Fatigue life analysis method for differential shell of electric drive assembly

Abstract

The invention particularly relates to a fatigue life analysis method for an electric drive assembly differential shell. The fatigue life analysis method comprises the steps: establishing a differential shell finite element model of the electric drive assembly differential shell; verifying the accuracy of the finite element model of the differential shell; calculating a stress relation of the successfully verified differential shell finite element model under a unit torque load; calculating a material S-N curve of the differential shell of the electric drive assembly, and calculating a corresponding relationship between fatigue life and stress according to the material S-N curve; taking the actually measured load spectrum of the differential shell of the electric drive assembly as load input, and calculating corresponding equivalent stress according to the stress relation under the unit torque load; and calculating and evaluating the fatigue life of the differential shell of the electric drive assembly according to the equivalent stress and the relationship between the fatigue life and the stress. According to the fatigue life analysis method, the influence of the impact load can be fully considered, and the actual bearing torque condition is better combined, so that the accuracy of the fatigue life analysis of the differential shell can be improved.

Description

technical field [0001] The invention relates to the technical field of fatigue life analysis of a differential case, in particular to a method for analyzing the fatigue life of a differential case of an electric drive assembly. Background technique [0002] The differential case is the intermediate link connecting the main reducer and the half shaft for power transmission, which is prone to fatigue failure at the planetary shaft hole, fatigue damage on the upper part of the window of the differential case, etc., which will lead to vehicle failure and personal injury . Therefore, in the prior art, many studies have been carried out on the strength, modal, and fatigue life of the differential case. For example, a foreign document divides the rotational position of the input shaft of the main reducer into 18 equal parts around the circumference, and analyzes the stress of the differential case under the rotating cyclic load, and obtains the damage accumulation of the different...

AI Technical Summary

Problems solved by technology

In addition, the rotation speed of the motor is wider during acceleration and deceleration, so that the reducer gear is affected by a large number of small loads, which in turn causes large fluctuations in the transmission load of the differential case of the electric drive assembly, resulting in fatigue damage to the differential case more difficult to determine

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