Disconnectable power transfer unit

A power transfer unit intermissively transferring torque about a first axis toward a second axis different from the first axis, comprising:

• a hollow input shaft rotatable about the first axis and so dimensioned as to allow penetration of an axle along the first axis;
• an intermediate shaft rotatable independently from the input shaft about the first axis;
• an output shaft in mesh with the intermediate shaft and rotatable about the second axis;
• a clutch disconnectably and drivingly coupling the input shaft with the intermediate shaft;
• a motor including a rotor rotating about the first shaft;
• an input member coupled with the rotor to be rotatable about the first axis and including an eccentric shaft eccentric from the first axis;
• a fixed member immovable about the first axis;
• an intermediate member fitting on the eccentric shaft to make an eccentric motion and meshing with the fixed member to make a rotary motion about the eccentric shaft;
• an output member rotatable about the first axis and engaging with and following the intermediate member;
• and
• a cam mechanism interposed between the output member and the clutch and converting the rotary motion of the output member into a motion in a direction of the first axis.