Abstract: Radial plunger hydraulic motor is widely used in medium and large mechanical equipment.However,due to its internal impact and fatigue wear problems,the life and performance of radial plunger hydraulic motor are affected to some extent.To solve these problems,an improved particle swarm optimization for optimization radial plunger hydraulic motor internal curves was proposed. The constant acceleration curve was reconstructed into the constant acceleration curve with compensation region to reduce the impact and the sudden change of the constant contact stress. Based on the Particle Swarm Optimization (PSO),an improved particle swarm optimization was constructed by adding adaptive nonlinear dynamic weight and multi-subpopulation competitive optimization strategy. The angle of each zone was reassigned and the internal curve of radial plunger hydraulic motor with compensation zone was reconstructed. The results before and after optimization show that the maximum contact stress decreases by 2.54 % and the abrupt value at the maximum contact stress decreases to 0. The contact stress no longer rises step by step,there is a rising process,and the impact is small. This research can provide reference for the design of radial plunger hydraulic motor,effectively reduce fatigue and wear,reduce impact,and extend the service life of hydraulic motor.

Key words: radial plunger hydraulic motor, internal curve, adaptive nonlinear dynamic weight, multi-subpopulation competitive optimization strategy, improved particle swarm optimization