关键词: 行星滚柱丝杠, 弹性变形, 螺旋曲面方程, 接触方程, 接触位置

Abstract: In order to reveal the mechanism between the elastic deformation of the thread teeth and the contact characteristics of helical surface, a calculation method for the contact position is proposed. The method is mooted based on the structural characteristics and load bearing principle of the planetary roller screw mechanism, which can simultaneously consider the deformation of the screw, roller and nut and the load distribution law of different thread contact sides. Based on the transmission principle of planetary roller screw mechanism and the tangent contact condition of helical surface, the helical surface equation and thread contact equation of screw, roller and nut considering elastic deformation are systematically constructed. The correctness of the established model is verified by comparing the calculation results of contact position parameters with existing models. The influence of load distribution on the contact radius and contact deflection angle of internal and external meshing helical surface is studied by considering the elastic deformation and the load distribution law of thread teeth. The results show that under the influence of elastic deformation, the contact positions of each pair of meshing thread teeth are constantly changing. The contact points between the screw and roller gradually move towards the direction of the middle diameter of roller and the major diameter of screw in addition to deviating from the center line of the screw and the roller. The contact points of nut-roller gradually move away from the tangent point of the pitch circle of the nut and roller, and the contact position always moves along the pitch circle of the roller.

Key words: planetary roller screw mechanism, elastic deformation, helical surface equation, contact equations, contact position