A Methodology for the Design of a Single-Sided Axial-Flux Permanent Magnet (AFPM) Motor for Lathe Machines

A single-sided axial-flux permanent magnet (AFPM) motor with a fractional slot concentrated winding (FSCW) is a suitable choice for low-speed and high-torque applications such as lathe machines. Having a disc-type structure with an FSCW allows increasing the number of poles to reduce the motor volume. There are various equivalent two-dimensional (2-D) models for the analysis of single-sided AFPM motors, but because of the complex structure, the optimal design of this motor type requires several three-dimensional (3-D) analyses. For example, using 2-D FEA for estimating magnets' eddy current losses and consequently, the motor efficiency could be misleading in the design process. This paper aims to provide a design workflow based on a combination of 2-D and 3-D FEA for the optimal design of a single-sided AFPM motor. The purpose is to segregate the calculation of different motor parameters such as magnetic loading, d- and q-inductance, static torque curve, efficiency, etc. from each other. This segregation makes the right selection of the proper model for the calculation of each motor parameter possible, which leads to a well-targeted design workflow. To evaluate the performance of the proposed method, a 4kW-750rpm motor for the lathe machine is designed. Simulation results are presented and discussed.