Abstract: In order to cut down the manufacturing cost of four in-wheel-motor drive electric vehicle, it is an effective way to reduce the items of parts and components and simplify the structure of chassis. Based on the optimum design of the suspension and steering mechanism, a new double-wishbone suspension mechanism with zero toe-in fluctuation is presented, and then a module structure composed of double-wishbone- suspension, torsion bar and in-wheel-motor is developed. Thus same structure of the suspension-in-wheel-motor module can be used in the front and rear wheel, and the results have successfully been applied in the development of the Spring Sunshine, which is a new type of four in-wheel-motor drive fuel cell vehicle with steer-by-wire.

Key words: Double-wishbone suspension, Four wheel drive fuel cell vehicle, In-wheel-motor Steer-by-wire, Spatial linkage