Patent ID: 7810798

Claim:
An electromagnetic actuator for active vibration damping device, comprising: a stator including a cylindrical shaped housing with a bottom wall and a coil member disposed within the housing, the housing having an adjustment hole open in a center of the bottom wall; a lid member attached onto the housing so as to cover the adjustment hole; a movable member disposed in a central hole of the coil member so as to be movable in an axial direction, the movable member having an insertion through hole formed piercing on a central axis thereof; a coupling rod inserted through the insertion through hole and positioned in the axial direction in relation to the movable member by a fixing member installed at one axial side of the coupling rod and a biasing member installed at an other axial side of the coupling rod so that oscillation force is applied to the coupling rod from the movable member when the coil member is energized; and an integrally molded stopper that is formed of a rubber elastic body having a ring shaped sealing unit positioned at an outer periphery part, a first stopper unit positioned at a center part, a coupling unit that mutually couples the ring shaped sealing unit and the first stopper unit, and a plurality of second stopper units located radially between the ring shaped sealing unit and the first stopper unit while being independent from one another in a circumferential direction, wherein the integrally molded stopper is superposed and mounted on an inner surface of the lid member such that the ring shaped sealing unit is compressed between the bottom wall of the housing and the lid member to thereby form a sealing mechanism that fluid-tightly close an opening of the adjustment hole, that the first stopper unit is arranged facing in the axial direction to a bottom end of the coupling rod with a first separation distance between axially facing surfaces of the first stopper unit and the coupling rod, that the second stopper units are arranged facing in the axial direction to a bottom edge surface of the movable member with a second separation distance between axially facing surfaces of the second stopper units and the movable member, and that the second separation distance is greater than the first separation distance.