Hybrid module with multi-gerotor pump

Abstract

A multi-gerotor pump includes a shaft, rotatable about an axis, a first gerotor pump, a second gerotor pump, a housing, and a reservoir. The first gerotor pump has a first inner gerotor rotationally fixed to the shaft and the second gerotor pump has a second inner gerotor, axially offset from the first inner gerotor, and rotationally fixed to the shaft. The housing has a first gerotor pump inlet channel and a first gerotor pump outlet channel, and a second gerotor pump inlet channel and a second gerotor pump outlet channel. The first gerotor pump outlet channel and the second gerotor pump inlet channel are in fluid communication with the reservoir.

What is claimed is: 
     
         1 . A multi-gerotor pump, comprising:
 a shaft, rotatable about an axis;   a first gerotor pump comprising a first inner gerotor rotationally fixed to the shaft;   a second gerotor pump comprising a second inner gerotor, axially offset from the first inner gerotor, rotationally fixed to the shaft;   a housing comprising:
 a first gerotor pump inlet channel and a first gerotor pump outlet channel; 
 a second gerotor pump inlet channel and a second gerotor pump outlet channel; and 
   a reservoir, wherein the first gerotor pump outlet channel and the second gerotor pump inlet channel are in fluid communication with the reservoir.   
     
     
         2 . The multi-gerotor pump of  claim 1  further comprising an electric pump motor for rotating the shaft. 
     
     
         3 . The multi-gerotor pump of  claim 2 , wherein:
 the first gerotor pump further comprises a first outer gerotor;   the electric pump motor is arranged to rotate the first outer gerotor; and   the first outer gerotor is arranged to rotate the first inner gerotor to rotate the shaft.   
     
     
         4 . The multi-gerotor pump of  claim 1  wherein:
 the first gerotor pump is a scavenger pump for transporting oil from an outlet of a hybrid module to the reservoir; and 
 the second gerotor pump is a cooling circuit pump for transporting the oil from the reservoir to a cooling circuit of the hybrid module. 
 
     
     
         5 . The multi-gerotor pump of  claim 4  wherein the scavenger pump has a larger pumping capacity than the cooling circuit pump. 
     
     
         6 . The multi-gerotor pump of  claim 4  wherein the cooling circuit comprises an oil cooler. 
     
     
         7 . The multi-gerotor pump of  claim 1  wherein the first gerotor pump inlet channel and the first gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir. 
     
     
         8 . The multi-gerotor pump of  claim 1  wherein the second gerotor pump inlet channel and the second gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir. 
     
     
         9 . The multi-gerotor pump of  claim 1  wherein the shaft extends axially into the reservoir. 
     
     
         10 . The multi-gerotor pump of  claim 9  wherein:
 the reservoir comprises an axial width; and 
 the second gerotor pump is disposed within the axial width of the reservoir. 
 
     
     
         11 . A hybrid module comprising:
 a module housing;   an e-machine comprising a stator fixed to the housing and a rotatable rotor; and   the multi-gerotor pump of  claim 1  arranged to circulate a cooling fluid throughout the module housing.   
     
     
         12 . The hybrid module of  claim 11 , wherein:
 the module housing comprises an outlet and a cooling circuit;   the first gerotor pump is a scavenger pump for transporting the cooling fluid from the outlet to the reservoir; and   the second gerotor pump is a cooling circuit pump for transporting the cooling fluid from the reservoir to the cooling circuit.   
     
     
         13 . The hybrid module of  claim 12 , wherein the outlet is arranged at a bottom of the module housing when the hybrid module is installed in a vehicle. 
     
     
         14 . The hybrid module of  claim 13 , wherein the outlet is arranged such that a cooling fluid level in the housing is less than a bottom of the rotatable rotor. 
     
     
         15 . The hybrid module of  claim 12 , wherein the reservoir is arranged on an axial side of the module housing when the hybrid module is installed in a vehicle. 
     
     
         16 . The hybrid module of  claim 12 , wherein the cooling circuit comprises a spray port in the module housing directed towards a top of the stator when the hybrid module is installed in a vehicle. 
     
     
         17 . The hybrid module of  claim 12 , wherein the cooling circuit comprises a cooling fluid cooler.