Dual pump system for automatic transmission augmentation, extended stop and start, and sailing

Abstract

A dual pump system for a motor vehicle transmission includes a first pump connected to and co-rotated with a pump shaft rotated during operation of a motor vehicle engine. A second pump is connected to a motor shaft of an electric motor. A one-way roller clutch is connected to the second pump and to the pump shaft. The one-way roller clutch is configured to allow the faster rotated one of the pump shaft or the motor shaft to drive the second pump. The pump shaft and the motor shaft can be co-axially aligned or positioned off-axis with respect to each other.

What is claimed is: 
     
         1 . A dual pump system of a transmission, comprising:
 a first pump connected to and co-rotated with a pump shaft rotated during operation of a motor vehicle engine;   a second pump connected to a motor shaft of an electric motor; and   a one-way roller clutch connected to the second pump and to the pump shaft;   wherein the one-way roller clutch is configured to allow the faster rotating one of the pump shaft or the motor shaft to drive the second pump.   
     
     
         2 . The dual pump system of  claim 1 , wherein the pump shaft and the motor shaft are co-axially aligned. 
     
     
         3 . The dual pump system of  claim 1 , wherein the second pump is a gerotor gear pump. 
     
     
         4 . The dual pump system of  claim 3 , further including a housing of the gerotor gear pump directly coupled to a pump housing of the first pump. 
     
     
         5 . The dual pump system of  claim 1 , wherein the second pump is a vane pump. 
     
     
         6 . The dual pump system of  claim 1 , wherein the second pump is a dual axis, dual gear pump. 
     
     
         7 . The dual pump system of  claim 6 , wherein a longitudinal axis of the motor shaft of the dual axis pump is offset from a longitudinal axis of the pump shaft. 
     
     
         8 . The dual pump system of  claim 1 , wherein the electric motor is a 12 volt DC brushless motor. 
     
     
         9 . The dual pump system of  claim 1 , wherein the electric motor is a 48 volt DC brushless motor. 
     
     
         10 . The dual pump system of  claim 1 , wherein the electric motor is a 300 volt DC brushless motor. 
     
     
         11 . The dual pump system of  claim 1 , wherein the electric motor is an 80 watt motor. 
     
     
         12 . The dual pump system of  claim 1 , wherein the electric motor is a 250 watt motor. 
     
     
         13 . The dual pump system of  claim 1 , wherein the one-way roller clutch permits the electric motor to be energized to rotate the motor shaft independently of the pump shaft when the pump shaft is not rotating and with the vehicle engine shut off, to provide hydraulic flow to a transmission. 
     
     
         14 . The dual pump system of  claim 1 , wherein when the electric motor is energized when the pump shaft is rotating thereby rotates the motor shaft of the electric motor at a rotational speed faster than a rotational speed of the pump shaft to augment a hydraulic flow from the first pump with a hydraulic flow from the second pump. 
     
     
         15 . A dual pump system of a transmission, comprising:
 a first pump defining a vane pump connected to and co-rotated with a pump shaft rotated during operation of a motor vehicle engine;   a second pump connected to a motor shaft of an electric motor; and   a one-way roller clutch connecting the motor shaft to the pump shaft; and   a bushing rotatably supporting the motor shaft to a housing, the housing positioned between and separating the first pump from the second pump.   
     
     
         16 . The dual pump system of  claim 15 , wherein the electric motor includes a motor rotor and a motor stator, the motor rotor, the motor stator and the second pump all contained within a single motor housing. 
     
     
         17 . The dual pump system of  claim 16 , wherein:
 the second pump defines a gerotor pump assembly;   the pump shaft and the motor shaft are co-axially aligned; and   the motor rotor and the motor stator at least partially surround the gerotor pump assembly.   
     
     
         18 . The dual pump system of  claim 15 , wherein when the electric motor is energized when the pump shaft is rotating, the motor shaft of the electric motor is rotated at a rotational speed faster than a rotational speed of the pump shaft to augment a hydraulic flow from the first pump with a hydraulic flow from the second pump. 
     
     
         19 . The dual pump system of  claim 15 , wherein when the electric motor is de-energized when the pump shaft is rotating, the pump shaft rotates the first pump, and also through engagement of the one-way roller clutch with the motor shaft co-rotates the second pump, thereby mechanically co-rotating both the first pump and the second pump at the same speed of rotation as the pump shaft. 
     
     
         20 . A dual pump system of a transmission, comprising:
 a first pump connected to and co-rotated with a pump shaft rotated during operation of a motor vehicle engine;   a second pump connected to a motor shaft of an electric motor; and   a one-way roller clutch connected to the second pump and to the pump shaft;   the one-way roller clutch configured such that:
 when the electric motor is de-energized and the pump shaft is rotating the one-way roller clutch co-rotates the motor shaft; 
 when the electric motor is energized and the pump shaft is rotating, the motor shaft of the electric motor rotates at a rotational speed faster than a rotational speed of the pump shaft to augment a hydraulic flow from the first pump with a hydraulic flow from the second pump; and 
 when the electric motor is energized and the pump shaft is not rotating, the motor shaft is rotated such that the second pump provides a hydraulic flow with no hydraulic flow generated from the first pump.