Fuel injection pump

Claim 1

A fuel injection pump for a diesel engine comprising a housing assembly, a rotor disposed within said housing assembly, means for driving said rotor in rotation at a speed corresponding to engine speed, said rotor comprising a pump body and a distributor shaft, a hydraulic head in said housing assembly, a bore in said hydraulic head for rotatably supporting said rotor distributor shaft, opposed pistons disposed within radial bores of said pump body, said pump body radial bores intersecting to form a pumping chamber, tappet assemblies associated with each said piston, an internal ring cam disposed in said housing concentrically with said rotor for cooperation with said tappet assemblies to provide a pumping movement of said pistons upon rotation of said rotor, means for varying the rotational position of said cam in response to changes in engine operating conditions, an axial bore within said distributor shaft communicating with said pumping chamber, a distributor slot in said distributor shaft, a plurality of spaced distributor ports in said hydraulic head, said distributor slot aligning sequentially with said distributor ports upon rotation of said rotor, passage means in said hydraulic head communicating with said distributor ports for connecting said ports with the engine fuel injection nozzles, a fuel gallery adjacent one end of said hydraulic head, means for supplying fuel under pressure to said fuel gallery, said pump body being disposed adjacent the other end of said hydraulic head at one end of said distributor shaft, the opposite end of said distributor shaft extending beyond said hydraulic head into said fuel gallery, a spill sleeve on said extending end of said distributor shaft, slot and port means on said distributor shaft and spill sleeve for providing a communication of said distributor shaft bore and said gallery to effect termination of injection, fuel metering control means for varying the position of said spill sleeve with respect to said distributor shaft in accordance with the operating conditions and the fuel demands of the engine, port closing means for providing fluid communication between said distributor shaft bore and said fuel gallery during an initial portion of the pumping stroke of said pistons and for cutting off said communication to initiate fuel injection, and timing control means for simultaneously changing the timing of the closing of said port closing means and the opening of said spill sleeve and distributor shaft slot and port means.