Research on interference fit strength of stator in high-power electric drive integrated housing for vehicles

Abstract The development of an integrated electric drive system has become a key trend for the future of the industry. By closely integrating and co-optimizing components of the drive system, this compact modular design not only reduces the number of parts but also significantly enhances power density and reliability. In terms of high-power electric drive integrated housings, larger stator outer diameters and output torque impose increased strength requirements on irregularly shaped housings. Interference fitting serves as the primary method of fitting the housing and stator, effectively enhancing structural strength. This study investigates the stress and strain distribution after interference fitting between the integrated housing and stator under various interference conditions. The results reveal the locations of maximum deformation and stress within the housing when interference fits range from 0.05 to 0.4 mm, as well as the stress-strain variation patterns in major directions. The positions of maximum deformation and stress remain unchanged due to the increase of interference, while both values exhibit a positive linear correlation with the amount of interference. When the interference is 0.05 mm, the maximum deformation and stress of the integrated housing are 0.084 mm and 33 MPa, respectively. As the interference increases to 0.4 mm, these values reach their peak at 0.6725 mm and 279.70 MPa. The distribution and values of these deformations and stresses can provide theoretical guidance for the precise processing and assembly of irregularly shaped housings.