Starter for internal combustion engine

A starter for an internal combustion engine comprising:

• a rotating shaft formed with a helical spline on an outer periphery thereof and which rotates by a rotation of a motor;
• a pinion gear helically splined to the rotating shaft and movable in an axial direction of the rotating shaft along a tooth surface of the helical spline;
• a receiving member disposed opposing an end surface in an axial direction of the pinion gear, moved by receiving an axial pushing force by a pushing member, and causing the pinion gear to engage with a ring gear of the internal combustion engine by a movement thereof, the pinion gear being configured to be rotatable relative to the receiving member;
• and
• a restricting part for restricting a movement of the pinion gear in a rotational direction when the pinion gear moves along the teeth surface of the helical spline,
• wherein the restricting part is disposed between an end face in the axial direction of the pinion gear and the receiving member, and restricts relative rotation between the pinion gear and the receiving member by a frictional force when the receiving member moves,
• wherein the restricting part is a buffer member haying elasticity, the buffer member being disposed between the end face in the axial direction of the pinion gear and the receiving member, and
• wherein a contact area of the buffer member with at least one of the pinion gear and the receiving member is larger in a moving state in which the receiving member is moving and the buffer member is elastically deformed than in a state where the receiving member is not moving and the buffer member is not elastically deformed.