Contact Performance Analysis And Parameter Optimization Design Of High-load Precision Ball Screw Pair

Ball screw is one of the main driving and executing elements in linear electromechanical actuator.Some electromechanical actuators used in aerospace devices have more critical demands for the comprehensive performance of ball screws.In view of this situation,it is essential to commence research on the contact characteristics,loading performance,optimization design and other issues of precision ball screw under high lift,in order to ultimately improve the comprehensive performance of precision ball screw in high load through relevant research.Therefore,based on the relevant mechanical theory and non-linear FEM in computational mechanics,this paper analyzes the elastoplastic contact mechanical characteristics of the ball screw involved in the research project,studies the influence of the ball rolling on the residual stress evolution of the raceway under high load,and analyzes and predicts the change of contact angle during the contact process.At the same time,in view of the phenomenon that the running stability of the ball screw used in the electromechanical actuator is reduced under some special working conditions,the finite element dynamic model is established and analyzed in this paper.According to the analysis results,the causes of the phenomenon are analyzed from the aspects of the friction selflocking effect of the ball screw,the impact of the ball in and out of the ball re-circulation,the impact of the ball in the ball re-circulation,etc.,and it is proposed that the design idea of reducing the probability of this phenomenon is given.According to the requirement of longterm and reliable operation of the electromechanical actuator,the external and internal factors that may cause the ball screw failure in the actuator are analyzed,and the influence of these failure modes and the idea of delaying the failure are discussed and analyzed.Then,the author designed and installed a practical ball screw test device according to the test requirements of the research project,and tested the ball screw involved in the project.In the experiment,the force response characteristics,temperature rise characteristics and vibration characteristics of ball screw driven by exciting force and constant force are analyzed.Finally,in order to improve the contact performance,this paper optimizes the contact parameters of ball screw based on the nonlinear optimization function of MATLAB,and verifies the rationality of the optimization results by using the finite element method.