| 摘要 |
A linear actuator has a stator with two stator coils 30 and pole plates 32 forming stator poles. A rotor is rotatably mounted to interact with the stator poles 32, the rotor comprising a hollow cup shaped permanent magnet 36 fitted to a rotor shaft 44 by coupler 38 and being supported by a bearing 28 located within the magnet, axially between axial ends of the permanent magnet 36. The location of the bearing, which may be a roller, needle, or ball bearing, at the approximate balance point of the rotor reduces risk of radial deflection. A single bearing or a combination of bearings may be used. An linear output shaft 20, which is co-axial with the rotor, is driven by the rotor through a screw connection 50. Thrust bearing 42 engages a spring preloaded thrust pad though a friction cup 56 which increases the holding force when the motor is not operating and a detent plate 34 may also be included to interact with the rotor poles. |
