Design of NdFeB bond magnets for in-wheel permanent magnet vernier machine

This paper proposes a permanent magnet vernier machine, PMVM, with outer rotor structure and shows its characteristics calculated by FEM. The authors have previously proposed employing NdFeB bond magnets PMVM. This machine satisfied the output characteristic required in the in-wheel machine for EV and showed high efficiency in computer simulations based on FEA. However, its design had some problems. The previously proposed machine was large for small truck. The air gap length was small, 0.6 mm. The coil end of the armature winding was large because it used the traditional fraction slot winding. Therefore, this paper discusses downsizing it with wider air gap and employing the concentrated winding. As a result, the new designed machine has attained the targeted torque, 600 Nm.