引入滚动体尺寸偏差的球轴承寿命模型
The Life Model for Bearing Considering the Ball Size Deviation

针对尺寸偏差引起的固定滚道应力循环状态的变化，提出了滚动轴承等效载荷态的概念，并在此基础之上，结合Lundberg-palmgren （L-P）寿命理论及Miner疲劳损伤累积假说，提出了一种修正L-P寿命模型。基于该疲劳寿命计算模型，以6008型普通深沟球轴承为例，考虑到滚动体尺寸偏差的分布形式，对滚动体尺寸偏差、载荷及游隙等因素对轴承疲劳寿命的影响进行了计算并对结果进行了统计学分析。模型预测结果与相关文献的试验数据进行了对比，得出如下结论：1） 尺寸偏差值增大，疲劳寿命系数降低；2） 随着载荷的增大，尺寸偏差对轴承疲劳寿命影响逐渐减弱；3） 存在一个较小的负游隙使得轴承疲劳寿命系数达到最小；4）滚动体尺寸偏差服从呈正态分布时，轴承疲劳寿命系数亦呈正态分布。
The inevitable size deviation in machining process induces the change of stress cycle state in fixed ring. Aiming at the change, the concept of equivalent loading state was proposed. Based on the equivalent loading state and combined Lundberg-palmgren (L-P) life theory with Miner's fatigue damage accumulationhypothesis, a modified L-P life model, including size deviation, was developed. By means of the life model, the effects of the size deviation, external load, and radial clearance were investigated in 6008 type deep groove ball bearing. Considering the statistical distribution of size deviation, statistics analysis of predicted results was conducted. The analytic results of the modified life model were compared with the experimental data of related literature, some conclusions were drawn as follows: 1) the life factor decrease with the increasing of size deviation; 2) the effect of the size deviation gradually decreases with the increasing of external load; 3) in particular negative clearance, the effect of the size deviation is worst; 4) if the size deviation is normally distributed, the distribution of life factors also obeys normal distribution