CVT lubrication: The effect of lubricants on the frictional characteristics of the belt‐pulley interface

Two tests for evaluating continuously variable transmission (CVT) lubricants have been developed using readily available test equipment and test parts. These tests have been designed to rank lubricants using a number of criteria relevant to the performance of the lubricant in a push-belt variator. These include overall level of friction, friction stability, temperature dependence of friction, and load dependence of friction. Testing lubricants of different types has shown the effect of lubricant chemistry on the parameters measured and indicates that some existing fluids, a CVT fluid and passenger car motor oil, as well as an experimental fluid, should give good performance in a continuously variable transmission using a push-belt variator.