Method and apparatus for cooling and lubricating an off-axis motor/generator

Abstract

The present invention provides a method for cooling and lubricating an off-axis motor/generator of a hybrid transmission. A transmission case at least partially defines a manifold. A transmission cover is mounted to the transmission case such that the off-axis motor/generator is retained therebetween. The transmission cover at least partially defines an oil passage. Oil is transferred through the manifold and onto a bearing device so that the bearing device is lubricated. Oil is also transferred through the oil passage and onto a torque transfer device such that the torque transfer device is lubricated. A corresponding apparatus for lubricating an off-axis motor/generator of a hybrid transmission is provided is similarly provided.

1 . A method for lubricating an off-axis motor/generator of a hybrid transmission comprising:
 providing a transmission case at least partially defining a manifold;   providing a transmission cover mounted to the transmission case such that the off-axis motor/generator is retained therebetween, said transmission cover at least partially defining an oil passage;   transferring oil through the manifold and onto a bearing device such that the bearing device is lubricated; and   transferring oil through the oil passage and onto a torque transfer device such that the torque transfer device is lubricated.   
     
     
         2 . The method of  claim 1 , further comprising transferring oil through the manifold and onto a second bearing device such that the second bearing device is lubricated. 
     
     
         3 . The method of  claim 1 , further comprising transferring oil through a hollow tube disposed along the central axis of a rotor before said transferring oil through the oil passage and onto a torque transfer device. 
     
     
         4 . The method of  claim 1 , wherein said transferring oil through the oil passage and onto a torque transfer device includes transferring oil through the orifice configured to regulate the application of oil onto the torque transfer device. 
     
     
         5 . The method of  claim 1 , wherein said transferring oil through the manifold and onto a bearing device includes transferring oil through the manifold and onto a bearing device adapted to rotatably support a rotor drum. 
     
     
         6 . The method of  claim 2 , wherein said transferring oil through the manifold and onto a second bearing device includes transferring oil through the manifold and onto a second bearing device adapted to rotatably support a rotor hub. 
     
     
         7 . The method of  claim 1 , wherein said transferring oil through the oil passage and onto a torque transfer device includes transferring oil through the oil passage and onto a chain configured to transfer off-axis motor/generator output to a transmission output shaft. 
     
     
         8 . A method for cooling and lubricating an off-axis motor/generator having a rotor and a stator disposed with a stator housing, said method comprising:
 providing a transmission case at least partially defining a manifold;   providing a transmission cover mounted to the transmission case such that the off-axis motor/generator is retained therebetween, said transmission cover at least partially defining an oil passage;   transferring oil into a coolant chamber defined between the transmission case and the stator housing in order to cool the off-axis motor/generator;   transferring oil through the manifold and onto a first bearing such that the first bearing is lubricated;   transferring oil through the manifold, through a hollow tube disposed along the central axis of the rotor, through the oil passage, and onto a torque transfer device such that the torque transfer device is lubricated; and   transferring oil through the manifold, through the hollow tube, and onto a second bearing such that the second bearing is lubricate.   
     
     
         9 . The method of  claim 8 , wherein said transferring oil through the manifold, through a hollow tube disposed along the central axis of the rotor, through the oil passage, and onto a torque transfer device includes transferring oil through an orifice configured to regulate the application of oil onto the torque transfer device. 
     
     
         10 . The method of  claim 8 , wherein said transferring oil through the manifold and onto a first bearing device includes transferring oil through the manifold and onto a first bearing device adapted to rotatably support a rotor drum. 
     
     
         11 . The method of  claim 8 , wherein said transferring oil through the manifold, through the hollow tube, and onto a second bearing device includes transferring oil through the manifold, through the hollow tube, and onto a second bearing device adapted to rotatably support a rotor hub. 
     
     
         12 . The method of  claim 8 , wherein said transferring oil through the manifold, through a hollow tube disposed along the central axis of the rotor, through the oil passage, and onto a torque transfer device includes transferring oil through the manifold, through a hollow tube disposed along the central axis of the rotor, through the oil passage, and onto a chain configured to transfer off-axis motor/generator output to a transmission output shaft. 
     
     
         13 . A hybrid transmission comprising:
 a transmission cast at least partially defining a manifold;   a transmission cover mounted to the transmission case, said transmission cover at least partially defining an oil passage; and   an off-axis motor/generator disposed between the transmission case and the transmission cover, said off-axis motor/generator comprising:
 a generally cylindrical stator disposed with a stator housing; 
 a generally cylindrical rotor circumscribed by the stator; 
 a hollow tube disposed along the central axis of the rotor; 
 a rotor drum mounted to the rotor and a rotor hub mounted to the rotor drum; 
 a first bearing configured to rotatably support the rotor drum, wherein oil is transferred through the manifold in order to lubricate the first bearing; 
 a second bearing configured to rotatably support the rotor hub, wherein oil is transferred through the manifold, and through the hollow tube in order to lubricate the second bearing; and 
 a torques transfer device coupled to the rotor hub such that output from the off-axis motor/generator can be transferred to a transmission output shaft, wherein oil is transferable through the manifold, through the hollow tube, and through the oil passage in order to lubricate the torque transfer device. 
   
     
     
         14 . The hybrid transmission of  claim 13 , further comprising a coolant chamber defined between the transmission case and the stator housing wherein oil is transferable into the coolant chamber to cool the off-axis motor/generator. 
     
     
         15 . The hybrid transmission of  claim 13 , wherein the rotor drum defines a tapered internal surface adapted to limit oil accumulation within the rotor drum. 
     
     
         16 . The hybrid transmission of  claim 13 , wherein the torque transfer device is a chain. 
     
     
         17 . The hybrid transmission of  claim 13 , wherein the torque transfer device is a transfer gear.