Abstract: A first retaining ring is disposed between a first outer circumferential groove provided in an outer circumferential surface of a radial bearing, and an inner circumferential groove of a cylindrical portion of a transmission case. A ring piece is provided with an outer ring of the radial bearing. The ring piece protrudes outward in a radial direction and is in contact with an output gear side end surface of the cylindrical portion in the axial direction. A return spring urges the piston in a direction opposite to a direction in which the pressure is applied by the piston. The return spring is retained in the axial direction by a second retaining ring. The second retaining ring is locked in a second outer circumferential groove of the ring piece.

Abstract: A first retaining ring is disposed between a first outer circumferential groove provided in an outer circumferential surface of a radial bearing, and an inner circumferential groove of a cylindrical portion of a transmission case. A ring piece is provided with an outer ring of the radial bearing. The ring piece protrudes outward in a radial direction and is in contact with an output gear side end surface of the cylindrical portion in the axial direction. A return spring urges the piston in a direction opposite to a direction in which the pressure is applied by the piston. The return spring is retained in the axial direction by a second retaining ring. The second retaining ring is locked in a second outer circumferential groove of the ring piece.