Active vibration damper and method of manufacturing active vibration damper

A method of manufacturing an active vibration damper, comprising the following steps of:

• preparing a linear actuator, in combination with an elastic connecting rubber, a plurality of additional mass bodies having different masses, and a housing;
• attaching the elastic connecting rubber to the linear actuator;
• optionally attaching at least one of the plurality of additional mass bodies to the linear actuator, based upon a frequency of vibration of a target member;
• and
• forming the housing, wherein the linear actuator comprises:
• a stator and a movable member exerting oscillation force on each other;
• 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 extend to both sides in an axial direction;
• and
• a pair of leaf springs elastically connecting projecting portions situated on axially both sides of the inner shaft member and the outer tube member,
• wherein the elastic connecting rubber is disposed outwardly from one axial side of the linear actuator and connects the inner shaft member and the outer tube member,
• wherein an outer peripheral edge of the elastic connecting rubber is bonded by vulcanization to an outside peripheral fastener fitting of large-diameter tubular shape and an inner peripheral edge of the elastic connecting rubber is bonded by vulcanization to an inside peripheral fastener fitting of smaller-diameter tubular shape,
• wherein the at least one additional mass body of the plurality of additional mass bodies is disposed further outward than the elastic connecting rubber from the one axial side of the linear actuator, and is selectively attachable to a mass body holding portion formed by an end portion of the inner shaft member of the linear actuator, the inner shaft member extending through 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, such that the at least one additional mass body is forcedly held between the inside peripheral fastener fitting and the fastening member, and
• wherein the housing has 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, and is fixed to the stator of the linear actuator so as to separate a relative displacement zone of the stator and the movable member from an external space while accommodating the pair of the leaf springs and the elastic connecting rubber.