Switchable powertrain

Abstract

A switchable powertrain includes a main gear set configured for gear ratio selection. The main gear set includes an input shaft, first gears coupled to a main shaft, and second gears coupled to a second shaft. The second gears are meshed with the first gears. The switchable powertrain further includes a first torque source, a second torque source, a clutch configured for selectively coupling the first torque source to the input shaft of the main gear set, and an adapter. The adapter includes a first selective coupling for forming a first adapter torque transfer pathway from the second torque source directly to the main shaft, and a second selective coupling for forming a second adapter torque transfer pathway from the second torque source, through the main gear set, and to the main shaft.

What is claimed is: 
     
         1 . A switchable powertrain, comprising:
 a first torque source for providing a first torque;   a second torque source for providing a second torque;   a main gear set configured for gear ratio selection, the main gear set comprising an input shaft, first gears coupled to a main shaft, and second gears coupled to a second shaft, the second gears being meshed with the first gears;   a clutch configured for selectively coupling the first torque source to the input shaft of the main gear set;   an adapter, comprising:
 a first selective coupling configured to selectively couple the second torque source to the main shaft; and 
 a second selective coupling configured to selectively the second torque source to the second shaft; and 
   an output;   wherein the adapter is configured to operate in a first configuration where the second torque source outputs the second torque to the first selective coupling and to the output without passing the second torque through the main gear set, and wherein the adapter is configured to operate in a second configuration where the second torque source outputs the second torque to the second selective coupling and to the output while passing the second torque through the main gear set.   
     
     
         2 . The switchable powertrain of  claim 1 , wherein the second torque source is integrated inside a housing of the adapter. 
     
     
         3 . The switchable powertrain of  claim 1 , wherein a rotational axis of the second torque source is coaxial with a rotational axis of the main shaft. 
     
     
         4 . The switchable powertrain of  claim 1 , wherein the second torque source outputs the second torque directly to the first selective coupling. 
     
     
         5 . The switchable powertrain of  claim 1 , wherein the adapter includes a gear mesh between the second torque source and the first selective coupling, and wherein the second torque outputs the second torque source to the first selective coupling via the gear mesh. 
     
     
         6 . The switchable powertrain of  claim 1 , wherein the adapter includes a three-way shifter, the three-way shifter comprising the first selective coupling, the second selective coupling, and a neutral position that decouples the second torque source from the main shaft. 
     
     
         7 . The switchable powertrain of  claim 1 , wherein the main gear set includes third gears coupled to a third shaft, and wherein the third gears are meshed with the first gears. 
     
     
         8 . The switchable powertrain of  claim 1 , wherein the second torque source is an electric motor electrically connected to a battery, and wherein the adapter is switchable to provide torque to the electric motor to charge the battery. 
     
     
         9 . The switchable powertrain of  claim 1  further comprising a range gear set coupled to the main shaft and configured to selectively apply a second gear ratio to the main shaft. 
     
     
         10 . The switchable powertrain of  claim 9 , wherein the first selective coupling is coupled between the range gear set and the main gear set along the main shaft. 
     
     
         11 . A switchable powertrain, comprising:
 a main gear set configured for gear ratio selection, the main gear set comprising an input shaft, first gears coupled to a main shaft, and second gears coupled to a second shaft, the second gears being meshed with the first gears;   a first torque source;   a second torque source;   a clutch configured for selectively coupling the first torque source to the input shaft of the main gear set; and   an adapter, comprising:
 a first selective coupling for forming a first adapter torque transfer pathway from the second torque source directly to the main shaft; and 
 a second selective coupling for forming a second adapter torque transfer pathway from the second torque source, through the main gear set, and to the main shaft. 
   
     
     
         12 . The switchable powertrain of  claim 11 , wherein the second torque source is integrated inside a housing of the adapter. 
     
     
         13 . The switchable powertrain of  claim 11 , wherein a rotational axis of the second torque source is coaxial with a rotational axis of the main shaft. 
     
     
         14 . The switchable powertrain of  claim 11 , wherein the second torque source outputs the second torque directly to the first selective coupling. 
     
     
         15 . The switchable powertrain of  claim 11 , wherein the adapter includes a gear mesh between the second torque source and the first selective coupling, and wherein the second torque outputs the second torque source to the first selective coupling via the gear mesh. 
     
     
         16 . The switchable powertrain of  claim 11 , wherein the adapter includes a three-way shifter, the three-way shifter comprising the first selective coupling, the second selective coupling, and a neutral position that decouples the second torque source from the main shaft. 
     
     
         17 . The switchable powertrain of  claim 11 , wherein the main gear set includes third gears coupled to a third shaft, and wherein the third gears are meshed with the first gears. 
     
     
         18 . The switchable powertrain of  claim 11 , wherein the second torque source is an electric motor electrically connected to a battery, and wherein the adapter is switchable to provide torque to the electric motor to charge the battery. 
     
     
         19 . The switchable powertrain of  claim 11  further comprising a range gear set coupled to the main shaft and configured to selectively apply a second gear ratio to the main shaft. 
     
     
         20 . The switchable powertrain of  claim 19 , wherein the first selective coupling is coupled between the range gear set and the main gear set along the main shaft.