US Patent 9797495 Clutch and differential device with same

A clutch to be combined with a rotary machine rotating about an axis is comprised of a rotary member including a first face perpendicular to the axis, a first bottom receding in an axial direction from the first face, and plural first clutch teeth being arranged in a circumferential direction and respectively projecting from both the first face and the first bottom; and a clutch member movable in the axial direction relative to the rotary member, the clutch member including a second bottom, plural second clutch teeth being arranged in a circumferential direction and respectively projecting from the second bottom to be respectively engageable with the plural first clutch teeth, and an internal peripheral wall connecting internal ends of the plural second clutch teeth and projecting in the axial direction toward the rotary member.