Analysis And Research On Meshing And Contact Characteristics Of Planetary Roller Screw Pair Considering The Influence Of Error

The planetary roller screw pair is used as the actuator of an electromechanical servo system,its high carrying capacity and reliability in the long run makes it ideal for harsh operating conditions and the heavy-load.However,there is still a significant gap between the domestically made planetary roller screw pair and the international advanced products in terms of bearing limit,transmission accuracy and reliability.This article starts from the structure of the standard planetary roller screw pair and discusses various errors that may occur during processing and assembly,then conducts theoretical research and experimental analysis on the meshing characteristics,contact characteristics and transmission accuracy considering the error state.Firstly,based on the structure of the standard planetary roller screw pair,the errors that may occur during processing and assembly are analyzed.Combined with the principle of meshing,the Euler theorem of rigid bodies and the principle of mechanism,the helical surface equation of the part with error parameters and the meshing equation of the standard planetary roller screw pair are established.The iterative method is used to solve the meshing position and the axial clearance,and then the influence of the pitch diameter error,the thread form error,the thread indexing error and the roller positioning error on the axial clearance and the meshing point is analyzed.Secondly,through the Hertz contact theory and the deformation coordination equation,a standard planetary roller screw pair load distribution model considering the error is established,combined with the influence law of the error on the contact characteristics,and the influence of different errors on the load distribution law is solved and analyzed.Finally,according to the principle of rigid body kinematics,the lead accuracy of the standard planetary roller screw pair is calculated,the influence of the error on the movement accuracy of the nut is analyzed,and a transmission accuracy test rig is built.The no-load and load transmission accuracy tests are carried out to verify the correctness of the analysis.The research content and results obtained in this paper can provide theoretical basis for the processing,acceptance and testing of standard planetary roller screws,and lay a foundation for the formulation of standard documents.