Radial piston pump with a roller plunger

• US 7,762,176 B2
• Filed: 07/27/2005
• Issued: 07/27/2010
• Est. Priority Date: 10/06/2004
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Vu, Ngoc-Tam
• Primary Examiner(s): Lazo; Thomas E
• Application Number:
  US11/576,798
• Publication Number:
  US 20080034959A1
• Time in Patent Office: 1,826 Days
• Field of Search: 92/72, 921/29, 921/65.R, 921/65.PR
• US Class Current: 92/72
• 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 radial piston pump has a pump housing (1) and at least one pump unit (2) with a pump piston (3) and a cylinder (4) wherein the pump piston (3) can be mounted such that it can be moved backwards and forth, wherein the pump unit (2) can be driven by means of a camshaft (5) mounted in the pump housing (1); and a roller plunger (6) is arranged between the camshaft (5) and the pump unit (2), consisting of a plunger (7) and a roller (8), wherein the plunger has a guide area (9) which is used to guide it a first slot-shaped guide groove (10) of the cylinder insert (4). The roller plunger (6) is thus reliably prevented from rotating inside the cylinder insert (4). The radial piston pumps are particularly suited for high rotational speeds occurring in high-pressure fuel pumps.

Claims

1. A radial piston pump, having a pump housing and at least one pump unit comprising a pump piston and a cylinder insert in which the pump piston is mounted such that the pump piston can be moved back and forth,

wherein the pump unit is configured to be driven by means of a camshaft mounted in the pump housing,

wherein a roller plunger comprising a plunger and a roller is arranged between the camshaft and the pump unit, wherein the plunger comprises a guide area configured to guide said plunger in a first slot-shaped guide groove of the cylinder insert, and

wherein the roller is guided in a second slot-shaped guide groove of the cylinder insert.

2. The radial piston pump according to claim 1, wherein the first slot-shaped guide groove is designed to be parallel to the longitudinal axis of the pump piston.

3. The radial piston pump according to claim 1, wherein the second slot-shaped guide groove is arranged at right-angles to the first slot-shaped guide groove.

4. The radial piston pump according to claim 1, wherein a return spring is arranged between the cylinder insert and the roller plunger.

5. The radial piston pump according to claim 4, wherein a contact surface for the return spring is embodied in each instance on the cylinder insert and on the roller plunger.

6. The radial piston pump according to claim 4, wherein the roller plunger includes a disk, which serves to accommodate the return spring.

7. The radial piston pump according to claim 1, wherein the plunger features a fork-shaped recess, between which the roller of the roller plunger is mounted in a rotatable manner by means of a roller bolt.

8. The radial piston pump according to claim 1, wherein the plunger is connected to the pump piston in a form-fit manner.

9. The radial piston pump according to claim 8, wherein the plunger features a T-groove, which forms the form-fit connection with a shoulder formed on the pump piston.

10. A radial piston pump, comprising:

a pump housing and at least one pump unit with a pump piston and a cylinder insert in which the pump piston is mounted such that the pump piston can be moved back and forth,

a camshaft mounted in the pump housing for driving the pump unit,

a roller plunger comprising a plunger and a roller, the roller plunger arranged between the camshaft and the pump unit, the plunger comprising a guide area configured to guide said plunger in a first slot-shaped guide groove of the cylinder insert, and

the roller is guided in a second slot-shaped guide groove of the cylinder insert.

11. The radial piston pump according to claim 10, wherein the first slot-shaped guide groove is designed to be parallel to the longitudinal axis of the pump piston.

12. The radial piston pump according to claim 10, wherein the second slot-shaped guide groove is arranged at right-angles to the first slot-shaped guide groove.

13. The radial piston pump according to claim 10, wherein a return spring is arranged between the cylinder insert and the roller plunger.

14. The radial piston pump according to claim 13, wherein

a contact surface for the return spring is embodied in each instance on the cylinder insert and on the roller plunger.

15. The radial piston pump according to claim 13, wherein the roller plunger includes a disk, which serves to accommodate the return spring.

16. The radial piston pump according to claim 10, wherein the plunger features a fork-shaped recess, between which the roller of the roller plunger is mounted in a rotatable manner by means of a roller bolt.

17. The radial piston pump according to claim 10, wherein the plunger is connected to the pump piston in a form-fit manner.

18. The radial piston pump according to claim 17, wherein the plunger features a T-groove, which forms the form-fit connection with a shoulder formed on the pump piston.

19. A radial piston pump, comprising:

a pump housing and at least one pump unit with a pump piston and a cylinder insert in which the pump piston is mounted such that the pump piston can be moved back and forth,

a camshaft mounted in the pump housing for driving the pump unit,

a roller plunger comprising a plunger and a roller, the roller plunger arranged between the camshaft and the pump unit, the plunger comprising a guide area configured to guide said plunger in a first slot-shaped guide groove of the cylinder insert, and

a return spring arranged between the cylinder insert and the roller plunger.