Integrated Design of In-Wheel Motor System on Rear Wheels for Small Electric Vehicle

Generally, In-Wheel motor system consists of suspension, steering, electric motor, friction brake, and wheel and varies with the combination structure of each component. However, the key point of In-Wheel motor system to be applied in small electric vehicle is the integration capability to meet the requirements such as wheel space, power performance, strength of components and so on. This paper describes integration methodology for In-Wheel motor system on the rear axle with the consideration of the restricted wheel space and unsprung mass. In addition, optimization of the motor housing is performed to improve mass and strength of the In-Wheel motor housing according to the test specification of weight transfer from the tire patch. It is found from the results that the prototype In-Wheel motor system meets the vehicle performances and strength requirements.