Fuel pump for an internal combustion engine

• US 6,951,165 B2
• Filed: 11/14/2002
• Issued: 10/04/2005
• Est. Priority Date: 01/11/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kuhn, Uwe, Pojar, Rolf, Nieslony, Markus
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): LESLIE, MICHAEL S
• Application Number:
  US10/432,744
• Publication Number:
  US 20040096337A1
• Time in Patent Office: 1,055 Days
• Field of Search: 92/72, 921/29, 922/55, 922/56
• US Class Current: 92/129
• CPC Class Codes: F04B 1/0426 Arrangements for pressing the pistons against the actuated cam; Arrangements for connecting the pistons to the actuated cam
• CPC Class Codes: F04B 1/0439 Supporting or guiding means for the pistons

Abstract

A fuel pump for an internal combustion engine, comprising a housing (14) in which a piston (16) is guided. A working chamber is confined in areas by the piston (16). An eccentric shaft or camshaft acts on the piston (16) on its end furthest from the working chamber. A prestressing element (30) loads the piston (16) against the eccentric shaft or camshaft. In order to reduce the fabrication costs of the fuel pump, the invention provides that a support member (40) that is separate from the piston (16) is provided, which said support member is interconnected with the end region (36) of the piston (16) closest to the eccentric shaft or camshaft, and against which the prestressing element (30) bears.

Claims

1. A fuel pump (10) for an internal combustion engine, comprising:

a housing (14), with at least one piston (16), with a working chamber (18) that is confined in areas by the piston (16), with an eccentric shaft (22) or camshaft that acts on the piston (16) at least indirectly on its end (36) furthest from the working chamber (18), and with a prestressing element (30) that loads the piston (16) at least indirectly against the eccentric shaft (22) or camshaft,

wherein a support member (40) that is separate from the piston (16) is provided, which said support member is interconnected with the end region (36) of the piston (16) closest to the eccentric shaft (22) or camshaft, and against which the prestressing element (30) bears, and further comprising a guide sleeve (68) capable of moving with the piston (16), which said guide sleeve cooperates with a guide section (62) secured to the housing,

wherein the guide sleeve (68) comprises a radially inwardly directed annular collar (66) that extends into an annular space (84) located between support member (40) and base part (28).

2. The fuel pump (10) according to claim 1, wherein the support member (40) comprises a support ring (52).

3. The fuel pump (10) according to claim 2, wherein the support member (40) is two-pieced and comprises a support ring (52) interconnected with the end region (36) of the piston (16) and an intermediate element (54) pushed onto the piston (16) between prestressing element (30) and support ring (52).

4. The fuel pump (10) according to claim 1, wherein one section (42) of the support member (40) abuts a retainer (78) that is accommodated, in areas, in a groove in the end region (36) of the piston (16) closest to the eccentric shaft (22) or camshaft.

5. The fuel pump (10) according to claim 1, wherein it comprises a guide sleeve (68) capable of moving with the piston (16), which said guide sleeve cooperates with a guide section (62) secured to the housing.

6. The fuel pump (10) according to claim 5, wherein the support member (40) is integral with the guide sleeve (68).

7. The fuel pump (10) according to claim 1, wherein the support member (40) comprises a radially inwardly directed annular collar (66) that rests against a radially outwardly directed annular collar (64) of the piston (16).

8. The fuel pump (10) according to claim 1, wherein said fuel pump comprises a base part (28) that abuts the end surface of the piston (16) closest to the eccentric shaft (22) or camshaft.

9. A fuel pump (10) for an internal combustion engine, comprising:

a housing (14), with at least one piston (16), with a working chamber (18) that is confined in areas by the piston (16), with an eccentric shaft (22) or camshaft that acts on the piston(16) at least indirectly on its end (36) furthest from the working chamber (18), and with a prestressing element (30) that loads the piston (16) at least indirectly against the eccentric shaft (22) or camshaft,

wherein a support member (40) that is separate from the piston (16) is provided, which said support member is interconnected with the end region (36) of the piston (16) closest to the eccentric shaft (22) or camshaft, and against which the prestressing element (30) bears, wherein said fuel pump comprises a base part (28) that abuts the end surface of the piston (16) closest to the eccentric shaft (22) or camshaft, and wherein the base part (28) comprises an upwardly extending section (70) that covers the support member (40) axially in areas, and the support member (40) is securely interconnected with the base part (28) via the upwardly extending section (70).

10. A fuel pump (10) for an internal combustion engine, comprising:

a housing (14), with at least one piston (16), with a working chamber (18) that is confined in areas by the piston (16), with an eccentric shaft (22) or camshaft that acts on the piston (16) at least indirectly on its end (36) furthest from the working chamber (18), and with a prestressing element (30) that loads the piston (16) at least indirectly against the eccentric shaft (22) or camshaft.

wherein a support member (40) that is separate from the piston (16) is provided, which said support member is interconnected with the end region (36) of the piston (16) closest to the eccentric shaft (22) or camshaft, and against which the prestressing element (30) bears, wherein said fuel pump comprises a base part (28) that abuts the end surface of the piston (16) closest to the eccentric shaft (22) or camshaft, and wherein the support member (40) comprises at least one bent-over section (48) that grips around the outside of the base part (28) and provides axial support for said base part and a support ring (52).