Patent ID: 8905208
Filing Date: 2014-12-09
Classification: F16D

Abstract:
1. A driving force transmission apparatus comprising: an outer rotating member having an inner peripheral spline portion at an inner periphery of the outer rotating member, the inner peripheral spline portion having a plurality of inner peripheral spline protrusions extending in a direction along a rotation axis; an inner rotating member relatively rotatably supported coaxially with the outer rotating member, the inner rotating member having an outer peripheral spline portion at an outer periphery of the inner rotating member, and the outer peripheral spline portion having a plurality of outer peripheral spline protrusions extending in the direction along the rotation axis; a main clutch including an outer clutch plate engaged with the inner peripheral spline portion so as to be axially movable and an inner clutch plate engaged with the outer peripheral spline portion so as to be axially movable, the main clutch being configured to couple the outer rotating member to the inner rotating member such that torque is transmittable; a cam mechanism including a first cam member and a second cam member, the cam mechanism being configured to cause the second cam member to generate pressing force for pressing the main clutch by relatively rotating the first cam member with respect to the second cam member; and an electromagnetic clutch mechanism including an armature engaged with the inner peripheral spline portion so as to be axially movable and an electromagnetic coil configured to generate electromagnetic force for axially moving the armature, the electromagnetic clutch mechanism being configured to apply rotation force to the cam mechanism for relatively rotating the first cam member and the second cam member with respect to each other at the time when the electromagnetic coil is energized, wherein the inner peripheral spline portion has a first region with which the outer clutch plate is engaged and a second region with which the armature is engaged, the inner peripheral spline portion having a facing surface between the first region and the second region, the facing surface facing the armature, and movement of the armature toward the first region is regulated by contact of the armature with the facing surface.