Patent ID: 8680723

Claim:
A linear actuator comprising: a stationary part comprising: a stator comprising a ring-shaped yoke having a pair of longitudinal sides and a pair of lateral sides, and a pair of teeth each extending inwardly from one of the pair of longitudinal sides; and a winding wound on one of the teeth; a movable part moveably disposed between the pair of teeth and comprising two pairs of permanent magnetic poles each facing one of the pair of teeth and an output shaft projecting in a first direction; and a pair of elastic members coupling the movable part to the pair of lateral sides of the yoke and configured to generate a returning force in a second direction perpendicular to the lateral sides of the yoke and parallel to the longitudinal sides of the yoke; wherein when the windings are electrified, the stationary part generates a magnetic field which interacts with the permanent magnetic poles to reciprocate the movable part relative to the stationary part in the second direction.