Vibration Transmission Characteristics and Measuring Points Analysis of Bearing Housing System

The vibration transmission characteristics of the bearing housing system are crucial for the system fault diagnosis based on vibration signals collected at various measuring points. To study its vibration transmission characteristics, a dynamic model of the rolling bearing housing system based on the elastic interface is established. The interference fit between the bearing outer ring and the bearing housing is modelled by contact pairs. The proposed model is verified by the experimental results, which demonstrate that the interference fit can be better simulated by contact pairs. Based on the comparisons between the vibration signals obtained from the defect point and the measuring points on the bearing surface, the transmission mechanism of the defect excitation and the generation mechanism of the bearing housing structural vibration are clarified. The change law of defect excitation through an interface and the effects of bearing operational conditions (load and speed) on the vibration signals of measuring points are summarized. The results show that the optimal measuring point on the bearing housing surface is the location that is closest to the defect when the bearing housing system is working under light loads or high speeds. However, when under low speeds, the preferred measuring points are the positions where the rigidity of the bearing housing structure is weak. The analysis results provide a theoretical basis for the sensor arrangement and improvement of fault diagnosis accuracy under different operating conditions.