• Title/Summary/Keyword: Tooth Profile Modification

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The Study for Estimation of the Surface Temperature Rise in Spur Gear Tooth (Spur Gear 치면의 표면상승온도 예측에 관한 연구)

  • 김희진;구영필;조용주
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.2
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    • pp.331-337
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    • 2001
  • A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaegers formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along ling of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.

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A Study on the Surface Temperature Rise in Spur Gear Part I - Flash Temperature (Spur Gear의 표면온도상승에 관한 연구 Part I - Flash Temperature)

  • 김희진;문석만;김태완;구영필;조용주
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.251-257
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    • 2000
  • A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaeger's formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along line of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.

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Simulation of Meshing for the Spur Gear Drive with Modified Tooth Surfaces

  • Seol, In-Hwan;Chung, Soon-Bae
    • Journal of Mechanical Science and Technology
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    • v.14 no.5
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    • pp.490-498
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    • 2000
  • The authors have proposed methods (lead crowning and profile modification) for modifying the geometry of spur gears and investigated the contact pattern as well as the transmission errors to recommend the appropriate amount of modification. Based on the investigation, dynamic load of the modified spur gear drive has been calculated, which is helpful to predict the life of the designed gear drive. Computer programs for simulation of meshing, contact and dynamics of the modified spur gears have been developed. The developed theory is illustrated with numerical examples.

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Optimization of the Gear Tooth Crowning Amount Considering Contact Subsurface Stress (표면아래응력을 고려한 기어이의 크라우닝 최적화에 관한 연구)

  • Lee, Sang-Don;Kim, Jong-Sung;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.25 no.1
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    • pp.38-42
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    • 2009
  • Gear is an essential component of an automotive. Crowning is used for tooth modification of a gear. The basic concept of gear tooth crowning is to reduce the stress concentration in edge of contact area and appropriate profile modifications can help gears to resist scoring, pitting, and tooth breakage. In this study, a method to determinate spur gear tooth crowning amount to make smooth surface stress and subsurface stress distribution is proposed. This method is based on the contact analysis.

An Upper-Bound Analysis for Closed-Die Forging of the Involute Spur Gears with Circular Arc Fillet (원호필렛-인벌류트 스퍼어 기어의 밀폐단조에 관한 상계해석)

  • Choi, J.C.;Hur, K.D.;Kim, C.H.;Choi, Y.
    • Transactions of Materials Processing
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    • v.3 no.1
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    • pp.97-109
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    • 1994
  • Closed-die forging of the spur gears with circular are fillet has been analyses by using the upper-bound method. A kinematically admissible velocity field has been developed, wherein, the tooth profile consists of the involute curve and the circular arc fillet. In the analysis, the deformation regions have been divided into eight zones. A constant frictional stress has been assumed on the contacting surfaces Utilizing the formulated velocity field, numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth, addendum modification coefficient and friction factor, on the relative forging pressure of spur gears. As the result of numerical calculations, the relative forging pressure does not change so much against the variation of module. On the other hand, the relative forging pressure increases at the final filling stage as the addendum modification coefficient increases.

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Study on Effect of Micro Tooth Shape Modification on Power Transmission Characteristics based on the Driving Gear of Rotating Machining Unit (마이크로 치형수정이 선회가공 유닛 구동기어의 동력전달 특성에 미치는 영향에 관한 연구)

  • Jang, Jeong-Hwan;Qin, Zhen;Kim, Dong-Seon;Wu, Yu-Ting;Lyu, Sung Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.6
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    • pp.91-97
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    • 2019
  • Rotating machining unit is a revolutionary product that can process worm shaft or spiral shaft with fast and precise, a rotary type cutting tool, which is attached to automatic lathe and processes spiral groove on outer circumference of round bar. In this work, a study on micro tooth shape modification method of driving gear train in the rotating machining unit was presented. To observe the effect on power transmission characteristics of the driving gear pair, visualize the gear meshing condition and the load distribution on the gear teeth by using the professional gear train analysis program RomaxDesigner. By comparing the repeated analysis results, the effect of micro tooth shape modification on power transmission characteristics on driving gear can be summarized. The optimized gears were fabricated and measured by precision tester as a validation in this research.

Torsional Vibration Analysis of a Spur Gear Pair with the Variable Mesh Stiffness (기어이의 변동물림강성을 고려한 비틀림진동해석)

  • Ryu, Jae-Wan;Han, Dong-Chul;Choi, Sang-Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.12
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    • pp.99-108
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    • 1999
  • A four-degree-of-freedom non-linear model with time varying mesh stiffness has been developed for the dynamic analysis of spur gear trains. The model includes a spur gear pair, two shafts, two inertias representing load and prime mover. In the model, developed several factors such as time varying mesh stiffness and damping, separation of teeth, teeth collision, various gear errors and profile modifications have been considered. Two computer programs are developed to calculate stiffness of a gear pair and transmission error and the dynamic analysis of modeled system using time integration method. Dynamic tooth and mesh forces, dynamic factors are calculated. Numerical examples have been given, which shows the time varying mesh stiffness ha a significant effect upon the dynamic tooth force and torsional vibrations.

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A Study on the Improvement of Transmission Error and Tooth Load Distribution using Micro-geometry of Compound Planetary Gear Reducer for Tractor Final Driving Shaft (트랙터 최종구동축용 복합유성기어 방식 감속기의 Micro-geometry를 이용한 전달 오차 및 치면 하중 분포 개선에 관한 연구)

  • Lee, Nam Gyu;Kim, Yong Joo;Kim, Wan Soo;Kim, Yeon Soo;Kim, Taek Jin;Baek, Seung Min;Choi, Yong;Kim, Young Keun;Choi, Il Su
    • Journal of Drive and Control
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    • v.17 no.1
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    • pp.1-12
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    • 2020
  • This study was to develop a simulation model of a compound planetary gear reducer for the final driving shaft using a gear analysis software (KISSsoft, Version 2017, KISSsoft AG, Switzerland). The aim of this study is to analyze transmission error and the tooth load distribution through micro-geometry using the simulation model. The tip and root relief were modified with Micro-geometry in the profile direction, and crowning was modified with Micro-geometry in the lead direction. The transmission error was analyzed using the PPTE (Peak to Peak Transmission Error) value, and the tooth load distribution was analyzed for the concentrated stress on the tooth surface. As a result of modifying tip and relief in the profile direction, the transmission error was reduced up to 40.7%. In the case of modifying crowning in the lead direction, the tooth load was more evenly distributed than before and decreased the stress on the tooth surface. After modifying the profile direction for the 1st and 2nd planetary gear train, the bending and contact safety factors were increased by 31.7% and 17%, and 18.3% and 12.5% respectively. Moreover, the bending and safety factors after modifying lead direction were increased by 59.5% and 32.7%, respectively for the 1st planetary gear train, and 59.6% and 43.6%, respectively for the 2nd planetary gear train. In future studies, the optimal design of a compound planetary gear reducer for the final driving shaft is needed considering both the transmission error and tooth load distribution.

Tooth Load Sharing and Deformation Overlap of Helical Gear Pairs for the Manual Transmission of Automobile (수동변속기 헬리컬 기어치의 접촉력 평가를 통한 변형간섭 해석)

  • 박수진;유완석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.6
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    • pp.190-196
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    • 2003
  • The load sharing and teeth deflection of helical gear system are analyzed to investigate the deformation overlap. The deformation overlap, which is calculated by the results of displacement analysis, is suggested as the basis for the tooth profile modification. Helical gear systems are formulated as contact problems, and solved by elastic contact theory and FEM. The developed computer program, which offers gear teeth deflection and deformation overlap, will be of much help to the improved design of manual transmissions for automobiles.

Cavity Design for Injection Molded Gears by the Compensation Method of Design Parameters (설계인자 보정방법에 의한 사출성형기어의 캐비티 설계)

  • Lee, Sung-Chul;Kim, Choong-Hyun;Kwon, Oh-Kwan;Huh, Yong-Jeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3142-3151
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    • 1996
  • As plastics shrink when changing from a molten to a solid state, mold cavities must by made larger than the product specification, In making molded gears, the teeth in the cavity must be carefully compensated for shrinkage so that the teeth of gears will have the correct profile. Two compensation methods are widely used in the cavity design. One is the compensation of a module and the other is the modification of a pressure angle and profile shifting coefficient. These methods, however, do not provide a gear cavity with all disign parameters for gears and several parameters are determined by experience. In this paper, the new design technique, namely the compensation method of design parameters, was proposed , which is based on the three kinds of shrinkage rates obtained from the measuring data of the prototype of molded gears. Using the shrinkage rates in the tip circle, tooth heigth and tooth thickness, we calculate the whole design parameters of a gear cavity. Thus, the gear cavity is considered as a complete gear with the compensated module, pressure angle, profile shifting coefficient, clearance coefficient and back lash amount so that the formula of gears can be applied to the cavity design effectively. Experimental results show that more precision molded gears can be made by using the proposed design method.