Planetary Roller Screw Design

Planetary roller screw,as a transmission mechanism that converts rotary motion into linear motion,has the advantages of high transmission precision,strong bearing capacity,high speed and high efficiency.Its comprehensive performance is very superior.At present,it has been gradually applied to aerospace,CNC machine tools,medical equipment,weapons and other occasions with high comprehensive performance requirements.At present,the development of planetary roller screw in China is still in its infancy,and there is still a certain gap with the performance of foreign products.Based on the operation principle of planetary roller screw and the combination of planetary drive and screw drive,this paper analyzes the angular velocity relationship between components,as well as the relationship between thread direction and head number,and obtains the lead formula.Then according to the analysis results,the overall structure is designed,and the thread meshing position and interference are solved based on the spiral surface meshing model The interference of the whole thread parameters is eliminated,and the no backlash engagement design of the thread pair is realized.Based on Hertz contact theory formula,the critical load and deformation of thread contact into plasticity are calculated according to Mises yield criterion.According to the thread load distribution model,the static load of planetary roller lead screw is calculated when the critical load is reached,and the static load of planetary roller screw when the plastic deformation reaches 1/10000 of roller profile diameter is solved.The finite element analysis based on ANSYS Workbench software verifies the correctness of the thread contact model and load distribution model;the dynamic simulation based on Adams software verifies the correctness of the operation principle analysis and structural design,and simulates the thread contact force and gear contact force;Based on ANSYS Workbench software,the first six natural frequencies and main vibration modes of planetary roller screw are obtained.Finally,all the parts of the planetary roller screw are made and assembled into a prototype.The load test device of planetary roller lead screw is designed,and the selection of some equipment and the check of some parts are given,which provides a reference for the performance test of planetary roller screw.