Patent ID: 6921999

Claim:
An electromagnetic rotary actuator, controlled by a single voltage, comprising: a rotor movable about an axis and including at least one permanent magnet having magnet poles; a stator having at least one winding; and an airgap formed between facing surfaces of the at least one permanent magnet and of the stator, wherein the at least one permanent magnet is arranged to have flux lines extending in the airgap substantially in a radial direction from or towards the axis; wherein the stator has at least three pole teeth made of a magnetically permeable material, the at least one winding applied around a central one of the at least three pole teeth, and the at least three pole teeth having end surfaces forming the facing surfaces of the stator and thus facing surfaces of the at least one permanent magnet over the airgap; wherein the magnet poles of the at least one permanent magnet of the rotor and the at least three pole teeth all have the same angular pitch, and wherein the rotor has a peak to peak movement that is substantially less than 360 degrees about the axis.