A lock-up clutch of a torque converter, which transmits a rotational force, which is received from an input member, to an output member, the lock-up clutch comprising:
- an outer carrier connected to any one of the input and output members so that a rotation thereof is restricted;
- an inner carrier connected to the other of the input and output members so that a rotation thereof is restricted, the inner carrier being disposed radially inward of the outer carrier;
- and
- a clutch pack provided between the outer and inner carriers in a radial direction and including a first friction plate connected to the outer carrier so that a rotation thereof is restricted, and a second friction plate connected to the inner carrier so that a rotation thereof is restricted, the first friction plate and the second friction plate are alternately disposed in an axial direction,
- wherein the outer carrier comprises:
- a plurality of first axial keys disposed to be spaced apart from one another in a circumferential direction and extending in the axial direction;
- and
- a plurality of first key grooves each provided between the two first axial keys adjacent to each other in the circumferential direction and all opened in centripetal and centrifugal directions,
- wherein the inner carrier comprises:
- a plurality of second axial keys disposed to be spaced apart from one another in the circumferential direction and extending in the axial direction;
- and
- a plurality of second key grooves each provided between the two second axial keys adjacent to each other in the circumferential direction and all opened in the centripetal and centrifugal directions,
- wherein the first friction plate comprises:
- a plurality of centrifugal keys disposed to be spaced apart from one another in the circumferential direction, extending in the centrifugal direction from an outer peripheral surface of the first friction plate, and inserted into the first key grooves;
- a plurality of first friction members disposed to be spaced apart from one another in the circumferential direction and provided on an axial surface of the first friction plate;
- and
- a plurality of first flow path grooves each provided between the two first friction members adjacent to each other in the circumferential direction and all opened in the centripetal and centrifugal directions, and
- wherein the second friction plate comprises:
- a plurality of centripetal keys disposed to be spaced apart from one another in the circumferential direction, extending in the centripetal direction from an inner peripheral surface of the second friction plate, and inserted into the second key groove;
- a plurality of second friction members disposed to be spaced apart from one another in the circumferential direction and provided on an axial surface of the second friction plate;
- and
- a plurality of second flow path grooves each provided between the two second friction members adjacent to each other in the circumferential direction and all opened in the centripetal and centrifugal directions.