Rotary reciprocating drive actuator

A rotary reciprocating drive actuator comprising:

• a movable member including a shaft and a movable magnet that is fixed to the shaft and has a ring shape, wherein a first half part and a second half part of the ring shape are magnetized to different poles, the ring shape being divided by a magnetic pole switching part extending in a direction orthogonal to an axis direction of the shaft;
• a fixing body including a pair of coils, a pair of core parts, a pair of magnetic poles, and a rotation angle position holding part, wherein the pair of coils causes reciprocating rotation of the movable member about the shaft by electromagnetic interaction with the movable magnet, the pair of coils are respectively wound around the pair of core parts, each of the pair of magnetic poles is provided at one end portion of a corresponding one of the pair of core parts, the pair of magnetic poles are disposed so as to sandwich the movable magnet therebetween in an X direction orthogonal to the axis direction, the rotation angle position holding part is disposed at a core of the fixing body on one side of the movable magnet in a Y direction orthogonal to the axis direction, and the rotation angle position holding part generates a magnetic attractive force between the rotation angle position holding part and the movable magnet so as to define an operation reference position for the reciprocating rotation, the operation reference position being a position where the magnetic pole switching part becomes parallel to the X direction,
• wherein
• each of the pair of magnetic pole is formed in an arc shape along an outer peripheral surface of the movable magnet from an opposing position facing the magnetic pole switching part of the movable magnet to a side where the rotation angle position holding part is disposed and to a side where the rotation angle position holding part is not disposed, the movable magnet being located at the operation reference position,
• an assembled magnetic member has a rectangular shape surrounding the movable member in a plane orthogonal to the axis direction, the core extends in the X direction along one edge of the rectangular shape, and the pair of core parts respectively extend in the Y direction along a pair of opposing edges of the rectangular shape that are different from the one edge, the assembled magnetic member including the pair of magnetic poles, the pair of core parts around which the pair of coils are respectively wound, and the core at which the rotation angle position holding part is disposed, and
• winding axes of the pair of coils extend along the Y direction.