Design of thin plate-type speed reducers using balls for robots

A review of the recent trends of robots would show that robots are gradually being miniaturized. However, most commercially available speed reducers suffer from the limitations in terms of structure and vibration when applied to small robots. A new speed reducer mechanism was designed to check the reducer ratio and contact points between the balls and inclined planes. Contact force analysis between the gear curves and the balls and contact force analysis between the balls and inclined planes were conducted using a numerical method and FEM analysis. This virtual prototype simulation provided essential data and analysis foundation for the physical prototype’s manufacture and testing. Meanwhile, it also provided the important basis for optimizing the tooth profile and the performance. A speed reducer was manufactured to check the performance. This manufactured thin plate-type speed reducer imposed less compressive stress on the tooth profile and the balls, which greatly increased the facility of the robot.