In the proportion relationship between the failure parts and modes of the reducer, the gear, bearing and shaft concentrate 90% of the failure proportion, among which the gear failure accounts for the largest proportion, making the fatigue failure of the transmission gear become an important factor limiting the transmission system and reliability. In the process of automobile driving, the reducer gear bears a series of loads such as torque from the driving motor, complex random excitation on the road surface, and self meshing impact, which makes the reducer gear bear a very complex random load. This random load is more likely to induce fatigue damage such as contact and bending of the reducer gear. At present, there have been many studies on the fatigue of reducer gears, but there are relatively few studies on the fatigue life of measured load spectrum. Taking the reducer gear as the research object, the gear contact stress load spectrum is calculated by measuring the load spectrum and combining Hertz contact theory. According to the corresponding transformation, the transformed reducer gear contact stress amplitude frequency relationship is obtained. Finally, combined with the relevant theory, the reducer gear contact fatigue life and the reducer gear life mileage corresponding to running a load spectrum mileage under this fatigue are obtained.
(1) The half axle load is collected, and the collected load is processed in ncode. According to the working principle of the reducer gear, the rotating rain flow is used for cycle counting, and the amplitude frequency relationship of the contact stress of the reducer gear is obtained.
(2) Through the contact fatigue theory, it is calculated that the contact fatigue life of the reducer gear based on the measured load spectrum is 4928, and the mileage after running a load spectrum is 72.86km. At this time, the mileage life of the corresponding electric vehicle reducer gear is 359100 km.