Abstract: An apparatus includes: a cam that has two cam members disposed facing each other and produces thrust in an axis direction; an attracting member that creates friction force by attracting the cam members into contact with the attracting member by magnetic attraction force; an attracted member that is attached to one cam member of the two so as to rotate integrally together with the one cam member and be relatively movable in the axis direction, and that is attracted by the attracting member into contact with the attracting member so that the friction force is produced; a first return spring that exerts elastic force on the attracted member so as to move the attracted member away from the attracting member against the magnetic attractive force; and a second return spring that exerts elastic force on the one cam member.

Abstract: An ECU of an engaging device is configured to feedback-control a current value so as to realize an engagement indicator current required for moving a sleeve in a position in an axial direction in which dog teeth may mesh with dog teeth in engaging operation. This performs releasing operation based on temporal transition of the current value during the engaging operation.

Abstract: An electromagnetic clutch includes a rotating member; an electromagnetic coil that is arranged on a rotational axis of the rotating member and generates electro-magnetic force; an output mechanism that has an armature to which return force in a direction away from the electromagnetic coil is applied by a return spring; a cam mechanism that is juxtaposed along the rotational axis to the output mechanism, and has a control cam that is unable to rotate relative to the rotating member, and a cam follower that is able to roll between the control cam and the armature; and a relative rotation restricting device that is arranged on an axis of the cam mechanism, and that is configured to restrict relative rotation between the armature and the control cam when the electromagnetic coil is in a de-energized state.

Abstract: An apparatus includes: a cam that has two cam members disposed facing each other and produces thrust in an axis direction; an attracting member that creates friction force by attracting the cam members into contact with the attracting member by magnetic attraction force; an attracted member that is attached to one cam member of the two so as to rotate integrally together with the one cam member and be relatively movable in the axis direction, and that is attracted by the attracting member into contact with the attracting member so that the friction force is produced; a first return spring that exerts elastic force on the attracted member so as to move the attracted member away from the attracting member against the magnetic attractive force; and a second return spring that exerts elastic force on the one cam member.

Abstract: An electromagnetic clutch includes a rotating member; an electromagnetic coil that is arranged on a rotational axis of the rotating member and generates electro-magnetic force; an output mechanism that has an armature to which return force in a direction away from the electromagnetic coil is applied by a return spring; a cam mechanism that is juxtaposed along the rotational axis to the output mechanism, and has a control cam that is unable to rotate relative to the rotating member, and a cam follower that is able to roll between the control cam and the armature; and a relative rotation restricting device that is arranged on an axis of the cam mechanism, and that is configured to restrict relative rotation between the armature and the control cam when the electromagnetic coil is in a de-energized state.