| 摘要 |
<p>A PMDC motor 10 has a casing 11 accommodating permanent magnets 34 of the stator and forms a flux return path. The wall thickness of the casing is such that the casing is magnetically saturated. A flux ring 30 is fitted to the casing 11 about the permanent magnets 34. The flux ring 30 has a substantial gap 35 between opposing edges 36 of the ring. The gap 35 in the flux ring is aligned with a space between the permanent magnets 34 so that the flux return path on one side of the motor is predominantly through the casing only whereas on the other side, it is through the casing and the flux ring thereby causing a shift in the centre of the magnetic field towards the side 31 with the flux ring 30 . <IMAGE></p> |
