Elastic shaft joint

An elastic shaft joint for coupling an end portion of a rotatable shaft to a rotary member for rotating upon a rotation of this shaft to absorb some displacement thereof in the axial direction and the direction of rotation, wherein said shaft is provided with a pair of outer-diameter side engagement surfaces which are substantially parallel to each other at two positions on the opposite sides in the radial direction of the outer peripheral surface of at least one end of the shaft, a coupling sleeve is disposed in the vicinity of an end portion of the shaft to be extended in the axial direction of said shaft, provided with inner-diameter side engagement surfaces which are substantially parallel to each other at two positions on the inner peripheral surface on the opposite sides in the radial direction in a half part in the axial direction closer to the one end of this shaft to face said outer-diameter side engagement surfaces with a gap therebetween in a neutral state in which no phase shift is generated with respect to the direction of rotation between said coupling sleeve and said shaft, a rotation limiting cylinder for limiting an amount of rotation of said shaft within said coupling sleeve, a retaining cylinder having a larger diameter than that of the rotation limiting cylinder is provided in the other half part of said coupling sleeve in the axial direction, which is a part closer to a middle portion of this shaft, a vibration absorbing member is provided between the inner peripheral surface of this retaining cylinder and the outer peripheral surface of one end of said shaft for preventing a vibration from being transmitted to and from the coupling sleeve in said neutral state so as to allow a displacement in the axial direction of said shaft with respect to this coupling sleeve, and the base portion of said rotary member to which the end portion of said shaft is coupled and fixed is formed to have a pair of restraint plate portions which are substantially parallel to each other and an opening on the lateral side thereof, and in the state in which the rotation limiting cylinder of said coupling sleeve is inserted between these two restraint plate portions through said lateral opening, these restraint plate portions are suppressed toward each other, thereby connecting and fixing said coupling sleeve to said rotary member.