Reliability Analysis and Evaluation of Differential System Based on low Load Strengthening Model

The differential is an important part of a driveline, and differential performance is related to the handling and stability performance of a vehicle. Thus, a differential with sound design structure and reasonable form and size parameters could lead to satisfactory driving performance. In this work, we analyze and evaluate the reliability of the key parts of a differential system. Firstly, each of key parts is regarded as a subsystem of a differential system, so the subsystem reliability models are obtained. A system reliability model is built based on the paths of the forces from the differential system, and system reliability is calculated. Secondly, according to the result of the analysis of system reliability and the use of the six sigma method, 45 steel or 1Cr18Ni9Ti utilized as the material for the worm shaft, system reliability is analyzed and discussed separately. Then, the reliability of the key parts and the overall system reliability increase with the low load strengthening characteristic of the material. Finally, according to the analysis and discussion, the level of system reliability matches that required for differential systems, and the cost is also considerably reduced, as demonstrated using the stress–strength interference and low‐load strengthening models. These results provide a theoretical basis for the improvement of the design of Torsen differentials. Similar methods can be used to develop automobile subsystems in the future. Copyright © 2015 John Wiley & Sons, Ltd.