Research on the velocity variation method for precise motion transmission

Abstract

A wide range of speed or torque is required for some types of robot. It is possible for the motors to realize a small range of speed or torque, but the range is limited to some degree because of the size, weight, and cost of motors. Therefore, it is impossible to realize all requirements if a reduction device with a ratio is used. Velocity variation devices using gears are widely used in industrial fields. However, the motion transmission from the input shaft to the output shaft is interrupted during the period when the velocity ratio varies. In order to solve this problem, we propose a velocity ratio variation method that can transmit motion continuously during the period when the velocity ratio is changing. The process of changing the velocity ratio in the proposed method is described, and an experimental device that can change the velocity ratio is constructed. The experimental results show that the proposed device can transmit motion between the input shaft and the output shaft continuously while the velocity ratio is changing, and thus confirm that the proposed method is effective in realizing constant motion transmission.