Patent ID: 8573569
Filing Date: 2013-11-05
Classification: F16F,H02K,Y10T

Abstract:
1. An active vibration damper comprising: an electromagnetic linear actuator incorporating a stator and a movable member exerting oscillation force on each other, the stator being attached to a target member whose vibration is to be damped while the movable member is elastically supported by the target member via an elastic connecting rubber; an inner shaft member fixed to the movable member so as to project to both sides in a direction in which the oscillation force exerts; an outer tube member comprising a coil and being fixed to the stator so as to be spaced apart peripherally outward from the inner shaft member and so as to extend to both sides in an axial direction; a pair of leaf springs elastically connecting projecting portions situated on axially both sides of the inner shaft member and the outer tube member; the elastic connecting rubber being disposed outwardly from one axial side of the linear actuator and connecting the inner shaft member and the outer tube member, an outer peripheral edge of the elastic connecting rubber being bonded by vulcanization to an outside peripheral fastener fitting of large-diameter tubular shape and an inner peripheral edge of the elastic connecting rubber being bonded by vulcanization to an inside peripheral fastener fitting of smaller-diameter tubular shape; a mass body holding portion formed by an end portion of the inner shaft member, the inner shaft member extending though the inside peripheral fastener fitting to an opposite side of the linear actuator with the inside peripheral fastener fitting being interposed between the end portion and the opposite side, and formed by a fastening member detachably fixed to the end portion of the inner shaft member, the mass body holding portion being capable of holding at least one additional mass body corresponding to a frequency of the vibration of the target member, the at least one additional mass body being disposed further outwardly than the elastic connecting rubber from the one axial side of the linear actuator; and a housing fixed to the stator of the linear actuator and separating a relative displacement zone of the stator and the movable member from an external space while accommodating the pair of leaf springs and the elastic connecting rubber, the housing having a structure dividable in the axial direction in which respective openings are secured to each other with an annular seal being interposed therebetween at an outer peripheral side of the elastic connecting rubber, wherein the at least one additional mass body is selected from a plurality of mass bodies having differing masses assorted for the linear, the plurality of mass bodies being attachable to the mass body holding portion while being forcedly held between the inside peripheral fastener fitting and the fastening member.