Rotation transmission device

A rotation transmission device comprising an input member, an output member provided around said input member through a bearing disposed at one end of said output member so as to be rotatable relative to said input member, a two-way clutch disposed between said input member and said output member, and an electromagnetic clutch disposed between said input member and said output member for selectively engaging and disengaging said two-way clutch, said two-way clutch being a mechanical clutch comprising a plurality of engaging elements, a retainer for retaining said engaging elements, and a switch spring biasing said retainer toward a neutral position where said engaging elements are not in engagement with at least one of said input member and said output member, said electromagnetic clutch comprising an armature coupled to said retainer so as to be non-rotatable but axially movable relative to said retainer, a rotor fixed to said output member so as to be non-rotatable relative to said output member and to axially face said armature, and an electromagnet axially facing said armature with said rotor disposed between said electromagnet and said armature, said electromagnet being selectively energized to pull said armature toward said electromagnet until said armature is pressed against said rotor, said input member being formed with an oil supply passage having an outlet port directly or indirectly communicating with a space defined between said two-way clutch and said electromagnetic clutch, whereby oil is supplied through said oil supply passage and said outlet port into said space to lubricate said two-way clutch, said rotation transmission device further including a pressure rise suppressor for preventing a rise in the pressure of oil supplied into said space through said oil supply passage.