Hybrid powertrain with centrifugally-actuated motor disconnect clutch and method of control

A hybrid vehicle having an axle and wheels connected to the axle and comprising:

• an electric motor having a rotatable rotor;
• a centrifugally-actuated clutch having:
• a collar, a drum radially surrounded by the collar, and a weighted shoe pivotably attached to the collar;
• wherein the weighted shoe is configured to transfer torque between the collar and the drum when a rotational speed of the collar in a first direction is below a first predetermined speed and is configured to release from the drum due to centrifugal force to prevent torque transfer between the collar and the drum when the rotational speed of the collar in the first direction of rotation is greater than a second predetermined speed;
• a gearing arrangement operatively connected to the axle and having a member connected to rotate with collar;
• wherein the gearing arrangement has a gear ratio between the collar and the axle;
• and wherein the rotor is configured to rotate with drum, the electric motor thus being operatively disconnected from the axle when the rotational speed of the axle is greater than the second predetermined speed divided by the gear ratio.

A method of controlling a hybrid vehicle comprising:

• monitoring a speed of rotation of a rotor of an electric motor;
• and
• varying one of the speed of rotation of the rotor and torque of the rotor when the monitored speed of rotation of the rotor indicates that a centrifugally-actuated clutch that transfers torque from the rotor to vehicle wheels is slipping;
• and wherein the centrifugally-actuated clutch is configured to disengage due to centrifugal force as rotational speed of the vehicle wheels increases, thereby disconnecting the rotor from the vehicle wheels.