Misalignment equation for the Van Doorne metal pushing V-belt continuously variable transmission

Abstract

The existence of belt/pulley misalignment in the Van Doorne metal pushing V-belt continuously variable transmission (CVT) has always been recognized by researchers and the manufacturers themselves. However, its effect has always been assumed to be negligible and search through the literature reveals no work published so far to verify this assumption. Misalignment of the belt may increase losses and the need to improve efficiency is now of paramount importance. This paper is an initial effort by the authors to address this area and study the geometrical behaviour of the belt misalignment theoretically. An equation to represent this geometrical behaviour has been developed and it is able to calculate the magnitude and position of the belt misalignment at different speed ratios and at different assembled zero belt misalignment speed ratios. The condition necessary to minimize the magnitude of the belt misalignment has been determined. Verification of the equation was obtained by using a solid modeller from a Unigraphics Version 10.4.0 computer aided design (CAD) package. It is intended that the findings from this study will enable the authors to study further the effect of misalignment on the efficiency and performance of the transmission.