Experimental study of transmission ratio changing mechanism for motorcycle applications

Abstract

Transmission ratio change in today’s motor cycle rubber belt Continuously Variable Transmission (CVT) are based on centrifugal forces resulted from engine revolution. Compare to manual transmission, this kind of CVT needs higher engine revolution to start engaging the transmision ratio which in turn requiring more fuel consumption. A transmission ratio change concept based on an Electro-mechanical actuator consisting of cam, actuator gears and DC motor has been developed to eliminate the dependancy of transmission ratio on engine revolution. The DC motor rotates the cam through actuator gears. The rotation of the cam causes the primary movable pulley sheave to move in axial direction, which in turn changing the belt-pulley pitch radius and changing the transmission ratio. This research aims to design and implement an electronic measurement system based on Arduino Uno as a data acquisition system and Matlab/Simulink as a controller program to obtain the measurement data of primary pulley and secondary pulley speeds and primary pulley axial position. Based on these data, the transmission ratio can be determined and the relationship between transmission ratio and primary pulley posistion can then be obtained. For future development, these measurement data will be used as important references when developing and testing the transmission ratio controller programs.