Design and Analysis of Electric Motor With Integrated Magnetic Spring for Cyclic Loads

Cyclic loads such as weaving looms have an oscillating load torque profile which negatively affects the motor size and power consumption. In this article, a novel electric motor with an integrated magnetic spring (EMMS) is proposed for cyclic loads. The magnetic spring provides the majority of the oscillating part of the load torque in a passive way, thereby reducing the power consumption. Besides, the design and analysis of the proposed EMMS are investigated for a weaving loom application. Moreover, the optimal design of the EMMS is manufactured and various measurements are obtained to validate the principle of the EMMS. It is found that the EMMS can effectively deliver about 40% of the load torque in a passive way. Interestingly, the amount of the delivered torque by the magnetic spring depends on the design choice. For a given load torque, the higher the delivered torque of the magnetic spring is, the lower the power consumption from the supply will be. However, this increases the manufacturing cost of the EMMS. Therefore, the torque of the magnetic spring is a design choice that is a compromise between the investment cost of the EMMS and the total cost of ownership.