Overview of Performance and Comparative Evaluation of Linear Tubular and Planar Consequent Pole PM Vernier Motor for Servo Applications

Tubular linear structures have been shown to offer higher torque density, power factor and efficiency in comparison with linear planar structures. In addition, these structures exhibit greater mechanical tolerance to misalignments and faults, which renders them advantageous in a variety of applications. The present paper evaluates a tubular permanent magnet Vernier motor with a consequent pole configuration. In this design, the magnets are arranged side by side in a Hal-Bach, surface and V-shaped array suitable for servo application. The end-effect and thrust force ripple are minimized, while the power factor and the average thrust force are enhanced, through the utilization of electrical and mechanical phase shifts of the modules with respect to each other and to the reference, in comparison to the planar structure. The predicted performances of both structures are validated through experimental validation.