摘要 |
A multistable electromagnetic actuator is provided which addresses a need for a more robust, reliable and energy efficient actuation device. It comprises an armature (10) having a permanent magnet (8), wherein the armature is movable between first and second stable positions, and two electric coils (14a,14b) disposed on opposing sides of the armature along its direction of movement, with their axes substantially aligned with said direction. A magnetic flux container (2) substantially surrounds the armature and the coils to contain magnetic flux generated thereby and to shield its interior from external magnetic flux. In each stable position magnetic flux generated by the permanent magnet (8) extends around a magnetic circuit path including the container so as to retain the armature in its stable position. Energising the coils (14a,14b) causes the armature (10) to move from one stable position to the other. It is suitable for a broad range of applications, including fluid flow control for example. |