Deformation pre-compensated optimization design of cam ring for low pulsation hydraulic motors

Cam-lobe radial-piston hydraulic motors are widely used in large machinery due to their excellent capability to withstand high loading at low speed.However,the line contact between the roller and cam ring generates elastic deformation of the cam ring under high loading,leading to obvious speed and torque pulsations and even the detrimental crawl problem of hydraulic motors.To address this issue,we propose a deformation pre-compensated optimization design approach to compensate for the cam ring deformation in advance,thereby eliminating the influence of cam ring deformation on the hydraulic motor’s pulsation.In this approach,the design process is divided into two steps:first,the overall profile of the cam ring is optimized based on the calculated elastic deformation;second,the local profile of cam ring is further optimized until the hydraulic motor’s pulsations no longer reduce.Finally,a case study is carried out to verify the effectiveness of this approach.The result indicates the pulsation rate of a deformation pre-compensated cam ring is 40%lower than that of an uncompensated one.This study offers an easy and feasible way to design an optimized cam ring profile for low pulsation hydraulic motors.