Transmission efficiency of one tooth difference sine tooth profile planetary reducer

Abstract

The structural size of space exploration and unmanned aerial vehicle manipulator is required to be as small as possible, and the weight must be as light as possible. However, the existing reducers have difficulties in achieving lightweight robot joint drive systems. For it, this paper proposes a single tooth difference continuous sine tooth profile K–H–V type planetary reducer in which pin type equi-speed output mechanism is used. Concerning the reducer, its structural composition and meshing characteristics are analyzed. Based on the findings, the meshing pair's force, the friction coefficient, and the meshing efficiency are investigated. The force and bearing efficiency of the planetary gear are studied, and the efficiency of the equi-speed output mechanism in addition to the total efficiency of the reducer are determined. Moreover, the efficiency of the reducer prototype is measured and compared to the calculated efficiencies. The results show that the gear modulus, the input speed, the surface roughness, and the lubricating oil viscosity have a significant effect on the meshing efficiency. Furthermore, the efficiency of the eccentric bearings is significantly lower than that of the non-eccentric bearings. Therefore, it can be increased by tuning the pressure angle, the tooth number of planetary gear, the tooth height, and the distribution circle radius of the pinhole. In addition, the power loss of the output mechanism has the greatest effect on transmission efficiency. Reducing the center distance, the inner diameter of the rotating arm bearing, and the tooth number of planetary gear, as well as increasing the outer diameter of the pin shaft can reduce the power loss of the output mechanism. The experimental efficiency of the reducer prototype is 82.47%, its computational efficiency is 83.72%, and its error is 1.25%, verifying the correctness of the efficiency calculation method.