Turbocharger oil supply passage check valve and method

Abstract

A turbocharger ( 500 ) for an internal combustion engine ( 400 ) includes a center housing ( 504 ) having an oil supply passage ( 412 ) in fluid communication with an oil pump ( 404 ). The oil pump ( 404 ) is in fluid communication with an oil reservoir ( 420 ) in the engine ( 400 ). An oil drain passage ( 418 ) is also in fluid communication with the oil reservoir ( 420 ). A check valve ( 401 ) is in fluid communication with the supply passage ( 412 ) and located between the oil pump ( 404 ) and the center housing ( 504 ) of the turbocharger ( 500 ) to prevent oil from passing from a portion of the oil supply passage ( 424 ) back to the oil pump ( 404 ).

1 . A turbocharger for an internal combustion engine comprising: 
 a center housing connected to a turbine housing and a compressor housing;    an oil supply passage in fluid communication with an oil pump, wherein the oil pump is in fluid communication with an oil reservoir;    an oil drain passage in fluid communication with the oil reservoir; and    a check valve disposed in fluid communication with the supply passage between said oil pump and the center housing of said turbocharger to prevent oil from passing from a portion of the oil supply passage to the oil pump.    
   
   
       2 . The turbocharger of  claim 1 , wherein the check valve is integrated into a fluid coupling, wherein the oil supply passage is a tube, and wherein the coupling is disposed at a distal end of the tube.  
   
   
       3 . The turbocharger of  claim 1 , wherein an amount of oil is disposed in the portion of the oil supply passage when the engine is not operating, wherein the amount of oil in the portion of the supply passage is adequate for lubrication of the center housing for a limited time, and wherein the limited time is adequate for the oil pump to supply oil to the supply passage when the engine is first started.  
   
   
       4 . The turbocharger of  claim 1 , wherein the check valve is disposed above the level of oil reservoir.  
   
   
       5 . The turbocharger of  claim 1 , further comprising an oil cooler disposed between the oil pump and the check valve.  
   
   
       6 . The turbocharger of  claim 1 , wherein the check valve includes a plug disposed in a chamber, and wherein the plug is pressed against a seat when the check valve is closed.  
   
   
       7 . The turbocharger of  claim 1 , wherein the check valve includes a flap disposed in a chamber, and wherein the flap is pressed against a substantially flat surface when the check valve is closed.  
   
   
       8 . A method for operating an engine having a turbocharger, comprising the steps of: 
 collecting oil in an internal volume of an internal combustion engine;    pumping oil from the engine internal volume with an oil pump;    supplying pumped oil flow to a center housing of a turbocharger through an oil supply passage when the internal combustion engine is operating;    draining oil from the center housing into the engine internal volume; and    maintaining a quantity of oil in the oil supply passage between the center housing of the turbocharger and a check valve, the check valve disposed between the center housing of the turbocharger and the oil pump, when the engine is not in operation.    
   
   
       9 . The method of  claim 8 , further comprising the step of cooling the pumped oil flow.  
   
   
       10 . The method of  claim 8 , opening the check valve when the engine is in operation.  
   
   
       11 . The method of  claim 8 , wherein quantity of oil maintained in the oil supply passage is adequate for lubrication of the center housing for a period of time after the engine is in operation.  
   
   
       12 . The method of  claim 8 , wherein the step of maintaining a quantity of oil in the oil supply passage is accomplished by closing the check valve when the engine is turned off, wherein the quantity of oil in the supply passage forms a column of oil which exerts a hydrostatic pressure, and wherein the check valve is closed by the hydrostatic pressure.  
   
   
       13 . The method of  claim 12 , wherein the step of closing the check valve includes at least one of sinking a plug in a chamber and pressing a flap against a surface.  
   
   
       14 . An internal combustion engine comprising: 
 an engine structure having an internal volume including an oil reservoir, wherein an amount of oil is collected in an oil pool in the reservoir;    a turbocharger mounted to said engine structure and having a center-housing connected to a turbine housing and a compressor housing, wherein the center-housing includes an oil supply passage and an oil drain passage, in fluid communication with the oil cavity;    an oil pump in fluid communication with the oil supply passage and the oil pool;    a check valve fluidly connecting the oil supply passage with the oil pump, wherein the check valve is arranged to prevent oil flow from the oil supply passage in the center-housing to the oil pump; and    a quantity of oil disposed between the check valve and the center housing when the engine is not in operation, wherein the quantity of oil is sufficient to lubricate the center housing when the engine is first operated.    
   
   
       15 . The internal combustion engine of  claim 14 , wherein the oil drain passage is in fluid communication with the oil reservoir.  
   
   
       16 . The internal combustion engine of  claim 14 , wherein the quantity of oil is disposed in an oil supply tube, and wherein the quantity of oil in the oil supply tube forms a standing column of fluid that exerts a hydrostatic pressure on the check valve.  
   
   
       17 . The internal combustion engine of  claim 14 , further comprising an oil cooler in fluid communication with the oil pump and the oil supply passage.  
   
   
       18 . The internal combustion engine of  claim 14 , wherein the check valve is integrated with an oil supply tube, said oil supply tube fluidly connecting the oil pump with the oil supply passage in the center housing of the turbocharger.  
   
   
       19 . The internal combustion engine of  claim 14 , further comprising an oil cooler disposed between the oil pump and the check valve.  
   
   
       20 . The internal combustion engine of  claim 19 , further comprising an oil filter disposed between the oil cooler and the check valve.