• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.275-282
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• 2004

The engine bearing transmits the powers from cylinder to crankshaft with small clearance between con-rod and crankpin. The minimum oil film thickness is a significant parameter in the operation of bearing. The contact pressure of bearing should be considered for the reason that elastic deformation of bearing be caused by contact pressure of bearing. There are important factors which are maintaining of minimum oil film thickness expecting of the length of maximum and minimum oil film thickness with changing of the loads to keep running normally. Furthermore, this study is very crucial to develop the design of engine bearing and crankshaft system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.267-268
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.147-148
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• 2007

• 한국자동차공학회논문집
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• 제12권4호
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• pp.36-41
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• 2004

The purpose of this paper is analyzing the oil film pressure distribution and the minimum oil film thickness for a connecting rod bearing using an A VL's EXCITE program. It is very important to understand optimized oil supplying holes and oil groove dimensions for supporting sufficiently inertia forces and gas pressures from the combustion chamber for a Diesel engine. The computed results indicate that the optimized oil groove width of a bearing and oil hole of a journal are recommended for high performance of a connecting rod bearing at the elastohydrodynamic lubrication zone. These results as design parameters are very useful data for a bearing designer as a firm reference of an automotive engine.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.34-34
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• 2004

The purpose of this paper is analyzing the oil film pressure distribution and the minimum oil film thickness for a connecting rod bearing using an A VL′s EXCITE program. It is very important to understand optimized oil supplying holes and oil groove dimensions for supporting sufficiently inertia forces and gas pressures from the combustion chamber for a Diesel engine. The computed results indicate that the optimized oil groove width of a bearing and oil hole of a journal are recommended for high performance of a connecting rod bearing at the elastohydrodynamic lubrication zone. These results as design parameters are very useful data for a bearing designer as a firm reference of an automotive engine.

• 대한기계학회논문집
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• 제15권6호
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• pp.1975-1981
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• 1991

본 연구에서는 완전히 불균일한 격자계를 사용하여 프로파일링을 한 원통형로 울러의 프로파일링 시작점 부근에서의 압력분포 및 유막형상과 함께 무차원변수의 변 화에 따른 최소유막의 거동을 상세히 조사하고자 한다. 이 결과에서 실제 로울리 베 어링의 로울러 프로파일의 설계시에 적용할 수 있는 새로운 기준을 제시하고자 한다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.364-373
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• 2001

This paper describes the variation of lubricant's temperature effects on elastohydrodynamic lubrication. The Newton-Raphson technique was used to solve the simultaneous system of Reynolds and elasticity equations. To show effects of lubricant's temperature, average temperature across the oil film was calculated using the energy equation. Pressure distribution, film shape, and temperature distribution were obtained for fully flooded conjunctions, and various dimensionless speed parameters while load and material parameters were held constant. Minimum film thickness were obtained for various material properties while load and velocity were held constant. It is drawn that the thermal effects have a strong influence on a minimum film thickness under high rolling velocity and slip ratio.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1994년도 제19회 학술대회
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• pp.65-71
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• 1994

유압 실린더용 유패킹의 접촉력, 접촉폭, 돌출발생 임계압력을 밀봉간극에 대하여 유한요소법을 이용하여 수치적으로 해석하였다. 초기 간섭량이 증가함에 따라 접촉력 및 접촉폭은 급격하게 증가하였다. 그러나 유압이 작용하는 상태에서 밀봉간극이 감소하면 시일의 돌출현상이 발생하는 임계압력은 보다 가파르게 증가함을 확인하였다. 초기 간섭량에 의한 접촉력으로 부터 유압 실린더의 누설에 관련된 사용 최저 유압을 연계하여 갑섭량이 설계되어야하고, 돌출발생 임계압력으로 부터는 사용 최고유압과 관련하여 간극이 설계되어야 하므로 이에 대한 수치해석적 설계자료를 제시하였다. 특히 시일립부의 접촉면을 나타내는 축방향에 따라서 접촉력 분포는 시일립 선단부와 돌출현상에 따른 상호 복잡한 결과의 중요성을 제시하였다. 이 결과는 윤활해석을 위한 탄성유체윤활 해석시 입력자료로 사용될 수 있어 실제 유막두께 해석 및 유동해석을 통하여 누설량 예측 등에 이용될 수 있는 설게자료이다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.269-274
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• 2004

It is important to decide the minimum film thickness and viscosity variations of a multigrade lubricant in the contact surface under the high pressure conditions. By carrying out acceleration, deceleration, and various sliding-rolling ratio movement between two contact bodies, it is experimented that film formation variations in the contact surface are captured with multigrade lubricants in order to exactly investigate the variations of film formations. Optical interference images are continuously captured with high resolution CCD camera during the captured period of acceleration, deceleration. The friction forces between the contacting bodies are also measured simultaneously with the film formation.

• Tribology and Lubricants
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• 제31권4호
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• pp.177-182
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• 2015

Tapered roller bearings are widely used in equipment where high combined thrust and radial loads are experienced. A certain amount of tilting between the tapered rollers and the races always occurs because of bending moment load conditions and shaft deflection. It is now well understood that a coherent elastohydrodynamic lubrication (EHL) film separates the rollers and races. In spite of extensive study on EHL problems for over half a century, relatively few studies have focused on the finite line contacts problem. This study presents a complete numerical analysis of the effects of roller tilting on the EHL characteristics in a tapered roller bearing. We systematically analyze this highly nonlinear problem using finite differences with fully non-uniform grids and the Newton-Raphson method. Detailed EHL pressure distributions and film shapes are presented under moderate loads and material parameters. A very small roller tilting significantly affects the pressure distributions and film shapes near both ends of the roller. Moreover, the effect of tilting on the EHL characteristics at the small end is much greater than that at the large end. Therefore, in designing optimum profiles for tapered roller bearings, the profile radius should be larger at the small end.