Modular Hybrid Transmission with a One Way Clutch

Abstract

A vehicle transmission system having a combustion engine, an electric motor and a transmission includes a first clutch operatively connected between the engine and the motor and a one way clutch. The one way clutch is connected in parallel with the first clutch that permits the engine to increase speed with the clutch disengaged until the engine speed matches the motor speed. The engine provides positive torque through the one way clutch to the motor and transmission upon matching the motor speed. The first clutch and the one way clutch may be a hybrid rocker one way clutch.

1 . A transmission system having a combustion engine, an electric motor and a transmission, the system comprising:
 a clutch operatively connected between the engine and the motor; and   a one way clutch connected in parallel with the clutch that permits the engine to increase speed with the clutch disengaged until the engine speed matches a motor speed, wherein the engine provides positive torque through the one way clutch to the motor and transmission upon matching the motor speed.   
     
     
         2 . The transmission system of  claim 1  wherein the clutch is a wet clutch that is shifted by hydraulic pressure from a hydraulic pump. 
     
     
         3 . The transmission system of  claim 1  wherein upon the engine speed matches the motor speed, the one way clutch limits a speed of rotation of the engine to a speed of rotation of the motor by over running the one way clutch in the event the speed of rotation of the engine exceeds the speed of rotation of the motor. 
     
     
         4 . The transmission system of  claim 1  wherein the one way clutch is a hybrid one way clutch that has rockers that may be shifted to engage the clutch in one rotational direction. 
     
     
         5 . The transmission system of  claim 4  wherein the clutch is a second hybrid one way clutch that has rockers that may be shifted to engage the clutch in one rotational direction. 
     
     
         6 . The transmission system of  claim 1  wherein the clutch is a hybrid one way clutch that has rockers that may be shifted to engage the clutch in one rotational direction. 
     
     
         7 . A transmission system for a vehicle that has a combustion engine, an electric motor and a transmission connected in series, the transmission system comprising:
 a one way clutch that slips in a first rotational drive direction; and   a hybrid one way clutch having selectively shifted rockers is connected in parallel to the one way clutch between the engine and the motor, the rockers are actuated when an engine speed matches a motor speed to shift the rockers from a bidirectional slip condition to a one way slip condition locked in the first rotational drive direction.   
     
     
         8 . The transmission system of  claim 7  wherein the rockers when actuated causes the hybrid one way clutch to slip in a second rotational drive direction. 
     
     
         9 . The transmission system of  claim 7  wherein when the engine speed matches the motor speed the one way clutch connects the engine to the transmission to transmit torque to a driveline of the vehicle. 
     
     
         10 . The transmission system of  claim 7  wherein the one way clutch is a second hybrid one way clutch that locks prior to when the engine speed matches the motor speed. 
     
     
         11 . A method of operating a transmission system for a vehicle that has a combustion engine, an electric motor and a transmission connected in series, a first clutch operatively connected between the engine and the motor, and a one way clutch connected in parallel with the first clutch, the method comprising:
 initiating an engine start operation;   disengaging the first clutch to disconnect the engine from the electric motor; and   engaging the one way clutch when an engine speed matches a motor speed.   
     
     
         12 . The method of  claim 11  wherein the first clutch is a hybrid one way clutch having rockers that are selectively shifted to connect the engine to the electric motor. 
     
     
         13 . The method of  claim 11  wherein the first clutch is a hydraulically actuated disconnect clutch. 
     
     
         14 . The method of  claim 11  wherein the first clutch is a hybrid one way clutch with electrically shifted rockers. 
     
     
         15 . The method of  claim 14  wherein the one way clutch is a second hybrid one way clutch with electrically shifted rockers. 
     
     
         16 . The method of  claim 11  wherein the one way clutch is a hybrid one way clutch with electrically shifted rockers.