Patent ID: 6993989

Claim:
A starting apparatus for starting an engine comprising: a drive motor; a housing; and a reduction gear including: a sun gear disposed to rotate by receiving an input from the drive motor; an internal gear arranged in the housing concentrically around the sun gear and movable in a circumferential direction with respect to the housing; a planetary gear meshing with the sun gear and the internal gear; a carrier rotatably supporting the planetary gear and outputting an input of the sun gear by reducing a speed thereof; and a rotation constraining unit to constrain movement of the internal gear, wherein the rotation constraining unit includes: a first protruding portion integrated with the internal gear to move with the internal gear in the circumferential direction, the first protruding portion protruding in a first direction parallel to an axial direction; a second protruding portion integrated with the housing to be unmovable in the circumferential direction with respect to the housing and opposed to the first protruding portion, the second protruding portion protruding in a direction directly opposite to the first direction; a shock absorbing member, including a main elastic block portion that is elastically held between the first protruding portion and the second protruding portion, to receive a reaction force applied to the internal gear when the drive motor starts to rotate the engine via the reduction gear; a first contact portion arranged at an interval from the first protruding portion in the circumferential direction and integrally movable with the first protruding portion; and a second contact portion arranged at an interval from the second protruding portion and disposed to be unmovable in the circumferential direction with respect to the housing, the second contact portion extending in the axial direction opposite to the first contact portion and opposing the first contact portion in the circumferential direction, wherein a compressing amount of the main elastic block portion due to a compressive force between the first protruding portion and the second protruding portion is restricted and a rotation of the internal gear is constrained when the first contact portion contacts the second contact portion.