滚珠丝杠副刚度影响因素及试验研究

Influence factors on stiffness of a ball screw

为提高滚珠丝杠副静态与动态分析精度,利用滚珠丝杠副中丝杠滚道的力与力矩平衡方程,并考虑变化的接触角及接触变形影响,建立联合载荷作用下精确的滚珠丝杠副刚度数学模型。并分析滚珠丝杠副刚度影响因素及规律,结果表明,滚珠丝杠副刚度随轴向、径向载荷的增大而变大,随倾覆力矩增加而减小;增大导程与减小滚道曲率比可提高滚珠丝杠副刚度;轴向刚度随轴向载荷、导程和滚道曲率比的改变所受影响最大,角刚度主要受径向载荷和倾覆力矩的影响,径向刚度受载荷与结构参数影响较小。通过与滚珠丝杠副轴向静刚度测量结果比较,所建模型合理、可靠。

To improve static and dynamic analysis accuracy of a ball screw, based on equilibrium equations of forces and moments acted on the ball and screw race, considering influence of variable contact angle and contact deformation, a precise mathematical model for the stiffness of the ball screw was established. Taking a ball screw as an example, the influence factors on its stiffness were anslyzed. The results showed that the stiffness of the ball screw increases with increase in axial and radial load, while decreases with increase in overturning moment; the stiffness also increases with increase in lead and with decrease in curvature ratios of raceway; the effects of axial load, lead and curvature ratios of raceway on the axial stiffness are significant; the main influence factors on the angular stiffness are radial load and overturning moment; the effects of load and structural parameters on the radial stiffness are smaller. The numerical simulations were compared with the measuring results of the static stiffness of the ball screw. The comparisons showed that the proposed model is reasonable and reliable.