Motion Experiment of Reducer-Integrated Motor Using Inscribed Planetary Gear Mechanism

Abstract

The motors for industrial robots and transporting robots are required to have high-precision positioning, large torque output, and small size. However, conventional motor systems have disadvantages in size or load-supporting capacity. To solve the problems, we proposed a novel reducer-integrated motor. The proposed reducer-integrated motor has a reducer using the differential gear mechanism which realizes the simultaneous engagement of two kinds of external and internal gear pairs: one with a small difference in teeth number and the other with no difference in teeth number. Inside the reducer, linear actuators are installed, which contributes to downsizing of the motor. Additionally, two gear pairs with no difference in teeth number are fixed on the base and the gear pair with a small difference in teeth number is set between them. These two kinds of gear pairs engage simultaneously and support the load torque. It is thought that the structure of the proposed motor can realize high load-supporting capacity and high stiffness. In this paper, the structure and movement of the proposed motor are explained. Then, the experiments are conducted to clarify the optimal input pattern for the accurate rotation by using the prototype of the proposed motor. Through the measurement, the optimal input pattern is suggested.