Design and analysis of coreless multi-layered permanent magnet synchronous motor

In recent years, small-size and high-torque motors are required for various purposes. For example, the joint of the power assists suit, the drive part of an electric wheelchair and haptic device etc. Among them, it is important that the motor used in the haptic device is a direct drive system. This is to reduce discomfort for users by high back drivability. In the case of a device in which the motor itself moves, the motor needs to be lightweight. Therefore, design and analysis of a coreless multi-layered permanent magnet synchronous motor are presented in this paper. The validity of designed motor is confirmed by comparing with SPMSM from the perspective of torque per weight in magnetic field analysis.