Pre-lubrication and soak-back system for a machine

Abstract

A lubrication system for an engine is disclosed. The lubrication system may have an oil pump configured to lubricate the engine. The lubrication system may also have a valve configured to direct oil from the oil pump to a fuel pump associated with the engine. The lubrication system may further have a controller. The controller may be configured to determine an operating speed of the engine. The controller may also be configured to adjust the valve to selectively direct the oil to the fuel pump based on the operating speed.

What is claimed is: 
     
         1 . A lubrication system for an engine, comprising:
 an oil pump configured to lubricate the engine;   a valve configured to direct oil from the oil pump to a fuel pump associated with the engine; and   a controller configured to:
 determine an operating speed of the engine; and 
 adjust the valve to selectively direct the oil to the fuel pump based on the operating speed. 
   
     
     
         2 . The lubrication system of  claim 1 , wherein the controller is configured to:
 open the valve when the operating speed of the engine is less than or about equal to a threshold operating speed; and   close the valve when the operating speed of the engine exceeds the threshold operating speed.   
     
     
         3 . The lubrication system of  claim 2 , wherein the valve is a first valve and the lubrication system further includes:
 a second valve configured to direct the oil from the oil pump to a turbocharger associated with the engine; and   a third valve configured to direct the oil from the oil pump to the engine.   
     
     
         4 . The lubrication system of  claim 3 , wherein each of the first valve, the second valve, and the third valve is a two position solenoid valve. 
     
     
         5 . The lubrication system of  claim 3 , wherein the controller is configured to direct a first flow of oil by opening the first valve and closing the second valve and the third valve. 
     
     
         6 . The lubrication system of  claim 5 , wherein the controller is configured to:
 direct a first portion of the first flow of oil to the fuel pump; and   direct a second portion of the first flow of oil to actuate an exhaust gas recirculation valve.   
     
     
         7 . The lubrication system of  claim 6 , wherein the controller is further configured to stop the oil pump when the operating speed of the engine exceeds the threshold operating speed. 
     
     
         8 . The lubrication system of  claim 3 , wherein the controller is configured to direct a second flow of oil to the turbocharger by opening the second valve and closing the first valve and the third valve. 
     
     
         9 . The lubrication system of  claim 8 , wherein the controller is configured to:
 determine whether the engine has been turned off;   start the oil pump when the engine has been turned off; and   direct the second flow of oil to the turbocharger.   
     
     
         10 . The lubrication system of  claim 3 , wherein the controller is configured to direct a third flow of oil to the engine by opening the third valve and closing the first valve and the second valve. 
     
     
         11 . The lubrication system of  claim 10 , wherein the controller is configured to:
 determine a first amount of time for which the engine has been off; and   direct the third flow of oil to the engine, when the first amount of time exceeds a threshold amount of time.   
     
     
         12 . A method of operating a machine, comprising:
 supplying oil for lubrication, using a first oil pump associated with the machine;   lubricating an engine associated with the machine using the oil;   starting the engine;   determining an operating speed of the engine; and   adjusting a valve to selectively direct the oil from the first oil pump to a fuel pump associated with the engine based on the operating speed.   
     
     
         13 . The method of  claim 12 , wherein adjusting the valve includes:
 opening the valve when the operating speed is less than or about equal to a threshold operating speed; and   closing the valve when the operating speed exceeds the threshold operating speed.   
     
     
         14 . The method of  claim 13 , wherein opening the valve includes:
 directing a first portion of a first flow of oil from the first oil pump to the fuel pump;   directing a second portion of the first flow of oil to an exhaust gas recirculation valve; and   actuating the exhaust gas recirculation valve using the second portion.   
     
     
         15 . The method of  claim 14 , wherein closing the valve further includes supplying the first flow of oil, using a second oil pump. 
     
     
         16 . The method of  claim 15 , further including:
 lubricating the engine for a first amount of time;   lubricating a turbocharger associated with the engine for a second amount of time; and   lubricating the fuel pump for a third amount of time.   
     
     
         17 . The method of  claim 16 , wherein lubricating the turbocharger includes:
 directing a second flow of oil from the first oil pump to the turbocharger; and   stopping the second flow of oil after the second amount of time.   
     
     
         18 . The method of  claim 17 , wherein lubricating the engine includes:
 determining a time interval for which the engine had been off;   directing a third flow of oil from the first oil pump to the engine, when the time interval exceeds a threshold time interval; and   stopping the third flow of oil after the first amount of time.   
     
     
         19 . The method of  claim 18 , further including:
 determining whether an engine off signal has been received;   turning off the engine in response to the engine off signal;   directing the second flow of oil to the turbocharger; and   stopping the second flow of oil after a fourth amount of time.   
     
     
         20 . A mobile machine comprising:
 an engine configured to propel the machine;   at least one turbocharger configured to supply air to the engine;   at least one exhaust gas recirculation valve configured to recirculate exhaust in the engine;   a fuel pump configured to supply fuel to the engine;   a sump configured to store oil for lubrication;   an oil pump configured to pump the oil from the sump;   a manifold configured to receive the oil from the oil pump, the manifold including:
 a first valve configured to direct the oil to the fuel pump and the exhaust gas recirculation valve; 
 a second valve configured to direct the oil to the turbocharger; and 
 a third valve configured to direct the oil to the engine; and 
   a controller configured to adjust the first valve to selectively direct the oil to the fuel pump based on an operating speed of the engine.