考虑非承载区的滚珠丝杠副承载性能分析

Analysis on load-bearing performance of ball screw pair considering unloaded zones

关键词:  滚珠丝杠副  载荷分布  反向器  非承载区  接触变形  静刚度

Key words:  ball screw pair  load distribution  reverser  unloaded zone  contact deformation  static stiffness

摘要:

为获得内循环滚珠丝杠副更为精确的载荷分布,优化滚珠丝杠副结构参数,以提高其承载性能,在传统连续载荷分布模型的基础上,考虑反向器这一非承载区,建立一种新型的载荷分布计算模型。首先,建立滚珠螺母/滚珠丝杠接触模型,并基于滚珠与滚道间的变形协调机理,获得连续载荷分布模型。其次,基于回珠曲线确定滚珠链的空间位置分布,并在此基础上,提出一种考虑非承载区滚珠的滚珠丝杠副载荷分布求解方法。利用该方法,量化对比了本文模型与传统连续载荷分布模型在全滚珠载荷与接触应力上的差异,并深入分析了反向器个数、不同滚珠直径对接触载荷,以及静刚度等关键承载特性的影响。最后,开展静态加载实验验证所提载荷分布模型的准确性。结果表明:通过本文提出的模型获得的轴向接触变形与实验相比最大误差为5.42％,静刚度与实验相比最大误差为6.69％,验证了所提模型的准确性,相比于传统模型,本文所提的模型与实验吻合度更高,这为滚珠丝杠副的精准设计提供一种方法。

Abstract:

To achieve a more accurate load distribution for ball screw pair with internal circulation and optimize structural parameters of ball screw pair to enhance load-bearing performance, this study established a novel load distribution computation model. Building upon the traditional continuous load distribution model, the proposed approach incorporated the unloaded zone induced by reversers. First, ball-nut and ball-screw contact models were established. Based on the deformation compatibility mechanism between balls and raceways, the continuous load distribution model was derived. Second, the spatial position distribution of the ball chain was determined according to the ball return curve. On this basis, a load distribution solution method for ball screw pair considering balls in unloaded zones was proposed. By using this method, quantitative comparisons were conducted between the proposed model and the traditional continuous load distribution model regarding full-ball loads and contact stresses. The effects of the number of reversers and different ball diameters on key load-bearing characteristics, such as contact loads and static stiffness, were thoroughly analyzed. Finally, static loading experiments were conducted to validate the accuracy of the proposed load distribution model. Experimental results show that the maximum error in axial contact deformation between the proposed model and experimental measurements is 5.42%, and the maximum error in static stiffness between them is 6.69%, confirming the proposed model’s accuracy. Compared to the traditional model, the proposed model exhibits higher agreement with experimental results, providing a method for the precise design of ball screw pair.