Rotary single-phase electromagnetic actuator

摘要

A single phase, rotary electromagnetic actuator comprising first and second stator assemblies, located in oppositely facing spaced apart positions along a common central axis, permits a magnetized disc magnet rotor to rotate about the common axis free of any magnetic attractive forces normally tending to move the disc magnet longitudinally along the axis, or alternatively to be located in a position to create a desired longitudinal attractive force. The entire assembly is maintained in operative positions by a circular belt which provides an inward facing lip on each side of which the stator assemblies are seated and which determines the magnetic airgap spacing for the disc. The invention may be implemented as a servo-actuator by the inclusion of an angular position sensor that uses the actuator rotor as the magnetic field emitter, and a receiver for the magnetic field and its contacts, located in the belt lip.

主权项

1. A rotary single-phase electromagnetic actuator comprising:
two stators with at least one of those stators being an active stator for generating a magnetic field, the active stator having a stator structure with two stator poles having two opposed inner parallel flat surfaces extending to a base and said other stator having two stator poles extending to a base, said two stator poles configured for single-phase activation, the two stators being axially spaced apart a predetermined distance defining an airgap with a dimension (E); wherein said two stator poles of said active stator are spaced apart a radial distance (D) separating said two opposed inner parallel flat surfaces along a direction perpendicular to said parallel flat surfaces such that a ratio of D to E (D/E) is in a range of 4 to 5; an inertia assembly comprising:
a shaft defining an axis;a disc magnet rotor absent a yoke of high permeability magnetic material mounted on the shaft for rotating the shaft, the rotor magnet being axially magnetized with a plurality of pole pairs of alternating polarity; the rotor being in the airgap and spaced from each stator by a predetermined distance; wherein the two stators are configured and positioned relative to one another so as to establish, when said at least one active stator is energized, a closed-loop magnetic flux circuit that flows between the two stators through the stator poles, said base of the active stator, said base of the other stator and the rotor, and wherein the interaction between the rotor's magnetic field and the magnetic fields of said stators is capable of generating a torque delivered to the shaft so as to produce an angular stroke of equal to or less than 180 degrees.