DRIVING FORCE TRANSMISSION APPARATUS

PROBLEM TO BE SOLVED: To provide a driving force transmission apparatus capable of regulating the movement of an armature to the side of a cam member without adding a member to secure an interval between the armature and the cam member.SOLUTION: A driving force transmission apparatus 2 includes: a housing 20; an inner shaft 23; a main clutch 3 having a first outer clutch plate 31 and a first inner clutch plate 32 engaging with a first outer periphery spline 230; a cam mechanism 4 generating a pressing force for pressing the main clutch 3; and a solenoid clutch mechanism 5. In an inner spline 210, an end surface 212a facing an armature 50 is formed between a first region 210a with which the first outer clutch plate 31 engages and a second region 210b with which the armature 50 engages. The armature 50 abuts on an end surface 212a, so that the movement of it to the side of the first region 210a is regulated.