Patent ID: 11939941
Assignee: DELPHI TECHNOLOGIES IP LIMITED
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 7:
8. A fuel pump comprising:
a pump body defining a low-pressure side, a high-pressure side, and a pumping chamber therebetween, the pump body further defining a central bore and a drain port extending from the central bore to the low-pressure side;
a sleeve within the central bore, the sleeve including upper and lower guide ribs and a cylindrical sidewall, the upper and lower guide ribs being outwardly convex and circumferentially disposed about an exterior of the sleeve, the upper and lower guide ribs being integrally formed with the cylindrical sidewall and axially spaced apart from each other, the sleeve being clamped in position with the central bore by a crimped portion of the pump body, the sleeve and the pump body being formed from metal such that an upper axial surface of the sleeve abuts the pump body to achieve a metal-on-metal sealing interface; and
a plunger, moveable within the sleeve, the plunger being mechanically actuated for compressing fuel within the pumping chamber;
wherein an outer diameter of the plunger and an inner diameter of the sleeve define a first diametral clearance, and wherein an outer diameter of the upper and lower guide ribs and an inner diameter of the central bore define a second diametral clearance, the second diametral clearance being at least 75% of the first diametral clearance to accommodate thermal expansion of the sleeve;
wherein the upper and lower guide ribs are separated by an intermediate portion of the sleeve, the intermediate portion defining an outer diameter less than the outer diameter of the upper and lower guide ribs.