行星滚柱丝杠副运动和力的传递是通过多个滚柱在丝杠和螺母之间的行星运动以及螺旋曲面的相互啮合来实现的。文中基于丝杠、螺母和滚柱的空间螺旋曲面特征，采用相应的参数方程建立了行星滚柱丝杠副的运动学分析模型；根据连续相切原理得到了接触点位置，再由接触点的运动特性推导了行星滚柱丝杠副的结构参数关系。在此基础上，模拟了丝杠、螺母和滚柱的空间运动轨迹，进一步得到了零件螺纹牙上的应力循环规律，并对行星滚柱丝杠副的工作寿命进行预测。结果表明：丝杠与滚柱在接触点处具有相对速度，螺母与滚柱的接触点为速度瞬心；滚柱与螺母上每个具体接触点承受着稳定的脉动循环接触应力的作用，而丝杠上每个具体接触点承受着周期性变幅循环接触应力的作用。

The movement and force transmission of planetary roller screw mechanism （PRSM） are realized by the planetary motion of multiple rollers and the meshing of their helical surfaces between the screw and the nut.Based on the characteristics of spatial helical surface of screw，nut and roller，the kinematic analysis model of PRSM is established by using the parametric equations of the screw，nut and roller in this paper.The positions of contact points are obtained according to the principle of continuous tangency.Then，the relationship between the structu-ral parameters of PRSM is deduced from the kinematics characteristics of the contact points.On this basis，the spatial motion trajectories of the screw，nut and roller are simulated，and the stress cycle behaviors on their threads are further obtained.Furthermore，the working life of the PRSM is predicted.The results show that there is a relative velocity at the contact point of the screw and roller，and the contact point of the nut and roller is the instantaneous center; and that each specific contact point on the roller and nut bears stable pulsating cyclic contact stress，while each specific contact point on the screw is subjected to cyclic contact stress with periodic amplitude variation.