极限载荷工况下滚珠丝杠副疲劳弹性寿命研究

滚珠丝杠副因高精度、高可靠性等特点,被广泛应用于机械、航空航天及核工业等领域。传统滚珠丝杠副寿命计算方法是以疲劳点蚀为失效判定依据,而在航空航天等极限载荷工况下,滚珠丝杠副需要在短时间内承受几近额定静载荷的负载,其主要失效形式将变为塑性变形失效。因此,基于疲劳点蚀的疲劳寿命理论和计算方法不再适用。基于滚珠丝杠副的塑性接触变形特性提出了疲劳弹性寿命的概念及计算方法。基于滚珠丝杠副刚性试验台设计了疲劳弹性寿命测试方法并进行了试验,发现提出的疲劳弹性寿命计算方法的误差在15%以内。通过灵敏度分析,对滚珠丝杠副疲劳弹性寿命的影响最大的为适应比,其次是接触角、导程、轴向载荷、丝杠节圆直径,滚珠直径最小。

Study on fatigue elastic life of ball screw pair under ultimate load condition

Ball screw pair is widely used in machinery, aerospace and nuclear industry, ete. due to its high precision and highreliability. In traditional ball screw pair life calculation method, fatigue pitting is adopted as the failure criterion. While under theultimate load eonditions such as the aerospace, ball serew pair is required to bear nearly rated statie load in a short time, the main failuremode becomes plastic deformation failure rather than fatigue pitting failure, the traditional fatigue life theory and calculation methodbased on fatigue pitting are no longer applicable. Based on the plastie contact deformation characteristies of the ball serew pair, theconcept and caleulation method of fatigue elastic life (FEL) of the ball screw pair were proposed. On the basis of the rigid test bench ofthe ball serew pair, the FEL test method was designed and tested. It is found that the error of the FEL caleulation method proposed inthis study is within 15%,The sensitivity analysis shows that the conformity factor has the greatest impact on the FEL of the ball scerewpair, followed by the contact angle, the lead, the axial load and the pitch diameter of the serew, and the ball diameter has the smallestimpact.