Patent ID: 6805538
Filing Date: 2004-10-19
Classification: F02M,F04B,Y10T

Abstract:
A fuel supply unit connected to a fuel tank for supplying high pressure fuel from the fuel tank to an engine via a common rail, the fuel tank having inner and outer surfaces, a top, and a bottom, the fuel supply unit comprising:a motor assembly mounted on the outer surface of the top of the fuel tank, the motor assembly including a motor having a motor shaft extending into the fuel tank; a pump assembly disposed within and adjacent to the bottom of the fuel tank, the pump assembly comprising a high pressure pump sub-assembly including a pump body having axially spaced top and bottom end portions and defining a plurality of plunger bores and a drive bore for providing fluid communication with the fuel tank, a pumping plunger disposed within each of the plunger bores, a drive member rotatable within the drive bore, and a high pressure line adapted for providing fluid communication with the common rail, each of the plunger bores extending radially from an inner end opening into the drive bore to an outer end in fluid communication with the high pressure line, each of the pumping plungers having radially inner and outer ends, the drive member having an external profile which engages the inner end of each pumping plunger for a portion of each revolution of rotation thereby actuating reciprocal movement of the pumping plungers within their respective plunger bores between radially inner and outer limit positions, the pump assembly also comprising a fine filter sub-assembly mounted to the top end portion of the pump body, the fine filter sub-assembly including a cannister and a fine filter element disposed within the cannister; and a support column rotatably connecting the motor shaft to the drive member; wherein reciprocation of each pumping plunger towards the inner limit position induces a low pressure in the outer end of the plunger bore, thereby drawing fuel into the outer end of the plunger bore via the drive bore without the aid of a low pressure pump, and reciprocation of each pumping plunger towards the outer limit position induces a high pressure in the outer end of the plunger bore, thereby discharging fuel from the outer end of the plunger bore into the high pressure line.