Title: Dynamics of CVT chain drives

Authors: J. Srnik, F. Pfeiffer

Addresses: Lehrstuhl B fur Mechanik, TU Munchen, 85747 Garching, Germany. Lehrstuhl B fur Mechanik, TU Munchen, 85747 Garching, Germany

Abstract: The dynamics of continuously variable transmissions (CVT) is characterised by the discrete structure of the chain, which causes the polygonal action. Hence the mechanical model contains each chain link and pulley as a separate body. While a chain link is part of a strand, only joint forces act on the chain links, whereas, in the contact situation, additional impulsive and frictional forces in the contact zones, between the chain links rocker pins and the tapered surfaces of the pulleys, have to be taken into account. In order to calculate the contact forces, Coulombs friction law as well as a time saving continuous approximation are applied. Due to the fact that the deformation of the pulleys has a decisive influence on the dynamics of the complete chain drive, the pulleys are described as an elastic multibody system. Simulation results show the influence of the cone pulleys deformation on the power transmission. A comparison of calculated and measured results verifies the model presented.

Keywords: dynamics of chains; elastic multibody system; contact mechanics; unilateral constraints.

DOI: 10.1504/IJVD.1999.001859

International Journal of Vehicle Design, 1999 Vol.22 No.1/2, pp.54-72

Published online: 18 Aug 2003 *

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