| 摘要 |
A linear actuator 1 comprises coils 3a, 3b and plural magnets 6a, 6b, 8, where the magnets are arranged in a Halbach configuration. The Halbach configuration of magnets may provide stronger magnetic fields in the vicinity of the coils 3a, 3b whilst reducing the magnetic fields in a shaft 5 region. A light weight non-magnetic plastic material may therefore be used as the shaft 5. A compact, quick and efficient actuator providing large uniform linear forces over the length of the actuator stroke and precise armature position control may be obtained. The linear actuator 1 may include two coils arranged in an E-shaped magnetic material core 2, where each gap 12a, 12b in the E-core 2 is arranged to be adjacent a respective radially polarised magnet 6a, 6b. The stroke of the armature may be limited such that the gaps 12a, 12b in the core 2 are always above the respective radially polarised magnets 6a, 6b. A sleeve 4 of non-magnetic material may be used to separate the stator from the armature of the actuator. A number of linear actuators may be linked in series. A circuit using feed back signals may be used to control the current applied to the coils of the actuator 1. |
