Patent ID: 7048516
Filing Date: 2006-05-23
Classification: F02M

Abstract:
1. A fuel pump for supplying fuel at high fuel pressures, the pump comprising: a stationary body having a plurality of radial cylinders connecting inwardly with a central fuel chamber and outwardly with follower recesses, the plurality of radial cylinders including a group of equiangularly spaced primary cylinders in the body, the plurality of radial cylinders including a group of secondary cylinders, each of the secondary cylinders paired with one of the primary cylinders spaced at a predetermined angle in advance of the secondary cylinders; inlet and outlet passages communicating with the fuel chamber; primary plungers reciprocable in the primary cylinders and outwardly engaging cam followers reciprocable in the follower recesses, the primary plungers actuated simultaneously by equiangularly spaced cam lobes; secondary plungers reciprocable in the secondary cylinders and outwardly engaging cam followers reciprocable in the follower recesses, the secondary plungers actuated by the cam lobes upon rotation of the body at the predetermined angle following actuation of the primary plungers; and a rotary internal cam engaging the cam followers and rotatably supported around the body, the cam configured to reciprocate the primary and secondary plungers in timed relation to sequentially draw fuel from the inlet passage into the central fuel chamber and alternately force fuel from the central fuel chamber to the outlet passage in response to rotation of the rotary cam, wherein the primary plungers force a first volume of fuel from the central fuel chamber to the outlet passage, wherein the secondary plungers force a second volume of fuel from the central fuel chamber to the outlet passage, and wherein the first volume is not equal to the second volume.