Brushless dc permanent magnet motors for traction drive systems

摘要

A brushless permanent magnet DC motor for use in a traction drive system has power density and high efficiency. The motor includes a multiple turn, fast insertion, double wave winding which does not have distinct interconnection wires between the coils (the interconnections are part of the coils), and the end turns are distributed on both sides of the stator core so as to minimize the size of the end turns. The housing is part of the stator and has integral, radially extending, circumferentially spaced cooling fins so that there is no thermal gap, or thermal contact, resistance between separate housing and stator components. The motor includes bearings mounting a shaft of the rotor of the motor, and structures for positively maintaining the bearings concentric with the stator to provide optimized service life. A stator assembly, per se, having novel windings may be utilized in other motors, and a novel method of winding a stator that is simple yet achieves the desired results of efficiency and minimized cost, are also provided.