Modal and Stress Analysis of Spur Gear in DC Motor Gearhead using Finite Element Model

( Pandu Sandi Pratama ),( Destiani Supeno ),( Seongwon Jeong ),( Cunsook Park ),( Jihee Woo ),( Eunsook Lee ),( Woojin Yoon ),( Wonsik Choi ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.1

In electric agricultural machine the gearhead is needed to convert the high speed low torque rotation motion generated by DC motor to lower speed high torque motion used by the vehicle. The gearhead consist of several spur gears works as reduction gears. Spur gear have straight tooth and are parallel to the axis of the wheel. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modeling and simulation of spur gears in DC motor gearhead is important to predict the actual motion behavior. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress including bending fatigue. 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 gearhead is simulated using ansys work bench software based on finite element method (FEM). The modal analysis was done to understand gearhead deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on gearhead to simulate the gear teeth bending stress and contact stress behavior. This methodology serves as an approach for gearhead design evaluation, and the study of gear stress behavior in DC motor gearhead which is needed in the small workshop scale industries.

Active learning strategy-based reliability assessment on the wear of spur gears

Hua-Ming Qian,Tudi Huang,Jing Wei,Hong-Zhong Huang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12

This study introduces the active learning strategy and Kriging model into the reliability assessment of spur gear wear. First, the wear model of spur gears is constructed based on Archard’s model, and its wear life is approximately estimated. Next, the uncertainty factors affecting the wear life are analyzed and quantified, which causes the reliability problem of spur gear wear. Then, the active learning Kriging model is introduced to estimate the wear reliability for highly efficient and highly accurate computation. Finally, the result analysis for a spur gear is provided, and the relevant results reveal the evolutionary law of spur gear wear depth with working pressure angle. Meanwhile, the wear reliability of spur gears is estimated by different learning functions for comparative analysis, and it is eventually estimated as approximately 99.45 %, which guides decision makers in engineering practice. In addition, Monte Carlo simulation is adopted to validate the accuracy of the estimated wear reliability of spur gears.

스퍼 기어의 FEM 해석 및 IRT 기법을 적용한 건전성 평가

노치성(Chi-Sung Roh),정윤수(Yoon-soo Jung),이경일(Gyung-Il Lee),김재열(Jae-Yeol Kim) 한국트라이볼로지학회 2016 한국윤활학회지(윤활학회지) Vol.32 No.4

As an economic, high quality, and highly reliable gear with low noise and low vibration is demanded, an overall finite element analysis regarding a gear is required. Also, an infrared thermography test, which is a quantitative testing technique, is demanded for safety and longer lifespan of gear products. In order to manufacture a gear product or to determine safety of a gear being used, it is necessary to precisely determine ingredients of a material constituting a gear and detect any internal defect. This study aims to realize a design that minimizes the spur gear displacement with respect to power during its rotation and ensures the spur gear control capacity by using a 3D model and the midasNFX program. This facilitates the assessment of the possibility of cracking by evaluating the stress intensity and focusing on the integrity of the spur gear. We prepare the specimen of the spur gear based on the possibility of cranking as per the result of the structural interpretation from an infrared ray thermal measuring technique. After cooling the spur gear, we perform experiments using thermography and halogen lamps and analyze the temperature data according to the results of the experiment. In the experiment which we use thermography after cooling, we find a rise in the temperature of the room. As a result, the defective part show temperatures lower than their surroundings while the normal parts have temperatures higher than the defective parts. Therefore, it possible to precisely identify defective part owing to its low temperature.

VisualLISP을 이용한 스퍼기어의 3차원 모델링에 관한 연구

이승수(Seung-Soo Lee),김민주(Min-Ju Kim),김태호(Tae Ho Kim),전언찬(Eon-Chan Jeon) 한국생산제조학회 2004 한국생산제조학회지 Vol.13 No.1

This paper describes the development of automatic shape design program for spur gear. It produces automatically third-dimensional surface and solid model used in CAD/CAM system with inputting simple measurements. This program can maximize user's convenience and get surface and solid model quickly as accepting GUI(graphic user interface). Automatic shape design program for spur gear was developed by VisualLISP, a developer program Besides, a geometrical method and a mathematical algorithm are used in this program Use frequency of a fine spur gear is on the increase recently and manufacture process of this gear is heat treatment after press processing with molding. In this press processing, the upper punch portion of a fine spur gear shape is drafted by CAM. Therefore, estimated that surface and solid model of spur gear used to CAM are needed in this research. In this research, after 2 ㎜ gear was modeled by auto shape design program, the upper punch portion of a fine spur gear was manufactured as giving third-dimensional model to CAM software and then, displayed the result as applying to press process.

기어자동설계프로그램의 치형 정밀도 검증에 관한 연구

조명제(M.J. JO),송호봉(H.B. SONG),김수용(S.Y. KIM),전정도(J.D. JEON),전언찬(E.C. JEON) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

The gear is a major mechanical element to transmit power between two close axes. Even though the involute curve and cycloid curve is used for the gear tooth, the involute curve is normally used because it is easy for the fabrication and assembly. In regard to the study of the gear design, lots of studies have been done until now but mostly weighted to the creation of drawing and two dimensional modeling. And price of the exclusive three dimensional gear design program is high, it is only used at the very confined work field. In this study, the automatic gear design program is developed to create three dimensional spur and helical gear model and profile which has involute tooth profile utilizing VisualLISP that is a user development program on the AutoCAD. And compared the each gear tooth profile one of which is created by the automatic gear design program and the other is created by KissSoft, Inventor that is commercially available utilizing Rapid-Form XOV that is an exclusive reverse engineering program. And performed gear cutting using wire-cut electric discharge machining and compared between gear profile and measured data of the fabricated gear using three dimensional scanner to measure accuracy of the gear. And confirmed interference and undercut of the gear using driving motor.

EFFECT OF RIM AND WEB THICKNESS ON TOOTH ROOT STRESS OF SPUR GEAR

박정호,정우진,박영준,김흥섭,서진범,박종상 한국자동차공학회 2024 International journal of automotive technology Vol.25 No.2

This study investigated the impact of spur gear rim and web thickness on root stress. A fi nite-element analysis model (FEM)was utilized and validated through a gear-bending test. Four gears with diff erent rim and web specifi cations, including a solidgear, were designed and tested using strain gages to measure their root stress. The 3D FEM was validated by comparing themeasured root stresses with that analyzed by the developed FEM. Using this model, a parametric study was conducted byvarying the web position, pressure angle, and module to investigate the eff ect of the backup ratio on the root stress ratio ofthe gear. A stress-ratio map was generated based on the results. This stress-ratio map was compared with the rim thicknessfactor ( YB ) for external spur gears specifi ed in ISO 6336-3. The comparison reveals that the rim thickness factor specifi edin ISO 6336 is overly conservative compared to values obtained in this study. Our results suggest that the thickness of boththe rim and web should be considered to reduce the weight of spur gears. These fi ndings can be applied to the design oflightweight spur gears.

Characteristics of transmission error and vibration of broken tooth contact

Dong-Hyung Lee,Kyung-Ho Moon,Woong-Yong Lee 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.12

One of the most important research topics relating to the development of a vibration-based condition monitoring system for a gearbox is that of quantitative analysis and testing of the effect of gear tooth damage on gearbox vibration. This paper presents a finite element model of the Transmission error (TE) and its associated characteristics, together with experimental results of vibration of broken tooth contact in a spur gear. The two-dimensional finite element model is developed to analyze the TE of the spur gear, and the TE for both the normal contact and broken tooth contact state of the spur gear pair are analyzed. As a result, the developed FE model well represents the difference in the static TE for a single-tooth and double-tooth contact of the undamaged and damaged gear pair. The Peak-to-peak magnitude of the static TE of the full-tooth fractured gear pair is significantly higher than that of undamaged gear pair. While the Peak-to-peak TE (PPTE) of the damaged gear tooth increases with increasing load, the ratio of PPTE of the undamaged gear pair and the full-tooth fractured gear pair decreases exponentially with increasing load. This shows that, to determine the fault level of gearbox, it is necessary to carefully apply the condition indicator when analyzing the impulse character of a vibration signal.

Modal and stress analysis of gear train design in portal axle using finite element modeling and simulation

JongBoon Ooi,Xin Wang,ChingSeong Tan,Jee-Hou Ho,Ying Pio Lim 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.2

The portal axle is a gearbox that is specially designed for off-road driving conditions. It is installed between the wheel and the axle shaft to give higher ground clearance to the vehicle. The modeling and simulation of spur gears in portal axle is important to predict the actual motion behavior. However, gear train design in portal axle is difficult to study comprehensively due to their relatively low cost and short product life cycle. In this study, modal analysis of portal axle is simulated using finite element method (FEM). Modal analysis is simulated on three different combinations of gear train system commonly designed for portal axle. The three gear trains being analyzed are gear train without idler gear, one idler gear and two idler gears. FEM static stress analysis is also simulated on three different gear trains to study the gear teeth bending stress and contact stress behavior of the gear trains in different angular positions from 0° to 18°. The single and double pair gear teeth contact are also considered. This methodology serves as a novel approach for gear train design evaluation,and the study of gear stress behavior in gear train which is needed in the small workshop scale industries.

스퍼기어와 헬리컬기어의 동적 특성 비교

박찬일(Park, Chan-Il),조도현(Cho, Do-Hyun) 한국소음진동공학회 2012 한국소음진동공학회 논문집 Vol.22 No.4

This work dealt with dynamic characteristics of spur gear and helical gear system to understand the gear vibration and noise. To find out dynamic characteristics in the gear system, a finite element model and an analytic model for the gear system were used. Using the models, the natural frequency and mode-shape characteristics of spur gears and helical gears were calculated. Two models show that natural frequencies of helical gears were lower than those of spur gears. Mode-shape characteristics of gear pairs by analytical model and some issues of finite element modeling were also discussed. Impact test was used to validate the finite element model.

스퍼 기어의 이뿌리 응력 해석에서 미끄럼 마찰의 영향

박찬일(Chan IL Park) 대한기계학회 2019 大韓機械學會論文集A Vol.43 No.7

스퍼 기어는 맞물림이 진행함에 따라 피치점을 중심으로 미끄럼 마찰력의 방향이 변하고, 이 마찰력에 의해 기어의 수직하중의 크기도 변한다. 이 연구에서는 모멘트 평형과 하중변형관계식을 이용하여 스퍼 기어에 작용하는 마찰력과 수직력을 계산하였다. 이 힘들을 사용하여, 스퍼 기어를 상용 유한요소 프로그램으로 모델링하고, 이뿌리 필렛부에 작용하는 응력을 해석하였다. 스퍼 기어를 평면응력 또는 평면 변형률 요소로 해석하여, 3차원 유한요소 모델과 비교한 결과 수치예제 모델은 평면응력으로 모델링한 것이 타당함을 보였다. 또한 미끄럼 마찰을 고려할 때는 고려하지 않을 때에 비해 한개의 치 물림에서 치 접근부의 이뿌리 응력이 상승하고, 치 퇴거부의 이뿌리 응력은 감소하였다. The direction of sliding frictional forces changes at the pitch point as the meshing of spur gears proceeds. The reversal of the frictional force changes the magnitude of normal force of spur gears. In this study, the frictional and normal forces of spur gears are calculated using the moment of equilibrium and the load-deformation equation. Using the forces, spur gears were modeled into commercial finite element code and the tooth root stress was analyzed. Spur gears were modeled into plane-strain and plane-stress 2D elements, and the tooth root stress of the 2D elements was compared to that of a 3D solid element. Results showed that the tooth root stress of a plane-stress 2D element was close to that of a 3D solid element. The tooth root stress of the single mesh when considering sliding friction was increased during the gear approach while the tooth root stress was decreased during the gear recess.