Abstract: A drive force transfer device is mounted on a four-wheel-drive vehicle having main drive wheels and auxiliary drive wheels. A cam mechanism presses a main clutch in the axial direction. An electromagnetic clutch mechanism actuates the cam mechanism and has an electromagnetic coil and a pilot clutch. When the electromagnetic coil is not energized, the pressing force of the cam mechanism, which is generated because of drag torque of the pilot clutch in the case where a output rotary member rotates faster than a input rotary member, is smaller than that generated because of drag torque of the pilot clutch in the case where the input rotary member rotates faster than the output rotary member.

Abstract: A drive force transfer device is mounted on a four-wheel-drive vehicle having main drive wheels and auxiliary drive wheels. A cam mechanism presses a main clutch in the axial direction. An electromagnetic clutch mechanism actuates the cam mechanism and has an electromagnetic coil and a pilot clutch. When the electromagnetic coil is not energized, the pressing force of the cam mechanism, which is generated because of drag torque of the pilot clutch in the case where a output rotary member rotates faster than a input rotary member, is smaller than that generated because of drag torque of the pilot clutch in the case where the input rotary member rotates faster than the output rotary member.

Abstract: An electromagnetic actuator includes a supporting member supporting an electromagnetic coil around which a wire is wound, a moving member positioned facing the supporting member so as to move forward and backward, and an actuating force transmitting member transmitting moving force of the moving member to a member to be actuated as an actuating force. The moving member is moved towards the supporting member by magnetic force generated by applying an electric current to the electromagnetic coil to apply the actuating force to the member to be actuated via the actuating force transmitting member. The electromagnetic coil includes a plurality of electromagnetic coils provided at the supporting member.

Abstract: An electromagnetic actuator includes a supporting member supporting an electromagnetic coil around which a wire is wound, a moving member positioned facing the supporting member so as to move forward and backward, and an actuating force transmitting member transmitting moving force of the moving member to a member to be actuated as an actuating force. The moving member is moved towards the supporting member by magnetic force generated by applying an electric current to the electromagnetic coil to apply the actuating force to the member to be actuated via the actuating force transmitting member. The electromagnetic coil includes a plurality of electromagnetic coils provided at the supporting member.