基于结合部刚度特性的滚珠丝杠副动态性能研究

Dynamic Characteristics Research of Ball Screw Pair Based on Stiffness Characteristics of Conjoint Interfaces

本文以某型号滚珠丝杠副为研究对象,通过合理简化模型,在充分考虑结合部对动态性能的影响情况下,准确地建立了滚珠丝杠副有限元模型,对滚珠丝杠副进行了模态分析,并研究了结合部刚度变化及螺母在丝杠上的位置对滚珠丝杠副固有频率的影响。结果表明:滚珠丝杠副的第一阶临界转速高于其最高转速,在其工作转速内不会发生共振;结合部采用弹性处理时更接近滚珠丝杠副的实际情况;随着螺母在丝杠上的往复运动,滚珠丝杠副的各阶固有频率呈现出不同的变化趋势;轴承结合部的刚度变化对滚珠丝杠副的固有频率有着重要的影响,在低刚度区域表现的非常明显;丝杠螺母结合部的刚度变化对固有频率也产生影响,但影响并不显著。

Taking a type ball screw pair as the research object, Through simplified model reasonably and the full consideration of influence of dynamic performance that conjoint interfaces to ball screw pair, the finite elements model of ball screw pair was built. Then the modal analysis was carried out on ball screw pair, The impact of ball screw pair frequency by the change of stiffness of conjoint interface and the change of nut position on the screw was also researched. The studies show that ： the maximum speed of ball screw pair is less than its first-order criti- cal speed. It can avoid the occurrence of resonance in its working speed range ; flexible handling the conjoint in- terfaces is closer to the actual situation ; with the nut movement on the screw, each natural frequency presents a different change trend. The change of bear＇ s conjoint interface stiffness has important impact on the natural fre- quency of ball screw pair, especially in the low stiffness range ; the change of stiffness for screw nut conjoint in- terfaces has a little impact on the natural freauencv of ball screw pair.