H

    2009-04-01

    We reviewed medical records from select wildlife rehabilitation facilities in California to determine the prevalence of injury in California Brown Pelicans (Pelecanus occidentalis), gulls (Larus spp.), and pinniped species (Zalophus californianus, Mirounga angustirostris, and Phoca vitulina) due to fishing gear entanglement and ingestion from 2001 to 2006. Of 9,668 Brown Pelican, gull, and pinniped cases described during the 6-yr study period (2001-06), 1,090 (11.3%) were fishing gear-related. Pelican injuries caused by fishing gear were most common in the Monterey Bay region, where 59.6% of the pelicans rescued in this area and admitted to a rehabilitation center were injured by fishing gear over the 6-yr period. The highest prevalence of fishing gear-related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds were seen in the San Diego region (3.7%). Despite these higher prevalences of gull and pinniped fishing gear-related injuries in these specific regions, there was no statistical significance in these trends. Juvenile gulls and pinnipeds were more commonly injured by fishing gear than adults (gulls: P = 0.03, odds ratio = 1.29; pinnipeds: P = 0.01, odds ratio = 2.07). Male pinnipeds were twice as likely to be injured by fishing gear as females (P gear-related injury cases that were successfully rehabilitated and released (percentage of cases successfully rehabilitated to the point of release out of the total number of fishing gear-related injury cases) was high in all three species groups (pelicans: 63%; gulls: 54%; pinnipeds: 70%). Fishing gear-related injuries in Brown Pelicans and gulls were highest in the fall, but there was only a significant difference between seasons for fishing gear-related injuries in pelicans. Fishing gear-related injuries in pinnipeds most commonly occurred in summer; however, a statistical difference was not detected between seasons for pinnipeds. Derelict

  12. Variable gearing in a biologically inspired pneumatic actuator array

    International Nuclear Information System (INIS)

    Azizi, Emanuel; Roberts, Thomas J

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. (paper)

  13. Variable gearing in a biologically inspired pneumatic actuator array.

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J

    2013-06-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions.

  14. VARIABLE GEARING IN A BIOLOGICALLY-INSPIRED PNEUMATIC ACTUATOR ARRAY

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J.

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle’s gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system’s gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. PMID:23462288

  15. Hybrid foundry patterns of bevel gears

    Directory of Open Access Journals (Sweden)

    Budzik G.

    2007-01-01

    Full Text Available Possibilities of making hybrid foundry patterns of bevel gears for investment casting process are presented. Rapid prototyping of gears with complex tooth forms is possible with the use of modern methods. One of such methods is the stereo-lithography, where a pattern is obtained as a result of resin curing with laser beam. Patterns of that type are applicable in precision casting. Removing of stereo-lithographic pattern from foundry mould requires use of high temperatures. Resin burning would generate significant amounts of harmful gases. In case of a solid stereo-lithographic pattern, the pressure created during gas burning may cause the mould to crack. A gas volume reduction may be achieved by using patterns of honeycomb structure. However, this technique causes a significant worsening of accuracy of stereo-lithographic patterns in respect of their dimensions and shape. In cooperation with WSK PZL Rzeszów, the Machine Design Department of Rzeszow University of Technology carried out research on the design of hybrid stereo-lithographic patterns. Hybrid pattern consists of a section made by stereo-lithographic process and a section made of casting wax. The latter material is used for stereo-lithographic pattern filling and for mould gating system. The hybrid pattern process consists of two stages: wax melting and then the burn-out of stereolithographic pattern. Use of hybrid patterns reduces the costs of production of stereolithographic patterns. High dimensional accuracy remains preserved in this process.

  16. 78 FR 17188 - Agency Information Collection Activities; Comment Request; Evaluation of the GEAR UP College...

    Science.gov (United States)

    2013-03-20

    ...; Comment Request; Evaluation of the GEAR UP College Savings Account Research Demonstration AGENCY... of Collection: Evaluation of the GEAR UP College Savings Account Research Demonstration. OMB Control..., Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP). This first Information...

  17. Wording in international law

    NARCIS (Netherlands)

    d' Aspremont, J.

    2012-01-01

    Since the demise of philosophical foundationalism and that of the Aristotelian idea of an inner meaning of words, scholarship about international law is no longer perceived as a mining activity geared towards the extraction of pre-existing meaning. Rather, international legal scholarship is in a

  18. Wording in International Law

    NARCIS (Netherlands)

    d' Aspremont, J.

    2012-01-01

    Since the demise of philosophical foundationalism and that of the Aristotelian idea of an inner meaning of words, the scholarship about international law is no longer perceived as a mining activity geared towards the extraction of pre-existing meaning. Rather, international legal scholarship is in a

  19. Survey gear calibration independent of spatial fish distribution

    DEFF Research Database (Denmark)

    Lewy, Peter; Nielsen, J. Rasmus; Hovgård, Holger

    2004-01-01

    Trawl surveys provide important information for evaluation of relative stock abundance fluctuations over time. Therefore, when survey gears or vessels are changed, it is important to compare the efficiency and selectivity of old and new gears and vessels. A method for estimation of conversion fac...

  20. Contact stress analysis of involute spur gear by Finite Element ...

    African Journals Online (AJOL)

    In this paper the contact stress in rolling-sliding contact of involute spur gear and the effect of coefficient of friction was analyzed. To achieve this, first, three dimensional involute spur gear pairs were developed in Solid works 2012 Premium and the 3D model was exported to ANSYS workbench 14.5. Next, the analysis was ...

  1. Adaptive landing gear concept—feedback control validation

    Science.gov (United States)

    Mikulowski, Grzegorz M.; Holnicki-Szulc, Jan

    2007-12-01

    The objective of this paper is to present an integrated feedback control concept for adaptive landing gears (ALG) and its experimental validation. Aeroplanes are subjected to high dynamic loads as a result of the impact during each landing. Classical landing gears, which are in common use, are designed in accordance with official regulations in a way that ensures the optimal energy dissipation for the critical (maximum) sink speed. The regulations were formulated in order to ensure the functional capability of the landing gears during an emergency landing. However, the landing gears, whose characteristics are optimized for these critical conditions, do not perform well under normal impact conditions. For that situation it is reasonable to introduce a system that would adapt the characteristics of the landing gears according to the sink speed of landing. The considered system assumes adaptation of the damping force generated by the landing gear, which would perform optimally in an emergency situation and would adapt itself for regular landings as well. This research covers the formulation and design of the control algorithms for an adaptive landing gear based on MR fluid, implementation of the algorithms on an FPGA platform and experimental verification on a lab-scale landing gear device. The main challenge of the research was to develop a control methodology that could operate effectively within 50 ms, which is assumed to be the total duration of the phenomenon. The control algorithm proposed in this research was able to control the energy dissipation process on the experimental stand.

  2. Nonlinear Vibroimpact Characteristics of a Planetary Gear Transmission System

    Directory of Open Access Journals (Sweden)

    Jianxing Zhou

    2016-01-01

    Full Text Available In order to research the vibroimpact characteristics of a planetary gear transmission system under high speed and lightly loaded conditions, a new modeling method is proposed. In the modeling process, linear spring was used to simulate gear mesh elasticity under heavy load cases, and Hertz contact theory was used to calculate the contact force of gear pair under light load cases. Then, effects of the working conditions on the system vibroimpact characteristics are analyzed. The results show that, with input speed growing, the mesh force produced obvious fluctuations on the resonance frequencies of the sun gear and carrier torsion vibration, ring gear’s transverse vibration under the heavy load. Under light load condition, the collision vibration occurs in the gear pair; the changing trend of the contact force shows strongly nonlinear characteristics. The time of mesh-apart in gears pair decreases gradually as the load is increased; until it reaches collision vibration threshold value, the gear pair is no longer mesh-apart. With increasing of the input speed, the time of mesh-apart is decreased gradually; the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline for planetary gear transmission low-noise design.

  3. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent...

  4. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    Science.gov (United States)

    Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  5. Evaluating Sex and Age Differences in ADI-R and ADOS Scores in a Large European Multi-Site Sample of Individuals with Autism Spectrum Disorder

    Science.gov (United States)

    Tillmann, J.; Ashwood, K.; Absoud, M.; Bölte, S.; Bonnet-Brilhault, F.; Buitelaar, J. K.; Calderoni, S.; Calvo, R.; Canal-Bedia, R.; Canitano, R.; De Bildt, A.; Gomot, M.; Hoekstra, P. J.; Kaale, A.; McConachie, H.; Murphy, D. G.; Narzisi, A.; Oosterling, I.; Pejovic-Milovancevic, M.; Persico, A. M.; Puig, O.; Roeyers, H.; Rommelse, N.; Sacco, R.; Scandurra, V.; Stanfield, A. C.; Zander, E.; Charman, T.

    2018-01-01

    Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and…

  6. Surface micromachined counter-meshing gears discrimination device

    Science.gov (United States)

    Polosky, Marc A.; Garcia, Ernest J.; Allen, James J.

    2000-12-12

    A surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock. Each of two CMG has a first portion of its perimeter devoted to continuous driving teeth that mesh with respective pinion gears. Each EMG also has a second portion of its perimeter devoted to regularly spaced discrimination gear teeth that extend outwardly on at least one of three levels of the CMG. The discrimination gear teeth are designed so as to pass each other without interference only if the correct sequence of partial rotations of the CMG occurs in response to a coded series of rotations from the pinion gears. A 24 bit code is normally input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect.

  7. Study of a spur gear dynamic behavior in transient regime

    Science.gov (United States)

    Khabou, M. T.; Bouchaala, N.; Chaari, F.; Fakhfakh, T.; Haddar, M.

    2011-11-01

    In this paper the dynamic behavior of a single stage spur gear reducer in transient regime is studied. Dynamic response of the single stage spur gear reducer is investigated at different rotating velocities. First, gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. Then, the dynamic response is computed using the Newmark method. After that, a parameter study is made on spur gear powered in the first place by an electric motor and in the second place by four strokes four cylinders diesel engine. Dynamic responses come to confirm a significant influence of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition.

  8. GEAR: A database of Genomic Elements Associated with drug Resistance

    Science.gov (United States)

    Wang, Yin-Ying; Chen, Wei-Hua; Xiao, Pei-Pei; Xie, Wen-Bin; Luo, Qibin; Bork, Peer; Zhao, Xing-Ming

    2017-01-01

    Drug resistance is becoming a serious problem that leads to the failure of standard treatments, which is generally developed because of genetic mutations of certain molecules. Here, we present GEAR (A database of Genomic Elements Associated with drug Resistance) that aims to provide comprehensive information about genomic elements (including genes, single-nucleotide polymorphisms and microRNAs) that are responsible for drug resistance. Right now, GEAR contains 1631 associations between 201 human drugs and 758 genes, 106 associations between 29 human drugs and 66 miRNAs, and 44 associations between 17 human drugs and 22 SNPs. These relationships are firstly extracted from primary literature with text mining and then manually curated. The drug resistome deposited in GEAR provides insights into the genetic factors underlying drug resistance. In addition, new indications and potential drug combinations can be identified based on the resistome. The GEAR database can be freely accessed through http://gear.comp-sysbio.org. PMID:28294141

  9. Generation of gear tooth surfaces by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  10. Dynamic Response of a Planetary Gear System Using a Finite Element/Contact Mechanics Model

    Science.gov (United States)

    Parker, Robert G.; Agashe, Vinayak; Vijayakar, Sandeep M.

    2000-01-01

    The dynamic response of a helicopter planetary gear system is examined over a wide range of operating speeds and torques. The analysis tool is a unique, semianalytical finite element formulation that admits precise representation of the tooth geometry and contact forces that are crucial in gear dynamics. Importantly, no a priori specification of static transmission error excitation or mesh frequency variation is required; the dynamic contact forces are evaluated internally at each time step. The calculated response shows classical resonances when a harmonic of mesh frequency coincides with a natural frequency. However, peculiar behavior occurs where resonances expected to be excited at a given speed are absent. This absence of particular modes is explained by analytical relationships that depend on the planetary configuration and mesh frequency harmonic. The torque sensitivity of the dynamic response is examined and compared to static analyses. Rotation mode response is shown to be more sensitive to input torque than translational mode response.

  11. Dynamic characteristic of electromechanical coupling effects in motor-gear system

    Science.gov (United States)

    Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

    2018-06-01

    Dynamic characteristics of an electromechanical model which combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system is analyzed in this study. The simulations reveal the effects of internal excitations or parameters like machine slotting, magnetic saturation, time-varying mesh stiffness and shaft stiffness on the system dynamics. The responses of the electromechanical system with PNM motor model are compared with those responses of the system with dynamic motor model. The electromechanical coupling due to the interactions between the motor and gear system are studied. Furthermore, the frequency analysis of the electromechanical system dynamic characteristics predicts an efficient way to detect work condition of unsymmetrical voltage sag.

  12. Analysis of Pitch Gear Deterioration using Indicators

    DEFF Research Database (Denmark)

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2011-01-01

    This work concerns a case study in the context of risk-based operation and maintenance of offshore wind turbines. For wind turbines with electrical pitch systems, deterioration can generally be observed at the pitch gear teeth; especially at the point where the blades are located during normal...... of the damage, and can be used for Bayesian updating of a damage model used for risk-based decision making. For this decision problem, the risk of failure should be compared to the cost of preventive maintenance. The hypothesis that the maximum pitch motor torque is an indicator of the damage size is supported...... changes in the temperature are the primary cause of the decrease. A model is established to remove the effect of the explained variation, and it is investigated if deterioration can be detected as changes in the peak torque. A small increase could be detected after the maintenance, but before...

  13. Investigating Vibration Properties of a Planetary Gear Set with a Cracked Tooth in a Planet Gear

    Science.gov (United States)

    2014-12-23

    sidebands appear at mfm±nfplanet± kfc or mfm±nfplanet±kfp, where m, n and k are all integers; fp represents rotation frequency of the planet gear and...region from 43 fm to 45 fm. Sidebands are not symmetric and sizable sidebands located at mfm±nfplanet± kfc or mfm±nfplanet±kfp, where m, n and k are

  14. The design and analysis of single flank transmission error testor for loaded gears

    Science.gov (United States)

    Houser, D. R.; Bassett, D. E.

    1985-01-01

    Due to geometrical imperfections in gears and finite tooth stiffnesses, the motion transmitted from an input gear shaft to an output gear shaft will not have conjugate action. In order to strengthen the understanding of transmission error and to verify mathematical models of gear transmission error, a test stand that will measure the transmission error of a gear pair at operating loads, but at reduced speeds would be desirable. This document describes the design and development of a loaded transmission error tester. For a gear box with a gear ratio of one, few tooth meshing combinations will occur during a single test. In order to observe the effects of different tooth mesh combinations and to increase the ability to load test gear pairs with higher gear ratios, the system was designed around a gear box with a gear ratio of two.

  15. Accelerator test of an improved Angle Detecting Inclined Sensor (ADIS) prototype with beams of {sup 78}Kr and fragments

    Energy Technology Data Exchange (ETDEWEB)

    Connell, J.J., E-mail: james.connell@unh.edu [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Lopate, C. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); McLaughlin, K.R. [Space Science Center and Department of Mechanical Engineering, University of New Hampshire, Durham, NH 03824 (United States)

    2016-11-21

    The measurement of cosmic rays and Solar energetic particles in space is basic to our understanding of the Galaxy, the Sun, phenomena in the heliosphere and the emerging field of space weather. For these reasons, cosmic ray instruments are common on both scientific spacecraft and operational spacecraft such as weather satellites. Cosmic rays and Solar energetic particles include ions over the full range of elements found in the Solar System. High-resolution measurements of the elemental and isotopic composition require the angle of incidence of these energetic ions be determined to correct for pathlength variation in detectors within an instrument. The Angle Detecting Inclined Sensor (ADIS) system is a simple detector configuration used to determine the angle of incidence of heavy ions in space instruments. ADIS replaces complex position sensing detectors (PSDs) with a system of simple, reliable and robust detectors inclined at an angle to the instrument axis. An ADIS instrument thus offers significant advantages in mass, power, telemetry and cost. In February 2008 an improved ADIS prototype was tested with a 150 MeV/u {sup 78}Kr beam at the National Superconducting Cyclotron Laboratory's (NSCL) Coupled Cyclotron Facility (CCF). This demonstrated a charge resolution of σ~0.3 e at Kr (Z=36), an exceptional charge resolution for such a simple instrument system.

  16. Multisite Study of New Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers

    Science.gov (United States)

    Kim, So Hyun; Thurm, Audrey; Shumway, Stacy; Lord, Catherine

    2013-01-01

    Using two independent datasets provided by National Institute of Health funded consortia, the Collaborative Programs for Excellence in Autism and Studies to Advance Autism Research and Treatment (n = 641) and the National Institute of Mental Health (n = 167), diagnostic validity and factor structure of the new Autism Diagnostic Interview (ADI-R)…

  17. Diagnostic Utility of the ADI-R and DSM-5 in the Assessment of Latino Children and Adolescents

    Science.gov (United States)

    Magaña, Sandy; Vanegas, Sandra B.

    2017-01-01

    Latino children in the US are systematically underdiagnosed with Autism Spectrum Disorder (ASD); therefore, it is important that recent changes to the diagnostic process do not exacerbate this pattern of under-identification. Previous research has found that the Autism Diagnostic Interview-Revised (ADI-R) algorithm, based on the Diagnostic and…

  18. Shared Memory Parallelization of an Implicit ADI-type CFD Code

    Science.gov (United States)

    Hauser, Th.; Huang, P. G.

    1999-01-01

    A parallelization study designed for ADI-type algorithms is presented using the OpenMP specification for shared-memory multiprocessor programming. Details of optimizations specifically addressed to cache-based computer architectures are described and performance measurements for the single and multiprocessor implementation are summarized. The paper demonstrates that optimization of memory access on a cache-based computer architecture controls the performance of the computational algorithm. A hybrid MPI/OpenMP approach is proposed for clusters of shared memory machines to further enhance the parallel performance. The method is applied to develop a new LES/DNS code, named LESTool. A preliminary DNS calculation of a fully developed channel flow at a Reynolds number of 180, Re(sub tau) = 180, has shown good agreement with existing data.

  19. Title: Accelerator Test of an Angle Detecting Inclined Sensor (ADIS) Prototype with Beams of 48Ca and Fragments

    Science.gov (United States)

    Connell, J. J.; Lopate, C.; McKibben, R. B.; Enman, A.

    2006-12-01

    The measurement and identification of high energy ions (> few MeV/n) from events originating on the Sun is of direct interest to the Living With a Star Program. These ions are a major source of Single Event Effects (SEE) in space-based electronics. Measurements of these ions also help in understanding phenomena such as Solar particle events and coronal mass ejections. These disturbances can directly affect the Earth and the near-Earth space environment, and thus human technology. The resource constraints on spacecraft generally mean that instruments that measure cosmic rays and Solar energetic particles must have low mass (a few kg) and power (a few W), be robust and reliable yet highly capable. Such instruments should identify ionic species (at least by element, preferably by isotope) from protons through the iron group. The charge and mass resolution of heavy ion instrument in space depends upon determining ions' angles of incidence. The Angle Detecting Inclined Sensor (ADIS) system is a highly innovative and uniquely simple detector configuration used to determine the angle of incidence of heavy ions in space instruments. ADIS replaces complex position sensing detectors (PSDs) with a system of simple, reliable and robust Si detectors inclined at an angle to the instrument axis. In August 2004 we tested ADIS prototypes with a 48Ca beam at the National Superconducting Cyclotron Laboratory's (NSCL) Coupled Cyclotron Facility (CCF). We demonstrate that our prototype charged particle instrument design with an ADIS system has a charge resolution of better than 0.25 e. An ADIS based system is being incorporated into the Energetic Heavy Ion Sensor (EHIS), one of the instruments in the Space Environment In-Situ Suite (SEISS) on the next generation of Geostationary Operational Environmental Satellite (GOES-R) System. An ADIS based system was also selected for the High Energy Particle Sensor (HEPS), one of the instruments in the Space Environment Sensor Suite (SESS) on the

  20. Two dimensional model of a permanent magnet spur gear

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand

    2005-01-01

    This paper presents calculation and measurement results of a high-performance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N/spl middot/m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...... of the loss components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81%. A large magnetic loss component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses...

  1. A study on the automated design system for gear

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H. Y.; Nam, G. J.; Oh, B. K. [Chungbuk National Univ., Cheongju (Korea, Republic of)

    2001-07-01

    A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.

  2. A study on the automated design system for gear

    International Nuclear Information System (INIS)

    Cho, H. Y.; Nam, G. J.; Oh, B. K.

    2001-01-01

    A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course

  3. Hybrid Gear Performance Under Loss-of-Lubrication Conditions

    Science.gov (United States)

    Laberge, Kelsen E.; Berkebile, Stephen P.; Handschuh, Robert F.; Roberts, Gary D.

    2017-01-01

    Hybrid composite gear technology is being investigated to increase power density in rotorcraft drive systems. These gears differ from conventional steel gears in that the structural web material is replaced with a lightweight carbon fiber composite. Past studies have focused on performance of this technology under normal operating conditions, however, for this technology to be viable it must also withstand adverse conditions. The study presented here evaluates the performance of hybrid gears under loss-of-lubrication conditions in NASA Glenn Research Centers Contact Fatigue Test Facility. Two experiments are presented using small-scale 3.5 inch (8.9 cm) pitch diameter hybrid gears and compared to a baseline steel gear pair. Results of these tests show that there are limitations to the use of a hexagonal interlock pattern between the steel and composite. There is also evidence that the presence of polymer in the gear during an oil out event has a potential to increase time to failure. Further studies are planned to expand on these initial findings.

  4. Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Antolick, Lance J.; Branning, Jeremy S.; Wade, Daniel R.; Dempsey, Paula J.

    2010-01-01

    The U.S. Army is currently expanding its fleet of Health Usage Monitoring Systems (HUMS) equipped aircraft at significant rates, to now include over 1,000 rotorcraft. Two different on-board HUMS, the Honeywell Modern Signal Processing Unit (MSPU) and the Goodrich Integrated Vehicle Health Management System (IVHMS), are collecting vibration health data on aircraft that include the Apache, Blackhawk, Chinook, and Kiowa Warrior. The objective of this paper is to recommend the most effective gear condition indicators for fleet use based on both a theoretical foundation and field data. Gear diagnostics with better performance will be recommended based on both a theoretical foundation and results of in-fleet use. In order to evaluate the gear condition indicator performance on rotorcraft fleets, results of more than five years of health monitoring for gear faults in the entire HUMS equipped Army helicopter fleet will be presented. More than ten examples of gear faults indicated by the gear CI have been compiled and each reviewed for accuracy. False alarms indications will also be discussed. Performance data from test rigs and seeded fault tests will also be presented. The results of the fleet analysis will be discussed, and a performance metric assigned to each of the competing algorithms. Gear fault diagnostic algorithms that are compliant with ADS-79A will be recommended for future use and development. The performance of gear algorithms used in the commercial units and the effectiveness of the gear CI as a fault identifier will be assessed using the criteria outlined in the standards in ADS-79A-HDBK, an Army handbook that outlines the conversion from Reliability Centered Maintenance to the On-Condition status of Condition Based Maintenance.

  5. Technology Innovation of Power Transmission Gearing in Aviation

    Science.gov (United States)

    Handschuh, Robert F.

    2009-01-01

    An overview of rotary wing evolution and innovations over the last 20 years was presented. This overview is provided from a drive system perspective. Examples of technology innovations that have changed and advanced drive systems of rotary wing vehicles will be provided. These innovations include full 6-axis CNC gear manufacture, face gear development to aerospace standards, health and usage monitoring, and gear geometry and bearing improvements. Also, an overview of current state-of-the-art activities being conducted at NASA Glenn is presented with a short look to fixed and rotary wing aircraft and systems needed for the future.

  6. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  7. A MATHEMATICAL MODEL OF CHP 2000 TYPE PROGRESSIVE GEAR

    Directory of Open Access Journals (Sweden)

    Paweł Lonkwic

    2016-12-01

    Full Text Available The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with the loading capacity from 8500 up to 20000 N.

  8. Engagement of Metal Debris into a Gear Mesh

    Science.gov (United States)

    Handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock, and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  9. Natural Characteristics of The Herringbone Gear Transmission System

    Science.gov (United States)

    Zhou, Jianxing; Sun, Wenlei; Cao, Li

    2018-03-01

    According to the structure characteristics of herringbone gear transmission, a more realistic dynamic model of the transmission system is built in consideration of the inner excitation, herringbone gears axial positioning and sliding bearing etc. The natural frequencies of the system are calculated, and the vibration mode is divided into symmetric vibration modes and asymmetric vibration modes. The time history of system dynamic force is obtained by solving the dynamic model. The effects of the connection stiffness of left and right sides of herringbone gears and axial support stiffness on natural characteristics are discussed.

  10. Modeling Noise Sources and Propagation in External Gear Pumps

    Directory of Open Access Journals (Sweden)

    Sangbeom Woo

    2017-07-01

    Full Text Available As a key component in power transfer, positive displacement machines often represent the major source of noise in hydraulic systems. Thus, investigation into the sources of noise and discovering strategies to reduce noise is a key part of improving the performance of current hydraulic systems, as well as applying fluid power systems to a wider range of applications. The present work aims at developing modeling techniques on the topic of noise generation caused by external gear pumps for high pressure applications, which can be useful and effective in investigating the interaction between noise sources and radiated noise and establishing the design guide for a quiet pump. In particular, this study classifies the internal noise sources into four types of effective load functions and, in the proposed model, these load functions are applied to the corresponding areas of the pump case in a realistic way. Vibration and sound radiation can then be predicted using a combined finite element and boundary element vibro-acoustic model. The radiated sound power and sound pressure for the different operating conditions are presented as the main outcomes of the acoustic model. The noise prediction was validated through comparison with the experimentally measured sound power levels.

  11. The Development of the Guide to Economic Analysis and Research (GEAR) Online Resource for Low- and Middle-Income Countries' Health Economics Practitioners: A Commentary.

    Science.gov (United States)

    Adeagbo, Chiaki Urai; Rattanavipapong, Waranya; Guinness, Lorna; Teerawattananon, Yot

    2018-05-01

    Public health authorities around the world are increasingly using economic evaluation to set priorities and inform decision making in health policy, especially in the development of health benefit packages. Nevertheless, researchers in low- and middle-income countries (LMICs) encounter many barriers when conducting economic evaluations. In 2015, the Health Intervention and Technology Assessment Program identified key technical and context-specific challenges faced in conducting and using health economic evaluations in LMICs. On the basis of these research findings, the Guide to Economic Analysis and Research (GEAR) online resource (www.gear4health.com) was developed as a reliable aid to researchers in LMICs that would help overcome those challenges. Funded by the Thailand Research Fund and the Bill and Melinda Gates Foundation, GEAR is a free online resource that provides a visual aid tool for planning economic evaluation studies (GEAR mind maps), a repository of national and international economic evaluation guidelines (GEAR guideline comparison), and an active link to a network of volunteer international experts (GEAR: Ask an expert). GEAR will evolve over time to provide relevant, reliable, and up-to-date information through inputs from its users (e.g., periodic survey on methodological challenges) and experts (e.g., in responding to users' questions). The objective of this commentary was to give a brief description of the development and key features of this unique collective information hub aimed at facilitating high-quality research and empowering health care decision makers and stakeholders to use economic evaluation evidence. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  12. The role of arginine and the modified arginine deiminase enzyme ADI-PEG 20 in cancer therapy with special emphasis on Phase I/II clinical trials.

    Science.gov (United States)

    Synakiewicz, Anna; Stachowicz-Stencel, Teresa; Adamkiewicz-Drozynska, Elzbieta

    2014-11-01

    The metabolic differences between normal, healthy cells and neoplastic cells have been exploited by anticancer therapies targeting metabolic pathways. Various studies of malignant processes have demonstrated disturbances in both arginine synthesis and metabolism that enhance or inhibit tumor cell growth. Consequently, there has been an increased interest in the arginine-depleting enzyme arginine deiminase (ADI) as a potential antineoplastic therapy. This review summarizes the literature on the potential anti-cancer therapeutics arginine and ADI, an arginine-catabolizing enzyme. The authors searched the MEDLINE database PubMed using the key words: 'arginine, 'ADI', 'arginine in cancer' and 'ADI and cancer'. The authors evaluate prospective randomized studies on cancer patients between 2004 and 2013 as well as ongoing research found through the US National Institutes of Health trial database. The results of current studies are promising but do not give unequivocal answers and so it is impossible to recommend arginine or its enzyme ADI as a therapeutic. In the opinion of the authors, further identification of arginine-dependent malignant tumors and their metabolism should be investigated. Furthermore, the use of these chemicals, in combination with other chemotherapeutics drugs, should be investigated and indeed may improve the success of arginine-depleting enzymes such as pegylated ADI (ADI-PEG20).

  13. 49 CFR 230.90 - Draw gear between steam locomotive and tender.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Draw gear between steam locomotive and tender. 230... Steam Locomotives and Tenders Draw Gear and Draft Systems § 230.90 Draw gear between steam locomotive and tender. (a) Maintenance and testing. The draw gear between the steam locomotive and tender...

  14. 50 CFR 660.319 - Open access fishery gear identification and marking.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Open access fishery gear identification... COAST STATES West Coast Groundfish-Open Access Fisheries § 660.319 Open access fishery gear identification and marking. (a) Gear identification. (1) Open access fixed gear (longline, trap or pot, set net...

  15. 75 FR 12462 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Removal of Gear...

    Science.gov (United States)

    2010-03-16

    ...; Removal of Gear Restriction for the U.S./Canada Management Area AGENCY: National Marine Fisheries Service...; removal of gear restrictions. SUMMARY: This action removes temporary gear restrictions in both the Eastern... Management Act (Magnuson- Stevens Act). DATES: Removal of the temporary gear restriction in the Western U.S...

  16. 46 CFR 97.37-33 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall be...

  17. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout their...

  18. 50 CFR Table 19 to Part 679 - Seabird Avoidance Gear Codes

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Codes 19 Table 19... ALASKA Pt. 679, Table 19 Table 19 to Part 679—Seabird Avoidance Gear Codes VESSEL LOGBOOK CODE SEABIRD AVOIDANCE GEAR OR METHOD. 1 Paired Streamer Lines: Used during deployment of hook-and-line gear to prevent...

  19. Stress analyses of pump gears produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Cetinel, Hakan [Celal Bayar Univ., Mechanical Engineering Dept. (Turkey); Yilmaz, Burak

    2013-06-01

    In this study, trochoidal type (gerotor) hydraulic pump gears were produced by powder metallurgy (P/M) technique. Several gears with different mechanical properties have been obtained by changing process variables. The tooth contact stresses were calculated analytically under particular operation conditions of the hydraulic pump. The 3D models have been obtained from real gears by using Capability Maturity Model (CMM, 3D scanning) operation and SOLIDWORKS software. Stress analyses were conducted on these 3D models by using ANSYS WORKBENCH software. It was found that the density increases by the increase of sintering duration and mechanical properties were positively affected by the increase of density. Maximum deformation takes place in the region of the outer gear where failure generally occurs with the minimum cross-section area.

  20. 29 CFR 1915.116 - Use of gear.

    Science.gov (United States)

    2010-07-01

    ... manually or by a crane, winch, hoist, or derrick, shall be completely opened. The beam or pontoon left in... employees are in the square of the hatch below. (p) Before loads or empty lifting gear are raised, lowered...

  1. Coefficient of friction of a starved lubricated spur gear pair

    International Nuclear Information System (INIS)

    Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng

    2016-01-01

    The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.

  2. Teaching Planetary Gear Trains with the Aid of Nomographs

    Directory of Open Access Journals (Sweden)

    Essam Lauibi Esmail

    2013-01-01

    Full Text Available Planetary gear trains (PGTs are introduced to undergraduate mechanical engineering students in the course of Theory of Machines. The complexity of the traditional methods for analyzing PGTs has kept many from becoming familiar with the capability of PGTs in mechanisms and machine design. In this paper a unified general formulation for simultaneously visualizing velocities, torques, and power flow through a train is presented on a single nomograph. Therefore, the increasing complex mechanical systems, such as automotive transmissions, are much easier to understand. Nomographs of Fundamental Gear Entities (FGEs are constructed based on the nomographs of their fundamental circuits, without specifying the exact gear dimensions. They are then unified in one system nomograph. Nomographs are promising to provide designers with an efficient tool for the design of geared mechanisms.

  3. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Soňa Benešová

    2013-09-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  4. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Sona Benesova

    2013-05-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  5. Toothed gear pumps for special applications; Zahnradpumpen fuer Sonderanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [WITTE PUMPS und TECHNOLOGY GmbH, Uetersen (Germany)

    2007-07-01

    Gear pumps are utilized in a big variety of industrial processes. This essay discusses the typical applications gear pumps are used for. Based on the general function of gear pumps the technical features of these different pump types are pointed out. The process parameters have been more or less the same for the last decades. Nowadays a higher demand regarding pressures and temperatures, sometimes even a combination of both, can be observed. This development is the challenge to go for special constructions and new materials. The range of applications is extended step by step, always aware of the fact, that these gear pumps are often operating at their specific limits. Finally some examples right from the plant give an overview over this development. (orig.)

  6. Characteristics study of the gears by the CAD/CAE

    Science.gov (United States)

    Wang, P. Y.; Chang, S. L.; Lee, B. Y.; Nguyen, D. H.; Cao, C. W.

    2017-09-01

    Gears are the most important transmission component in machines. The rapid development of the machines in industry requires a shorter time of the analysis process. In traditional, the gears are analyzed by setting up the complete mathematical model firstly, considering the profile of cutter and coordinate systems relationship between the machine and the cutter. It is a really complex and time-consuming process. Recently, the CAD/CAE software is well developed and useful in the mechanical design. In this paper, the Autodesk Inventor® software is introduced to model the spherical gears firstly, and then the models can also be transferred into ANSYS Workbench for the finite element analysis. The proposed process in this paper is helpful to the engineers to speed up the analyzing process of gears in the design stage.

  7. Experimental Research on Vibrations of Double Harmonic Gear Transmission

    Directory of Open Access Journals (Sweden)

    Sava Ianici

    2017-11-01

    Full Text Available Gears transmission can be important sources of vibration in the mechanical system structures and can have a significant share in the overall vibration level. The current trend of significant increase in powers and speeds transmitted by modern mechanical systems, along with the size reduction, may cause a worsening of the behaviour of transmissions with gears in terms of vibration, especially when the optimization criteria were not respected in the design, execution and installation phase. This paper presents a study of vibrations that occur in a double harmonic gear transmission (DHGT, based on experimental research. The experimental researches revealed that in a double harmonic gear transmission the vibrations are initiated and develop in the multipara harmonics engagement of the teeth and in the kinematic couplings materialized between the wave generator and the flexible toothed wheel. These vibrations are later transmitted by means of the shafts and bearings to the transmission housing, respectively, through the walls of it, propagating in the air.

  8. Feedforward Control of Gear Mesh Vibration Using Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Gerald T. Montague

    1994-01-01

    Full Text Available This article presents a novel means for suppressing gear mesh related vibrations. The key components in this approach are piezoelectric actuators and a high-frequency, analog feed forward controller. Test results are presented and show up to a 70% reduction in gear mesh acceleration and vibration control up to 4500 Hz. The principle of the approach is explained by an analysis of a harmonically excited, general linear vibratory system.

  9. Darwin-industrien i højt gear

    DEFF Research Database (Denmark)

    Kjærgaard, Peter C.

    2008-01-01

    Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december......Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december...

  10. Investigation of the paired-gear method in selectivity studies

    DEFF Research Database (Denmark)

    Sistiaga, Manu; Herrmann, Bent; Larsen, R.B.

    2009-01-01

    was repeated throughout the eight cases in this investigation. When using the paired-gear method, the distribution of the estimated L50 and SR is wider; the distribution of the estimated split parameter has a higher variability than the true split; the estimated mean L50 and SR can be biased; the estimated...... recommend that the methodology used to obtain selectivity estimates using the paired-gear method be reviewed....

  11. Hydrostatic self-locking bevel differential gear; Hydrostatisch selbstsperrendes Kegelraddifferentialgetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Kalmbach, K.

    2001-07-01

    The product range of the rail vehicle industry comprises the construction of railroad material for long-distance and short-distance transport. This includes, for example, locomotives and cars, subway, light railway and tramway cars as well as rail vehicle equipment. The development of the industry is determined by the demand for transport services and government actions for the extension of railways and procurement of suitable vehicle types. In contrast to road vehicles, differential gears are only used in a negligible percentage of rail vehicles. Primarily in the short-distance rail transport sector, the demand for differential gears is growing due to increased drive power, smaller wheel diameters, lower vehicle mass with higher load capacity, the introduction of low-floor technology as well as the requirement of employing ever more quiet vehicles. In hydrostatic self-locking differential gears, oil is supplied to the gears within the differential gearbox. They only rotate relative to each other when the differential gear performs a compensation movement. In this case, oil is transported in the tooth space to the meshing of the gears, where it is displaced due to the meshing and must drain through tight gaps. The pressure generated by this process acts against the compensation movement of the gear, and the drive torque is transmitted to the wheel that has the higher friction. The achievable locking torque is linearly dependent on the differential speed of the drive wheel. This locking effect is achieved without wear-prone components and works automatically without active external intervention. The design space required corresponds to that of conventional differential gears, as the locking effect is integrated in the existing design. (orig.)

  12. Analisa Kekuatan Spiral Bevel Gear Dengan Variasi Sudut Spiral Menggunakan Metode Elemen Hingga

    OpenAIRE

    Deta Rachmat Andika; Agus Sigit Pramono

    2017-01-01

    Seiring perkembangan zaman,  teknologi roda gigi dituntut untuk mampu mentransmisikan daya yang besar dengan efisiensi yang besar pula. Pada jenis intersecting shaft gear, tipe roda gigi payung spiral (spiral bevel gear)  merupakan perkembangan dari roda gigi payung bergigi lurus (straight bevel gear). Kelebihan dari spiral bevel gear antara  lain adalah kemampuan transmisi daya dan efisiensi yang lebih besar pada geometri yang sama serta tidak terlalu berisik. Akan tetapi spiral bevel gear j...

  13. Continued Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Delgado, Irebert R.; Dempsey, Paula J.; Antolick, Lance J.; Wade, Daniel R.

    2013-01-01

    This paper details analyses of condition indicator performance for the helicopter nose gearbox within the U.S. Army's Condition-Based Maintenance Program. Ten nose gearbox data sets underwent two specific analyses. A mean condition indicator level analysis was performed where condition indicator performance was based on a 'batting average' measured before and after part replacement. Two specific condition indicators, Diagnostic Algorithm 1 and Sideband Index, were found to perform well for the data sets studied. A condition indicator versus gear wear analysis was also performed, where gear wear photographs and descriptions from Army tear-down analyses were categorized based on ANSI/AGMA 1010-E95 standards. Seven nose gearbox data sets were analyzed and correlated with condition indicators Diagnostic Algorithm 1 and Sideband Index. Both were found to be most responsive to gear wear cases of micropitting and spalling. Input pinion nose gear box condition indicators were found to be more responsive to part replacement during overhaul than their corresponding output gear nose gear box condition indicators.

  14. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  15. [Information, knowledge and healthcare practice: professionals participation as the key element of the gear].

    Science.gov (United States)

    Adam, Paula; Permanyer-Miralda, Gaietà; Solà-Morales, Oriol; Canela-Soler, Jaume

    2010-02-01

    This article analyzes the role of ICT within the complicated gear between information, knowledge and healthcare practices, which particular focus on two specific cases: the digitalization process of the healthcare system and the application of knowledge into the healthcare practices. In both cases, international and local experiences suggest, and sometimes demonstrate the importance of the participation, capacity-building and empowerment of healthcare practitioners for the generation, transfer and use of information and knowledge empowered by the digital tools which should bring into the system better performance, more efficacy, efficiency, equity, equality, security, quality. 2010 Elsevier España S.L. All rights reserved.

  16. Diagnostic Utility of the ADI-R and DSM-5 in the Assessment of Latino Children and Adolescents.

    Science.gov (United States)

    Magaña, Sandy; Vanegas, Sandra B

    2017-05-01

    Latino children in the US are systematically underdiagnosed with Autism Spectrum Disorder (ASD); therefore, it is important that recent changes to the diagnostic process do not exacerbate this pattern of under-identification. Previous research has found that the Autism Diagnostic Interview-Revised (ADI-R) algorithm, based on the Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition, Text Revision (DSM-IV-TR), has limitations with Latino children of Spanish speaking parents. We evaluated whether an ADI-R algorithm based on the new DSM-5 classification for ASD would be more sensitive in identifying Latino children of Spanish speaking parents who have a clinical diagnosis of ASD. Findings suggest that the DSM-5 algorithm shows better sensitivity than the DSM-IV-TR algorithm for Latino children.

  17. Bebida com adição de soro de leite e fibra alimentar prebiótica

    Directory of Open Access Journals (Sweden)

    Mirela Guedes Bosi

    2013-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a aceitação sensorial de bebida não fermentada, com adição de inulina e polpa de acerola. Seis formulações foram desenvolvidas, com adição de 0, 20, 40, 60, 80 e 100% de soro. O pH do soro foi 6,59, e a acidez de 0,103% de ácido lático. Utilizou-se a escala hedônica de nove pontos no teste de aceitação. As médias hedônicas das amostras com 0, 20 e 40% de soro não diferiram significativamente e variaram entre 6 e 8 pontos. As bebidas desenvolvidas com até 60% de soro são alternativas interessantes para o aproveitamento desse subproduto em laticínios.

  18. Adição de soro de leite e café na qualidade do doce de leite pastoso

    OpenAIRE

    Ferreira,Larissa de Oliveira; Pimenta,Carlos José; Santos,Gabriella; Ramos,Thaís de Melo; Pereira,Patrícia Aparecida Pimenta; Pinheiro,Ana Carla Marques

    2012-01-01

    Este trabalho foi realizado com o objetivo de verificar o efeito da substituição de leite por soro de leite e o efeito da adição de café na qualidade química e sensorial do doce de leite. Foi utilizado um fatorial completo 2², com dois níveis (±1) com a adição de três pontos centrais (0) e dois níveis de pontos axiais (±1,41). Os resultados obtidos foram analisados pela metodologia estatística de superfície de resposta e os dados do teste de aceitação foram analisados pela metodologia de mapa...

  19. Correlation of nodular austempered ductile iron (ADI) microstructural parameters and fatigue properties using an approach based on fracture mechanics

    International Nuclear Information System (INIS)

    Dias, Jose Felipe; Fonseca, Vinicius Rizzuti; Godefroid, Leonardo Barbosa; Ribeiro, Gabriel de Oliveira

    2010-01-01

    An investigation has been accomplished to check the effect of temperature and austempering time on austempered ductile iron (ADI) properties by means of fracture toughness (K_C) and fatigue threshold (∆K_t_h) tests. The correlation of ADI microstructural parameters and ADI two mechanical parameters: KC and Kth, is evaluated. Three sets of samples have ben extracted from ADI casting Y blocks produced in industrial conditions.and austenitized at 900°C for 1.5 hour. The austempering process has been performed in the following ways: the first set was austenitized at 300 deg C for 4 hours, the second set at 360°C for 1.5 hour and the third at 360°C for 0.6 hour. These distinct austempering processes have been adopted in order to obtain distinct microstructures containing austenite with two different carbon rates and two ferritic cell sizes. The materials have been characterized by means of optical and electronic microscopy, X-ray diffraction and mechanical tests. All materials have presented equivalent fatigue crack propagation rates, fracture toughness in the range between 94 and 128 MPa·m"1"/"2 and ∆K_t_h in the range between 5,7 and 6,4 MPa·m"1"/"2. The experimental results have confirmed the effect of microstructural properties (austenitic volumetric rate, austenitic carbon rate, ferritic cell size, total matrix carbon content) on fracture toughness (K_C) and fatigue threshold (∆K_t_h). Further, it was found that following parameters: fracture toughness (K_C), fatigue threshold ((∆K_t_h) and impact strength are correlated with the total matrix carbon content and ferritic cell size. (author)

  20. [Is Władysław Ołtuszewski a creator of modern phoniatrics in Poland?].

    Science.gov (United States)

    Kierzek, A

    1995-01-01

    In 1880 Władysław Ołtuszewski founded the faulty articulation infirmary, which was functioning until 1892. He was also working (1884-1892) at the department of Dr Heryng, one of the pioneers of Polish laryngology. He was involved in a welfare work in Warsaw Charity Society. He supported his interest in physiopathology of speech with studies in foreign centres in Germany and France. In 1892 he founded the "Warsaw Therapeutic Institution for persons stricken with speech deviations". It was the first phoniatric infirmary. He was delivering lectures, talks and he published tens papers in field of speech physiopathology. He was indicating the connection of dysphasia with psychiatric disorders. The author has presented in his article the main assumptions of the most valuable book by Ołtuszewski: Study of the science on speech and its deviations, and speech hygiene, published in 1905, pointing out that compared with the books by foreign authors the contents of this one was much ampler and more modern. He has also presented the comprehensive picture of Ołtuszewski's scientific output and wide non-scientific interests.

  1. The Effect of Hydrogen on the Mechanical Properties of Cast Irons and ADI with Various Carbon Equivalent and Graphite Morphology

    International Nuclear Information System (INIS)

    Cho, Yong Gi; Lee, Kyung Sub

    1989-01-01

    The effect of hydrogen on the mechanical properties of cast irons, flake, CV graphite cast iron ductile iron and ADI have been investigated. The effects of various carbon equivalent, graphite morphology and matrix have been analyzed to determine the predominant factor which influences on the hydrogen embrittlement. The effect of various carbon equivalent on the embrittlement was little in the similar graphite morphology. The embrittlement of ferrite matrix changed by heat treatment was less than that of pearlite matrix. In the case of ADI, the tendency of hydrogen embrittlement of lower bainite matrix was less remarkable than that of upper banite matrix. As the result of hydrogen charging, the tendency of interface decohesion between matrix-graphite was increased in flake G.C.I., and the trend from ductile fracture mode to brittle fracture mode was observed in CV G.C.I and ductile iron. Lower bainite in ADI showed the ductile fracture mode. Hydrogen solubility of lower bainite was higher than that of upper bainite

  2. HUBUNGAN PERSONAL HYGIENE DENGAN KEBERADAAN ESCHERICHIA COLI PADA MAKANAN DI TEMPAT PENGOLAHAN MAKANAN (TPM BUFFER AREA BANDARA ADI SOEMARMO SURAKARTA

    Directory of Open Access Journals (Sweden)

    Fitka Romanda

    2017-01-01

    Full Text Available Keberadaan Escherichia coli dalam sumber air atau makanan merupakan indikasi pasti terjadinya  kontaminasi tinja manusia. Kontaminasi ini dapat berdampak pada Kejadian Luar Biasa keracunan makanan di negara berkembang, termasuk di Indonesia. Adanya kontaminasi Escherichia coli pada makanan dapat disebabkan faktor personal hygiene penjamah makanan yang kurang baik. Penelitian ini bertujuan untuk mengetahui adanya hubungan personal hygiene penjamah makanan dengan Escherichia coli. Penelitian ini menggunakan metode observasional dengan pendekatan cross sectional. Subyek penelitian adalah 65 penjamah makanan dan 65 sampel makanan di 22 tempat pengolahan makanan buffer area Bandara Adi Soemarmo Surakarta. Hasil penelitian menunjukan adanya hubungan personal hygiene dengan keberadaan Escherichia coli pada makanan di Tempat Pengolahan Makanan Buffer Area Bandara Adi Soemarmo Surakarta dengan uji statistik dengan Chi Square didapatkan p value (0,000 dan kekuatan hubungan sedang dengan nilai C (0,477. Berdasarkan hasil penelitian, disimpulkan terdapat hubungan personal hygiene penjamah makanan dengan keberadaan Escherichia coli pada makanan di tempat pengolahan makanan (TPM buffer area Bandara Adi Soemarmo Surakarta.   Kata kunci. Personal Hygiene, Escherichia coli, Buffer Area

  3. One-step leapfrog ADI-FDTD method for simulating electromagnetic wave propagation in general dispersive media.

    Science.gov (United States)

    Wang, Xiang-Hua; Yin, Wen-Yan; Chen, Zhi Zhang David

    2013-09-09

    The one-step leapfrog alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is reformulated for simulating general electrically dispersive media. It models material dispersive properties with equivalent polarization currents. These currents are then solved with the auxiliary differential equation (ADE) and then incorporated into the one-step leapfrog ADI-FDTD method. The final equations are presented in the form similar to that of the conventional FDTD method but with second-order perturbation. The adapted method is then applied to characterize (a) electromagnetic wave propagation in a rectangular waveguide loaded with a magnetized plasma slab, (b) transmission coefficient of a plane wave normally incident on a monolayer graphene sheet biased by a magnetostatic field, and (c) surface plasmon polaritons (SPPs) propagation along a monolayer graphene sheet biased by an electrostatic field. The numerical results verify the stability, accuracy and computational efficiency of the proposed one-step leapfrog ADI-FDTD algorithm in comparison with analytical results and the results obtained with the other methods.

  4. Unveiling the Mechanism of Arginine Transport through AdiC with Molecular Dynamics Simulations: The Guiding Role of Aromatic Residues.

    Directory of Open Access Journals (Sweden)

    Eva-Maria Krammer

    Full Text Available Commensal and pathogenic enteric bacteria have developed several systems to adapt to proton leakage into the cytoplasm resulting from extreme acidic conditions. One such system involves arginine uptake followed by export of the decarboxylated product agmatine, carried out by the arginine/agmatine antiporter (AdiC, which thus works as a virtual proton pump. Here, using classical and targeted molecular dynamics, we investigated at the atomic level the mechanism of arginine transport through AdiC of E. coli. Overall, our MD simulation data clearly demonstrate that global rearrangements of several transmembrane segments are necessary but not sufficient for achieving transitions between structural states along the arginine translocation pathway. In particular, local structural changes, namely rotameric conversions of two aromatic residues, are needed to regulate access to both the outward- and inward-facing states. Our simulations have also enabled identification of a few residues, overwhelmingly aromatic, which are essential to guiding arginine in the course of its translocation. Most of them belong to gating elements whose coordinated motions contribute to the alternating access mechanism. Their conservation in all known E. coli acid resistance antiporters suggests that the transport mechanisms of these systems share common features. Last but not least, knowledge of the functional properties of AdiC can advance our understanding of the members of the amino acid-carbocation-polyamine superfamily, notably in eukaryotic cells.

  5. Enhancement of naphthalene tolerance in transgenic Arabidopsis plants overexpressing the ferredoxin-like protein (ADI1) from rice.

    Science.gov (United States)

    Fu, Xiao-Yan; Zhu, Bo; Han, Hong-Juan; Zhao, Wei; Tian, Yong-Sheng; Peng, Ri-He; Yao, Quan-Hong

    2016-01-01

    The ADI1 Arabidopsis plants enhanced tolerance and degradation efficiency to naphthalene and had great potential for phytoremediation of naphthalene in the plant material before composting or harvesting and removal. Naphthalene is a global environmental concern, because this substance is assumed to contribute considerably to human cancer risk. Cleaning up naphthalene contamination in the environment is crucial. Phytoremediation is an efficient technology to clean up contaminants. However, no gene that can efficiently degrade exogenous recalcitrant naphthalene in plants has yet been discovered. Ferredoxin (Fd) is a key player of biological electron transfer reaction in the PAH degradation process. The biochemical pathway for bacterial degradation of naphthalene has been well investigated. In this study, a rice gene, ADI1, which codes for a putative photosynthetic-type Fd, has been transformed into Arabidopsis thaliana. The transgenic Arabidopsis plants enhanced tolerance and degradation efficiency of naphthalene. Compared with wild-type plants, transgenic plants assimilated naphthalene from the culture media faster and removed more of this substance. When taken together, our findings suggest that breeding plants with overexpressed ADI1 gene is an effective strategy to degrade naphthalene in the environment.

  6. Modulation of NO and ROS production by AdiNOS transduced vascular cells through supplementation with L-Arg and BH4: implications for gene therapy of restenosis.

    Science.gov (United States)

    Forbes, Scott P; Alferiev, Ivan S; Chorny, Michael; Adamo, Richard F; Levy, Robert J; Fishbein, Ilia

    2013-09-01

    Gene therapy with viral vectors encoding for NOS enzymes has been recognized as a potential therapeutic approach for the prevention of restenosis. Optimal activity of iNOS is dependent on the intracellular availability of L-Arg and BH4 via prevention of NOS decoupling and subsequent ROS formation. Herein, we investigated the effects of separate and combined L-Arg and BH4 supplementation on the production of NO and ROS in cultured rat arterial smooth muscle and endothelial cells transduced with AdiNOS, and their impact on the antirestenotic effectiveness of AdiNOS delivery to balloon-injured rat carotid arteries. Supplementation of AdiNOS transduced endothelial and vascular smooth muscle cells with L-Arg (3.0 mM), BH4 (10 μM) and especially their combination resulted in a significant increase in NO production as measured by nitrite formation in media. Formation of ROS was dose-dependently increased following transduction with increasing MOIs of AdiNOS. Exposure of RASMC to AdiNOS tethered to meshes via a hydrolyzable cross-linker, modeling viral delivery from stents, resulted in increased ROS production, which was decreased by supplementation with BH4 but not L-Arg or L-Arg/BH4. Enhanced cell death, caused by AdiNOS transduction, was also preventable with BH4 supplementation. In the rat carotid model of balloon injury, intraluminal delivery of AdiNOS in BH4-, L-Arg-, and especially in BH4 and L-Arg supplemented animals was found to significantly enhance the antirestenotic effects of AdiNOS-mediated gene therapy. Fine-tuning of iNOS function by L-Arg and BH4 supplementation in the transduced vasculature augments the therapeutic potential of gene therapy with iNOS for the prevention of restenosis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Estimation of seafloor impact from demersal trawls, seines and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael

    a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...

  8. Vibration and Operational Characteristics of a Composite-Steel (Hybrid) Gear

    Science.gov (United States)

    Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan

    2014-01-01

    Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.

  9. Vibration Propagation of Gear Dynamics in a Gear-Bearing-Housing System Using Mathematical Modeling and Finite Element Analysis

    Science.gov (United States)

    Parker, Robert G.; Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.

    2012-01-01

    Vibration and noise caused by gear dynamics at the meshing teeth propagate through power transmission components to the surrounding environment. This study is devoted to developing computational tools to investigate the vibro-acoustic propagation of gear dynamics through a gearbox using different bearings. Detailed finite element/contact mechanics and boundary element models of the gear/bearing/housing system are established to compute the system vibration and noise propagation. Both vibration and acoustic models are validated by experiments including the vibration modal testing and sound field measurements. The effectiveness of each bearing type to disrupt vibration propagation is speed-dependent. Housing plays an important role in noise radiation .It, however, has limited effects on gear dynamics. Bearings are critical components in drivetrains. Accurate modeling of rolling element bearings is essential to assess vibration and noise of drivetrain systems. This study also seeks to fully describe the vibro-acoustic propagation of gear dynamics through a power-transmission system using rolling element and fluid film wave bearings. Fluid film wave bearings, which have higher damping than rolling element bearings, could offer an energy dissipation mechanism that reduces the gearbox noise. The effectiveness of each bearing type to disrupt vibration propagation in explored using multi-body computational models. These models include gears, shafts, rolling element and fluid film wave bearings, and the housing. Radiated noise is mapped from the gearbox surface to surrounding environment. The effectiveness of rolling element and fluid film wave bearings in breaking the vibro-acoustic propagation path from the gear to the housing is investigated.

  10. The Selected Problems of Studies of Aircraft Landing Gear

    Directory of Open Access Journals (Sweden)

    Rośkowicz Marek

    2016-12-01

    Full Text Available The article portrays the results of experimental studies conducted in the field of static strength test of main landing gear of lightweight aircraft as well as in the area of establishing the pneumatic tyre characteristics of main landing gear. The studies were carried out in compliance with methodologies of performing studies for the purposes of solutions implemented in aviation structures. It was stated that static strength tests of landing gear should not be done with the use of shock absorbers, due to the fact that this element, distinguished by high viscoelastic properties, by being statically loaded, is subject to displacements that do not occur during normal operation of the aircraft. Excessive displacements of shock absorber result in the load distribution in other landing gear elements being incompatible with project assumptions, which in turn leads to this strength test being interrupted, bearing in mind significantly lower loads than anticipated. It was also concluded that in order to determine pneumatic tyre characteristics it is not necessary to carry out tests on the whole landing gear strut, because the results obtained in the compression test of the wheel itself with pneumatic tyre are identical as the results acquired during tests conducted in accordance with methodology. Test preparation process with the use of the wheel itself and its realization is less time-consuming, less expensive and does not entail the necessity to build complex test stands.

  11. Materials and lubrication for gear and bearing surfaces in uhv

    International Nuclear Information System (INIS)

    Kirby, R.E.; Collet, G.J.; Garwin, E.L.

    1980-06-01

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing, and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 250 0 C, and at room temperature must operate at pressures in the 10 -9 to 10 -10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined to (by bushings) and rotated on a fixed shaft, while the other gear was driven by a commercial rotary motion feedthrough which was rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. 10 5 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91,000. Materials for gears included stainless steel, beryllium copper, and aluminum alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome, and a MoS 2 -graphite-sodium silicate mixture. The successful gear pair was Ag-plated Al alloy and MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed

  12. Advanced Manufacture of Spiral Bevel and Hypoid Gears

    Directory of Open Access Journals (Sweden)

    Vilmos Simon

    2016-11-01

    Full Text Available In this study, an advanced method for the manufacture of spiral bevel and hypoid gears on CNC hypoid generators is proposed. The optmal head-cutter geometry and machine tool settings are determined to introduce the optimal tooth surface modifications into the teeth of spiral bevel and hypoid gears. The aim of these tooth surface modifications is to simultaneously reduce the tooth contact pressure and the transmission errors, to maximize the EHD load carrying capacity of the oil film, and to minimize power losses in the oil film. The proposed advanced method for the manufacture of spiral bevel and hypoid gears is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions and on the use of a CNC hypoid generator. An algorithm is developed for the execution of motions on the CNC hypoid generator using the optimal relations on the cradle-type machine. Effectiveness of the method was demonstrated by using spiral bevel and hypoid gear examples. Significant improvements in the operating characteristics of the gear pairs are achieved.

  13. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    Science.gov (United States)

    Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

    2011-01-01

    An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.

  14. Effects on Diagnostic Parameters After Removing Additional Synchronous Gear Meshes

    Science.gov (United States)

    Decker, Harry J.

    2003-01-01

    Gear cracks are typically difficult to diagnose with sufficient time before catastrophic damage occurs. Significant damage must be present before algorithms appear to be able to detect the damage. Frequently there are multiple gear meshes on a single shaft. Since they are all synchronous with the shaft frequency, the commonly used synchronous averaging technique is ineffective in removing other gear mesh effects. Carefully applying a filter to these extraneous gear mesh frequencies can reduce the overall vibration signal and increase the accuracy of commonly used vibration metrics. The vibration signals from three seeded fault tests were analyzed using this filtering procedure. Both the filtered and unfiltered vibration signals were then analyzed using commonly used fault detection metrics and compared. The tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 5000 revolutions per minute and torques from 184 to 228 percent of design load. The inability to detect these cracks with high confidence results from the high loading which is causing fast fracture as opposed to stable crack growth. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.

  15. The study about planetary gearbox virtual prototyping with nonlinear gear contact characteristics

    International Nuclear Information System (INIS)

    Yin Huabing; Zhou Guangming

    2010-01-01

    The virtual prototypes of gear transmission system built in most multi-body dynamic software have difficulties in describing the gear mesh characteristics. The gear mesh contact is modelled as rigid contact and this is not accurate for the gear mesh contact, which is elastic or flexible. The gear contact formula used in the multi-body dynamic software does not reveal the gear contact nonlinear stiffness characteristic. The model built with gear meshing contact is difficult to solve because of its time-consuming algorithm. In the paper a new method is put forward to build the virtual prototype of planetary gearbox system according to the nonlinear mesh stiffness and mesh phase obtained through FEM models. This new FEM method of gear mesh stiffness calculation is much more accurate than the common formulas. The gear mesh nonlinear stiffness of sun gear- pinion and pinion-ring gear of all the planetary gear sets in gearbox are obtained through MATALB code, which is used to read and plot the analyzing result data. The gear mesh phase differences between different pinions with suns or rings of different planetary gear set can be also obtained. With all these data modelled in simulink (or other software) and integrated with the multi-body dynamic planetary gearbox model and the gear meshing contact problem in multi-body gear models is solved easily and accurately. The interfaces for gear mesh stiffness and mesh phases are designed for multi-body dynamic model and simulink. The nonlinear planetary gear set prototyping models are integrated to become the whole planetary gear box model and the whole vehicle system model built in multi-body dynamic software can be integrated to simulate different duty conditions. At last high speed input is put into the nonlinear planetary transmission model and the different duty cases are simulated. The dynamic characteristics of different parts are obtained. The dynamic characteristic comparison between nonlinear and linear models is made

  16. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2009-01-01

    Full Text Available An adaptive landing gear is a landing gear (LG capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~validated model of a real, passive landing gear as a reference. Potential for improvement is estimated statistically in terms of the mean and median (significant peak strut forces as well as in terms of the extended safe sinking velocity range. Three control strategies are verified experimentally using a laboratory test stand.

  17. Worm gearing for valve automation; Schneckengetriebe fuer die Armaturenautomatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Herbstritt, Michael [AUMA Riester GmbH und Co. KG, Muellheim (Germany)

    2010-11-15

    Part-turn gearboxes are indispensable for exertion of the torques necessary for large part-turn valves. Torque demand has increased in the past decade, as a result, for example, of the use of pipelines of ever greater diameters in large conurbations, and of the operation of such pipelines at ever higher pressures. The design principle of a worm gear is useful in this context. Worm gearing systems with initial torques of up to 675,000 Nm are now available. The design of gearing systems capable of handling forces of this magnitude necessitates great know-how and experience. The very maximum of reliability is a basic requirement for actuator systems for applications involving such dimensions, since a failure may have catastrophic consequences. (orig.)

  18. Geared-elevator flutter study. [transonic flutter characteristics of empennage

    Science.gov (United States)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    The paper describes an experimental and analytical study of the transonic flutter characteristics of an empennage flutter model having an all-movable horizontal tail with a geared elevator. Two configurations were flutter tested: one with a geared elevator and one with a locked elevator with the model cantilever-mounted on a sting in the wind tunnel. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter boundary was nearly flat at transonic speeds for both configurations. It was found that an analysis which treated the elevator as a discrete surface predicted flutter dynamic pressure levels better than analyses which treated the stabilizer and elevator as a warped surface. Warped-surface methods, however, predicted more closely the experimental flutter frequencies and Mach number trends.

  19. 3D MODELLING WITH THE SAMSUNG GEAR 360

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2017-02-01

    Full Text Available The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.

  20. Ideas for Testing of Planetary Gear Sets of Automotive Transmissions

    Directory of Open Access Journals (Sweden)

    Achtenová Gabriela

    2017-06-01

    Full Text Available The article describes the concept of modular stand, where is possible to provide tests of gear pairs with fixed axes from mechanical automotive gearboxes, as well as tests of separate planetary sets from automatic gearboxes. Special attention in the article will be paid to the variant dedicated for testing of planetary gear sets. This variant is particularly interesting because: 1 it is rarely described in the literature, and 2 this topology allows big simplification with respect to testing of standard gearwheels. In the planetary closed-loop stand it is possible to directly link two identical planetary sets. Without any bracing flange or other connecting clutches, shafts or gear sets, just two planetary sets face-to-face will be assembled and connected to the electric motor.

  1. An efficient finite element solution for gear dynamics

    International Nuclear Information System (INIS)

    Cooley, C G; Parker, R G; Vijayakar, S M

    2010-01-01

    A finite element formulation for the dynamic response of gear pairs is proposed. Following an established approach in lumped parameter gear dynamic models, the static solution is used as the excitation in a frequency domain solution of the finite element vibration model. The nonlinear finite element/contact mechanics formulation provides accurate calculation of the static solution and average mesh stiffness that are used in the dynamic simulation. The frequency domain finite element calculation of dynamic response compares well with numerically integrated (time domain) finite element dynamic results and previously published experimental results. Simulation time with the proposed formulation is two orders of magnitude lower than numerically integrated dynamic results. This formulation admits system level dynamic gearbox response, which may include multiple gear meshes, flexible shafts, rolling element bearings, housing structures, and other deformable components.

  2. Detection of Pitting in Gears Using a Deep Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Yongzhi Qu

    2017-05-01

    Full Text Available In this paper; a new method for gear pitting fault detection is presented. The presented method is developed based on a deep sparse autoencoder. The method integrates dictionary learning in sparse coding into a stacked autoencoder network. Sparse coding with dictionary learning is viewed as an adaptive feature extraction method for machinery fault diagnosis. An autoencoder is an unsupervised machine learning technique. A stacked autoencoder network with multiple hidden layers is considered to be a deep learning network. The presented method uses a stacked autoencoder network to perform the dictionary learning in sparse coding and extract features from raw vibration data automatically. These features are then used to perform gear pitting fault detection. The presented method is validated with vibration data collected from gear tests with pitting faults in a gearbox test rig and compared with an existing deep learning-based approach.

  3. An enhancement to the NA4 gear vibration diagnostic parameter

    Science.gov (United States)

    Decker, Harry J.; Handschuh, Robert F.; Zakrajsek, James J.

    1994-01-01

    A new vibration diagnostic parameter for health monitoring of gears, NA4*, is proposed and tested. A recently developed gear vibration diagnostic parameter NA4 outperformed other fault detection methods at indicating the start and initial progression of damage. However, in some cases, as the damage progressed, the sensitivity of the NA4 and FM4 parameters tended to decrease and no longer indicated damage. A new parameter, NA4* was developed by enhancing NA4 to improve the trending of the parameter. This allows for the indication of damage both at initiation and also as the damage progresses. The NA4* parameter was verified and compared to the NA4 and FM4 parameters using experimental data from single mesh spur and spiral bevel gear fatigue rigs. The primary failure mode for the test cases was naturally occurring tooth surface pitting. The NA4* parameter is shown to be a more robust indicator of damage.

  4. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  5. HOW TO STEER THE TRANSMISSION RATIO OF PLANETARY CONTINUOUSLY ADJUSTABLE GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    A. M. Dankov

    2016-01-01

    Full Text Available The known attempts to create a continuously-adjustable gear train with solid gears have led to development of some so-called adaptive gears. The most structurally simple version of continuously- adjustable gear train is a two-wheel planetary gear. It is an obvious fact that an active regulation of gear ratio for the gear should be based on the presence of con- trolled elements (parameters and a mechanism for their control. In respect of the mentioned gear one of the controlled elements that is a compound central toothed gear has such controlled parameter as a nominal pitch diameter. In this case it can rotate or remain motionless. Other controlled element which is a planetary carrier has its own radius as a controlled parameter and makes a rotary motion with a great speed of a leading element. The purpose of the control mechanism is to ensure radial displacement of central toothed gear and planet gear sectors in the working gear. The paper describes the mechanism modifications and considers two variants for transfer of control action from its source to an object to be controlled. The transfer is ensured by mechanical gears (two variants and hydraulics.

  6. The Strength Analysis of Differential Planetary Gears of Gearbox for Concrete Mixer Truck

    Science.gov (United States)

    Bae, M. H.; Bae, T. Y.; Kim, D. J.

    2018-03-01

    The power train of mixer gearbox for concrete mixer truck includes differential planetary gears to get large reduction ratio for operating mixer a drum and simple structure. The planetary gears are very important part of a mixer gearbox where strength problems namely gear bending stress, gear compressive stress and scoring failure are the main concern. In the present study, calculating specifications of the differential planetary gears and analyzing the gear bending and compressive stresses as well as scoring factor of the differential planetary gears gearbox for an optimal design of the mixer gearbox in respect to cost and reliability are investigated. The analyses of actual gear bending and compressive stresses of the differential planetary gears using Lewes & Hertz equation and verifications of the calculated specifications of the differential planetary gears evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears. In addition, we also analyze actual gear scoring factor as well as evaluate the possibility of scoring failure of the differential planetary gear.

  7. From design to manufacturing of asymmetric teeth gears using computer application

    Science.gov (United States)

    Suciu, F.; Dascalescu, A.; Ungureanu, M.

    2017-05-01

    The asymmetric cylindrical gears, with involutes teeth profiles having different base circle diameters, are nonstandard gears, used with the aim to obtain better function parameters for the active profile. We will expect that the manufacturing of these gears became possible only after the design and realization of some specific tools. The paper present how the computer aided design and applications developed in MATLAB, for obtain the geometrical parameters, in the same time for calculation some functional parameters like stress and displacements, transmission error, efficiency of the gears and the 2D models, generated with AUTOLISP applications, are used for computer aided manufacturing of asymmetric gears with standard tools. So the specific tools considered one of the disadvantages of these gears are not necessary and implicitly the expected supplementary costs are reduced. The calculus algorithm established for the asymmetric gear design application use the „direct design“ of the spur gears. This method offers the possibility of determining first the parameters of the gears, followed by the determination of the asymmetric gear rack’s parameters, based on those of the gears. Using original design method and computer applications have been determined the geometrical parameters, the 2D and 3D models of the asymmetric gears and on the base of these models have been manufacturing on CNC machine tool asymmetric gears.

  8. Hybrid Gear Preliminary Results-Application of Composites to Dynamic Mechanical Components

    Science.gov (United States)

    Handschuh, Robert F.; Roberts Gary D.; Sinnamon, R.; Stringer, David B.; Dykas, Brian D.; Kohlman, Lee W.

    2012-01-01

    Composite spur gears were fabricated and then tested at NASA Glenn Research Center. The composite material served as the web of the gear between the gear teeth and a metallic hub for mounting to the torque-applying shaft. The composite web was bonded only to the inner and outer hexagonal features that were machined from an initially all-metallic aerospace quality spur gear. The Hybrid Gear was tested against an all-steel gear and against a mating Hybrid Gear. As a result of the composite to metal fabrication process used, the concentricity of the gears were reduced from their initial high-precision value. Regardless of the concentricity error, the hybrid gears operated successfully for over 300 million cycles at 10000 rpm and 490 in.*lbs torque. Although the design was not optimized for weight, the composite gears were found to be 20% lighter than the all-steel gears. Free vibration modes and vibration/noise tests were also conduct to compare the vibration and damping characteristic of the Hybrid Gear to all-steel gears. The initial results indicate that this type of hybrid design may have a dramatic effect on drive system weight without sacrificing strength.

  9. Time domain series system definition and gear set reliability modeling

    International Nuclear Information System (INIS)

    Xie, Liyang; Wu, Ningxiang; Qian, Wenxue

    2016-01-01

    Time-dependent multi-configuration is a typical feature for mechanical systems such as gear trains and chain drives. As a series system, a gear train is distinct from a traditional series system, such as a chain, in load transmission path, system-component relationship, system functioning manner, as well as time-dependent system configuration. Firstly, the present paper defines time-domain series system to which the traditional series system reliability model is not adequate. Then, system specific reliability modeling technique is proposed for gear sets, including component (tooth) and subsystem (tooth-pair) load history description, material priori/posterior strength expression, time-dependent and system specific load-strength interference analysis, as well as statistically dependent failure events treatment. Consequently, several system reliability models are developed for gear sets with different tooth numbers in the scenario of tooth root material ultimate tensile strength failure. The application of the models is discussed in the last part, and the differences between the system specific reliability model and the traditional series system reliability model are illustrated by virtue of several numerical examples. - Highlights: • A new type of series system, i.e. time-domain multi-configuration series system is defined, that is of great significance to reliability modeling. • Multi-level statistical analysis based reliability modeling method is presented for gear transmission system. • Several system specific reliability models are established for gear set reliability estimation. • The differences between the traditional series system reliability model and the new model are illustrated.

  10. Magnetic transmission gear finite element simulation with iron pole hysteresis

    Science.gov (United States)

    Filippini, Mattia; Alotto, Piergiorgio; Glehn, Gregor; Hameyer, Kay

    2018-04-01

    Ferromagnetic poles in a magnetic transmission gear require particular attention during their design process. Usually, during the numerical simulation of these devices the effects of hysteresis for loss estimation are neglected and considered only during post-processing calculations. Since the literature lacks hysteresis models, this paper adopts a homogenized hysteretic model able to include eddy current and hysteresis losses in 2D laminated materials for iron poles. In this article the results related to the hysteresis in a magnetic gear are presented and compared to the non-hysteretic approach.

  11. Gear Fault Detection Based on Teager-Huang Transform

    Directory of Open Access Journals (Sweden)

    Hui Li

    2010-01-01

    Full Text Available Gear fault detection based on Empirical Mode Decomposition (EMD and Teager Kaiser Energy Operator (TKEO technique is presented. This novel method is named as Teager-Huang transform (THT. EMD can adaptively decompose the vibration signal into a series of zero mean Intrinsic Mode Functions (IMFs. TKEO can track the instantaneous amplitude and instantaneous frequency of the Intrinsic Mode Functions at any instant. The experimental results provide effective evidence that Teager-Huang transform has better resolution than that of Hilbert-Huang transform. The Teager-Huang transform can effectively diagnose the fault of the gear, thus providing a viable processing tool for gearbox defect detection and diagnosis.

  12. Procedure for the automatic mesh generation of innovative gear teeth

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.

  13. Electron Beam Welding of Gear Wheels by Splitted Beam

    Directory of Open Access Journals (Sweden)

    Dřímal Daniel

    2014-06-01

    Full Text Available This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max..

  14. Induction heating of gears - pulsing dual-frequency concept

    Directory of Open Access Journals (Sweden)

    R. Przyłucki

    2013-04-01

    Full Text Available The paper concerns analysis of gears hardening process. In order to obtain required temperature distribution several variations of single and combined frequencies for selected gear-wheel configurations were considered. The paper includes the calculation models and analysis of geometry and current intensity as well frequency influence on temperature distribution of the tooth surface. All calculations have been carried out by means of the use of Flux3D simulation program, which enables to provide, coupled electromagnetic and temperature fields analysis.

  15. Investigation of noise sources and propagation in external gear pumps

    Science.gov (United States)

    Opperwall, Timothy J.

    Oil hydraulics is widely accepted as the best technology for transmitting power in many engineering applications due to its advantages in power density, control, layout flexibility, and efficiency. Due to these advantages, hydraulic systems are present in many different applications including construction, agriculture, aerospace, automotive, forestry, medical, and manufacturing, just to identify a few. Many of these applications involve the systems in close proximity to human operators and passengers where noise is one of the main constraints to the acceptance and spread of this technology. As a key component in power transfer, displacement machines can be major sources of noise in hydraulic systems. Thus, investigation into the sources of noise and discovering strategies to reduce noise is a key part of applying fluid power systems to a wider range of applications, as well as improving the performance of current hydraulic systems. The present research aims to leverage previous efforts and develop new models and experimental techniques in the topic of noise generation caused by hydrostatic units. This requires challenging and surpassing current accepted methods in the understanding of noise in fluid power systems. This research seeks to expand on the previous experimental and modeling efforts by directly considering the effect that system and component design changes apply on the total sound power and the sound frequency components emitted from displacement machines and the attached lines. The case of external gear pumps is taken as reference for a new model to understand the generation and transmission of noise from the sources out to the environment. The lumped parameter model HYGESim (HYdraulic GEar machine Simulator) was expanded to investigate the dynamic forces on the solid bodies caused by the pump operation and to predict interactions with the attached system. Vibration and sound radiation were then predicted using a combined finite element and boundary

  16. Computerized Design and Generation of Gear Drives With a Localized Bearing Contact and a Low Level of Transmission Errors

    Science.gov (United States)

    Litvin, F.; Chen, J.; Seol, I.; Kim, D.; Lu, J.; Zhao, X.; Handschuh, R.

    1996-01-01

    A general approach developed for the computerized simulation of loaded gear drives is presented. In this paper the methodology used to localize the bearing contact, provide a parabolic function of transmission errors, and simulate meshing and contact of unloaded gear drives is developed. The approach developed is applied to spur and helical gears, spiral bevel gears, face-gear drives, and worm-gear drives with cylindrical worms.

  17. Efeito da adição de proteína do soro do leite como substituto do trigo na formulação de bolos sem adição de açúcar

    Directory of Open Access Journals (Sweden)

    Jéssica Pazzaro Soares

    2017-11-01

    Full Text Available Resumo A proteína do soro do leite (PSL é um produto da fabricação de queijos, que apresenta elevado valor nutricional e atributos funcionais. Sua utilização em produtos de panificação favorece aspectos físicos, como a emulsão e a capacidade de estabilização, além de melhorar características sensoriais. O presente estudo teve como objetivo elaborar bolos sem adição de açúcar, utilizando-se a PSL como substituto do trigo, bem como avaliar suas características físicas, químicas, sensoriais e microbiológicas. O efeito da adição de PSL e margarina em bolos foi avaliado por meio de um delineamento central composto rotacional de segunda ordem. Os tratamentos selecionados foram avaliados por meio de análise sensorial e caracterizados quanto à composição centesimal, além de se proceder à avaliação microbiológica após 15 dias de armazenamento. A adição de até 11,98 g/100 g de margarina influenciou de forma expressiva na redução da altura dos bolos. O tratamento com teor intermediário de PSL (30 g/100 g e menor teor de margarina (6,72 g/100 g obteve melhor aceitabilidade e, quando comparado ao controle, maior conteúdo de proteínas. As condições microbiológicas foram satisfatórias, atendendo à legislação vigente, mesmo após 15 dias de armazenamento.

  18. Research on vibration signal analysis and extraction method of gear local fault

    Science.gov (United States)

    Yang, X. F.; Wang, D.; Ma, J. F.; Shao, W.

    2018-02-01

    Gear is the main connection parts and power transmission parts in the mechanical equipment. If the fault occurs, it directly affects the running state of the whole machine and even endangers the personal safety. So it has important theoretical significance and practical value to study on the extraction of the gear fault signal and fault diagnosis of the gear. In this paper, the gear local fault as the research object, set up the vibration model of gear fault vibration mechanism, derive the vibration mechanism of the gear local fault and analyzes the similarities and differences of the vibration signal between the gear non fault and the gears local faults. In the MATLAB environment, the wavelet transform algorithm is used to denoise the fault signal. Hilbert transform is used to demodulate the fault vibration signal. The results show that the method can denoise the strong noise mechanical vibration signal and extract the local fault feature information from the fault vibration signal..

  19. Enhanced Computer Aided Simulation of Meshing and Contact With Application for Spiral Bevel Gear Drives

    National Research Council Canada - National Science Library

    Litvin, F

    1999-01-01

    An integrated tooth contact analysis (TCA) computer program for the simulation of meshing and contact of gear drives that calculates transmission errors and shift of hearing contact for misaligned gear drives has been developed...

  20. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike

    2016-01-01

    such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

  1. 14 CFR 23.729 - Landing gear extension and retraction system.

    Science.gov (United States)

    2010-01-01

    ... retracted) position. If switches are used, they must be located and coupled to the landing gear mechanical... burst, or rocks, water, and slush that may enter the landing gear bay. [Doc. No. 4080, 29 FR 17955, Dec...

  2. Possiblity of substituting 12XH3A steel in the manufacture of gears for a Sova motorcycle gearing box

    Science.gov (United States)

    Abramov, L. M.; Karabanov, V. P.; Abramov, V. L.; Astakhin, A. S.

    1996-03-01

    The experimental work describes the possibility of substituting the expensive alloying steel 12XH3A for the low-cost material (steel 40X) in manufacturing gears of the motor cycle gearing box. It ban be achieved on the basis of the obtained results and with the help of laser melting treatment of small-alloying steel. We can speak about the dependence of laser melting radiation efficiency on the regimes and procedures. The breakage of the gearing box of the motor cycle 'Sova' may be explained by the low carry ability of its first gearing box gear. This investigation includes the determination of the cause of this problem. One of the most wide spread methods of such decisions is the substitution of the used materials by another. The most important criteria for the new materials are: (1) the increase of mechanical characteristics (solidity, plasticity); (2) the increase of such characteristics as hardness, specific percussive viscosity; (3) the improvement of the technological characteristics; (4) the condencention of the manufacturing expenditures (economical effect). In accordance with these creations some materials (35X, 40X, 20XH, 40XHM steels) were chosen. The best material is 40X steel, because it allows us to treat the gears by laser radiation with the surface melt. Surface melt allows us to produce: (1) martensite structure with high solidity and low percussive viscosity; (2) martensite structure with chrome carbides and high percussive viscosity, but low plasticity; (3) amorphous or monocrystallic structures with the best characteristics. The last structure has the best characteristics because dislocation defects in such material are practically absent. Also, the amorphous surface of the materials is the most interesting. The spirit of the investigation is to define the parameters of production such as radiation power, size of laser spot, and speed of spot.

  3. Dynamic load-sharing characteristic analysis of face gear power-split gear system based on tooth contact characteristics

    Science.gov (United States)

    Dong, Hao; Hu, Yahui

    2018-04-01

    The bend-torsion coupling dynamics load-sharing model of the helicopter face gear split torque transmission system is established by using concentrated quality standard, to analyzing the dynamic load-sharing characteristic. The mathematical models include nonlinear support stiffness, time-varying meshing stiffness, damping, gear backlash. The results showed that the errors collectively influenced the load sharing characteristics, only reduce a certain error, it is never fully reached the perfect loading sharing characteristics. The system load-sharing performance can be improved through floating shaft support. The above-method will provide a theoretical basis and data support for its dynamic performance optimization design.

  4. Gear shift strategies for automotive transmissions

    NARCIS (Netherlands)

    Ngo, D.V.

    2012-01-01

    The development history of automotive engineering has shown the essential role of transmissions in road vehicles primarily powered by internal combustion engines. The engine with its physical constraints on the torque and speed requires a transmission to have its power converted to the drive power

  5. Research of Planetary Gear Fault Diagnosis Based on Permutation Entropy of CEEMDAN and ANFIS

    NARCIS (Netherlands)

    Kuai, Moshen; Cheng, Gang; Pang, Y.; Li, Yong

    2018-01-01

    For planetary gear has the characteristics of small volume, light weight and large transmission ratio, it is widely used in high speed and high power mechanical system. Poor working conditions result in frequent failures of planetary gear. A method is proposed for diagnosing faults in planetary gear

  6. Minimizing tooth bending stress in spur gears with simplified shapes of fillet and tool shape determination

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2015-01-01

    by different standards, with the ISO standard probably being the most common one. Gears are manufactured using two principally different tools: rack tools and gear tools. In this work, the bending stress of involute teeth is minimized by shape optimization made directly on the final gear. This optimized shape...

  7. Light and Heavy Tactical Wheeled Vehicle Fuel Consumption Evaluations Using Fuel Efficient Gear Oils (FEGO)

    Science.gov (United States)

    2016-05-01

    UNCLASSIFIED LIGHT AND HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FUEL EFFICIENT GEAR OILS (FEGO) FINAL... HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FUEL EFFICIENT GEAR OILS (FEGO) FINAL REPORT TFLRF No. 477 by Adam C...August 2014 – March 2016 4. TITLE AND SUBTITLE LIGHT AND HEAVY TACTICAL WHEELED VEHICLE FUEL CONSUMPTION EVALUATIONS USING FEUL EFFICIENT GEAR OILS

  8. 77 FR 36998 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...

    Science.gov (United States)

    2012-06-20

    ... Collection; Comment Request; Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY: National... under the Shrimp Fishery Management Plan (FMP). The regulations for the Gulf Shrimp Vessel and Gear... and Gear Characterization Form. The form will be provided by NMFS at the time of permit application...

  9. 78 FR 40436 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...

    Science.gov (United States)

    2013-07-05

    ... Collection; Comment Request; Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY: National... under the Shrimp Fishery Management Plan (FMP). The regulations for the Gulf Shrimp Vessel and Gear... Gear Characterization Form. The form will be provided by NMFS at the time of permit application and...

  10. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each clutch...

  11. 76 FR 5402 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Gear...

    Science.gov (United States)

    2011-01-31

    ... for OMB Review; Comment Request; Gear Certification ACTION: Notice. SUMMARY: The Department of Labor...) sponsored information collection request (ICR) titled, ``Gear Certification,'' to the Office of Management... cranes, derricks, and accessory gear used in the longshoring, marine terminal, and shipyard industries...

  12. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering gear...

  13. 75 FR 17055 - Gray's Reef National Marine Sanctuary Regulations on the Use of Spearfishing Gear; Correction

    Science.gov (United States)

    2010-04-05

    ... Spearfishing Gear; Correction AGENCY: Office of National Marine Sanctuaries (ONMS), National Ocean Service (NOS... Federal Register on February 19, 2010 (75 FR 7361) on the use and possession of spearfishing gear in Gray..., that included a description of new requirements on the use and possession of spearfishing gear in Gray...

  14. 76 FR 16610 - Proposed Information Collection; Comment Request; Pacific Islands Region Vessel and Gear...

    Science.gov (United States)

    2011-03-24

    ... Collection; Comment Request; Pacific Islands Region Vessel and Gear Identification Requirements AGENCY... and gear, as specified in 50 CFR 665 and 50 CFR 300. Vessels registered for use with a permit issued... require that certain fishing gear must be marked. In the pelagic longline fisheries, the vessel operator...

  15. 75 FR 58373 - Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP)

    Science.gov (United States)

    2010-09-24

    ... Readiness for Undergraduate Programs (GEAR UP) AGENCY: Office of Postsecondary Education, Department of Education. ACTION: Notice of intent to fund down the fiscal year (FY) 2008 grant slate for the GEAR UP Program. SUMMARY: The Secretary intends to use the grant slate developed in FY 2008 for the GEAR UP...

  16. Investigating GEAR-Up College Readiness Program's Influence on Postsecondary Decisions of Rural Hispanic Youth

    Science.gov (United States)

    Boydstun, Kelli Dawn

    2016-01-01

    This qualitative case study investigated how the GEAR-Up college readiness program influenced the postsecondary decisions of Hispanic students who participated in the GEAR-Up program for the recommended six-year period in a rural school district in Texas. It was not known how long-term participation in the GEAR-Up program at a rural school…

  17. Motor Integrated Permanent Magnet Gear with a Wide Torque-Speed Range

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Matzen, Torben N.; Jahns, T. M.

    2009-01-01

    This paper present a new motor integrated permanent magnet gear with a wide torque-speed range. In the paper a 35 kW permanent magnet motor with a base speed of 4000 rpm and a top speed of 14000 rpm is integrated into a permanent magnetic gear with a gearing ratio of 8.67. The design process...

  18. 75 FR 55301 - Proposed Information Collection; Comment Request; Northeast Region Gear Identification Requirements

    Science.gov (United States)

    2010-09-10

    ...., buoys, radar reflectors, or other methods identified in the regulations). The number of gear in the case... be responsible for marking several strings of a given type of gear, or may use multiple different gear types that require marking for identification and visibility. The display of the identifying...

  19. Development of a high-performance magnetic gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank Thorleif

    2005-01-01

    components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81 %. A large magnetic 1055 component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses of magnetic origin...

  20. Use of Protective Gear in Bird Flu Outbreak Response

    Centers for Disease Control (CDC) Podcasts

    CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDC’s journal, Emerging Infectious Diseases.

  1. Materials and lubrication for gear and bearing surfaces in UHV

    International Nuclear Information System (INIS)

    Kirby, R.E.; Collet, G.J.; Garwin, E.L.

    1981-01-01

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 250 0 C, and at room temperature must operate at pressures in the 10 -9 to 10 -10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined by bushings to a fixed shaft on which it rotated, while the other gear was driven through a commercial rotary motion feedthrough rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. equal to 10 5 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91 000. Materials for gears included stainless steel, beryllium copper and aluminium alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome and a MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed. (orig.)

  2. PRINCIPLE "EARLY MATCHING" AERODYNAMIC DESIGN AIRCRAFT WITH LANDING GEAR HOVERCRAFT

    Directory of Open Access Journals (Sweden)

    V. P. Morozov

    2015-01-01

    Full Text Available The principle of "early matching" aircraft aerohydrodynamic layouts with air cushion landing gear is suggested. Application of this principle is considered as an example of adaptation to the ball screw base circuit of light transport aircraft. The principle, other than weight, aerodynamic, technological and operational requirements includes additional project activities related to the installation of ball screws.

  3. 181 checklist and assessment of efficiency of some traditional gears

    African Journals Online (AJOL)

    Department of Fisheries And Aquaculture, University Of Agriculture, P.M.B. 2373,. Makurdi ... The efficiency and use of the gears and crafts was also seasonally ... water, fishing extensively with baskets and ... improved by the introduction of a few .... Fish Culture in undrainable ponds. Reed W, J. Burchard, A.J Hopson and J.

  4. Four-gear strata tiltmeter. Evaluation of resolution capacity

    Energy Technology Data Exchange (ETDEWEB)

    Balhar, M.

    1984-01-01

    Provides condensed technical characteristics of a four-gear NPS-1 tiltmeter with high resolution. Unit is necessary to determine azimuths and drop angles of strata. Also provides a summarized substantiation of the focusing micro-unit of the tiltmeter. Based on measurements carried out on a turntable and a model borehole, potential errors in determining stratification features were established.

  5. Gear-based species selectivity and potential interactions between ...

    African Journals Online (AJOL)

    ... and competition between different co-occurring fisheries is therefore important for the implementation of ecosystem based fisheries management interventions. In this study, we used multivariate and ecological approaches to evaluate gear competition and interactions between artisanal and aquarium fishers using a case ...

  6. Impedance Synthesis Based Vibration Analysis of Geared Transmission System

    Directory of Open Access Journals (Sweden)

    Yafeng Ren

    2017-01-01

    Full Text Available The severity of gear noise response depends on the sensitivity of geared rotor system dynamics to the transmission error. As gearbox design trending towards lighter weight and lower noise, the influence of housing compliance on system dynamic characteristics cannot be ignored. In this study, a gear-shaft-bearing-housing coupled impedance model is proposed to account for the effect of housing compliance on the vibration of geared transmission system. This proposed dynamic model offers convenient modeling, efficient computing, and ability to combine computed parameters with experimental ones. The numerical simulations on system dynamic characteristics are performed for both a rigid housing configuration and a flexible one. Natural frequencies, dynamic mesh forces, and dynamic bearing reaction loads are computed, and the housing compliance contribution on system dynamic characteristics is analyzed. Results show that increasing housing compliance will decrease the system natural frequencies and will affect the dynamic bearing reaction loads significantly but have very little influence on the dynamic mesh force. Also, the analysis shows that bearing stiffness has significant influence on the degree of housing contribution on system dynamic characteristics.

  7. Marine Hydrokinetic Power Take-Off Using Magnetic Gearing

    OpenAIRE

    Bird, Jonathan Z.

    2014-01-01

    This paper reviews different power take-off approaches for rotary based marine hydrokinetic power generation. The technology for wind power generation is used as a guide. A discussion on the potential benefits of utilizing magnetic gearing is presented. University of North Carolina at Chapel Hill. Coastal Studies Institute

  8. LOADING OF MECHANICAL TRANSMISSION OF TROLLEYBUS TRACTION DRIVING GEAR

    Directory of Open Access Journals (Sweden)

    A. I. Safonov

    2009-01-01

    Full Text Available The paper analyzes factors that determine dynamic loads of mechanical transmission of trolleybus traction driving gear. The paper proposes a methodology for determination of calculative moments of loading transmission elements. Results of the research are analyzed and recommendations on  dynamic reduction of trolleybus transmission are given in the paper. 

  9. Involute Spur Gear Template Development by Parametric Technique ...

    African Journals Online (AJOL)

    There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric ...

  10. 50 CFR 600.510 - Gear avoidance and disposal.

    Science.gov (United States)

    2010-10-01

    ... gear in the EEZ. (3) If these articles or substances are encountered, or in the event of accidental or... Section 600.510 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... include: (1) The name of the reporting vessel. (2) A description of the incident and articles retrieved...

  11. Customization of worm gear drives; Schneckengetriebemotoren werden kundenspezifisch angepasst

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Reinhold

    2009-08-31

    As a result of the diverse wishes of their customers, producers of motors and gears are faced with strongly varying machine and system configurations. It may be necessary to develop components that are not part of the manufacturer's original portfolio but may be obtained by new developments or further development of existing components. (orig.)

  12. From testbed to reality grid computing steps up a gear

    CERN Multimedia

    2004-01-01

    "UK plans for Grid computing changed gear this week. The pioneering European DataGrid (EDG) project came to a successful conclusion at the end of March, and on 1 April a new project, known as Enabling Grids for E-Science in Europe (EGEE), begins" (1 page)

  13. Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

    Science.gov (United States)

    Dempsey, Paula J.; Zakrajsek, James J.

    2001-01-01

    NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

  14. Dynamics of simple gearing model with flexible planetary pins

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk; Radolfová, Alena

    2016-01-01

    Roč. 821, č. 2016 (2016), s. 284-281 ISSN 1660-9336 R&D Projects: GA TA ČR TA04011656 Institutional support: RVO:61388998 Keywords : lanetary gearings set * vibrations * rig wheel excitation * driving aggregate Subject RIV: BI - Acoustics

  15. A New Acoustic Emission Sensor Based Gear Fault Detection Approach

    Directory of Open Access Journals (Sweden)

    Junda Zhu

    2013-01-01

    Full Text Available In order to reduce wind energy costs, prognostics and health management (PHM of wind turbine is needed to ensure the reliability and availability of wind turbines. A gearbox is an important component of a wind turbine. Therefore, developing effective gearbox fault detection tools is important to the PHM of wind turbine. In this paper, a new acoustic emission (AE sensor based gear fault detection approach is presented. This approach combines a heterodyne based frequency reduction technique with time synchronous average (TSA and spectrum kurtosis (SK to process AE sensor signals and extract features as condition indictors for gear fault detection. Heterodyne technique commonly used in communication is first employed to preprocess the AE signals before sampling. By heterodyning, the AE signal frequency is down shifted from several hundred kHz to below 50 kHz. This reduced AE signal sampling rate is comparable to that of vibration signals. The presented approach is validated using seeded gear tooth crack fault tests on a notational split torque gearbox. The approach presented in this paper is physics based and the validation results have showed that it could effectively detect the gear faults.

  16. The contact drag of towed demersal fishing gear components

    Science.gov (United States)

    O'Neill, F. G.; Summerbell, K.; Ivanović, A.

    2018-01-01

    The contact demersal towed fishing gears make with the seabed can lead to penetration of the substrate, lateral displacement of the sediment and a pressure field transmitted through the sediment. It will also contribute to the overall drag of the fishing gear. Consequently, there can be environmental effects such as habitat alteration and benthic mortality, and impacts to the fuel efficiency of the fishing operation which will affect emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we present the results of experimental trials that measure the contact drag of a range of elements that represent some of the components of towed demersal gears that are in contact with the seabed. We show that the contact drag of the gear components depends on their weight, geometry, the type of sediment on which they are towed and whether they are rolling or not. As expected, the contact drag of each gear component increases as its weight increases and the drag of fixed elements is greater than that of the rolling ones. The dependence on aspect ratio is more complex and the drag (per unit area) of narrow cylinders is less than that of wider ones when they roll on the finer sediment or are fixed (not permitted to roll) on the coarser sediment. When they roll on the coarse sediment there is no dependence on aspect ratio. Our results also suggest that fixed components may penetrate the seabed to a lesser depth when they are towed at higher speeds but when they roll there is no such relationship.

  17. Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

    Directory of Open Access Journals (Sweden)

    Y. Gui

    2014-01-01

    Full Text Available Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

  18. Optimization of PHEV Power Split Gear Ratio to Minimize Fuel Consumption and Operation Cost

    Science.gov (United States)

    Li, Yanhe

    A Plug-in Hybrid Electric Vehicle (PHEV) is a vehicle powered by a combination of an internal combustion engine and an electric motor with a battery pack. The battery pack can be charged by plugging the vehicle to the electric grid and from using excess engine power. The research activity performed in this thesis focused on the development of an innovative optimization approach of PHEV Power Split Device (PSD) gear ratio with the aim to minimize the vehicle operation costs. Three research activity lines have been followed: • Activity 1: The PHEV control strategy optimization by using the Dynamic Programming (DP) and the development of PHEV rule-based control strategy based on the DP results. • Activity 2: The PHEV rule-based control strategy parameter optimization by using the Non-dominated Sorting Genetic Algorithm (NSGA-II). • Activity 3: The comprehensive analysis of the single mode PHEV architecture to offer the innovative approach to optimize the PHEV PSD gear ratio.

  19. Coupled lateral-torsional-axial vibrations of a helical gear-rotor-bearing system

    Science.gov (United States)

    Li, Chao-Feng; Zhou, Shi-Hua; Liu, Jie; Wen, Bang-Chun

    2014-10-01

    Considering the axial and radial loads, a mathematical model of angular contact ball bearing is deduced with Hertz contact theory. With the coupling effects of lateral, torsional and axial vibrations taken into account, a lumped-parameter nonlinear dynamic model of helical gearrotor-bearing system (HGRBS) is established to obtain the transmission system dynamic response to the changes of different parameters. The vibration differential equations of the drive system are derived through the Lagrange equation, which considers the kinetic and potential energies, the dissipative function and the internal/external excitation. Based on the Runge-Kutta numerical method, the dynamics of the HGRBS is investigated, which describes vibration properties of HGRBS more comprehensively. The results show that the vibration amplitudes have obvious fluctuation, and the frequency multiplication and random frequency components become increasingly obvious with changing rotational speed and eccentricity at gear and bearing positions. Axial vibration of the HGRBS also has some fluctuations. The bearing has self-variable stiffness frequency, which should be avoided in engineering design. In addition, the bearing clearance needs little attention due to its slightly discernible effect on vibration response. It is suggested that a careful examination should be made in modelling the nonlinear dynamic behavior of a helical gear-rotor-bearing system.

  20. Elasto-dynamic analysis of a gear pump-Part III: Experimental validation procedure and model extension to helical gears

    Science.gov (United States)

    Mucchi, E.; Dalpiaz, G.

    2015-01-01

    This work concerns external gear pumps for automotive applications, which operate at high speed and low pressure. In previous works of the authors (Part I and II, [1,2]), a non-linear lumped-parameter kineto-elastodynamic model for the prediction of the dynamic behaviour of external gear pumps was presented. It takes into account the most important phenomena involved in the operation of this kind of machine. The two main sources of noise and vibration are considered: pressure pulsation and gear meshing. The model has been used in order to foresee the influence of working conditions and design modifications on vibration generation. The model's experimental validation is a difficult task. Thus, Part III proposes a novel methodology for the validation carried out by the comparison of simulations and experimental results concerning forces and moments: it deals with the external and inertial components acting on the gears, estimated by the model, and the reactions and inertial components on the pump casing and the test plate, obtained by measurements. The validation is carried out comparing the level of the time synchronous average in the time domain and the waterfall maps in the frequency domain, with particular attention to identify system resonances. The validation results are satisfactory globally, but discrepancies are still present. Moreover, the assessed model has been properly modified for the application to a new virtual pump prototype with helical gears in order to foresee gear accelerations and dynamic forces. Part IV is focused on improvements in the modelling and analysis of the phenomena bound to the pressure evolution around the gears in order to achieve results closer to the measured values. As a matter of fact, the simulation results have shown that a variable meshing stiffness has a notable contribution on the dynamic behaviour of the pump but this is not as important as the pressure phenomena. As a consequence, the original model was modified with the

  1. Generation of helical gears with new surfaces topology by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.; Hsiao, C. L.; Handschuh, Robert F.

    1993-01-01

    Analysis of helical involute gears by tooth contact analysis shows that such gears are very sensitive to angular misalignment that leads to edge contact and the potential for high vibration. A new topology of tooth surfaces of helical gears that enables a favorable bearing contact and a reduced level of vibration is described. Methods for grinding of the helical gears with the new topology are proposed. A TCA (tooth contact analysis) program for simulation of meshing and contact of helical gears with the new topology has been developed. Numerical examples that illustrate the proposed ideas are discussed.

  2. Vehicle transmission gear 2009; Getriebe in Fahrzeugen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the VDI Conference 'Vehicle Transmission Gears' at 30th June to 1st May, 2009 in Friedrichshafen (Federal Republic of Germany), the following lectures were held: (1) Production site Germany - Home in trend (B.O. Braun); (2) Luk CVT Technology - Efficiency, comfort, dynamics (A. Teubert); (3) The new BMW eight-speed automatic gear (J. Kretschmer); (4) Influence of transmission concept and design on simulated fuel consumption in official customer driving cycles (A. Schmidt); (5) GETRAG PowerShift {sup registered} - Extended driving functionalities due to controllable double clutch (A. Pawlenka); (6) New efficient transmission strategy in automatic transmission in the city bus (H. Nolzen); (7) Electronic controllers for gears: decision about design concepts und applied technologies on the basis of the place of installation in vehicles (P. Bertelshofer); (8) Coupled systems based on magnetorheological fluids (D. Gueth); (9) Investigation of setting losses of diaphragm springs in dry-running couplings according to given conditions (P. Merkel); (10) Influence of material properties and heat balance on the tribologic behaviour of dry-running friction couplings (C. Spaeth); (11) A contribution to massively transformed components of gears for the reduction of consumption and resources saving (G. Quintenz); (12) An economic production of transmission shafts by means of near netshape transformation also in the area of commercial vehicles (E. Rauschnabel); (13) Potentials and transformation of design and process optimization in the serial production using hypoid interlocking as an example (A. Dietrich); (14) Development of automated manual transmission (Se-il Song); (15) Integration of new functions to GETRAG PowerShift {sup registered} Transmissions of transversal, transaxle powertrains (I. Steinberg); (16) Automatedmanual transmission - The forgotten concept for the future? (B.-R. Hoehn); (17) A new back-torque limiter for high power motorcycles

  3. Experiences of how fishers grab opportunities in (more) free regulation of gear

    DEFF Research Database (Denmark)

    Qvist Eliasen, Søren; Mortensen, Lars O.; Ulrich, Clara

    In the Minidisc project 14 vessels fished under conditions corresponding to free choose of gear. Based on the skippers initial idea of gear adjustment and a subsequent interview 6 months later the experiences of the skippers´ choice of “free” gear, the process for adjusting it and the tools...... for evaluating the efficiency and selectivity are discussed. Only incremental development using elements from previous used gear and other fisheries were found. Gear development took place in an interaction between the skipper and trawl maker, while no research was involved. This indicates that free choice...... of gear (under monitored discard ban) would lead to incremental adjustments. Parts of the fleet would have difficulties in evaluating the gear and subsequently optimise by adjusting. This would leave a need for support for development of evaluation procedures, especially among the small vessels. Radical...

  4. Wear of Spur Gears Having a Dithering Motion and Lubricated with a Perfluorinated Polyether Grease

    Science.gov (United States)

    Krantz, Timothy; Oswald, Fred; Handschuh, Robert

    2007-01-01

    Gear contact surface wear is one of the important failure modes for gear systems. Dedicated experiments are required to enable precise evaluations of gear wear for a particular application. The application of interest for this study required evaluation of wear of gears lubricated with a grade 2 perfluorinated polyether grease and having a dithering (rotation reversal) motion. Experiments were conducted using spur gears made from AISI 9310 steel. Wear was measured using a profilometer at test intervals encompassing 10,000 to 80,000 cycles of dithering motion. The test load level was 1.1 GPa maximum Hertz contact stress at the pitch-line. The trend of total wear as a function of test cycles was linear, and the wear depth rate was approximately 1.2 nm maximum wear depth per gear dithering cycle. The observed wear rate was about 600 times greater than the wear rate for the same gears operated at high speed and lubricated with oil.

  5. Five-Axis Milling of Large Spiral Bevel Gears: Toolpath Definition, Finishing, and Shape Errors

    Directory of Open Access Journals (Sweden)

    Álvaro Álvarez

    2018-05-01

    Full Text Available In this paper, a five-axis machining process is analyzed for large spiral-bevel gears, an interesting process for one-of-kind manufacturing. The work is focused on large sized spiral bevel gears manufacturing using universal multitasking machines or five-axis milling centers. Different machining strategies, toolpath patterns, and parameters are tested for both gear roughing and finishing operations. Machining time, tools’ wear, and gear surface are analyzed in order to determine which are the best strategies and parameters for large modulus gear manufacturing on universal machines. The case study results are discussed in the last section, showing the capacity of a universal five-axis milling for this niche. Special attention was paid to the possible affectations of the metal surfaces, since gear durability is very sensitive to thermo-mechanical damage, affected layers, and flank gear surface state.

  6. Correlation of Gear Surface Fatigue Lives to Lambda Ratio (Specific Film Thickness)

    Science.gov (United States)

    Krantz, Timothy Lewis

    2013-01-01

    The effect of the lubrication regime on gear performance has been recognized, qualitatively, for decades. Often the lubrication regime is characterized by the specific film thickness being the ratio of lubricant film thickness to the composite surface roughness. Three studies done at NASA to investigate gearing pitting life are revisited in this work. All tests were done at a common load. In one study, ground gears were tested using a variety of lubricants that included a range of viscosities, and therefore the gears operated with differing film thicknesses. In a second and third study, the performance of gears with ground teeth and superfinished teeth were assessed. Thicker oil films provided longer lives as did improved surface finish. These datasets were combined into a common dataset using the concept of specific film thickness. This unique dataset of more 258 tests provides gear designers with some qualitative information to make gear design decisions.

  7. The Absolute Deviation Rank Diagnostic Approach to Gear Tooth Composite Fault

    Directory of Open Access Journals (Sweden)

    Guangbin Wang

    2017-01-01

    Full Text Available Aiming at nonlinear and nonstationary characteristics of the different degree with single fault gear tooth broken, pitting, and composite fault gear tooth broken-pitting, a method for the diagnosis of absolute deviation of gear faults is presented. The method uses ADAMS, respectively, set-up dynamics model of single fault gear tooth broken, pitting, and composite fault gear tooth broken-pitting, to obtain the result of different degree of broken teeth, pitting the single fault and compound faults in the meshing frequency, and the amplitude frequency doubling through simulating analysis. Through the comparison with the normal state to obtain the sensitive characteristic of the fault, the absolute value deviation diagnostic approach is used to identify the fault and validate it through experiments. The results show that absolute deviation rank diagnostic approach can realize the recognition of gear single faults and compound faults with different degrees and provide quick reference to determine the degree of gear fault.

  8. Investigation on the static and dynamic structural behaviors of a regional aircraft main landing gear by a new numerical methodology

    Directory of Open Access Journals (Sweden)

    Francesco Caputo

    2018-01-01

    Full Text Available In this paper, a new methodology supporting the design of landing gears is proposed. Generally, a preliminary step is performed with simplified FE model, usually one-dimensional, to achieve the reaction forces involving each component during all aforementioned aircraft operations. Though this approach gives a valid support to the designer, it is characterized by several problems, such as the related approximations. So, it is important, by a numerical point of view, to develop an isostatic FE model equivalent to the real one. In fact, if the landing gear is modelled as hyperstatic, the static equilibrium equations are insufficient for determining the internal forces and reactions on each sub-component; so, the modelled material properties and geometries assume an increasing importance, which gets the model too approximating. The proposed methodology consists of achieving the reaction forces by means of multibody simulations, by overcoming such problems, since each component is modelled as rigid. In this paper, also a FE model for the investigation of the structural response is proposed. Aimed to Certification by Analysis purposes, the developed multibody and the FE models have been assessed against an experimental landing gear drop test carried out by Magnaghi Aeronautica S.p.A., according to the EASA CS 25 regulations

  9. Performance evaluation on vibration control of MR landing gear

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D Y; Nam, Y J; Park, M K [Graduate School, Pusan National University, Busan 609-735 (Korea, Republic of); Yamane, R [Kokushikan University, 4-28-1 Setagaya, Setagaya-ku, Tokyo 154-8515 (Japan)], E-mail: ldy5577@yahoo.co.kr, E-mail: mkpark1@pusan.ac.kr

    2009-02-01

    This paper is concerned with the applicability of the developed MR damper to the landing gear system for the attenuating undesired shock and vibration in the landing and taxing phases. First of all, the experimental model of the MR damper is derived based on the results of performance evaluations. Next, a simplified skyhook controller, which is one of the most straightforward, but effective approaches for improving ride comport in vehicles with active suspensions, is formulated. Then, the vibration control performances of the landing gear system using the MR damper are theoretically evaluated in the landing phase of the aircraft. A series of simulation analyses show that the proposed MR damper with the skyhook controller is effective for suppressing undesired vibration of the aircraft body. Finally, the effectiveness of the simulation results are additionally verified via HILS (Hardware-in-the-loop-simulation) method.

  10. Inferring Gear Damage from Oil-Debris and Vibration Data

    Science.gov (United States)

    Dempsey, Paula

    2006-01-01

    A system for real-time detection of surface-fatigue-pitting damage to gears for use in a helicopter transmission is based on fuzzy-logic used to fuse data from sensors that measure oil-borne debris, referred to as "oil debris" in the article, and vibration signatures. A system to detect helicopter-transmission gear damage is beneficial because the power train of a helicopter is essential for propulsion, lift, and maneuvering, hence, the integrity of the transmission is critical to helicopter safety. To enable detection of an impending transmission failure, an ideal diagnostic system should provide real-time monitoring of the "health" of the transmission, be capable of a high level of reliable detection (with minimization of false alarms), and provide human users with clear information on the health of the system without making it necessary for them to interpret large amounts of sensor data.

  11. Interrelationship between autism diagnostic observation schedule-generic (ADOS-G), autism diagnostic interview-revised (ADI-R), and the diagnostic and statistical manual of mental disorders (DSM-IV-TR) classification in children and adolescents with mental retardation

    NARCIS (Netherlands)

    de Bildt, A; Sytema, S; Ketelaars, C; Kraijer, D; Mulder, E; Volkmar, F; Minderaa, R

    The interrelationship between the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule-Generic (ADOS-G) and clinical classification was studied in 184 children and adolescents with Mental Retardation (MR). The agreement between the ADI-R and ADOS-G was fair, with a

  12. Interrelationship between Autism Diagnostic Observation Schedule-Generic (ADOS-G), Autism Diagnostic Interview-Revised (ADI-R), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) Classification in Children and Adolescents with Mental Retardation

    Science.gov (United States)

    de Bildt, Annelies; Sytema, Sjoerd; Ketelaars, Cees; Kraijer, Dirk; Mulder, Erik; Volkmar, Fred; Minderaa, Ruud

    2004-01-01

    The interrelationship between the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule-Generic (ADOS-G) and clinical classification was studied in 184 children and adolescents with Mental Retardation (MR). The agreement between the ADI-R and ADOS-G was fair, with a substantial difference between younger and older…

  13. VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Grzegorz PERUŃ

    2014-09-01

    Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.

  14. ASSEMBLY DESIGN OPTIMIZATION FOR GEAR PUMP HYDRAULIC UNITS

    Directory of Open Access Journals (Sweden)

    ŞCHEAUA Fanel

    2012-09-01

    Full Text Available This paper presents a model for gear pump assembly design realized in Solid Edge V20. The aim is to highlight modelling aspects for solid part components and how to achieve an assembly from several component parts. Can be noted that computer aided design (CAD software can provide multiple options of representing various designed components, assemblies containing up to hundreds of items and part component motion simulation.

  15. Manufacturing Technology Research Needs of the Gear Industry

    Science.gov (United States)

    1987-12-31

    needs technical and financial help along with time to regain a little of its former position as a world class industry. The development of the National...8217 Association (BGMA) and the Instituite of Mechanical Engineers (IMechE) have recently jointly established the British Gear Assocation (BGA). Within the BGA is...Issues - Definition - Definition o Quality of Product or Function - Objectives - Bow are we Operating Now? o Response or Lead Time - Financial Impact

  16. Use of Protective Gear in Bird Flu Outbreak Response

    Centers for Disease Control (CDC) Podcasts

    2008-12-29

    CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDC’s journal, Emerging Infectious Diseases.  Created: 12/29/2008 by Emerging Infectious Diseases.   Date Released: 12/29/2008.

  17. An Artificial Intelligence Approach for Gears Diagnostics in AUVs.

    Science.gov (United States)

    Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano

    2016-04-12

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  18. New progressive technology of flat gears processing development

    Directory of Open Access Journals (Sweden)

    Михайло Володимирович Маргуліс

    2015-11-01

    Full Text Available Relevant scientific and technical problems in relation to mechanical engineering is development of new technological processes that make it possible to achieve high accuracy and durability of machine parts that meet the requirements imposed on them. So it is important to develop a new method to make a flat gear teeth by plastic deformation of the ingot. The article deals with the actual problem of improving productivity and quality of plane wheels teeth that are widely used in advanced wave, planetary and other transmissions. A progressive method to produce flat gear teeth gear by plastic deformation of the ingot with two knurl rollers alternately moving reciprocally in the direction not intersecting the axis of the ingot mounting surface has been described in the article. The working surface of the rollers corresponds to the resulting shape of the teeth. The schemes of the teeth installing and knurling have been shown. The necessary material and the heat treatment of the knurling tools have been described. Its use will significantly increase the wear resistance of the working surfaces of the teeth and their durability as well as to increase productivity and its manufacturing costs. The material of the rollers is BC15steel. The surface layer of the knurling tools was subjected to nitration, surface hardness being up to 65 HRC. Knurling is made in the5236P shaper suited for this purpose

  19. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  20. Die design and process optimization of plastic gear extrusion

    Science.gov (United States)

    Zhang, Lei; Fu, Zhihong; Yao, Chen; Zang, Gongzheng; Wan, Yue

    2018-01-01

    The flow velocity of the melt in the extruder was simulated by using software Polyflow, and the size of the die channel with the best flow uniformity was obtained. The die profile shape is obtained by reverse design. The length of the shaping section is determined by Ansys transient thermal analysis. According to the simulation results, the design and manufacture of extrusion die of plastic gear and vacuum cooling setting were obtained. The influence of the five process parameters on the precision of the plastic gear were studied by the single factor analysis method, such as the die temperature T, the screw speed R, the die spacing S, the vacuum degree M and the hauling speed V. The optimal combination of process parameters was obtained by using the neural network particle swarm optimization algorithm(T = 197.05 °C, R = 9.04rpm, S = 67mm, M = -0.0194MPa). The tooth profile deviation of the extruded plastic gear can reach 9 level of accuracy.

  1. An Artificial Intelligence Approach for Gears Diagnostics in AUVs

    Directory of Open Access Journals (Sweden)

    Graciliano Nicolás Marichal

    2016-04-01

    Full Text Available In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles, where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  2. Analysis of gear reducer housing using the finite element method

    Science.gov (United States)

    Miklos, I. Zs; Miklos, C. C.; Alic, C. I.; Raţiu, S.

    2018-01-01

    The housing is an important component in the construction of gear reducers, having the role of fixing the relative position of the shafts and toothed wheels. At the same time, the housing takes over, via the bearings, the shaft loads resulting when the toothed wheel is engaging another toothed mechanism (i.e. power transmission through belts or chains), and conveys them to the foundation on which it is anchored. In this regard, in order to ensure the most accurate gearing, a high stiffness of the housing is required. In this paper, we present the computer-aided 3D modelling of the housing (in cast version) of a single stage cylindrical gear reducer, using the Autodesk Inventor Professional software, on the principle of constructive sizing. For the housing resistance calculation, we carried out an analysis using the Autodesk Simulation Mechanical software to apply the finite element method, based on the actual loads, as well as a comparative study of the stress and strain distribution, for several tightening values of the retaining bolts that secure the cover and the foundation housing.

  3. Development of Plastic Gear for Power Transmission : Abnormal Wear on the Tooth Root and Tooth Fracture near Pitch Point

    OpenAIRE

    Terashima, Kenichi; Tsukamoto, Naohisa; Nishida, Noriteru; Shi, Jiasun

    1986-01-01

    Plastic gears have many excellent characteristics which are locking in metallic gears, such as corrosion resistance, self-lubrication, quiet running, and so forth. The meshing behavior of plastic gears is very different from that of metallic gears. Therefore, the life estimation is very difficult for plastic gears. In this paper, generating and growing mechanisms of abnormal wear which appears fatally near the root of plastic tooth are analyzed, and then it is clarified that tooth fractures w...

  4. Molecular Dynamics Simulation of a Multi-Walled Carbon Nanotube Based Gear

    Science.gov (United States)

    Han, Jie; Globus, Al; Srivastava, Deepak; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    We used molecular dynamics to investigate the properties of a multi-walled carbon nanotube based gear. Previous work computationally suggested that molecular gears fashioned from (14,0) single-walled carbon nanotubes operate well at 50-100 gigahertz. The gears were formed from nanotubes with teeth added via a benzyne reaction known to occur with C60. A modified, parallelized version of Brenner's potential was used to model interatomic forces within each molecule. A Leonard-Jones 6-12 potential was used for forces between molecules. The gear in this study was based on the smallest multi-walled nanotube supported by some experimental evidence. Each gear was a (52,0) nanotube surrounding a (37,10) nanotube with approximate 20.4 and 16,8 A radii respectively. These sizes were chosen to be consistent with inter-tube spacing observed by and were slightly larger than graphite inter-layer spacings. The benzyne teeth were attached via 2+4 cycloaddition to exterior of the (52,0) tube. 2+4 bonds were used rather than the 2+2 bonds observed by Hoke since 2+4 bonds are preferred by naphthalene and quantum calculations by Jaffe suggest that 2+4 bonds are preferred on carbon nanotubes of sufficient diameter. One gear was 'powered' by forcing the atoms near the end of the outside buckytube to rotate to simulate a motor. A second gear was allowed to rotate by keeping the atoms near the end of its outside buckytube on a cylinder. The ends of both gears were constrained to stay in an approximately constant position relative to each other, simulating a casing, to insure that the gear teeth meshed. The stiff meshing aromatic gear teeth transferred angular momentum from the powered gear to the driven gear. The simulation was performed in a vacuum and with a software thermostat. Preliminary results suggest that the powered gear had trouble turning the driven gear without slip. The larger radius and greater mass of these gears relative to the (14,0) gears previously studied requires a

  5. Elderly Adi women of Arunachal Pradesh: "living encyclopedias" and cultural refugia in biodiversity conservation of the Eastern Himalaya, India.

    Science.gov (United States)

    Singh, Ranjay K; Rallen, Orik; Padung, Egul

    2013-09-01

    Elderly women of a particular socioecological system are considered to be "living encyclopedias" in biocultural knowledge systems. These women play a pivotal role in retaining and passing on biodiversity-related traditional knowledge to the next generations. Unfortunately the fast changing sociocultural values and the impact of modernity have rendered their knowledge somewhat less valuable and they are being treated as "cultural refugia." Our study on the importance of these women in the conservation of indigenous biodiversity was conducted in 14 randomly selected villages dominated by the Adi tribe of East Siang District, Arunachal Pradesh (northeast India). Data were collected from 531 women (381 elderly and 150 young to middle aged) during 2003-2008 using conventional social science methods and participatory rural appraisal. One innovative method, namely "recipe contest," was devised to mobilize Adi women of each village in order to energies them and explore their knowledge relating to traditional foods, ethnomedicines, and conservation of indigenous biodiversity. Results indicated that 55 plant species are being used by elderly Adi women in their food systems, while 34 plant species are integral parts of ethnomedicinal practices. These women identified different plant species found under multistory canopies of community forests. Elderly women were particularly skilled in preparing traditional foods including beverages and held significantly greater knowledge of indigenous plants than younger women. Lifelong experiences and cultural diversity were found to influence the significance of biodiversity use and conservation. The conservation of biodiversity occurs in three different habitats: jhum lands (shifting cultivation), Morang forest (community managed forests), and home gardens. The knowledge and practice of elderly women about habitats and multistory vegetations, regenerative techniques, selective harvesting, and cultivation practices contribute

  6. Elderly Adi Women of Arunachal Pradesh: "Living Encyclopedias" and Cultural Refugia in Biodiversity Conservation of the Eastern Himalaya, India

    Science.gov (United States)

    Singh, Ranjay K.; Rallen, Orik; Padung, Egul

    2013-09-01

    Elderly women of a particular socioecological system are considered to be "living encyclopedias" in biocultural knowledge systems. These women play a pivotal role in retaining and passing on biodiversity-related traditional knowledge to the next generations. Unfortunately the fast changing sociocultural values and the impact of modernity have rendered their knowledge somewhat less valuable and they are being treated as "cultural refugia." Our study on the importance of these women in the conservation of indigenous biodiversity was conducted in 14 randomly selected villages dominated by the Adi tribe of East Siang District, Arunachal Pradesh (northeast India). Data were collected from 531 women (381 elderly and 150 young to middle aged) during 2003-2008 using conventional social science methods and participatory rural appraisal. One innovative method, namely "recipe contest," was devised to mobilize Adi women of each village in order to energies them and explore their knowledge relating to traditional foods, ethnomedicines, and conservation of indigenous biodiversity. Results indicated that 55 plant species are being used by elderly Adi women in their food systems, while 34 plant species are integral parts of ethnomedicinal practices. These women identified different plant species found under multistory canopies of community forests. Elderly women were particularly skilled in preparing traditional foods including beverages and held significantly greater knowledge of indigenous plants than younger women. Lifelong experiences and cultural diversity were found to influence the significance of biodiversity use and conservation. The conservation of biodiversity occurs in three different habitats: jhum lands (shifting cultivation), Morang forest (community managed forests), and home gardens. The knowledge and practice of elderly women about habitats and multistory vegetations, regenerative techniques, selective harvesting, and cultivation practices contribute

  7. A New Model of the Fractional Order Dynamics of the Planetary Gears

    Directory of Open Access Journals (Sweden)

    Vera Nikolic-Stanojevic

    2013-01-01

    Full Text Available A theoretical model of planetary gears dynamics is presented. Planetary gears are parametrically excited by the time-varying mesh stiffness that fluctuates as the number of gear tooth pairs in contact changes during gear rotation. In the paper, it has been indicated that even the small disturbance in design realizations of this gear cause nonlinear properties of dynamics which are the source of vibrations and noise in the gear transmission. Dynamic model of the planetary gears with four degrees of freedom is used. Applying the basic principles of analytical mechanics and taking the initial and boundary conditions into consideration, it is possible to obtain the system of equations representing physical meshing process between the two or more gears. This investigation was focused to a new model of the fractional order dynamics of the planetary gear. For this model analytical expressions for the corresponding fractional order modes like one frequency eigen vibrational modes are obtained. For one planetary gear, eigen fractional modes are obtained, and a visualization is presented. By using MathCAD the solution is obtained.

  8. Modelling of teeth of a gear transmission for modern manufacturing technologies

    Science.gov (United States)

    Monica, Z.; Banaś, W.; Ćwikla, G.; Topolska, S.

    2017-08-01

    The technological process of manufacturing of gear wheels is influenced by many factors. It is designated depending on the type of material from which the gear is to be produced, its heat treatment parameters, the required accuracy, the geometrical form and the modifications of the tooth. Therefor the parameters selection process is not easy and moreover it is unambiguous. Another important stage of the technological process is the selection of appropriate tools to properly machine teeth in the operations of both roughing and finishing. In the presented work the focus is put first of all on modern production methods of gears using technologically advanced instruments in comparison with conventional tools. Conventional processing tools such as gear hobbing cutters or Fellows gear-shaper cutters are used from the beginning of the machines for the production of gear wheels. With the development of technology and the creation of CNC machines designated for machining of gears wheel it was also developed the manufacturing technology as well as the design knowledge concerning the technological tools. Leading manufacturers of cutting tools extended the range of tools designated for machining of gears on the so-called hobbing cutters with inserted cemented carbide tips. The same have be introduced to Fellows gear-shaper cutters. The results of tests show that is advantaged to use hobbing cutters with inserted cemented carbide tips for milling gear wheels with a high number of teeth, where the time gains are very high, in relation to the use of conventional milling cutters.

  9. Hardness and microstructure analysis of damaged gear caused by adhesive wear

    Science.gov (United States)

    Mahendra, Rizky Budi; Nugroho, Sri; Ismail, Rifky

    2018-03-01

    This study was a result from research on repairing project of damaged elevator gear box. The objective of this research is to analyze the failure part on elevator gearbox at flourmill factory. The equipment was damaged after one year installed and running on factory. Severe wear was occurred on high speed helical gear. These helical gear was one of main part of elevator gearbox in flour mill manufacture. Visually, plastic deformation didn't occurred and not visible on the failure helical gear shaft. Some test would be performed to check the chemical composition, microstructure and hardness of failure helical gear. The material of failure helical gear shaft was a medium carbon steel alloy. The microstructure was showed a martensitic phase formed on the surface to the center area of gear shaft. Otherwise, the depth of hardness layer slight formed on surface and lack depth of hardness layer was a main trigger of severe wear. It was not enough to resist wear due to friction caused by rolling and sliding on surface between high speed gear and low speed gear. Enhancement of hardness layer on surface and depth of hardness layer will make the component has more long life time. Furthermore, to perform next research is needed to analyze the reliability of enhanced hardness on layer and depth of hardness layer on helical gear shaft.

  10. Face-gear drives: Design, analysis, and testing for helicopter transmission applications

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face-gears in helicopter transmissions was explored. A light-weight, split-torque transmission design utilizing face-gears is described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, grinding, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. An analytical study showed that the face-gear drive is relatively insensitive to gear misalignment with respect to transmission errors, but the tooth contact is affected by misalignment. A method of localizing the bearing contact to permit operation with misalignment was explored. Two new methods for grinding of the face-gear tooth surfaces were also investigated. The proper choice of shaft stiffness enabled good load sharing in the split-torque transmission design. Face-gear experimental studies were also conducted. These tests demonstrated the feasibility of face-gears in high-speed, high-load applications such as helicopter transmissions.

  11. The Design of Intelligent Repair Welding Mechanism and Relative Control System of Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available Effective repair of worn big gear has large influence on ensuring safety production and enhancing economic benefits. A kind of intelligent repair welding method was put forward mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. Big gear repair welding mechanism was designed in this paper. The work principle and part selection of big gear repair welding mechanism was introduced. The three dimensional mode of big gear repair welding mechanism was constructed by Pro/E three dimensional design software. Three dimensional motions can be realized by motor controlling ball screw. According to involute gear feature, the complicated curve motion on curved gear surface can be transformed to linear motion by orientation. By this way, the repair welding on worn gear area can be realized. In the design of big gear repair welding mechanism control system, Siemens S7-200 series hardware was chosen. Siemens STEP7 programming software was chosen as system design tool. The entire repair welding process was simulated by experiment simulation. It provides a kind of practical and feasible method for the intelligent repair welding of big worn gear.

  12. Motor-park people shift gear.

    Science.gov (United States)

    Nnoli, C

    1992-01-01

    White, U.S. homosexual males were primarily affected in the early stages of the AIDS pandemic. Some Western researchers argued, however, that the syndrome originated in Africa. Strong political and social response to this notion resulted in only an anemic response to the growing AIDS epidemic in Nigeria. Nonetheless, the Stop AIDS Organization finally launched the Motor Park AIDS Education Program (MPAEP) in 1988, for health and education outreach to populations at risk of STDs and HIV infection. Specifically targeted are long-distance truck drivers, their young male assistants known as motor boys, and the barmaids, prostitutes, and homeless juveniles who frequent motor parks where these drivers rest while on the road. Many of these long-haul drivers have unprotected casual and commercial sex, both homosexual and heterosexual, take drugs, and suffer high rates of STDs. Marginalized, 75% illiterate, and speaking a variety of languages, these populations tend to be largely ignorant of the incurable nature of AIDS. Over 45% of motor park populations are estimated to be infected with an STD, or to have a future re-infection. These drivers are optimal vectors for the spread of HIV both internationally and within Nigeria. MPAEP workers work 6 days/week in the larger interstate motor parks to reach out to their predominantly male customers. They meet a host of primary health needs, and refer STD clients for testing and treatment. Drug use and homosexuality are 2 topics of discussion especially taboo in African society which have nonetheless been vigorously researched by MPAEP. Many drivers are unacknowledged bisexuals who have sex with their motor boys. Workers therefore explain the need to use condoms in same-sex activity without specifically mentioning homosexuality. Many Nigerians deny the existence of HIV and AIDS, are reluctant to speak about sex, and consider MPAEP workers to be intruders. Despite opposition in Muslim- dominated Northern Nigeria, however, program

  13. Gear wear monitoring by modulation signal bispectrum based on motor current signal analysis

    Science.gov (United States)

    Zhang, Ruiliang; Gu, Fengshou; Mansaf, Haram; Wang, Tie; Ball, Andrew D.

    2017-09-01

    Gears are important mechanical components for power transmissions. Tooth wear is one of the most common failure modes, which can present throughout a gear's lifetime. It is significant to accurately monitor gear wear progression in order to take timely predictive maintenances. Motor current signature analysis (MCSA) is an effective and non-intrusive approach which is able to monitor faults from both electrical and mechanical systems. However, little research has been reported in monitoring the gear wear and estimating its severity based on MCSA. This paper presents a novel gear wear monitoring method through a modulation signal bispectrum based motor current signal analysis (MSB-MCSA). For a steady gear transmission, it is inevitable to exist load and speed oscillations due to various errors including wears. These oscillations can induce small modulations in the current signals of the driving motor. MSB is particularly effective in characterising such small modulation signals. Based on these understandings, the monitoring process was implemented based on the current signals from a run-to-failure test of an industrial two stages helical gearbox under a moderate accelerated fatigue process. At the initial operation of the test, MSB analysis results showed that the peak values at the bifrequencies of gear rotations and the power supply can be effective monitoring features for identifying faulty gears and wear severity as they exhibit agreeable changes with gear loads. A monotonically increasing trend established by these features allows a clear indication of the gear wear progression. The dismantle inspection at 477 h of operation, made when one of the monitored features is about 123% higher than its baseline, has found that there are severe scuffing wear marks on a number of tooth surfaces on the driving gear, showing that the gear endures a gradual wear process during its long test operation. Therefore, it is affirmed that the MSB-MSCA approach proposed is reliable

  14. A Tooth Flank Crowning Method by Applying a Novel Crossed Angle Function Between the Hob Cutter and Work Gear in the Gear Hobbing Process

    Directory of Open Access Journals (Sweden)

    Wu Yu-Ren

    2016-01-01

    Full Text Available In this paper, a novel longitudinal tooth flank crowning method is proposed by setting the crossed angle between the hob cutter and work gear as a linear function of hob’s traverse feed movement in the gear hobbing process. However, this method makes twisted tooth flanks on the hobbed work gear. Therefore, a variable pressure angle hob cutter is applied to obtain an anti-twist tooth flank of hobbed work gear. A computer simulation example is performed to verify the superiority of the proposed novel hobbing method by comparing topographies of the crowned work gear surfaces hobbed by a standard hob cutter and a variable pressure angle hob cutter.

  15. Integration of a silicon-based microprobe into a gear measuring instrument for accurate measurement of micro gears

    International Nuclear Information System (INIS)

    Ferreira, N; Krah, T; Jeong, D C; Kniel, K; Härtig, F; Metz, D; Dietzel, A; Büttgenbach, S

    2014-01-01

    The integration of silicon micro probing systems into conventional gear measuring instruments (GMIs) allows fully automated measurements of external involute micro spur gears of normal modules smaller than 1 mm. This system, based on a silicon microprobe, has been developed and manufactured at the Institute for Microtechnology of the Technische Universität Braunschweig. The microprobe consists of a silicon sensor element and a stylus which is oriented perpendicularly to the sensor. The sensor is fabricated by means of silicon bulk micromachining. Its small dimensions of 6.5 mm × 6.5 mm allow compact mounting in a cartridge to facilitate the integration into a GMI. In this way, tactile measurements of 3D microstructures can be realized. To enable three-dimensional measurements with marginal forces, four Wheatstone bridges are built with diffused piezoresistors on the membrane of the sensor. On the reverse of the membrane, the stylus is glued perpendicularly to the sensor on a boss to transmit the probing forces to the sensor element during measurements. Sphere diameters smaller than 300 µm and shaft lengths of 5 mm as well as measurement forces from 10 µN enable the measurements of 3D microstructures. Such micro probing systems can be integrated into universal coordinate measuring machines and also into GMIs to extend their field of application. Practical measurements were carried out at the Physikalisch-Technische Bundesanstalt by qualifying the microprobes on a calibrated reference sphere to determine their sensitivity and their physical dimensions in volume. Following that, profile and helix measurements were carried out on a gear measurement standard with a module of 1 mm. The comparison of the measurements shows good agreement between the measurement values and the calibrated values. This result is a promising basis for the realization of smaller probe diameters for the tactile measurement of micro gears with smaller modules. (paper)

  16. Insights into the molecular basis for substrate binding and specificity of the wild-type L-arginine/agmatine antiporter AdiC.

    Science.gov (United States)

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Gapsys, Vytautas; Ucurum, Zöhre; de Groot, Bert L; Fotiadis, Dimitrios

    2016-09-13

    Pathogenic enterobacteria need to survive the extreme acidity of the stomach to successfully colonize the human gut. Enteric bacteria circumvent the gastric acid barrier by activating extreme acid-resistance responses, such as the arginine-dependent acid resistance system. In this response, l-arginine is decarboxylated to agmatine, thereby consuming one proton from the cytoplasm. In Escherichia coli, the l-arginine/agmatine antiporter AdiC facilitates the export of agmatine in exchange of l-arginine, thus providing substrates for further removal of protons from the cytoplasm and balancing the intracellular pH. We have solved the crystal structures of wild-type AdiC in the presence and absence of the substrate agmatine at 2.6-Å and 2.2-Å resolution, respectively. The high-resolution structures made possible the identification of crucial water molecules in the substrate-binding sites, unveiling their functional roles for agmatine release and structure stabilization, which was further corroborated by molecular dynamics simulations. Structural analysis combined with site-directed mutagenesis and the scintillation proximity radioligand binding assay improved our understanding of substrate binding and specificity of the wild-type l-arginine/agmatine antiporter AdiC. Finally, we present a potential mechanism for conformational changes of the AdiC transport cycle involved in the release of agmatine into the periplasmic space of E. coli.

  17. Delayed recovery of adipsic diabetes insipidus (ADI) caused by elective clipping of anterior communicating artery and left middle cerebral artery aneurysms.

    Science.gov (United States)

    Tan, Jeffrey; Ndoro, Samuel; Okafo, Uchenna; Garrahy, Aoife; Agha, Amar; Rawluk, Danny

    2016-12-16

    Adipsic diabetes insipidus (ADI) is an extremely rare complication following microsurgical clipping of anterior communicating artery aneurysm (ACoA) and left middle cerebral artery (MCA) aneurysm. It poses a significant challenge to manage due to an absent thirst response and the co-existence of cognitive impairment in our patient. Recovery from adipsic DI has hitherto been reported only once. A 52-year-old man with previous history of clipping of left posterior communicating artery aneurysm 20 years prior underwent microsurgical clipping of ACoA and left MCA aneurysms without any intraoperative complications. Shortly after surgery, he developed clear features of ADI with adipsic severe hypernatraemia and hypotonic polyuria, which was associated with cognitive impairment that was confirmed with biochemical investigations and cognitive assessments. He was treated with DDAVP along with a strict intake of oral fluids at scheduled times to maintain eunatremia. Repeat assessment at six months showed recovery of thirst and a normal water deprivation test. Management of ADI with cognitive impairment is complex and requires a multidisciplinary approach. Recovery from ADI is very rare, and this is only the second report of recovery in this particular clinical setting.

  18. Influence of the Selected Factors on Thermal Fatigue of the ADI in an Aspect of its Suitability as the Material for Metal Moulds

    Directory of Open Access Journals (Sweden)

    Zych J.

    2014-06-01

    Full Text Available W pracy przedstawiono wyniki badań odporności na zmęczenie cieplne dwóch gatunków żeliwa ADI (EN-GJS-1200-2 i EN-GJS-800-8. Badania prowadzono na autorskim stanowisku badawczym stosując oporowe nagrzewanie próbek, wg metody L.F. Cottina. Odporność na zmęczenie cieplne jest podstawowym kryterium w ocenie przydatności tworzywa (materiału na formy metalowe, które podlegają cyklicznemu nagrzewaniu. Oceniono wpływ maksymalnej temperatury (Tmax, cykli cieplnych na ich liczbę do pęknięcia próbki, analizowano zmiany struktury żeliwa ADI. zmiany twardości i wytrzymałości. Stwierdzono, iż przy cyklicznym nagrzewaniu do <500°C, żeliwo ADI zachowuje swoją pierwotną strukturę ausferrytu nawet po wykonaniu ponad 10.000 cykli cieplnych. Takie zachowanie żeliwa ADI predysponuje go jako materiał na formy metalowe stosowane w odlewnictwie ciśnieniowym, a więc przy odlewaniu głównie stopów Mg i Zn, ale również dla mniejszych odlewów wykonywanych ze stopów Al.

  19. The Discriminative Ability and Diagnostic Utility of the ADOS-G, ADI-R, and GARS for Children in a Clinical Setting

    Science.gov (United States)

    Mazefsky, Carla A.; Oswald, Donald P.

    2006-01-01

    Recent years have seen a surge of interest in assessment instruments for diagnosing autism in children. Instruments have generally been developed and evaluated from a research perspective. The Autism Diagnostic Observation Schedule-Generic (ADOS-G), Autism Diagnostic Interview-Revised (ADI-R), and Gilliam Autism Rating Scale (GARS) have received…

  20. Reacções de Ciclo-Adição na Síntese de Novos Heterociclos Funcionalizados

    OpenAIRE

    Lopes, Susana Margarida Martins

    2012-01-01

    Tese de doutoramento em Química, na especialidade de Síntese Orgânica O trabalho apresentado nesta dissertação teve como objectivo principal a síntese de novos compostos heterocíclicos funcionalizados via reacções de cicloadição. Este objectivo foi alcançado através do estudo de reacções de ciclo-adição 1,3- dipolar de alenoatos, na qual estes podem funcionar como percusores de dipolos e como dipolarófilos. Uma outra vertente estudada foi a reacção de hetero-Diels-Alder de n...

  1. The impact of various distance between axes of worm gear on torque value. Worm gear test stand

    Science.gov (United States)

    Sobek, M.; Baier, A.; Grabowski, Ł.

    2017-08-01

    Transferring both rotational and translational movements in systems used in the automotive industry is a very important and complex issue. In addition, the situation becomes much more difficult and complicated when the design of the transition system requires a high precision of operation as well as a well definite and long operating life. Such requirements are imposed on all components of today’s motor vehicles. However, particular attention is paid to the elements that directly or indirectly affect the safety of persons traveling in the vehicle. Such components are undoubtedly components included as parts of the steering system of the vehicle. Power steering systems have been present in motor vehicles for more than a century. They go through continuous metamorphosis and they are getting better and better. Current power steering systems are based on an electric motor and some kind of transmission. Depending on the position of the drive relative to the steering column, different configurations of the transmission are used. This article will cover issues related to tests of power steering gearing using a worm drive. The worm drive is a very specific example of a propulsion system that uses twisted axles. Normally, in this type of transition you can find two gear units with the axis mounted with a 90° angle between. The components of the worm drive are a worm and a worm gear, also called a worm wheel. In terms of the geometrical form, the worm resembles a helical spur gear. The shape of the worm is similar to the shape of a screw with a trapezoidal thread. A correct matching of these two components ensures proper operation of the entire transmission. Incorrect positioning of the components in relation to each other can significantly reduce the lifetime of the drive unit, and also lead to abnormal work, eg by raising the noise level. This article describes a test method of finding the appropriate distance between the axles of both worm drive units by testing the

  2. Natural Frequencies and Vibrating Modes for a Magnetic Planetary Gear Drive

    Directory of Open Access Journals (Sweden)

    Lizhong Xu

    2012-01-01

    Full Text Available In this paper, a dynamic model for a magnetic planetary gear drive is proposed. Based on the model, the dynamic equations for the magnetic planetary gear drive are given. From the magnetic meshing forces and torques between the elements for the drive system, the tangent and radial magnetic meshing stiffness is obtained. Using these equations, the natural frequencies and the modes of the magnetic planetary gear drive are investigated. The sensitivity of the natural frequencies to the system parameters is discussed. Results show that the pole pair number and the air gap have obvious effects on the natural frequencies. For the planetary gear number larger than two, the vibrations of the drive system include the torsion mode of the center elements, the translation mode of the center elements, and the planet modes. For the planetary gear number equal to two, the planet mode does not occur, the crown mode and the sun gear mode occur.

  3. Dynamic Analysis of Helical Planetary Gear Sets under Combined Force and Moment Loading

    Directory of Open Access Journals (Sweden)

    Yanfang Liu

    2017-01-01

    Full Text Available The dynamic behavior of a single-stage planetary gear set with helical gears of multishaft automotive automatic transmissions has been studied, in which one component of the planetary gear set is imposed by additional external vertical and axial loading from countershaft gear pair in addition to the moment. Under these combined loading conditions, the contributions of the deflections of the ring gear and the carrier cannot be neglected. A three-dimensional nonlinear time-variant dynamic model considering not only the transverse, torsional, axial, and rotational motions of the gears but also the elasticity of the mounted shafts has been developed by combining the lumped parameter method with finite element method. The natural modes and the forced vibration responses due to static transmission errors have been obtained. The proposed dynamic model is employed to describe the effects of the combined external loading condition and positioning on the dynamic behavior of a four-planet system.

  4. Analysis of dynamic capacity of low-contact-ratio spur gears using Lundberg-Palmgren theory

    Science.gov (United States)

    Coy, J. J.

    1975-01-01

    A concise mathematical model is developed for surface fatigue life of low-contact-ratio spur gears. The expected fatigue life of the pinion, gear, or gear sets may be calculated from the model. An equation for the dynamic capacity of the gear set was also derived in terms of the transmitted tangential tooth load which will give a 10-percent fatigue life of one million pinion revolutions. The theoretical life was compared with experimental data for a set of VAR AISI 9310 gears operating at a Hertz stress of 1.71X10 to the 9th power newtons per square meter (248,000 psi) and 10 000 revolutions per minute. Good agreement was obtained between the experimental and theoretical surface fatigue life of the gears.

  5. Integrating Condition Indicators and Usage Parameters for Improved Spiral Bevel Gear Health Monitoring

    Science.gov (United States)

    Dempsey, Paula J.; Handschuh, Robert F.; Delgado, Irebert, R.

    2013-01-01

    The objective of this study was to illustrate the importance of combining Health Usage Monitoring Systems (HUMS) data with usage monitoring system data when detecting rotorcraft transmission health. Three gear sets were tested in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Damage was initiated and progressed on the gear and pinion teeth. Damage progression was measured by debris generation and documented with inspection photos at varying torque values. A contact fatigue analysis was applied to the gear design indicating the effect temperature, load and reliability had on gear life. Results of this study illustrated the benefits of combining HUMS data and actual usage data to indicate progression of damage for spiral bevel gears.

  6. Evaluation of a vibration diagnostic system for the detection of spur gear pitting failures

    Science.gov (United States)

    Townsend, Dennis P.; Zakrajsek, James J.

    1993-01-01

    A vibration diagnostic system was used to detect spur gear surface pitting fatigue in a closed-loop spur gear fatigue test rig. The diagnostic system, comprising a personal computer with an analog-to-digital conversion board, a diagnostic system unit, and software, uses time-synchronous averaging of the vibration signal to produce a vibration image of each tooth on any gear in a transmission. Several parameters were analyzed including gear pair stress wave and raw baseband vibration, kurtosis, peak ratios, and others. The system provides limits for the various parameters and gives a warning when the limits are exceeded. Several spur gear tests were conducted with this system and vibration data analyzed at 5-min. intervals. The results presented herein show that the system is fairly effective at detecting spur gear tooth surface fatigue pitting failures.

  7. Rational Design of Spur Gears Directed to Increase Efficiency and Decrease Loss by Friction

    OpenAIRE

    Gonzalo González Rey; Alejandra García Toll; María Eugenia García Domínguez

    2010-01-01

    External parallel-axis cylindrical gears are considered as very efficient means for transmitting mechanical power, but for requirements of maximum efficiency in the current machines and equipments a precision in the procedures of calculation of power losses is necessary. In this sense, the Technical Report ISO / TR 14179-1:2001 offers formulas with empirical and theoretical bases to evaluate the gear efficiency considering gear mesh losses, windage and churning losses, and losses by bearings ...

  8. Design aspects of harmonic drive gear and performance improvement of its by problems identification: A review

    Science.gov (United States)

    Routh, Bikash

    2018-04-01

    The present paper aims at review on different aspects of harmonic drive gear to identify literature gap for future research. The present article is started first making the comparative study of harmonic drive gear over conventional gear, highlighting its historical background, its application, limitation etc. and then describing working principle of each and every components of it with detail dimensioning and modelling. The present article is further extended to study the different design aspects i.e. synthesis of tooth profiles, lubrication, stress, strain, torque, load sharing, kinematics error and vibration in details etc., identifying problems and then suggesting future perspective for the performance improvement of harmonic drive gear.

  9. Analysis and Compensation for Gear Accuracy with Setting Error in Form Grinding

    Directory of Open Access Journals (Sweden)

    Chenggang Fang

    2015-01-01

    Full Text Available In the process of form grinding, gear setting error was the main factor that influenced the form grinding accuracy; we proposed an effective method to improve form grinding accuracy that corrected the error by controlling the machine operations. Based on establishing the geometry model of form grinding and representing the gear setting errors as homogeneous coordinate, tooth mathematic model was obtained and simplified under the gear setting error. Then, according to the gear standard of ISO1328-1: 1997 and the ANSI/AGMA 2015-1-A01: 2002, the relationship was investigated by changing the gear setting errors with respect to tooth profile deviation, helix deviation, and cumulative pitch deviation, respectively, under the condition of gear eccentricity error, gear inclination error, and gear resultant error. An error compensation method was proposed based on solving sensitivity coefficient matrix of setting error in a five-axis CNC form grinding machine; simulation and experimental results demonstrated that the method can effectively correct the gear setting error, as well as further improving the forming grinding accuracy.

  10. Sizing Optimization and Strength Analysis for Spread-type Gear Reducers

    Directory of Open Access Journals (Sweden)

    Wei-Hsuan Hsu

    2014-08-01

    Full Text Available A reducer is now developed towards the trend of customization service and cost-saving. In this study, a sizing program for the reducer has been developed in order to replace the manual sizing process. We aim at the total center distance of the gear reducer for optimization to reduce gear volume and weight. Also, we checked constrains such as, tooth root bending, tooth contact strength, gear shaft endangered cross-section, bearing life, gear shaft deflection, and torsion angle deformation, etc., to obtain reliable drive strength. Comparisons of sizes and weights before and after optimization confirm that the purpose for reducing production cost is achieved.

  11. Fault feature analysis of cracked gear based on LOD and analytical-FE method

    Science.gov (United States)

    Wu, Jiateng; Yang, Yu; Yang, Xingkai; Cheng, Junsheng

    2018-01-01

    At present, there are two main ideas for gear fault diagnosis. One is the model-based gear dynamic analysis; the other is signal-based gear vibration diagnosis. In this paper, a method for fault feature analysis of gear crack is presented, which combines the advantages of dynamic modeling and signal processing. Firstly, a new time-frequency analysis method called local oscillatory-characteristic decomposition (LOD) is proposed, which has the attractive feature of extracting fault characteristic efficiently and accurately. Secondly, an analytical-finite element (analytical-FE) method which is called assist-stress intensity factor (assist-SIF) gear contact model, is put forward to calculate the time-varying mesh stiffness (TVMS) under different crack states. Based on the dynamic model of the gear system with 6 degrees of freedom, the dynamic simulation response was obtained for different tooth crack depths. For the dynamic model, the corresponding relation between the characteristic parameters and the degree of the tooth crack is established under a specific condition. On the basis of the methods mentioned above, a novel gear tooth root crack diagnosis method which combines the LOD with the analytical-FE is proposed. Furthermore, empirical mode decomposition (EMD) and ensemble empirical mode decomposition (EEMD) are contrasted with the LOD by gear crack fault vibration signals. The analysis results indicate that the proposed method performs effectively and feasibility for the tooth crack stiffness calculation and the gear tooth crack fault diagnosis.

  12. Reliability optimization design of the gear modification coefficient based on the meshing stiffness

    Science.gov (United States)

    Wang, Qianqian; Wang, Hui

    2018-04-01

    Since the time varying meshing stiffness of gear system is the key factor affecting gear vibration, it is important to design the meshing stiffness to reduce vibration. Based on the effect of gear modification coefficient on the meshing stiffness, considering the random parameters, reliability optimization design of the gear modification is researched. The dimension reduction and point estimation method is used to estimate the moment of the limit state function, and the reliability is obtained by the forth moment method. The cooperation of the dynamic amplitude results before and after optimization indicates that the research is useful for the reduction of vibration and noise and the improvement of the reliability.

  13. Integrating Oil Debris and Vibration Gear Damage Detection Technologies Using Fuzzy Logic

    Science.gov (United States)

    Dempsey, Paula J.; Afjeh, Abdollah A.

    2002-01-01

    A diagnostic tool for detecting damage to spur gears was developed. Two different measurement technologies, wear debris analysis and vibration, were integrated into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual measurement technologies. This diagnostic tool was developed and evaluated experimentally by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spur Gear Fatigue Test Rig. Experimental data were collected during experiments performed in this test rig with and without pitting. Results show combining the two measurement technologies improves the detection of pitting damage on spur gears.

  14. Performance-based gear metrology kinematic, transmission, error computation and diagnosis

    CERN Document Server

    Mark, William D

    2012-01-01

    A mathematically rigorous explanation of how manufacturing deviations and damage on the working surfaces of gear teeth cause transmission-error contributions to vibration excitations Some gear-tooth working-surface manufacturing deviations of significant amplitude cause negligible vibration excitation and noise, yet others of minuscule amplitude are a source of significant vibration excitation and noise.   Presently available computer-numerically-controlled dedicated gear metrology equipment can measure such error patterns on a gear in a few hours in sufficient detail to enable

  15. Research on cutting vibration characteristics of face-milling involute gear

    Directory of Open Access Journals (Sweden)

    Chengzhe JIN

    2017-10-01

    Full Text Available Traditional machining methods, such as gear hobbing, gear shaping and gear milling, etc, are commonly used for cutting machining of gear tooth profile, which cannot meet huge machining demand of gears to a certain extent. This article proposes to utilize a face-milling machining method in involute gear machining, which can be used to reduce production cost effectively. Cutting vibration generated during cutting machining has a direct effect on the machining accuracy and machined surface quality of workpiece. Therefore, it is desiderated to perform in-depth research regarding this issue. ADAMS software was used to establish a rigid-flexible coupling virtual prototyping model of face-milling gear milling system and a cutting vibration system model. Cutting vibration analysis was performed for face-milling gear by adopting quick sine frequency sweep method, so that the frequency response characteristics of workpiece in three directions X, Y and Z and space were acquired. The research results will provide reference and theoretical foundation for actual application of face-milling gear machining technology.

  16. Performance Investigation of a Full-Scale Hybrid Composite Bull Gear

    Science.gov (United States)

    LaBerge, Kelsen; Handschuh, Robert; Roberts, Gary; Thorp, Scott

    2016-01-01

    Hybrid composite gears have been investigated as a weight saving technology for rotorcraft transmissions. These gears differ from conventional steel gears in that the structural material between the shaft interface and the gear rim is replaced with a lightweight carbon fiber composite. The work discussed here is an extension of previous coupon level hybrid gear tests to a full-scale bull gear. The NASA Glenn Research Center High-Speed Helical Gear Rig was modified for this program allowing several hybrid gear web configurations to be tested while utilizing the same gear rim. Testing was performed on both a baseline (steel) web configuration and a hybrid (steel-composite)configuration. Vibration, orbit and temperature data were recorded and compared between configurations. Vibration levels did not differ greatly between the hybrid and steel configurations, nor did temperature differential between inlet and outlet. While orbit shape displayed differences between the hybrid and baseline configurations, the general overall amplitude was comparable. The hybrid configuration discussed here successfully ran at 3300 hp(2,460 kW), however, progressive growth of the orbit while running at this test condition discontinued the test. Researchers continue to search for the cause of this orbit shift.

  17. Advanced Gear Alloys for Ultra High Strength Applications

    Science.gov (United States)

    Shen, Tony; Krantz, Timothy; Sebastian, Jason

    2011-01-01

    Single tooth bending fatigue (STBF) test data of UHS Ferrium C61 and C64 alloys are presented in comparison with historical test data of conventional gear steels (9310 and Pyrowear 53) with comparable statistical analysis methods. Pitting and scoring tests of C61 and C64 are works in progress. Boeing statistical analysis of STBF test data for the four gear steels (C61, C64, 9310 and Pyrowear 53) indicates that the UHS grades exhibit increases in fatigue strength in the low cycle fatigue (LCF) regime. In the high cycle fatigue (HCF) regime, the UHS steels exhibit better mean fatigue strength endurance limit behavior (particularly as compared to Pyrowear 53). However, due to considerable scatter in the UHS test data, the anticipated overall benefits of the UHS grades in bending fatigue have not been fully demonstrated. Based on all the test data and on Boeing s analysis, C61 has been selected by Boeing as the gear steel for the final ERDS demonstrator test gearboxes. In terms of potential follow-up work, detailed physics-based, micromechanical analysis and modeling of the fatigue data would allow for a better understanding of the causes of the experimental scatter, and of the transition from high-stress LCF (surface-dominated) to low-stress HCF (subsurface-dominated) fatigue failure. Additional STBF test data and failure analysis work, particularly in the HCF regime and around the endurance limit stress, could allow for better statistical confidence and could reduce the observed effects of experimental test scatter. Finally, the need for further optimization of the residual compressive stress profiles of the UHS steels (resulting from carburization and peening) is noted, particularly for the case of the higher hardness C64 material.

  18. Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters

    Directory of Open Access Journals (Sweden)

    Hüseyin Ilgü

    2018-03-01

    Full Text Available The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures (Tms of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg, agmatine, l-arginine methyl ester, and l-arginine amide. The resulting Tms indicated stabilization of AdiC variants upon ligand binding, in which Tms and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5, an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family.

  19. Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters.

    Science.gov (United States)

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Colas, Claire; Ucurum, Zöhre; Schlessinger, Avner; Fotiadis, Dimitrios

    2018-03-20

    The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures ( T m s) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide. The resulting T m s indicated stabilization of AdiC variants upon ligand binding, in which T m s and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5), an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family.

  20. Motor Integrated Permanent Magnet Gear in a Battery Electrical Vehicle

    DEFF Research Database (Denmark)

    Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø

    2015-01-01

    This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV......) and the background for the specifications are elaborated. Simulated as well as measured results of rotational losses of the first and second version are compared. The efficiency of the new design is investigated and compared to three direct drive motors in a few operating points and the MIPMG v.2 seems superior when...

  1. Methodology for Structural Calculation of Gear Teeth with Unconventional Profile

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having made reference to the structural analysis used in the study of gear wheel teeth, we then move on to the state of the art on the topic. We proceed to identify the boundary conditions used in the structural analysis of unconventional teeth with sides having a profile of an involute of a circle but with different pressure angles in each of the two sides. A procedure for the discretization of traditional teeth and of innovative teeth is presented and compared with the discretization obtained using current software.

  2. On Noise Generation and Dynamic Transmission Error of Gears

    OpenAIRE

    Henriksson, Mats

    2009-01-01

    Noise from heavy trucks is an important environmental issue. Several sources contribute to the total noise level of a vehicle, such as the engine, gearbox, tires, etc. The tonal noise from the gearbox can be very disturbing for the driver, even if the noise level from the gearbox is lower than the total noise level. The human ear has a remarkable way of detecting pure tones of which the noise from loaded gears consists of. To be allowed to sell a heavy truck within the European Union, the so ...

  3. Plasmonic rack-and-pinion gear with chiral metasurface

    Science.gov (United States)

    Gorodetski, Yuri; Karabchevsky, Alina

    2016-04-01

    The effect of circularly polarized beaming excited by traveling surface plasmons, via chiral metasurface is experimentally studied. Here we show that the propagation direction of the plasmonic wave, evanescently excited on the thin gold film affects the handedness of the scattered beam polarization. Nanostructured metasurface leads to excitation of localized plasmonic modes whose relative spatial orientation induces overall spin-orbit interaction. This effect is analogical to the rack-and-pinion gear: the rotational motion into the linear motion converter. From the practical point of view, the observed effect can be utilized in integrated optical circuits for communication systems, cyber security and sensing.

  4. Firefighter burn injuries: predictable patterns influenced by turnout gear.

    Science.gov (United States)

    Kahn, Steven A; Patel, Jignesh H; Lentz, Christopher W; Bell, Derek E

    2012-01-01

    Approximately 100 firefighters suffer fatal injuries annually and tens of thousands receive nonfatal injuries. Many of these injuries require medical attention and restricted activity but may be preventable. This study was designed to elucidate etiology, circumstances, and patterns of firefighter burn injury so that further prevention strategies can be designed. In particular, modification of protective equipment, or turnout gear, is one potential strategy to prevent burn injury. An Institutional Review Board-approved retrospective review was conducted with records of firefighters treated for burn injury from 2005 to 2009. Data collected included age, gender, TBSA, burn depth, anatomic location, total hospital days per patient, etiology, and circumstances of injury. Circumstances of injury were stratified into the following categories: removal/dislodging of equipment, failure of equipment to protect, training errors, and when excessive external temperatures caused patient sweat to boil under the gear. Over the 4-year period, 20 firefighters were treated for burn injury. Mean age was 38.9 ± 8.9 years and 19 of 20 patients were male. Mean burn size was 1.1 ± 2.7% TBSA. Eighteen patients suffered second-degree burns, while two patients suffered first-degree burns. Mean length of hospitalization was 2.45 days. Scald burns were responsible for injury to 13 firefighters (65%). Flame burns caused injury to four patients (20%). Only three patients received contact burns (15%). The face was the site most commonly burned, representing 29% of injuries. The hand/wrist and ears were the next largest groups, with 23 and 16% of the injuries, respectively. Other areas burned included the neck (10%), arm (6.5%), leg (6.5%), knees (3%), shoulders (3%), and head (3%). Finally, the circumstance of injury was evaluated for each patient. Misuse and noncontiguous areas of protective equipment accounted for 14 of the 20 injuries (70%). These burns were caused when hot steam

  5. Identification of mine rescue equipment reduction gears technical condition

    Science.gov (United States)

    Gerike, B. L.; Klishin, V. I.; Kuzin, E. G.

    2017-09-01

    The article presents the reasons for adopting intelligent service of mine belt conveyer drives concerning evaluation of their technical condition based on the diagnostic techniques instead of regular preventative maintenance. The article reveals the diagnostic results of belt conveyer drive reduction gears condition taking into account the parameters of lubricating oil, vibration and temperature. Usage of a complex approach to evaluate technical conditions allows reliability of the forecast to be improved, which makes it possible not only to prevent accidental breakdowns and eliminate unscheduled downtime, but also to bring sufficient economic benefits through reduction of the term and scope of work during overhauls.

  6. Influência da adição de taninos elágicos na qualidade de vinhos merlot da região da Campanha

    Directory of Open Access Journals (Sweden)

    Deisi Cerbaro

    2016-10-01

    Full Text Available No âmbito das técnicas de vinificação existem vários recursos disponíveis para potencializar a qualidade de vinhos. Frente às imensas possibilidades de combinações que podem resultar em vinhos de qualidade única este trabalho teve como objetivo avaliar o efeito e os benefícios da aplicação de taninos elágicos em substituição total ou parcial de anidrido sulfuroso nas propriedades químicas de vinhos da variedade Merlot. No experimento foram realizados os seguintes tratamentos: T1 (testemunha, vinificação tradicional com adição de metabissulfito de potássio 20 g.hL-1; T2 (vinificação tradicional sem adição de metabissulfito de potássio e sem adição de tanino; T3 (vinificação tradicional com adição de tanino elágico 30 g.hL-1; T4 (vinificação tradicional com adição de tanino elágico 30 g.hL-1 e metabissulfito de potássio 10 g.hL-1. Os tratamentos foram avaliados após a descuba, após o término da fermentação malolática e após o engarrafamento. Os resultados obtidos através deste trabalho indicam que é tecnicamente possível a produção de vinho tinto Merlot jovem sem a adição de SO2. Porém, mais estudos são necessários para otimização das técnicas de vinificação empregadas e a relação destas com os parâmetros avaliados.

  7. A phase 1/1B trial of ADI-PEG 20 plus nab-paclitaxel and gemcitabine in patients with advanced pancreatic adenocarcinoma.

    Science.gov (United States)

    Lowery, Maeve A; Yu, Kenneth H; Kelsen, David Paul; Harding, James J; Bomalaski, John S; Glassman, Danielle C; Covington, Christina M; Brenner, Robin; Hollywood, Ellen; Barba, Adalberto; Johnston, Amanda; Liu, Kay Chia-Wei; Feng, Xiaoxing; Capanu, Marinela; Abou-Alfa, Ghassan K; O'Reilly, Eileen M

    2017-12-01

    ADI-PEG 20 is a pegylated form of the arginine-depleting enzyme arginine deiminase. Normal cells synthesize arginine with the enzyme argininosuccinate synthetase (ASS1); ADI-PEG 20 selectively targets malignant cells, which lack ASS1. A single-arm, nonrandomized, open-label, phase 1/1B, standard 3 + 3 dose escalation with an expansion cohort of 9 patients at the recommended phase 2 dose (RP2D) was conducted. Patients who had metastatic pancreatic cancer, up to 1 line of prior treatment (the dose-escalation cohort) or no prior treatment (the expansion cohort), and an Eastern Cooperative Oncology Group performance status of 0 to 1 were included. Patients received both gemcitabine (1000 mg/m 2 ) and nab-paclitaxel (125 mg/m 2 ) for 3 of 4 weeks and intramuscular ADI-PEG 20 at 18 mg/m 2 weekly (cohort 1) or at 36 mg/m 2 weekly (cohort 2 and the expansion cohort).The primary endpoint was to determine the maximum tolerated dose and RP2D of ADI-PEG 20 in combination with nab-paclitaxel and gemcitabine. Eighteen patients were enrolled. No dose-limiting toxicities (DLTs) were observed in cohort 1; cohort 2 was expanded to 6 patients because of 1 DLT occurrence (a grade 3 elevation in bilirubin, aspartate aminotransferase, and alanine aminotransferase). The most frequent adverse events (AEs) of any grade were neutropenia, thrombocytopenia, leukopenia, anemia, peripheral neuropathy, and fatigue; all 18 patients experienced grade 3/4 AEs. The most frequent grade 3/4 toxicities, regardless of the relation with any drugs, included neutropenia (12 patients or 67%), leukopenia (10 patients or 56%), anemia (8 patients or 44%), and lymphopenia (6 patients or 33%). The RP2D for ADI-PEG 20 was 36 mg/m 2 weekly in combination with standard-dose gemcitabine and nab-paclitaxel. The overall response rate among patients treated at the RP2D in the first-line setting was 45.5% (5 of 11).The median progression-free survival time for these patients treated at the RP2D was 6.1 months (95

  8. Comparison of First Gear Performance for Manual and Automatic Transmissions

    Directory of Open Access Journals (Sweden)

    Kyle Stottlemyer

    2011-01-01

    Full Text Available The purpose of this project is to compare the first gear performance of an automobile for both its manual and automatic transmission options. Each transmission type has a different gear ratio, which yields a different acceleration curve for each transmission throughout the torque-rpm curve of the engine. The method of integral calculus was used to find an equation which could be used to solve for time at any point in the car's acceleration. The automobile velocity versus time was then graphed to compare each transmissions acceleration trend. This process is similar to that which automotive companies may use when determining what type of transmission to pair with a particular vehicle. By observing the trends in the acceleration graphs, it was determined that there are specific advantages and disadvantages to each type of transmission. Which transmission is the “better” choice is dependent on what application the automobile will be used for (e.g. racing, day-to-day driving, towing/hauling.

  9. Electrohydraulic drive system with planetary superposed PS 16 gears

    Energy Technology Data Exchange (ETDEWEB)

    Graetz, A.; Klimek, K.H.; Welz, H.

    1988-10-20

    During the nine-month period of use of the electrohydraulic drive system with PS 16 superposed planetary gear and hydrostatic support advance of 800 m was achieved on the 250 m long face in the Geitling 2 seam at the Niederberg colliery. No appreciable difficulties occurred in the hydraulic system and with the PS 16 superposed planetary gear in the entire period. Uniform load distribution between the two drives was proved until the end of the working even with a chain elongation difference up to 3% observed during the final phase of operation. In contrast to normal operation thermal disconnections and motor failures no longer occurred. After accurate adjustment of the pressures the system operated successfully. The time utilisation of the equipment was improved by 15% to 65.7%. The quick and reliable response of the hydraulics in the event of overloading ensured that no chain cracks occurred. The four connector fractures were attributable to fatigue failures. The material-protecting method of operation was proved by the quiet running of the chain and substantially longer operating time, e.g. of the chain and sprocket. To prove the efficiency of the new drive system, comprehensive measurements were undertaken. It emerged during these measurements that in contrast to the conventional drives the load equalisation ensures that the total installed power is available if required. However, the freeing capacity of the plough could not be fully utilised because of the missing conveyor cross-section.

  10. Contactless Mechanical Components: Gears, Torque Limiters and Bearings

    Directory of Open Access Journals (Sweden)

    Jose Luis Perez-Diaz

    2014-12-01

    Full Text Available Contactless mechanical components are mechanical sets for conversion of torque/speed, whose gears and moving parts do not touch each other, but rather they provide movement with magnets and magnetic materials that exert force from a certain distance. Magneto-mechanical transmission devices have several advantages over conventional mechanisms: no friction between rotatory elements (no power losses or heat generation by friction so increase of efficiency, no lubrication is needed (oil-free mechanisms and no lubrication auxiliary systems, reduced maintenance (no lubricant so no need of oil replacements, wider operational temperature ranges (no lubricant evaporation or freezing, overload protection (if overload occurs magnet simply slides but no teeth brake, through-wall connection (decoupling of thermal and electrical paths and environmental isolation, larger operative speeds (more efficient operative conditions, ultralow noise and vibrations (no contact no noise generation. All these advantages permit us to foresee in the long term several common industrial applications in which including contactless technology would mean a significant breakthrough for their performance. In this work, we present three configurations of contactless mechanical passive components: magnetic gears, magnetic torque limiters and superconducting magnetic bearings. We summarize the main characteristic and range of applications for each type; we show experimental results of the most recent developments showing their performance.

  11. Radiostethoscopes: an innovative solution for auscultation while wearing protective gear.

    Science.gov (United States)

    Candiotti, Keith A; Rodriguez, Yiliam; Curia, Luciana; Saltzman, Bruce; Shekhter, Ilya; Rosen, Lisa; Birnbach, David J

    2011-01-01

    To demonstrate a radiostethoscope that could be modified and successfully used while wearing protective gear to solve the problem of auscultation in a hazardous material or infectious disease setting. This study was a randomized, prospective, and blinded investigation. The study was conducted at the University of Miami-Jackson Memorial Hospital Center for Patient Safety. Two blinded anesthesiologists using a radiostethoscope performed a total of 100 assessments (50 each) to evaluate endotracheal tube position on a human patient simulator (HPS). Each lung of the HPS was ventilated separately using a double lumen tube. Four ventilation patterns (ie, right lung ventilation only; left lung ventilation only; ventilation of both lungs; and an esophageal intubation or no breath sounds) were simulated. The ventilation pattern was determined randomly and participants were blinded. An Ambu-Bag was used for ventilation. An assistant moved the radiostethoscope to the right and left lung fields and then to the abdomen of the HPS while ventilating. Subjects had to identify the ventilation pattern after listening to all three locations. A third member of the research team collected responses. Each subject, who wore both types of respirator (positive and negative), performed a total of 25 trials. Participants later compared the two types of respirators and their ability to auscultate for breath sounds. Subjects were able to verify the correct ventilation pattern in all attempts (100 percent). Radiostethoscopes appear to provide a viable solution for the problem of patient auscultation while wearing protective gear.

  12. Infant Positioning, Baby Gear Use, and Cranial Asymmetry.

    Science.gov (United States)

    Zachry, Anne H; Nolan, Vikki G; Hand, Sarah B; Klemm, Susan A

    2017-12-01

    Objectives This study aimed to identify predictors of cranial asymmetry. We hypothesize that among infants diagnosed with cranial asymmetry in the sampled region, there is an association between exposure to more time in baby gear and less awake time in prone and side-lying than in infants who do not present with this condition. Methods The study employed a cross sectional survey of caregivers of typically developing infants and infants diagnosed with cranial asymmetry. Results A mutivariable model reveals that caregivers of children who are diagnosed with cranial asymmetry report their children spending significantly less time in prone play than those children without a diagnosis of cranial asymmetry. Side-lying and time spent in baby gear did not attain statistical significance. Conclusions for Practice Occupational therapists, physical therapists, pediatricians, nurses and other health care professionals must provide parents with early education about the importance of varying positions and prone play in infancy and address fears and concerns that may serve as barriers to providing prone playtime.

  13. Journal Bearing Analysis Suite Released for Planetary Gear System Evaluation

    Science.gov (United States)

    Brewe, David E.; Clark, David A.

    2005-01-01

    Planetary gear systems are an efficient means of achieving high reduction ratios with minimum space and weight. They are used in helicopter, aerospace, automobile, and many industrial applications. High-speed planetary gear systems will have significant dynamic loading and high heat generation. Hence, they need jet lubrication and associated cooling systems. For units operating in critical applications that necessitate high reliability and long life, that have very large torque loading, and that have downtime costs that are significantly greater than the initial cost, hydrodynamic journal bearings are a must. Computational and analytical tools are needed for sufficiently accurate modeling to facilitate optimal design of these systems. Sufficient physics is needed in the model to facilitate parametric studies of design conditions that enable optimal designs. The first transient journal bearing code to implement the Jacobsson-Floberg-Olsson boundary conditions, using a mass-conserving algorithm devised by Professor Emeritus Harold Elrod of Columbia University, was written by David E. Brewe of the U.S. Army at the NASA Lewis Research Center1 in 1983. Since then, new features and improved modifications have been built into the code by several contributors supported through Army and NASA funding via cooperative agreements with the University of Toledo (Professor Ted Keith, Jr., and Dr. Desikakary Vijayaraghavan) and National Research Council Programs (Dr. Vijayaraghavan). All this was conducted with the close consultation of Professor Elrod and the project management of David Brewe.

  14. Appraisal of boundary layer trips for landing gear testing

    Science.gov (United States)

    McCarthy, Philip; Feltham, Graham; Ekmekci, Alis

    2013-11-01

    Dynamic similarity during scaled model testing is difficult to maintain. Forced boundary layer transition via a surface protuberance is a common method used to address this issue, however few guidelines exist for the effective tripping of complex geometries, such as aircraft landing gears. To address this shortcoming, preliminary wind tunnel tests were performed at Re = 500,000. Surface transition visualisation and pressure measurements show that zigzag type trips of a given size and location are effective at promoting transition, thus preventing the formation of laminar separation bubbles and increasing the effective Reynolds number from the critical regime to the supercritical regime. Extension of these experiments to include three additional tripping methods (wires, roughness strips, CADCUT dots) in a range of sizes, at Reynolds number of 200,000 and below, have been performed in a recirculating water channel. Analysis of surface pressure measurements and time resolved PIV for each trip device, size and location has established a set of recommendations for successful use of tripping for future, low Reynolds number landing gear testing.

  15. Fiber Optic Strain Sensor for Planetary Gear Diagnostics

    Science.gov (United States)

    Kiddy, Jason S.; Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    This paper presents a new sensing approach for helicopter damage detection in the planetary stage of a helicopter transmission based on a fiber optic strain sensor array. Complete helicopter transmission damage detection has proven itself a difficult task due to the complex geometry of the planetary reduction stage. The crowded and complex nature of the gearbox interior does not allow for attachment of sensors within the rotating frame. Hence, traditional vibration-based diagnostics are instead based on measurements from externally mounted sensors, typically accelerometers, fixed to the gearbox exterior. However, this type of sensor is susceptible to a number of external disturbances that can corrupt the data, leading to false positives or missed detection of potentially catastrophic faults. Fiber optic strain sensors represent an appealing alternative to the accelerometer. Their small size and multiplexibility allows for potentially greater sensing resolution and accuracy, as well as redundancy, when employed as an array of sensors. The work presented in this paper is focused on the detection of gear damage in the planetary stage of a helicopter transmission using a fiber optic strain sensor band. The sensor band includes an array of 13 strain sensors, and is mounted on the ring gear of a Bell Helicopter OH-58C transmission. Data collected from the sensor array is compared to accelerometer data, and the damage detection results are presented

  16. 29 CFR 1919.28 - Unit proof tests-cranes and gear accessory thereto.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Unit proof tests-cranes and gear accessory thereto. 1919.28... Loads; Heat Treatment; Competent Persons § 1919.28 Unit proof tests—cranes and gear accessory thereto. (a) Except as noted in paragraph (e) of this section, cranes and other hoisting machines, together...

  17. Development and validation of a new reference cylindrical gear for pitch measurement

    DEFF Research Database (Denmark)

    Malberg, Maria Pia Sammartini; De Chiffre, Leonardo

    2000-01-01

    A new type of master gear, the Gauge Block Gear (GBG), was developed for the performance verification of coordinate measuring machines (CMMs), for the specific task of pitch and chordal tooth thickness measurement. Its main characteristic is the replacement of the teeth with gauge blocks, in order...

  18. Improvement in surface fatigue life of hardened gears by high-intensity shot peening

    Science.gov (United States)

    Townsend, Dennis P.

    1992-04-01

    Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

  19. ACCURACY RESEARCH OF THE DIAMETRICAL SIZES FORMING AT GEAR SHAPING BY STEPPED CUTTER

    Directory of Open Access Journals (Sweden)

    N. M. Rasulov

    2015-09-01

    Full Text Available The paper presents research results of forming accuracy for diametrical sizes at gear shaping with stepped cutter and the traditional method. Analysis of static technological dimensional pitch size chain of wheels being cut is performed. It was revealed that the most of transmission errors of the wheels, formed by the traditional gear-shaped cutter are caused by manufacturing and installation error of the cutter and result from the formation of each tooth of the wheel with a certain tool. This is not the case with gear shaping by step cutter since at that, the profiles of all gear teeth are formed by means of tooth profile mostly remote from the tool rotation axis. Analysis of occurrence of setting-up errors typical for the above gear shaping methods has been performed. At gear shaping with stepped cutter there are no setting-up error components. It was revealed that this fact causes the absence of errors in the tool position before its each double motion. The accuracy of diametrical sizes increases. Formation mechanism of tool installation errors and workpiece are also given and their analysis is presented. Findings in the field of gear shaping with stepped cutter comply with results of research carried out by the other authors in the field of traditional gear shaping.

  20. Diversity of selective and non-selective fishing gear and their impact ...

    African Journals Online (AJOL)

    This survey was conducted in Al-Kalakla Fishery (KF) and Jabel Awlia Dam Fishery (JADF) in the White Nile River, Khartoum state to identify the selective and non-selective fishing gear. The results showed the selective fishing gear represented by gill-nets and seine nets (beach nets) in both fisheries with clear variation in ...

  1. Effect of gear shift and engine start losses on control strategies for hybrid electric vehicles

    NARCIS (Netherlands)

    Ngo, V.; Hofman, T.; Steinbuch, M.; Serrarens, A.

    2012-01-01

    In this paper, energetic loss models in the events of shifting gear and starting engine in a parallel Hybrid Electric Vehicle equipped with an Automated Manual Transmission (AMT) will be introduced. The optimal control algorithm for the start-stop, power split and gear shift problem based on Dynamic

  2. Exploring the Relationship between Student Involvement in GEAR UP and Academic Achievement

    Science.gov (United States)

    Kennedy, Renea F.

    2016-01-01

    The purpose of this study was to examine the relationship between GEAR UP academic support services and student achievement. GEAR UP is an evidence-based college readiness program. This study focused on a subset of academic support services designed to impact student achievement including: academic mentoring, math tutoring, English tutoring, study…

  3. The Impact of GEAR UP on College Readiness for Students in Low Income Schools

    Science.gov (United States)

    Bausmith, Jennifer Merriman; France, Megan

    2012-01-01

    The purpose of this study was to evaluate the impact of the Gaining Early Awareness and Readiness for Undergraduate Program (GEAR UP) on college readiness outcomes using a quasi-experimental design. GEAR UP is designed to increase the number of low-income students who are prepared to enter and succeed in postsecondary education by providing 6-year…

  4. An Application of Reverse Engineering in Design of the Spur Gear

    Directory of Open Access Journals (Sweden)

    Adem Çiçek

    2010-06-01

    Full Text Available In this study, it is aimed that the gear parameters required the design of a spur gear are obtained by use of reverse engineering techniques. Therefore, point cloud of tooth profile of the manufactured spur gear is extracted by a coordinate measuring machine (CMM. The gear parameters are derived by processing the obtained point cloud. 3D model of the spur gear are modeled through this parameters in a CAD environment. In the system, a hybrid programming approach is used. Generating and processing the point cloud, extraction of the gear parameters are performed by Visual BASIC programming language. 3D modeling in the CAD environment is performed also by AutoLISP programming language due to programming simplicity. These two softwares are provided to be in harmony by integrating them. In the study, SolidworksTM and AutoCADTM are selected as CAD environments. With this study, an alternative approach for the design of the spur gear is presented and modeling of the gears in the CAD environment is carried out using reverse engineering techniques.

  5. Gear technical contributions to an ecosystem approach in the Danish bottom set nets fisheries

    DEFF Research Database (Denmark)

    Savina, Esther

    on passive gears is partly due to historical focus on active gears, but also because data collection and analysis calls for the development of appropriate innovative assessment methodologies to properly assess the new type of information which has to be gathered as part of an Ecosystem Approach to Fisheries...

  6. 46 CFR 122.320 - Steering gear, controls, and communication system tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for a...

  7. Effector trafficking: RXLR-dEER as extra gear for delivery into plant cells

    NARCIS (Netherlands)

    Govers, F.; Bouwmeester, K.

    2008-01-01

    When driving a car with automatic transmission, one hardly notices that extra gears give more power to the car. But in a car with manual transmission, one is constantly aware that even one gear shift helps to reach your goal much more efficiently. For Phytophthora pathogens, a domain characterized

  8. Slip Torque Investigation and Magnetic Redesign of Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Frandsen, Tommy Vestergaard; Rasmussen, Peter Omand

    2015-01-01

    This paper presents an investigation of 20% difference between the measured and calculated slip torque of a Motor Integrated Permanent Magnet Gear (MIPMG) prototype. The High Speed (HS) side of the Magnetic Gear (MG) was fixed by loading the motor when conducting the slip torque measurement. Susp...

  9. 29 CFR Appendix II to Part 1918 - Tables for Selected Miscellaneous Auxiliary Gear (Mandatory)

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Tables for Selected Miscellaneous Auxiliary Gear (Mandatory) II Appendix II to Part 1918 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND.... 1918, App. II Appendix II to Part 1918—Tables for Selected Miscellaneous Auxiliary Gear (Mandatory...

  10. Colorado GEAR UP Program Design and Its Effect on Student Perceptions of Postsecondary Education

    Science.gov (United States)

    Mendelsberg, Scott

    2012-01-01

    Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) is a federal program aimed at equalizing access to higher education for low-income students. GEAR UP, created in 1998, attempts to provide information and support about higher education to students beginning no later than the seventh grade while promoting lasting…

  11. 78 FR 15009 - Extension of Deadline; Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP...

    Science.gov (United States)

    2013-03-08

    ... DEPARTMENT OF EDUCATION Extension of Deadline; Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP)--College Savings Account Research Demonstration Project AGENCY: Office of... published in the Federal Register (78 FR 4838) a notice inviting applications for the GEAR UP College...

  12. Distribution of Microstructure and Vickers Hardness in Spur Bevel Gear Formed by Cold Rotary Forging

    Directory of Open Access Journals (Sweden)

    Wuhao Zhuang

    2014-11-01

    Full Text Available Cold rotary forging is a novel metal forming technology which is widely used to produce the high performance gears. Investigating the microstructure and mechanical property of cold rotary forged gears has a great significance in improving their service performance. In this study, the grain morphology in different regions of the spur bevel gear which is processed by cold rotary forging is presented. And the distribution regulars of the grain deformation and Vickers hardness in the transverse and axial sections of the gear tooth are studied experimentally. A three-dimensional rigid-plastic FE model is developed to simulate the cold rotary forging process of a spur bevel gear under the DEFORM-3D software environment. The variation of effective strain in the spur bevel gear has been investigated so as to explain the distribution regulars of the microstructure and Vickers hardness. The results of this research thoroughly reveal the inhomogeneous deformation mechanisms in cold rotary forging of spur bevel gears and provide valuable guidelines for improving the performance of cold rotary forged spur bevel gears.

  13. 33 CFR 164.76 - Towline and terminal gear for towing alongside and pushing ahead.

    Science.gov (United States)

    2010-07-01

    ... towing alongside and pushing ahead. 164.76 Section 164.76 Navigation and Navigable Waters COAST GUARD... Towline and terminal gear for towing alongside and pushing ahead. The owner, master, or operator of each vessel towing alongside or pushing ahead shall ensure that the face wires, spring lines, and push gear...

  14. 29 CFR Appendix III to Part 1918 - The Mechanics of Conventional Cargo Gear (Non-mandatory)

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false The Mechanics of Conventional Cargo Gear (Non-mandatory.... 1918, App. III Appendix III to Part 1918—The Mechanics of Conventional Cargo Gear (Non-mandatory) Note: This appendix is non-mandatory and provides an explanation of the mechanics in the correct spotting of...

  15. Simulation-based investigation of the paired-gear method in cod-end selectivity studies

    DEFF Research Database (Denmark)

    Herrmann, Bent; Frandsen, Rikke; Holst, René

    2007-01-01

    In this paper, the paired-gear and covered cod-end methods for estimating the selectivity of trawl cod-ends are compared. A modified version of the cod-end selectivity simulator PRESEMO is used to simulate the data that would be collected from a paired-gear experiment where the test cod-end also ...

  16. Research on Gear Shifting Process without Disengaging Clutch for a Parallel Hybrid Electric Vehicle Equipped with AMT

    Directory of Open Access Journals (Sweden)

    Hui-Long Yu

    2014-01-01

    Full Text Available Dynamic models of a single-shaft parallel hybrid electric vehicle (HEV equipped with automated mechanical transmission (AMT were described in different working stages during a gear shifting process without disengaging clutch. Parameters affecting the gear shifting time, components life, and gear shifting jerk in different transient states during a gear shifting process were deeply analyzed. The mathematical models considering the detailed synchronizer working process which can explain the gear shifting failure, long time gear shifting, and frequent synchronizer failure phenomenon in HEV were derived. Dynamic coordinated control strategy of the engine, motor, and actuators in different transient states considering the detailed working stages of synchronizer in a gear shifting process of a HEV is for the first time innovatively proposed according to the state of art references. Bench test and real road test results show that the proposed control strategy can improve the gear shifting quality in all its evaluation indexes significantly.

  17. Life test failure of harmonic gears in a Two-axis Gimbal for the Mars Reconnaissance Orbiter Spacecraft

    Science.gov (United States)

    Johnson, Michael R.; Gehling, Russ; Head, Ray

    2006-01-01

    This paper will present a process for increasing the stiffness of harmonic gear assemblies and recommend a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.

  18. Surface topography of cylindrical gear wheels after smoothing in abrasive mass, honing and shot peening

    International Nuclear Information System (INIS)

    Michalski, J; Pawlus, P; Zelasko, W

    2011-01-01

    The present paper presents the analysis of surface topography of gear teeth as the result of final machining processes. Teeth of multiple cylindrical gears shaped by grinding were smoothed in abrasive mass, honed or shot peened. The measurement of gears were made using coordinate measuring machine and 3D surface topography stylus instrument. The following deviations were studied; pitch deviation, total pitches deviations, variation of teeth thickness and deviation of gear radial run-out. Changes in teeth surface topography during machining process were determined. 3D surface topography parameters, surface directionality as well as areal autocorrelation and power spectral density functions were taken into consideration. As the results of the analysis, the best surface topography with regard to gear operational properties was recommended.

  19. On the automatic generation of FEM models for complex gears - A work-in-progress report

    Science.gov (United States)

    Drago, R. J.

    1982-01-01

    A description is presented of the development and use of a preprocessor to create a NASTRAN finite element model of a complex spur, helical, or spiral bevel gear quickly, inexpensively, and accurately. The preprocessor creates a ready to run NASTRAN input deck including the executive, case control, and bulk data sections. It generates nodes and solid elements to model spur, helical, or spiral bevel gear teeth with integral shafting. Either a complete gear shafting model or a symmetric model is created. The fundamental building block of the gear model is the base layer. The base layer is the mesh configuration of one layer of one tooth segment which is in turn duplicated, translated, and rotated to create the completed model of the gear. Once the base layer is created, the construction of the finite element model is straightforward.

  20. Thermal Behavior of Aerospace Spur Gears in Normal and Loss-of-Lubrication Conditions

    Science.gov (United States)

    Handschuh, Robert F.

    2015-01-01

    Testing of instrumented spur gears operating at aerospace rotorcraft conditions was conducted. The instrumented gears were operated in a normal and in a loss-of-lubrication environment. Thermocouples were utilized to measure the temperature at various locations on the test gears and a test utilized a full-field, high-speed infrared thermal imaging system. Data from thermocouples was recorded during all testing at 1 hertz. One test had the gears shrouded and a second test was run without the shrouds to permit the infrared thermal imaging system to take data during loss-of-lubrication operation. Both tests using instrumented spur gears were run in normal and loss-of-lubrication conditions. Also the result from four other loss-of-lubrication tests will be presented. In these tests two different torque levels were used while operating at the same rotational speed (10000 revolutions per minute).

  1. Near-net shape manufacturing of miniature spur gears by wire spark erosion machining

    CERN Document Server

    Gupta, Kapil

    2016-01-01

    This work describes an experimental investigation with the aim to evaluate and establish wire spark erosion machining (WSEM) as a viable alternative for high quality miniature gear manufacturing. External spur type miniature brass (ASTM 858) gears with 12 teeth, 9.8 mm outside diameter and 5 mm face width were manufactured by WSEM. The research work was accomplished in four distinct experimental stages viz., preliminary, pilot, main and confirmation. The aim, scope and findings of each stage are progressively presented and discussed. In essence, the investigation found that it was possible to manufacture miniature gears to high quality by using WSEM. Gears up to DIN 5 quality with a good surface finish (1.2 µm average roughness) and satisfactory surface integrity were achieved. The results suggest that WSEM should be considered a viable alternative to conventional miniature gear manufacturing techniques and that in some instances it may even be superior. This work will prove useful to researchers and profess...

  2. A Procedure for 3-D Contact Stress Analysis of Spiral Bevel Gears

    Science.gov (United States)

    Kumar, A.; Bibel, G.

    1994-01-01

    Contact stress distribution of spiral bevel gears using nonlinear finite element static analysis is presented. Procedures have been developed to solve the nonlinear equations that identify the gear and pinion surface coordinates based on the kinematics of the cutting process and orientate the pinion and the gear in space to mesh with each other. Contact is simulated by connecting GAP elements along the intersection of a line from each pinion point (parallel to the normal at the contact point) with the gear surface. A three dimensional model with four gear teeth and three pinion teeth is used to determine the contact stresses at two different contact positions in a spiral bevel gearset. A summary of the elliptical contact stress distribution is given. This information will be helpful to helicopter and aircraft transmission designers who need to minimize weight of the transmission and maximize reliability.

  3. Finishing aeronautical planetary herringbone gear wheels in container vibrating smoothing machine

    Directory of Open Access Journals (Sweden)

    Jacek MICHALSKI

    2015-12-01

    Full Text Available The paper presents the technological process of abrasive-chemical machining wheel bearing surface of the cylindrical herringbone gears planetary gear in vibrating container smoothing machine according to Isotropic Finishing ISF® technology of the REM Chemicals Inc. company. Gear wheels are made of stainless Pyrowear 53 and subjected to carburizing, hardening, cold working and low tempering. The change in value of deviation indicators for the kinematic accuracy, smoothness and geometric structure of the machined surfaces of the gear teeth after smoothing compared with the contoured grinding were analyzed. The findings are different a characteristic performance on the surface of the tooth side along the outline, especially with a higher value at the head of the tooths. This creates a need for appropriate modification of the lateral surface of the teeth in the process of contoured grinding. The results of the mechanical strength of the samples gear wheel after the smoothing process and evaluating the hydrogen embrittlement are presented.

  4. Evaluation of Bending Strength of Carburized Gears Based on Inferential Identification of Principal Surface Layer Defects

    Science.gov (United States)

    Masuyama, Tomoya; Inoue, Katsumi; Yamanaka, Masashi; Kitamura, Kenichi; Saito, Tomoyuki

    High load capacity of carburized gears originates mainly from the hardened layer and induced residual stress. On the other hand, surface decarburization, which causes a nonmartensitic layer, and inclusions such as oxides and segregation act as latent defects which considerably reduce fatigue strength. In this connection, the authors have proposed a formula of strength evaluation by separately quantifying defect influence. However, the principal defect which limits strength of gears with several different defects remains unclarified. This study presents a method of inferential identification of principal defects based on test results of carburized gears made of SCM420 clean steel, gears with both an artificial notch and nonmartensitic layer at the tooth fillet, and so forth. It clarifies practical uses of presented methods, and strength of carburized gears can be evaluated by focusing on principal defect size.

  5. The Optimal Design Method and Standardized Mathematical Model of Tooth Profile Modification of Spur Gear

    Directory of Open Access Journals (Sweden)

    Wenjie Mei

    2016-01-01

    Full Text Available The paper reports a tooth profile modification method of spur gear. After establishing a standardized mathematical model for optimized tooth profile and simulating meshing process with ANSYS finite element analysis, we obtained 625 groups of gear models with different modification parameters. The group with minimum transmission errors owns the optimal parameters. Genetic algorithm was adopted in the entire process for the purpose of reducing the variation of transmission errors in meshing process. The arc and parabolic modification were doing the same processing. After comparing the transmission errors fluctuation produced by the meshing process of gear of nonmodification with arc modification and parabolic modification, we found that the best modification effects of arc modification and parabolic modification were both reduced by 90%. The modification method makes the gear drive process more stable and efficient, and it is also promising in general application for gear drive.

  6. Review on common calibration and measurement practises for measuring gears on CMMs

    DEFF Research Database (Denmark)

    Sammatini-Malberg, Maria-Pia; De Chiffre, Leonardo

    , in order to give an overview of the improvements achieved in the last 25 years. Special attention is paid to gear metrology on coordinate measuring machines (CMMs). Calibration chains for the major gear geometrical quantities developed by Physikalisch-Technische Bundesanstalt (PTB) as well as their recent...... results obtained in gear standards measurement uncertainties are presented. This review also describes the design and development of a new type of master gear: the Gauge Block Gear (GBG).The GBG was developed for the performance verification of CMMs, for the specific task of pitch and chordal tooth...... thickness measurement. Its main characteristic is the replacement of the teeth with gauge blocks, in order to achieve direct traceability of the chordal tooth thickness...

  7. Gear noise, vibration, and diagnostic studies at NASA Lewis Research Center

    Science.gov (United States)

    Zakrajsek, J. J.; Oswald, F. B.; Townsend, D. P.; Coy, J. J.

    1990-01-01

    The NASA Lewis Research Center and the U.S. Army Aviation Systems Command are involved in a joint research program to advance the technology of rotorcraft transmissions. This program consists of analytical as well as experimental efforts to achieve the overall goals of reducing weight, noise, and vibration, while increasing life and reliability. Recent analytical activities are highlighted in the areas of gear noise, vibration, and diagnostics performed in-house and through NASA and U.S. Army sponsored grants and contracts. These activities include studies of gear tooth profiles to reduce transmission error and vibration as well as gear housing and rotordynamic modeling to reduce structural vibration and transmission and noise radiation, and basic research into current gear failure diagnostic methodologies. Results of these activities are presented along with an overview of near-term research plans in the gear noise, vibration, and diagnostics area.

  8. Influence of the shot-peening treatment on the CRF gearing behaviour

    International Nuclear Information System (INIS)

    Molinie, D.; Lemaire, E.; Randrianarivo, L.; Dorier, C.

    1998-01-01

    Surface damage are observed in service on CRF case-hardened cases. Such damage is like surface fatigue which appears in the form of frosting and can come to a micro-spalling or even a spalling damage. Survey and studies realised on gears affected by such damage, led EDF and the manufacturer to search for appropriated solutions since 1985 (optimisation of the gear bottom profile, care of the grinding and the thermochemical processing, use of oils with higher viscosity). Simulations on a running wheel device can reproduce the meshing conditions on simplified specimen. The aim is to study the influence of residual stresses following a severe grinding and shot peening treatments. An empiric selection was realised among different shot peening treatments. Endurance tests are realised on case-hardened gears with or without shot-peening treatments. Compared with standard grinded gears, it appears that the shot-peening selected increases up to 40% the gear lifetime till extended spalling. (authors)

  9. The influence of demersal trawl fishing gears on the resuspension of dinoflagellate cysts.

    Science.gov (United States)

    Brown, Lyndsay; Bresnan, Eileen; Summerbell, Keith; O'Neill, Finbarr Gerard

    2013-01-15

    To investigate the influence of towed demersal fishing gears on dinoflagellate cyst resuspension, towing trials with four gear components were carried out at three sites of differing sediment type in the Moray Firth, Scotland. Samples of sediment plumes were collected using plankton nets mounted on a towed sledge. Diversity of resuspended dinoflagellate cysts was similar at all sites and included Protoperidinium and Gonyaulax spp., Proroceratium reticulatum and unidentified 'round brown' cysts. Cyst concentrations per gram of resuspended sediment varied by gear component and sediment particle size distribution. Gear components with lower hydrodynamic drag generated wakes with smaller shear stresses, mobilising fewer larger sand particles, giving larger concentrations of cysts. Muddy sediments contained higher cyst concentrations which declined with increasing grain size. This study has shown that fishing gear and sediment type can influence the redistribution of dinoflagellate cysts and highlights the importance this may have in relation to dinoflagellate blooms. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  10. Resistência à compressão de argamassas em função da adição de fibra de coco

    OpenAIRE

    Silva,Everton J. da; Silva,Paola D. da; Marques,Maria L.; Fornari Junior,Celso C. M.; Garcia,Fermin C.; Luzardo,Francisco H. M.

    2014-01-01

    Neste trabalho se propôs analisar a influência que a variação do comprimento da fibra de coco exerce na resistência à compressão da argamassa, em busca de se determinar, experimentalmente, o comprimento mais próximo ao tamanho crítico. Foram confeccionadas argamassas com adição (0,3% em relação ao volume total da mistura) de 6 comprimentos diferentes de fibras de coco: 12,5; 25,0; 37,5; 50,0; 62,5 e 75,0 mm, além de uma argamassa de referência sem adição de fibra de coco. Para a avaliação do ...

  11. Estudo da influência da adição de cinzas de carvão mineral nas propriedades da cerâmica vermelha

    OpenAIRE

    Zanin,T. L.; Klitzke,W.; Luz Jr.,L. F. L.

    2013-01-01

    A adição de resíduos industriais em cerâmicas vermelhas tem sido o alvo de diversos estudos, onde se busca uma destinação final adequada ao resíduo e melhoria das características da cerâmica. Neste trabalho, avaliou-se a adição de cinzas leves de carvão mineral oriundas de uma usina termelétrica existente em Figueira, PR. Foram preparadas misturas de 0, 10, 20, 30, 40 e 50% de cinzas em argila e produzidos corpos de prova de 6 cm x 2 cm x 0,5 cm por calcinação a 950 ºC. Avaliou-se os parâmetr...

  12. The ArcD1 and ArcD2 arginine/ornithine exchangers encoded in the arginine deiminase (ADI) pathway gene cluster of Lactococcus lactis

    NARCIS (Netherlands)

    Noens, Elke E E; Kaczmarek, Michał B; Żygo, Monika; Lolkema, Juke S

    2015-01-01

    The arginine deiminase pathway (ADI) gene cluster in Lactococcus lactis contains two copies of a gene encoding an L-arginine/L-ornithine exchanger, the arcD1 and arcD2 genes. The physiological function of ArcD1 and ArcD2 was studied by deleting the two genes. Deletion of arcD1 resulted in loss of

  13. Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers: Application in a Non-US Sample of 1,104 Children

    Science.gov (United States)

    de Bildt, Annelies; Sytema, Sjoerd; Zander, Eric; Bölte, Sven; Sturm, Harald; Yirmiya, Nurit; Yaari, Maya; Charman, Tony; Salomone, Erica; LeCouteur, Ann; Green, Jonathan; Bedia, Ricardo Canal; Primo, Patricia García; van Daalen, Emma; de Jonge, Maretha V.; Guðmundsdóttir, Emilía; Jóhannsdóttir, Sigurrós; Raleva, Marija; Boskovska, Meri; Rogé, Bernadette; Baduel, Sophie; Moilanen, Irma; Yliherva, Anneli; Buitelaar, Jan; Oosterling, Iris J.

    2015-01-01

    The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, "J Autism Dev Disord" 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of the algorithms. The diagnostic…

  14. Optimization of the buffer layer of a side polished fiber slab coupler based on 3 D ADI beam propagation method

    International Nuclear Information System (INIS)

    Lee, Cherl Hee; Kim, Cheol; Park, Jae Hee

    2008-01-01

    A side polished fiber slab coupler has been widely applied to a sensor, which has the advantages of short response time, simple manufacturing process, and reusability as well as in line fiber component. A new type of a side polished fiber sensor providing remote sensing with an improved performance was also recently developed. The side polished fiber slab coupler is modeled as a fiber to planar waveguide coupler with four layers, including the fiber cladding, a buffer layer, planar waveguide and overlay material. The coupling effects by the buffer layer of a side polished fiber slab coupler are analyzed by using 3 dimensional alternating direction implicit (ADI)beam propagation method, where the refractive index and thickness of the buffer layer were tuned for efficient light coupling. The coupling is easily tuned and more occurred by the refractive index and thickness of the buffer layer for efficient coupling. This study tried to optimize the buffer layer parameters for achieving the desired light coupling and power transfer performance

  15. Adição de frações por estimativa a partir do referencial de metade e de inteiro

    Directory of Open Access Journals (Sweden)

    Maria Soraia Silva Cruz

    2014-12-01

    Full Text Available O presente estudo investigou o papel desempenhado pelos referenciais de inteiro e de metade na resolução de adição de frações por estimativa. Crianças (8-9 anos de classe média alunas do ensino fundamental resolveram as mesmas adições de frações em diferentes situações: por estimativa, usando o referencial de metade (Tarefa 1, por estimativa, usando o referencial de inteiro (Tarefa 2 e utilizando o simbolismo matemático apenas (Tarefa 3. Observou-se que embora não resolvessem as adições por meio do simbolismo matemático, as crianças faziam estimativas apropriadas com base no referencial de inteiro e de metade, tendo o mesmo bom desempenho com ambos os referenciais. Concluiu-se que pontos de referência desempenham papel importante no raciocínio lógico-matemático.

  16. 77 FR 67580 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Jig Gear in the...

    Science.gov (United States)

    2012-11-13

    ... Vessels Using Jig Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... vessels using jig gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t...

  17. 75 FR 68381 - Gear Certification Standard; Extension of the Office of Management and Budget's (OMB) Approval of...

    Science.gov (United States)

    2010-11-05

    ... DEPARTMENT OF LABOR Occupational Safety and Health Administration [Docket No. OSHA-2010-0042] Gear... extend OMB approval of the information collection requirements specified in the Gear Certification... effective and efficient means of enabling employers and workers to determine if cargo gear, equipment and/or...

  18. 77 FR 65640 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2012-10-30

    ... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... vessels using pot gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is... gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t...

  19. 78 FR 7280 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2013-02-01

    ... Vessels Using Pot Gear in the Western Regulatory Area of the Gulf of Alaska AGENCY: National Marine... using pot gear in the Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to... vessels using pot gear in the Western Regulatory Area of the GOA. DATES: Effective 1200 hrs, Alaska local...

  20. 77 FR 62464 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2012-10-15

    ... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2012 Pacific cod total allowable catch apportioned to vessels using pot gear in the Central...

  1. 77 FR 8177 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2012-02-14

    ... Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine Fisheries...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific cod by vessels using pot gear in the... season allowance of the 2012 Pacific cod total allowable catch apportioned to vessels using pot gear in...

  2. 77 FR 14305 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Jig Gear in the...

    Science.gov (United States)

    2012-03-09

    ... Using Jig Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine Fisheries...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific cod by vessels using jig gear in the... season allowance of the 2012 Pacific cod total allowable catch apportioned to vessels using jig gear in...

  3. 77 FR 6683 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2012-02-09

    ... Using Pot Gear in the Western Regulatory Area of the Gulf of Alaska AGENCY: National Marine Fisheries...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific cod by vessels using pot gear in the... season allowance of the 2012 Pacific cod total allowable catch apportioned to vessels using pot gear in...

  4. 78 FR 10102 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Vessels Using Pot Gear in the...

    Science.gov (United States)

    2013-02-13

    ... Vessels Using Pot Gear in the Central Regulatory Area of the Gulf of Alaska AGENCY: National Marine... gear in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent... pot gear in the Central Regulatory Area of the GOA. DATES: Effective 1200 hours, Alaska local time (A...

  5. Compressibilities and viscosities of reference, vegetable, and synthetic gear lubricants

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Lugo, Luis; Fernández, Josefa

    2014-01-01

    Nowadays, one of the primary choices of base oils for environmentally aware lubricants is vegetable oils. This is due to their good natural biodegradability and very low toxicity in combination with very good lubricity characteristics. The development of new vegetable-based lubricants requires...... values of six gear lubricants, two of them reference mineral oils and the other four developed biodegradable oils based in high oleic sunflower oil or in synthetic esters. It was found that all of the lubricants have both similar compressibilities and similar expansivities. Dowson and Higginson, Zhu.......06%. Dowson and Higginson and Zhu and Wen equations of state do not predict well the isothermal compressibilities, with AAD % being around 45% for both equations. Moreover, the viscosities were measured in the temperature range from 278.15 to 373.15 K at atmospheric pressure for these oils, and the viscosity...

  6. Innovative Design of Cam-Controlled Planetary Gear Trains

    Directory of Open Access Journals (Sweden)

    Wen-Hsiang Hsieh

    2011-10-01

    Full Text Available The objective of this paper is to perform the innovation design for the new structures of cam-controlled planetary gear trains (CCPGTs, based on the creative mechanism design methodology. Firstly, the design requirements and design constraints are summarized according to the kinematics characteristics of existing CCPGTs. Then, the (4, 5 and (5, 7 graphs are generated by the theory of number synthesis. After that, the atlas of feasible specialized graphs is obtained. Finally, the atlas of new designs is obtained through the particularization process. In addition, an illustrated example is given, and the feasibility of the design is verified by computer simulation using ADAMS software. The result indicates that new design can produce a more wide range of non-uniform motion than the existing design. Therefore, they are better alternatives for driving a variable speed input mechanism.

  7. Experimental Evaluation of a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter

    2011-01-01

    This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...... and inductances are all in line with finite element calculations. However very high rotational losses are present in the prototype and these losses are higher than the calculations. Some of the losses are present due to poor aspects in the fabrication of the prototype, while others are identified to be caused...... by a non optimal diameter/length aspect ratio. The torque density is superior, the copper losses is only a fraction of the copper losses in other traction motors. With the proposed aspects to reduce the rotational losses is it believed that the unit has a great potential....

  8. Surface micromachined counter-meshing gears discrimination device

    International Nuclear Information System (INIS)

    Polosky, M.A.; Garcia, E.J.; Allen, J.J.

    1998-01-01

    This paper discusses the design, fabrication and testing of a surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock, A 24 bit code is input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect. The motivation for the development of this device is based on occurrences referred to as High Consequence Events, A High Consequence Event is an event where an inadvertent operation of a system could result in the catastrophic loss of life, property, or damage to the environment

  9. Control Design for an Advanced Geared Turbofan Engine

    Science.gov (United States)

    Chapman, Jeffryes W.; Litt, Jonathan S.

    2017-01-01

    This paper describes the design process for the control system of an advanced geared turbofan engine. This process is applied to a simulation that is representative of a 30,000 lbf thrust class concept engine with two main spools, ultra-high bypass ratio, and a variable area fan nozzle. Control system requirements constrain the non-linear engine model as it operates throughout its flight envelope of sea level to 40,000 ft and from 0 to 0.8 Mach. The control architecture selected for this project was developed from literature and reflects a configuration that utilizes a proportional integral controller integrated with sets of limiters that enable the engine to operate safely throughout its flight envelope. Simulation results show the overall system meets performance requirements without exceeding system operational limits.

  10. GEARS: An Enterprise Architecture Based On Common Ground Services

    Science.gov (United States)

    Petersen, S.

    2014-12-01

    Earth observation satellites collect a broad variety of data used in applications that range from weather forecasting to climate monitoring. Within NOAA the National Environmental Satellite Data and Information Service (NESDIS) supports these applications by operating satellites in both geosynchronous and polar orbits. Traditionally NESDIS has acquired and operated its satellites as stand-alone systems with their own command and control, mission management, processing, and distribution systems. As the volume, velocity, veracity, and variety of sensor data and products produced by these systems continues to increase, NESDIS is migrating to a new concept of operation in which it will operate and sustain the ground infrastructure as an integrated Enterprise. Based on a series of common ground services, the Ground Enterprise Architecture System (GEARS) approach promises greater agility, flexibility, and efficiency at reduced cost. This talk describes the new architecture and associated development activities, and presents the results of initial efforts to improve product processing and distribution.

  11. Firefighter Down! How to Rapidly Remove Turnout Gear.

    Science.gov (United States)

    ALexander, John G

    2016-04-01

    The rescue of an injured colleague--and probably a good friend--is an emotionally charged event. A common initial response could be to remove everything as quickly as possible. Keep in mind that we have accepted practices for the removal of motorcycle equipment and football gear. There are also procedures for removing a patient from a vehicle or swimming pool. These all exist to protect a patient from further injury. We now have established practices for removing a firefighter from a window, or down a ladder. Why then do the procedures stop? Once a firefighter is rescued from a hot zone, he deserves the same level of consideration a football player, motorcycle rider or any other patient receives. We should not be in such a hurry that we don't care how we remove a protective ensemble. The injured firefighter deserves a system, or a procedure, that may be practiced by others and reduce the chance of further injury during

  12. Demonstrations of bio-inspired perching landing gear for UAVs

    Science.gov (United States)

    Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

    2016-04-01

    Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

  13. A Control Strategy for Mode Transition with Gear Shifting in a Plug-In Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Kyuhyun Sim

    2017-07-01

    Full Text Available The mode transition from electric propulsion mode to hybrid propulsion mode is important with regard to the power management strategy of plug-in hybrid electric vehicles (PHEVs. This is because mode transitions can occur frequently depending on the power management strategies and driving cycles, and because inadequate mode transitions worsen the fuel efficiency and drivability. A pre-transmission parallel PHEV uses a clutch between the internal combustion engine (ICE and the electric motor (EM to connect or disconnect the power source of the ICE for a mode transition. The mode transition requires additional energy consumption for clutch speed synchronization, and is accompanied by a drivetrain shock due to clutch engagement. This paper proposes a control strategy for the mode transition with gear-shifting to resolve the problems of energy consumption and drivetrain shock. Through the development of a PHEV performance simulator, we analyze the mode transition characteristics and propose a control strategy considering the vehicle acceleration and gear state. The control strategy reduces the duration required for the mode transition by moving the start time of the mode transition. This helps to improve energy efficiency while maintaining adequate drivability.

  14. Evaluation of Spur Gear Pair on Tooth Root Bending Stress in Radial Misalignment Contact Condition

    Directory of Open Access Journals (Sweden)

    Lias M.R.

    2014-07-01

    Full Text Available This paper evaluates the effects of radial misalignment contact on the tooth root bending stress values of spur gear pair during the gear meshing cycle. Radial misalignment (H is denoted as the deviation of the pinion nominal position with respect to the gear tooth along the pinion axis to the gear which happened from manufacturing assembly errors (AE. A model based on involute 3D parametric CAD geometry, of spur gear design ISO 6336:2006 is analysed with allowable AE values from minimum 10μm to maximum 40μm with Finite-Element Method (FEM model based methodology using a dynamics module from ANSYS. Main parameters of interest are the Tooth root bending stress (TRBS in H condition with AE along the critical region with respect to face width of pinion-gear section. A comparison between standard High point single tooth contact models (HPSTC to this model showed a good agreement that H with AE had great influence on TRBS as the values’ increase. Radial misalignment influence factor (RMIF was introduced as indication of TRBS values in consideration of H due to AE shows and inverted patterns higher for pinion, give a good justification that the pinion is weaker compared to the gear.

  15. Dynamic analysis of spiral bevel and hypoid gears with high-order transmission errors

    Science.gov (United States)

    Yang, J. J.; Shi, Z. H.; Zhang, H.; Li, T. X.; Nie, S. W.; Wei, B. Y.

    2018-03-01

    A new gear surface modification methodology based on curvature synthesis is proposed in this study to improve the transmission performance. The generated high-order transmission error (TE) for spiral bevel and hypoid gears is proved to reduce the vibration of geared-rotor system. The method is comprised of the following steps: Firstly, the fully conjugate gear surfaces with pinion flank modified according to the predesigned relative transmission movement are established based on curvature correction. Secondly, a 14-DOF geared-rotor system model considering backlash nonlinearity is used to evaluate the effect of different orders of TE on the dynamic performance a hypoid gear transmission system. For case study, numerical simulation is performed to illustrate the dynamic response of hypoid gear pair with parabolic, fourth-order and sixth-order transmission error derived. The results show that the parabolic TE curve has higher peak to peak amplitude compared to the other two types of TE. Thus, the excited dynamic response also shows larger amplitude at response peaks. Dynamic responses excited by fourth and sixth order TE also demonstrate distinct response components due to their different TE period which is expected to generate different sound quality or other acoustic characteristics.

  16. Fault Diagnosis for a Multistage Planetary Gear Set Using Model-Based Simulation and Experimental Investigation

    Directory of Open Access Journals (Sweden)

    Guoyan Li

    2016-01-01

    Full Text Available The gear damage will induce modulation effects in vibration signals. A thorough analysis of modulation sidebands spectral structure is necessary for fault diagnosis of planetary gear set. However, the spectral characteristics are complicated in practice, especially for a multistage planetary gear set which contains close frequency components. In this study, a coupled lateral and torsional dynamic model is established to predict the modulation sidebands of a two-stage compound planetary gear set. An improved potential energy method is used to calculate the time-varying mesh stiffness of each gear pair, and the influence of crack propagation on the mesh stiffness is analyzed. The simulated signals of the gear set are obtained by using Runge-Kutta numerical analysis method. Meanwhile, the sidebands characteristics are summarized to exhibit the modulation effects caused by sun gear damage. At the end, the experimental signals collected from an industrial SD16 planetary gearbox are analyzed to verify the theoretical derivations. The results of experiment agree well with the simulated analysis.

  17. Research of Planetary Gear Fault Diagnosis Based on Permutation Entropy of CEEMDAN and ANFIS

    Directory of Open Access Journals (Sweden)

    Moshen Kuai

    2018-03-01

    Full Text Available For planetary gear has the characteristics of small volume, light weight and large transmission ratio, it is widely used in high speed and high power mechanical system. Poor working conditions result in frequent failures of planetary gear. A method is proposed for diagnosing faults in planetary gear based on permutation entropy of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN Adaptive Neuro-fuzzy Inference System (ANFIS in this paper. The original signal is decomposed into 6 intrinsic mode functions (IMF and residual components by CEEMDAN. Since the IMF contains the main characteristic information of planetary gear faults, time complexity of IMFs are reflected by permutation entropies to quantify the fault features. The permutation entropies of each IMF component are defined as the input of ANFIS, and its parameters and membership functions are adaptively adjusted according to training samples. Finally, the fuzzy inference rules are determined, and the optimal ANFIS is obtained. The overall recognition rate of the test sample used for ANFIS is 90%, and the recognition rate of gear with one missing tooth is relatively high. The recognition rates of different fault gears based on the method can also achieve better results. Therefore, the proposed method can be applied to planetary gear fault diagnosis effectively.

  18. Dynamic investigation of a locomotive with effect of gear transmissions under tractive conditions

    Science.gov (United States)

    Chen, Zaigang; Zhai, Wanming; Wang, Kaiyun

    2017-11-01

    Locomotive is used to drag trailers to move or supply the braking forces to slow the running speed of a train. The electromagnetic torque of the motor is always transmitted by the gear transmission system to the wheelset for generation of the tractive or braking forces at the wheel-rail contact interface. Consequently, gear transmission system is significant for power delivery of a locomotive. This paper develops a comprehensive locomotive-track vertical-longitudinal coupled dynamics model with dynamic effect of gear transmissions. This dynamics model enables considering the coupling interactions between the gear transmission motion, the vertical and the longitudinal motions of the vehicle, and the vertical vibration of the track structure. In this study, some complicated dynamic excitations, such as the gear time-varying mesh stiffness, nonlinear gear tooth backlash, the nonlinear wheel-rail normal contact force and creep force, and the rail vertical geometrical irregularity, are considered. Then, the dynamic responses of the locomotive under the tractive conditions are demonstrated by numerical simulations based on the established dynamics model and by experimental test. The developed dynamics model is validated by the good agreement between the experimental and the theoretical results. The calculated results reveal that the gear transmission system has strong dynamic interactions with the wheel-rail contact interface including both the vertical and the longitudinal motions, and it has negligible effect on the vibrations of the bogie frame and carbody.

  19. A Comparative Study of Simulated and Measured Gear-Flap Flow Interaction

    Science.gov (United States)

    Khorrami, Mehdi R.; Mineck, Raymond E.; Yao, Chungsheng; Jenkins, Luther N.; Fares, Ehab

    2015-01-01

    The ability of two CFD solvers to accurately characterize the transient, complex, interacting flowfield asso-ciated with a realistic gear-flap configuration is assessed via comparison of simulated flow with experimental measurements. The simulated results, obtained with NASA's FUN3D and Exa's PowerFLOW® for a high-fidelity, 18% scale semi-span model of a Gulfstream aircraft in landing configuration (39 deg flap deflection, main landing gear on and off) are compared to two-dimensional and stereo particle image velocimetry measurements taken within the gear-flap flow interaction region during wind tunnel tests of the model. As part of the bench-marking process, direct comparisons of the mean and fluctuating velocity fields are presented in the form of planar contour plots and extracted line profiles at measurement planes in various orientations stationed in the main gear wake. The measurement planes in the vicinity of the flap side edge and downstream of the flap trailing edge are used to highlight the effects of gear presence on tip vortex development and the ability of the computational tools to accurately capture such effects. The present study indicates that both computed datasets contain enough detail to construct a relatively accurate depiction of gear-flap flow interaction. Such a finding increases confidence in using the simulated volumetric flow solutions to examine the behavior of pertinent aer-odynamic mechanisms within the gear-flap interaction zone.

  20. Topology of modified helical gears and Tooth Contact Analysis (TCA) program

    Science.gov (United States)

    Litvin, Faydor L.; Zhang, Jiao

    1989-01-01

    The contents of this report covers: (1) development of optimal geometries for crowned helical gears; (2) a method for their generation; (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact of the crowned helical gears; and (4) modelling and simulation of gear shaft deflection. The developed method for synthesis was used to determine the optimal geometry for a crowned helical pinion surface and was directed to localize the bearing contact and guarantee favorable shape and a low level of transmission errors. Two new methods for generation of the crowned helical pinion surface are proposed. One is based on the application of a tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The other is based on a crowning pinion tooth surface with predesigned transmission errors. The pinion tooth surface can be generated by a computer-controlled automatic grinding machine. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined. The gear shaft deformation was modelled and investigated. It was found that the deflection of gear shafts has the same effect as gear misalignment.