Power Transmission Device With Friction Clutch And Power-Operated Clutch Actuator

A power transmission device, comprising:

• a rotary input member;
• a rotary output member;
• a transfer clutch operably disposed between said rotary input and output members;
• and
• a clutch actuator for controlling engagement of said transfer clutch, said clutch actuator including an electric motor, a geared drive unit driven by said electric motor, and a clutch operator for converting rotation of said geared drive unit into translation of an actuator member relative to said transfer clutch, said geared drive unit including a pinion gear driven by said electric motor and a face gear meshed with said pinion gear and having a ramp angle accommodating transverse movement of said face gear relative to said pinion gear, said face gear driving said clutch operator for causing translation of said actuator member in response to rotation of said pinion gear.

A torque transfer mechanism for transferring drive torque from a rotary input member to a rotary output member, comprising:

• a friction clutch having a clutch pack operably disposed between the input and output members, and an actuator plate moveable between a first position whereat a minimum clutch engagement force is exerted on said clutch pack and a second position whereat a maximum clutch engagement force is exerted on said clutch pack;
• a clutch actuator for moving said actuator plate between its first and second positions, said clutch actuator including an electric motor, a pinion gear driven by said electric motor, a face gear meshed with said pinion gear such that said face gear axially translates in response to driven rotation of said pinion gear, and a clutch apply operator for converting axial movement of said face gear into translational movement of said actuator plate, wherein said face gear includes a ramp angle adapted to compensate for axial movement relative to said pinion gear;
• and
• a control system for actuating said electric motor so as to control rotary movement of said face gear between a first angular position and a second angular position, wherein said face gear is located in a first axial position when said face gear is rotated to its first angular position so as to cause said actuator plate to be located in its first position, and wherein said face gear is located in a second axial position when said face gear is rotated to its second angular position so as to cause said actuator plate to move to its second position.

A power transmission device, comprising:

• a rotary input shaft adapted to receive drive torque from a power source;
• a rotary output shaft adapted to provide drive torque to an output device;
• a friction clutch operably disposed between said rotary input and output shafts;
• a clutch actuator for generating and applying a clutch engagement force to said friction clutch, said clutch actuator including an electric motor, a geared drive unit driven by said electric motor and a clutch operator actuated by said geared drive unit, said geared drive unit including a pinion gear driven by said electric motor and a face gear meshed with said pinion gear, said clutch operator including a first cam member and a second cam member fixed for rotation with said face gear that is adapted to move axially in response to rotation relative to said first cam member for controllably varying the magnitude of said clutch engagement force applied to said friction clutch;
• and
• a control system for actuating said electric motor for causing said geared drive unit to control the direction and amount of rotation of said face gear.