以深沟球轴承为研究对象,建立钢球与内外滚道的滚动接触模型,在疲劳寿命的计算中考虑轴承的运动特性。考虑球轴承中同时承载的滚动体个数随时间变化,提出了一种更为准确的载荷分布计算模型。分析了相同外部载荷作用下,不同游隙、不同转速对轴承内部载荷的影响。针对4种不同运动状态下的深沟球轴承,分析内圈、外圈和滚动体上一点的接触应力随时间的变化规律,计算得到其载荷序列。考虑内外圈不同运动状态对轴承应力循环次数的影响,对Lundberg-Palmgren(L-P)寿命模型进行了修正,计算了轴承内圈、外圈、滚动体以及轴承整体的寿命。对比不同运动状态下两种模型计算的寿命,在仅有一个套圈旋转时,修正的寿命与初始L-P寿命较为一致,当两个套圈同时旋转时,修正的L-P寿命与常用的L-P寿命计算结果存在较大差异。
For deep groove ball bearing, the rolling contact model of ball, inner and outer raceways is established. The motion characteristics of rolling bearing are considered in the calculation of fatigue life. A more accurate load distribution calculation model is proposed by considering the number of rolling elements loaded in the ball bearing. Effects of different clearance and speed on load distribution inside the bearing under the same external load are analyzed. For four different motion states of deep groove ball bearing, contact stress variation of points on inner ring, outer ring and ball was computed, and the load sequences are analyzed. The Lundberg-Palmgren(L-P) life model is modified to consider the influences of different motion states on the number of stress cycles in the bearing. The lives of inner race, outer race, rolling elements and the overall bearing are calculated. The lives under different motion states are compared with both the L-P model and the new modified L-P model, which show well agreement under the situation when one of the races is rotating; however, when both of the races are rotating, the lives of bearings calculated with the modified L-P model and the L-P model are quite different from each other.