Research on detection system for measuring ring gear tooth root strain of planetary gearbox with fiber bragg grating (FBG)

Abstract

With the rapid development of robot technology, more and more intelligent robots serve for people in many fields. The gearbox is important for many robots. Planetary gearbox is widely applied to mechanical transmission in many fields because of its excellent advantages. However, the fault occurs frequently owing to the severe work conditions. The traditional fault diagnosis methods based on vibration signal cannot effectively monitor the planetary gearbox fault. In contrast, the fault can influence the tooth root strain more directly, so that the signal to noise ratio of the tooth root strain is higher than others, and it is a better vector for fault feature. Fault diagnosis method of planetary gearbox based on tooth root strain is proposed to overcome the difficulty in fault diagnosis of planetary gearbox. The rationality of measuring ring gear tooth root strain of planetary gearbox with FBG is discussed in this paper to diagnosis the planetary gearbox healthy condition, and then a detection system for measuring ring gear tooth root strain of planetary gearbox with FBG is designed, which can measure the change of FBG reflection wavelength in order to get the tooth root strain information, and it has some advantages of high-speed, wide-range and high-resolution. Further more, the detection system can accomplish the backward filtering of the ring gear tooth root strain so as to lay the foundation for fault diagnosis of planetary gearbox based on ring gear tooth root strain.