Title: The effects of crankshaft offset on the engine friction

Authors: M.-R. Cho, J.-S. Kim, D.-Y. Oh, D.-C. Han

Addresses: Senior Research Engineer, Gasoline Engine Test Team, Power Train R&D Centre, Hyundai Motor Co, 772–1, Changduk-dong, Whasung-city, Kyonggi-do, 445–850, Korea. Senior Research Engineer, Gasoline Engine Test Team, Power Train R&D Centre, Hyundai Motor Co, 772–1, Changduk-dong, Whasung-city, Kyonggi-do, 445–850, Korea. Senior Research Engineer, Gasoline Engine Test Team, Power Train R&D Centre, Hyundai Motor Co, 772–1, Changduk-dong, Whasung-city, Kyonggi-do, 445–850, Korea. Professor, School of Aerospace and Mechanical Engineering, Seoul National University, San 56–1, Shilim-dong, Kwanak-gu, Seoul, 151–742, Korea.

Abstract: This paper reports on the effects of crankshaft offset on the engine friction. The effects of crank offset are investigated through the theoretical analysis. In this study, the mathematical models are presented for evaluating the friction level of each engine parts. From the predicted results, the crank offset influences on the side force acted on the piston pin and sliding speed of piston. With application of crank offset, the friction loss of piston skirt is significantly reduced. The optimal crank offset to minimise the friction losses is variable according to the operating conditions, and the offset effect is reduced as engine speed and load increase As can be seen in the presented results, crank offset is very effective to reduce the engine friction.

Keywords: crankshaft; engine; friction; offset; piston skirt; side force.

DOI: 10.1504/IJVD.2003.003183

International Journal of Vehicle Design, 2003 Vol.31 No.2, pp.187-201

Published online: 14 Jul 2003 *

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