Electronically-commutated DC motor for vehicle propulsion drive

摘要

The motor has a permanent magnet rotor (50) with an even number of permanent magnet poles (54, 56), arranged at a constant relative spacing. The rotor rotates within a cylindrical air-gap (55), between the rotor and a self-supporting stator winding (32), exhibiting a uniform magnetic field with radial field lines and alternating field polarities. The stator winding has straight winding sections (34, 36) parallel to the rotor rotation axis (45), of corresponding width to the rotor poles, each exhibiting a single current direction. The conductor material of each winding section is provided by one or more filament bundles (39) with individually insulated thin filaments, which have a dia. of 0.4mm or less and are twisted within the bundle. The conductor material is embedded in a hardened plastics resin with the resulting stator winding containing between 70 and 90% by vol. of the conductor material.