Abstract
Over the past two decades, extensive research has been conducted on developing vehicle transmission that meet the goals of reduced exhaust emissions and increased vehicle efficiency. A continuously variable transmission (CVT) is an emerging automotive transmission technology that offers a continuum of gear ratios between desired limits. Although a CVT plays a crucial role in the plan to improve the vehicle fuel economy, its complete potential has not been realized in a mass-production vehicle. The present research focuses on developing a simulation-based model of chain CVT in order to understand the influence of clearance on its dynamic performance. A detailed planar multibody model of a chain CVT is developed in order to accurately capture the excitation dynamics characterized by the discrete structure of the chain. A suitable model for clearance between the chain links is embedded into this multibody model of the chain CVT. Friction between the chain link and the pulley sheaves is modeled using continuous Coulomb approximation theory. The results highlight the influence of clearance parameters on the dynamic performance, the axial force requirements, and the torque transmitting capacity of a chain CVT drive.
Keywords: Chain, CVT, Continuous Variable Transmission, Multibody system, Nonlinear