摘要 |
<p>A rotary electromagnetic actuator comprises a rotatable shaft carrying a rotor which is rotatable relative to a stator. A magnetic circuit is set up which comprises the stator and the rotor, the reluctance of the magnetic circuit being dependent on the relative rotational orientation of the rotor and stator and decreasing in a particular direction of rotation such that the reluctance is a minimum at an equilibrium position to which the rotor is therefore biased. The rotor is selectively impelled to advance away from the equilibrium position, subsequently again becoming part of a magnetic circuit, the reluctance of which decreases in the direction of rotation to a minimum at an equilibrium position to which the rotor becomes biased. The actuator provides unidirectional rotation for successive actuations at substantially uniform torque and is suitable for use in actuating rotary devices such as rotary valves.</p> |