Power transmission dynamics in micro and macro slip regions for a metal v-belt continuously variable transmission under external vibrations

In this paper, the power transmission dynamics of a metal v-belt continuously variable transmission (CVT) under external vibration conditions were investigated for the micro and macro slip regions. A CVT variator simulator was developed based on the CVT power transmission dynamics. Using the simulator, the influence of a slip on the external vibration transmission characteristics was analyzed in time and frequency domain. From the analysis results, it was found that the external vibration transmission characteristics were different between the micro slip region and the macro slip region. In the micro slip region, the vibrations of the primary and the secondary pulleys were coupled, which means that the vibration characteristics of the primary and secondary pulleys are determined by the torque vibrations characteristics of both the primary and secondary torque. However, in the macro slip region, the vibrations of the pulleys are decoupled and the vibration characteristic of each pulley is determined by the torque vibration of the corresponding side. Experiments were performed to validate the external vibration transmission characteristics for the load torque fluctuation. The test results were in good agreement with the simulation results. It is expected that the different vibration transmission characteristics of the micro and macro slip regions can be used to detect a macro slip in the CVT variator during actual operation.