Development of a DC brush motor with 50% weight and volume reduction using an Nd-Fe-B anisotropic bonded magnet

There is a need to reduce the weight and size of dc brush motors for automobile use. In the current study, sintered ferrite magnets were replaced by Nd-Fe-B anisotropic bonded magnets in an effort to reduce the size and weight of the motor. Finite-element analysis was carried out, and a four-pole anisotropic magnet was determined to be optimal. Based on these results, an actual 35-W brush motor for power automobile seats was test produced. A roughly 50% reduction of weight and volume was realized in this test-produced motor, which also maintained the same torque as the currently used ferrite motor.