Electric machine having segmented stator with shield elements

摘要

An electric machine comprises a substantially circular rotor 242 and a stator, wherein the stator comprises at least one substantially arcuate segment 200. Stator segments may be spaced apart (e.g. two segments arranged diametrically) and configured so that when in use the magnetic flux paths generated in one stator segment are contained within that segment as shown in fig 4. In a permanent magnet machine, a magnetic shield structure 625a may be integrally formed with the segment.. Alternatively the shield may comprise a separate portion which engages the ends of the segments (fig 10 not shown). The end portions of the segments 320RST which form tabs may be slotted to engage mounting hooks 320F or the hooks may be arranged to engage the inner radial surface of the segment (fig 6b not shown). Alternatively the tabs maybe provided with a bore to receive a fixing element. A number of segments may define a complete circle. The pole ratio between stator and rotor may be expressed as R= (2P*360/(segment arc)) ± 2. The machine may be used in a motor vehicle component. An inductor or a reluctance machine arrangement is also disclosed.