Rolling bearing local fault vibration mechanism research is the theoretical basis of advanced bearing fault diagnosis and size measurement technology. In this paper, the additional displacement and impact force excitation of inner and outer ring local faults under low speed and heavy load condition are analysed, and rolling bearing local fault vibration model is established. The simulated dual impulse characteristics have higher accuracy under low speed and heavy load condition compared with other traditional local fault models. The outer and inner ring fault simulated dual impulse interval errors are 6.7% and 1.1%, respectively. Then the local fault vibration mechanism is analysed, and the influence of heavy load condition on dual impulse characteristic is not negligible. Finally, a size measurement method of bearing local fault based on vibration model is proposed. Two sizes of outer ring fault bearing are tested in four different working conditions, and the average measurement error is 3.78%. The results show that the proposed method can overcome the influence of different working conditions and accurately measure different local fault sizes.

滚动轴承局部故障振动机理研究是先进轴承故障诊断和尺寸测量技术的理论基础。本文分析了低速重载条件下内、外圈局部故障的附加位移和冲击力激励，建立了滚动轴承局部故障振动模型。与其他传统局部故障模型相比，模拟的双脉冲特性在低速重载条件下具有更高的精度。外环和内环故障模拟的双脉冲间隔误差分别为 6.7% 和 1.1%。然后分析局部故障振动机理，重载工况对双脉冲特性的影响不可忽略。最后，提出了一种基于振动模型的轴承局部故障尺寸测量方法。两种尺寸的外圈故障轴承在四种不同的工况下进行测试，平均测量误差为3.78%。结果表明，所提出的方法能够克服不同工况的影响，准确测量不同局部故障的大小。