Fuel pump

Abstract

A fuel pump is provided for pressurising fuel in a high-pressure fuel injection system. The fuel pump comprises a pump head, a pumping element, a frame and a casing. The pump head has a pumping chamber that is arranged to receive fuel to be pressurised. The pumping element is arranged to reciprocate responsive to movement of a driving element, the pumping element defining, in part, the pumping chamber so that, in use, as the pumping element reciprocates, a force, transferred from the driving element, is applied to the fuel within the pumping chamber to pressurise the fuel. The frame is arranged to support the driving element and the pump head. The casing defines an internal volume for containing fluid, wherein at least a part of the frame, at least a part of the drive element, and at least a part of the pumping element are received in the casing.

1 . A fuel pump for pressurising fuel in a high-pressure fuel injection system, the fuel pump comprising:
 a pump head having a pumping chamber that is arranged to receive fuel to be pressurised;   a pumping element arranged to reciprocate responsive to movement of a driving element, the pumping element defining, in part, the pumping chamber so that, in use, as the pumping element reciprocates, a force, transferred from the driving element, is applied to the fuel within the pumping chamber to pressurise the fuel;   a frame arranged to support the driving element and the pump head; and   a casing defining an internal volume for containing fluid;   wherein at least a part of the frame, at least a part of the driving element, and at least a part of the pumping element are received in the casing.   
     
     
         2 . The fuel pump according to  claim 1 , wherein the frame is arranged to hold the pump head and driving element in fixed positions relative to one another to support the transfer of force from the driving element to the pump head. 
     
     
         3 . The fuel pump according to  claim 1 , wherein the frame is constructed from a material having higher strength than a material from which the casing is constructed. 
     
     
         4 . The fuel pump according to  claim 1 , wherein the frame is formed of a single piece. 
     
     
         5 . The fuel pump according to  claim 4 , wherein the frame is formed of a single piece by means of an extrusion process. 
     
     
         6 . The fuel pump according to  claim 1 , wherein the casing is formed of a plastics-based material. 
     
     
         7 . The fuel pump according to  claim 1 , wherein the frame is arranged for mounting the fuel pump to an engine component. 
     
     
         8 . The fuel pump ( 1 ) according to  claim 7 , further comprising:
 a mounting arrangement for connecting the frame of the fuel pump to the engine component.   
     
     
         9 . The fuel pump according to  claim 8 , wherein the casing and the mounting arrangement each comprise a complementary interference feature arranged for preventing rotation of the mounting arrangement with respect to the casing. 
     
     
         10 . The fuel pump according to  claim 9 , wherein one of the complementary interference features comprises a protrusion and the other complementary interference feature comprises a recess. 
     
     
         11 . The fuel pump according to  claim 1 , wherein the casing comprises one or more integrated components including one or more of a back-leak device to aid recirculation of fluid, and a fuel inlet to deliver fuel to the fuel pump. 
     
     
         12 . The fuel pump according to  claim 1 , wherein the driving element is formed from a plurality of parts including a shaft portion and a cam portion. 
     
     
         13 . The fuel pump according to  claim 12 , wherein the cam portion is constructed from a higher strength material than the shaft portion. 
     
     
         14 . The fuel pump according to  claim 1 , wherein the pump head is received within the casing. 
     
     
         15 . The fuel pump according to  claim 1 , wherein the frame comprises at least one bearing arranged to support the drive element for rotational movement with respect to the bearing.