Pure Electric Vehicle Integrated Drive Axle Development

With the continuous advancement of science technology and the development of economy.Car ownership is on the rise,the energy crisis and environmental pollution received more and more attention.Under such circumstances,electric vehicles with energy-saving and pollution-free have begun to develop at a high speed.The drive axle is not only one of the main components of the car,it is also an important component of automotive powertrain.The complex working conditions and the harsh working environment during the working process make the drive axle must meet enough strength and stiffness.So the design of the electric vehicle drive axle is very significant,the main content of this article:(1)According to the design drawings of the drive axle provided by the company,design calculations for gears according to the Mechanical Design Manual,using the 3D design software SolidWorks to build the 3D digital model of the transaxle.Theoretical calculation of the drive axle,determine load application position and constraint position;Theoretical calculation of gears,determine load application position and constraint position.After completing the establishment of the transaxle 3d model,import the drive axle housing 3D digital model into HyperMesh,geometric cleaning,meshing,grid quality checking,and establishment of connection relationships,complete the establishment of the finite element model of the drive axle housing.(2)According to the actual working condition of the drive axle housing,select the maximum vertical force condition,maximum lateral force condition,maximum driving force condition,maximum braking force condition for static analysis,the results show: Drive axle housing under maximum vertical force,its deformation mainly occurs in the middle of the drive axle,the maximum deformation is 1.2mm;The position with higher stress is mainly distributed at the position of the spring seat and the variable cross section of the half shaft casing,its maximum stress is 156.9MPa.Drive axle housing under maximum driving force,the deformation mainly occurs at both ends of the axle housing and the middle of the drive axle,The maximum deformation is 0.73 mm,The location of the greater stress mainly occurs around the spring seat and at the variable cross section of the half shaft casing,its maximum stress is 112.8MPa.Drive axle housing under maximum braking force,its deformation mainly occurs in the middle of the drive axle,the maximum deformation is 0.93mm;The location of the stress is mainly at the spring seat and its surroundings,its maximum stress is 151.6MPa.Drive axle housing under maximum lateral force conditions,the deformation mainly occurs at the right end of the axle housing,the maximum deformation is 0.55mm;Large stresses mainly occur at the spring seat and its surroundings,the stress on the variable cross section of the right shaft tube and the axle housing is also large,Its maximum stress is 214.2MPa.Simulation analysis of the half shaft,the results show: The location of the stress is mainly at the root of the semi-axle spline,the stress at the transition position between the half shaft and the flange is also large,its maximum stress is 668.8Mpa.Gear meshing analysis of gears using ANSYS,the results show: The larger stress of the primary gear mainly occurs at the gear contact and the gear root position,its maximum stress is 298.94 MPa.The large stress of the secondary gear mainly occurs at the gear contact and the gear root position,its maximum stress is 661.92 MPa.Constrained modal analysis of the Drive axle housing,the results show: The lowest frequency of the drive axle housing is 74.5 HZ,Avoid external frequencies such as road excitation.(3)Based on the maximum vertical force condition,fatigue analysis of the Drive axle housing,the results show: Strain and fatigue cracks occur at the variable cross section of axle housing and half shaft sleeve,the minimum fatigue life of the drive axle housing is 657100 times;Based on the maximum vertical force condition,fatigue analysis of the transaxle assembly,the results show: Strain and fatigue cracks occur at the variable cross section of axle housing and half shaft sleeve,the minimum fatigue life of the drive axle assembly is 748900 times.(4)Design the integrated shaft,through theoretical calculations,the integrated shaft design is in line with the requirements;Redesigned motor end cap and main reducer housing according to the newly designed integral shaft;Then perform finite element analysis on the transaxle assembly,the results show: Under maximum vertical force conditions,the deformation of the drive axle assembly mainly occurs in the middle of the drive axle,the maximum deformation is 1.0mm;Larger stress locations occur mainly at the spring seat and at the variable cross section,its maximum stress is 133.8MPa.Fatigue analysis of new drive axle assemblies,the results show: Based on the maximum vertical force condition of the transaxle assembly,strain and fatigue cracks occur at the variable cross section of axle housing and half shaft sleeve,the minimum fatigue life of the drive axle assembly is 683100 times.