Gear Vibration Signal Extraction Based on Meshing Impact Under Heavy Load Condition

Abstract

Gearboxes are the fundamental and key equipment in most rotating machines, they are also considered as one of the main sources of vibration. To assess the health state of the gearbox, it is of great significance to extract its vibration from the system. The gear meshing frequency is generally thought to contain rich information that reflects its health state. In this paper, the gear mesh impact theory is first introduced to explain the causes of the meshing impacts. The transient dynamics analysis is used to study the relationship between the gear meshing impact and the load applied to the system. The results show that the heavier the load, the stronger the meshing impacts. To prove our point, the gear vibration data is acquired from the test rig experiment. The analysis results show that when the gear rotates under heavy load, the meshing impacts will excite the structure resonance, so the meshing frequency is modulated to the high-frequency band as the meshing impacts. The fast kurtogram (FK) method is used to determine the modulated frequency band. By filtering and enveloping the high-frequency modulated signal, the gear meshing frequency component can be successfully extracted.