| 摘要 |
A brushless synchronous rotary electrical machine comprises stationary stator and "rotor" windings. Only the rotor moves. The rotor winding is a stationary helical winding, concentric with the rotor shaft and attached to the stator armature. Variation in time of the magnetic field associated with the rotor is provided by one or more magnetically interactive (ferromagnetic or ferrimagnetic) projections from the rotor that sweep past the sides of the rotor winding as the shaft rotates. Because all windings are stationary, brushes and rings are not needed. The geometries of the rotor, of the stator windings, and of the magnetically interactive part of the stator armature are arranged so that the entire length of the wire in the windings participates in the generation of AC current (in a generator) or torque (in a motor), and so that loss of power to eddy currents is minimized. In preferred embodiments of the machine as a generator, the geometries of the rotor and of the stator armature are chosen to ensure that the magnetic field through the AC winding changes sign cyclically. |
