Variable output pump

Abstract

An variable output pump is disclosed. The variable output pump having a rotatable first shaft, a first pumping element mounted to the rotatable first shaft, and a coupling mechanism configured to couple the first pumping element to the first shaft for rotation therewith in a first mode, and decouple the first pumping element from the rotatable first shaft in a second mode. A method for varying the output of a fluid pump is also disclosed. The method including rotating a first pumping element and a second pumping element; and preventing rotation of the first pumping element in response to an increase in fluid pressure, while continuing to rotate the second pumping element.

1 . A variable output pump, comprising:
 a rotatable first shaft;   a first pumping element mounted to the rotatable first shaft; and   a coupling mechanism configured to couple the first pumping element to the first shaft for rotation therewith in a first mode, and decouple the first pumping element from the rotatable first shaft in a second mode.   
     
     
         2 . The variable output pump of  claim 1  wherein the coupling mechanism switches between the first mode and the second mode in response to a change in fluid pressure. 
     
     
         3 . The variable output pump of  claim 2  wherein the coupling mechanism switches between the first mode and the second mode in response to a change in fluid temperature. 
     
     
         4 . The variable output pump of  claim 1  further comprising a second pumping element mounted to the rotatable first shaft, wherein the second pumping element remains coupled to the first shaft in the second mode. 
     
     
         5 . The variable output pump of  claim 1  wherein the first pumping element is a first gear and the second pumping element is a second gear, and the pump further comprises a third gear configured to mate with the first gear and a fourth gear configured to mate with the second gear 
     
     
         6 . The variable output pump of  claim 5  wherein the third gear is mounted on a second rotatable shaft and the fourth gear is mounted on a third rotatable shaft. 
     
     
         7 . The variable output pump of  claim 1  comprising a plunger configured to translate axially between a first position and a second position to switch the variable output pump from the first mode to the second mode. 
     
     
         8 . The variable output pump of  claim 8  further comprising a biasing element configured to bias the plunger toward the first position. 
     
     
         9 . The variable output pump of  claim 8  wherein the plunger includes an interface configured to prevent the first pumping element from rotating when the plunger is in the second position. 
     
     
         10 . The variable output pump of  claim 1  further comprising a drive element configured to move radially inward to decouple the first pumping element from the rotatable first shaft. 
     
     
         11 . A method for varying the output of a fluid pump, comprising:
 rotating a first pumping element and a second pumping element; and   preventing rotation of the first pumping element in response to an increase in fluid pressure, while continuing to rotate the second pumping element.   
     
     
         12 . The method of  claim 11  wherein the step of rotating a first pumping element and a second pumping element further comprising rotating a first shaft. 
     
     
         13 . The method of  claim 12  comprising decoupling the first pumping element from the first shaft. 
     
     
         14 . The method of  claim 13  comprising opening a fluid passage in response to a fluid temperature exceeding a temperature threshold. 
     
     
         15 . A power system, comprising:
 an engine;   a sump configured to hold a volume of fluid; and   a variable output pump configured to draw fluid from the sump and deliver the fluid to the engine, the variable output pump, comprising:
 a rotatable first shaft; 
 a first pumping element mounted to the rotatable first shaft; and 
 a coupling mechanism configured to couple the first pumping element to the first shaft for rotation therewith in a first mode, and decouple the first pumping element from the rotatable first shaft in a second mode. 
   
     
     
         16 . The power system of  claim 15  wherein the coupling mechanism switches between the first mode and the second mode in response to a change in a pressure of the fluid. 
     
     
         17 . The power system of  claim 16  wherein the coupling mechanism switches between the first mode and the second mode in response to a change in fluid temperature. 
     
     
         18 . The power system of  claim 15  further comprising a second pumping element mounted to the rotatable first shaft, wherein the second pumping element remains coupled to the first shaft in the second mode. 
     
     
         19 . The power system of  claim 17  wherein the first pumping element is a first gear and the second pumping element is a second gear, and the pump further comprises a third gear configured to mate with the first gear and a fourth gear configured to mate with the second gear. 
     
     
         20 . The variable output pump of  claim 15  comprising an interface configured to prevent the first pumping element from rotating when the coupling mechanism is in the second mode.