Study of Shaft Drive Continuously Variable Transmission

2nd Report, Effect of Low Spin Disk

Abstract

The novel mechanism CVT (Shaft Drive CVT) was developed by the authors. The input and output shafts with conical disks are parallel and an idler shaft having conical rollers at both ends is placed perpendicular to the input/output shafts. This idler shaft transmits torque from the input shaft to the output shaft and its linear motion produces the speed variation by changing the contact point between the input/output disk and the idler roller. The purpose of this report is to design a curved shape of disk to decrease an amount of spin caused by the changing of contact point, because the spin has an adverse effect on traction contact performance and is responsible for an increase of power loss. The design procedure of novel concave disk and roller is shown and their effect is evaluated by using the prototype CVT. The speed -transmitted efficiency of 1.5% was improved in case of transmitted power 0.7 kW.