Effect of the electromagnetic force on the power-train vibration of the in-wheel motor driving system with rubber bushings

For an in-wheel motor driving system with rubber bushings, the driving motor is integrated into the wheel. A magnet gap deformation of the motor will be inevitably caused by the road excitation, which will produce an unbalanced electromagnetic force and influence the power-train vibration. Furthermore, the rim is flexibly connected to the motor rotor by rubber bushings, and a strong coupling and nonlinear vibration of the power-train in all directions can be demonstrated under the electromagnetic excitations. Thus, a 14-degree-of-freedom coupling vibration model of the power-train is first developed for the in-wheel motor driving system with rubber bushings, including the bushing and bearing models. Then, the mathematical model is deduced using a Lagrangian approach. Finally, based on the model, a coupling vibration analysis is conducted under different electromagnetic force excitations. The results indicate that there are coupling vibration components in the torsional direction, except the one-time rotat...