Automobile drive axle housing itself needs to bear a lot of load,in addition to be responsible for the transfer of load,the use situation is very bad,often due to the impact load and alternating load deformation and fracture,which requires that the drive axle housing has enough yield strength and stiffness to meet the requirements of its use.
The role of the drive axle housing is to support and protect the main reducer,differential and axle,etc.In addition,it is the main component of the driving system,it also has the following functions.
1,together with the front axle to bear the weight of the car.
2,so that the left and right driving wheel axial relative position is fixed.
3.When the car is running,it bears the reaction force,bending moment and braking moment from the driving wheel,and it is transmitted to the frame through the suspension.
Drive axle housing belongs to the plate and shell structure,the main parts of the upper and lower axle housing are welded by the heat sheet stamping forming of the same thickness;The bushings at both ends are made of seamless steel tubes.Shell units are selected to divide the bridge housing structure into grids,and the average size of the grid is 5mm.
The main body of the axle housing is made of LG600QK steel,which has high strength and good forming performance.
Boundary conditions and loads
Driving axle housing has high requirements for impact resistance,so it is necessary to check whether the strength and stiffness of driving axle housing can meet the design requirements under full load vertical bending,impact and braking conditions.
1)Vertical bending at full load.Reference standard QC/T533-1999 automobile drive axle bench test method"load and constraint,the rated load G=5.5 tons,rear axle loading position for the plate spring pin hole,constraints on both ends of the drive axle shell shaft sleeve and the wheel hub bearing contact area at the corresponding node Y axis and Z axis displacement degrees of freedom in two directions and around two axes rotational degree of freedom.
2)Impact situation.The impact load coefficient is set as K1=2.5,the load size is 2.5 times of Case 1,and the constraint conditions are the same as Case 1.
3)Braking condition.The manufacturer of the driving axle housing points out that when the car is braking in an emergency due to an emergency situation in the process of driving,the vertical load is F=G*K2/2,where K2 is the weight transfer coefficient of the car during the emergency braking,and K2=0.8.The weight braking inertia force on the leaf spring is:T=G*K2*K3/2,where the ground adhesion coefficient of K3 is,and K3=0.8.Constraint the displacement degrees of freedom in the Y axis and Z axis directions and the rotational degrees of freedom about the three axes of the corresponding nodes at the contact surface area between the bushings at both ends of the driving axle housing and the hub bearing.
After the axle housing body is replaced with LR1500HS material,the strength backup coefficient under full load vertical bending reaches the prescribed limit.In addition,the main body of the axle housing is reduced by 22.4,accounting for 33.3%,which realizes the lightweight design of the axle housing.
