Vehicle auxiliary pump control

Abstract

A vehicle includes a main pump and an auxiliary pump, each configured to provide fluid to a hydraulic circuit. A motor is configured to drive the auxiliary pump. A controller is configured to determine a temperature of the motor, compare the temperature of the motor to a first predetermined operating threshold, and disable the auxiliary pump and enable the main pump if the temperature of the motor is above the first predetermined operating threshold. A method of controlling fluid flow in the vehicle includes determining a temperature of the motor, comparing the temperature to the first predetermined operating threshold, and disabling the auxiliary pump and enabling the main pump if the temperature of the motor is above the first predetermined operating threshold.

1 . A vehicle comprising:
 a main pump configured to provide fluid to a hydraulic circuit;   an auxiliary pump configured to provide fluid to the hydraulic circuit;   a motor configured to drive the auxiliary pump; and   a controller configured to determine a temperature of the motor, compare the temperature of the motor to a first predetermined operating threshold, and disable the auxiliary pump and enable the main pump if the temperature of the motor is above the first predetermined operating threshold.   
     
     
         2 . A vehicle as set forth in  claim 1 , further comprising a sensor configured to measure the temperature of the motor. 
     
     
         3 . A vehicle as set forth in  claim 1 , wherein the controller is configured to estimate the temperature of the motor. 
     
     
         4 . A vehicle as set forth in  claim 1 , wherein the controller is configured to allow the auxiliary pump to be enabled if the temperature of the motor falls below a second predetermined operating threshold. 
     
     
         5 . A vehicle as set forth in  claim 4 , wherein the first predetermined operating threshold and the second predetermined operating threshold each represents a different temperature. 
     
     
         6 . A vehicle as set forth in  claim 1 , further comprising an engine configured to provide a torque to drive the main pump. 
     
     
         7 . A vehicle as set forth in  claim 1 , wherein the motor is configured to provide a torque to drive the auxiliary pump. 
     
     
         8 . A vehicle as set forth in  claim 1 , wherein the controller is configured to disable the auxiliary pump by generating a control signal that commands the motor to turn off. 
     
     
         9 . A vehicle as set forth in  claim 1 , further comprising an engine configured to drive the main pump, and wherein the controller is configured to enable the main pump by generating a control signal that commands the engine to turn on. 
     
     
         10 . A method of controlling fluid flow in a vehicle, the method comprising:
 determining a temperature of a motor driving the auxiliary pump;   comparing the temperature to a first predetermined operating threshold;   disabling the auxiliary pump if the temperature of the motor is above the first predetermined operating threshold; and   enabling a main pump if the temperature of the motor is above the first predetermined operating threshold.   
     
     
         11 . A method as set forth in  claim 10 , wherein disabling the auxiliary pump includes commanding the motor to turn off. 
     
     
         12 . A method as set forth in  claim 10 , wherein enabling the pump includes commanding an engine driving the main pump to turn on. 
     
     
         13 . A method as set forth in  claim 10 , further comprising allowing the motor to turn on to drive the auxiliary pump and allowing the main pump to be disabled if the temperature is below a second predetermined operating threshold. 
     
     
         14 . A method as set forth in  claim 10 , wherein determining the temperature of the motor includes measuring the temperature of the motor with a sensor. 
     
     
         15 . A method as set forth in  claim 10 , wherein determining the temperature of the motor includes estimating a temperature of the motor. 
     
     
         16 . A method as set forth in  claim 10 , wherein disabling the auxiliary pump includes setting a flag indicating that the auxiliary pump is not available for use. 
     
     
         17 . A method as set forth in  claim 16 , further comprising clearing the flag if the temperature of the motor is below a second predetermined operating threshold. 
     
     
         18 . A vehicle comprising:
 a main pump configured to provide fluid to a hydraulic circuit;   an auxiliary pump configured to provide fluid to the hydraulic circuit;   a motor configured to drive the auxiliary pump by providing a torque to the auxiliary pump;   an engine configured to drive the main pump by providing a torque to the main pump; and   a controller configured to determine a temperature of the motor, compare the temperature of the motor to a first predetermined operating threshold, and disable the auxiliary pump and enable the main pump if the temperature of the motor is above the first predetermined operating threshold, wherein the controller is configured to disable the auxiliary pump by commanding the motor to turn off and enable the main pump by commanding the engine to turn on; and   wherein the controller is configured to allow the auxiliary pump to be enabled if the temperature of the motor falls below a second predetermined operating threshold.   
     
     
         19 . A vehicle as set forth in  claim 18 , further comprising a sensor configured to measure the temperature of the motor. 
     
     
         20 . A vehicle as set forth in  claim 18 , wherein the controller is configured to estimate the temperature of the motor.