不同安装方式下行星滚柱丝杠副载荷分布研究

Load Distribution of Planetary Roller Screw Mechanism with Different Installations

综合考虑行星滚柱丝杠副轴段刚度、螺纹牙刚度和接触刚度及安装方式、受力状态等因素,建立了行星滚柱丝杠副螺纹牙载荷分布计算模型。在对计算模型验证的基础上,详细分析了安装方式、受力状态、结构参数和牙型参数等对螺纹牙载荷分布的影响规律。结果表明,决定螺纹牙载荷分布规律的主要因素是行星滚柱丝杠副的材料参数、结构参数与安装方式,其中丝杠与螺母的轴向累积弹性变形是引起行星滚柱丝杠副螺纹牙载荷分布不均的主要原因。螺纹牙刚度对载荷分布的影响较小,随着螺纹牙刚度的减小,载荷分布不均程度逐渐降低。此外,滚柱螺纹牙个数与螺距对载荷分布的影响很大,载荷分布不均程度随着螺纹牙个数的增大或螺距的增大而增大。

A model for calculating load distributions of threads in Planetary Roller Screw Mechanism（PRSM） with different installations is developed,in which the shaft stiffness,thread stiffness and contact stiffness of screw,rollers and nut in PRSM are taken into consideration. The proposed model is verified in comparison with an existing model. The effects of installations,load conditions,structural parameters and thread form parameters on the load distributions of threads are studied thoroughly. The results and their analysis show preliminarily that：（1） The main factors which affect the load distribution are material parameters,structural parameters and installation;（2） The accumulative axial deformations of screw and nut are the main reasons which cause the uneven distribution of loads acting on threads;（3） The load distribution among threads becomes slightly evener when the thread stiffness is decreased;（4） The tooth number of rollers and pitch of the threads will remarkably affect the load distribution,and the load distribution will be more uneven with the increase of the tooth number or pitch.