Increase of Traction Coefficient by Means of Microtexture (2nd Report, Optimization of Parameter in Microtexture and Application to Actual CVT)

Abstract

The first report describes longitudinal surface texture was the best for improving the traction coefficient. Therefore, the longitudinal surface texture was optimized using the 4-roller tester. The test results made it clear that the groove depth, groove pitch and also the radius of curvature of the convex portion of the rolling elements are important parameters of the longitudinal grooves for improving the traction coefficient while assuring high durability at the same time. Furthermore, an attempt was made of increase traction coefficient of an actual CVT variator by using an optimized longitudinal surface texture. The test result proves that a traction coefficient can be improved by optimizing microtexture without spoiling durability.