Fuel feed for motor-driven high pressure fuel pump

A high-pressure fuel pump comprising:

• a variable speed direct current motor (22) having a motor housing (20) with a first end and a second end, with a fuel inlet (38) located at said first end, and a drive shaft (26) at said second end;
• a pump drive housing (44) having a sealed connection to the motor housing (20), said drive housing (44) defining a drive chamber (67);
• an eccentric drive (28) in the drive chamber (67) and coupled to the drive shaft (26), the eccentric drive (28) comprising:
• a drive follower (66) defining a recess including a female thread;
• a plunger-retaining insert (72) including a male thread that mates with the drive follower (66) female thread, said plunger-retaining insert (72) including a radially inward projecting shoulder having an inner limit;
• and
• a thrust washer (74) beneath the inward projecting shoulder and extending radially inward of the inner limit;
• a pumping plunger (30) with a driven end (62) connected to the eccentric drive (28) to convert rotation of the drive shaft (26) into reciprocating motion of the pumping plunger (30) in a plunger bore (31) that alternately expands and restricts the volume of a pumping chamber (33) by a pumping end (63) of the pumping plunger (30) moving into and away from the pumping chamber (33), the driven end (62) of the pumping plunger (30) includes a radially outward projecting flange (64) permanently secured to the driven end (62) of the pumping plunger (30), said flange (64) retained within the recess defined by the drive follower (66) by the thrust washer (74), which spans a radial gap between the inner limit of the inward projecting shoulder and an outer limit of the radially outward projecting flange (64);
• a pump body (54) having a sealed connection to the pump drive housing (44) and partially defining the pumping chamber (33);
• an inlet opening (41) fluidly connecting the drive chamber (67) to a pump inlet (40);
• an inlet check valve (47) located within the pump inlet (40) that opens as the pumping plunger (30) moves away from the pumping chamber (33) to draw fuel into the pumping chamber (33), and closes as the pumping plunger (30) moves into the pumping chamber (33) to compress fuel in the pumping chamber (33) enabling fuel to pass through the inlet check valve (47) after passing through the inlet opening (41) from the drive chamber (67);
• an outlet check valve (50) that closes as the pumping plunger (30) moves away from the pumping chamber (33), and opens as the pumping plunger (30) moves into the pumping chamber (33) when fuel pressure in the pumping chamber (33) exceeds fuel pressure in the fuel system downstream of the outlet check valve (50);
• wherein fuel flows from the fuel inlet (38) through the motor housing (20), the drive chamber (67) and the inlet opening (41) to the pumping chamber (33).