High Pressure Pump

Patent metadata

Field	Value
Publication number	US-2016208796-A1
Application number	US-201414758295-A
Country	US
Kind code	A1
Filing date	Aug 6, 2014
Priority date	Oct 14, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

A high pressure pump of a common rail pump system includes a pump body having a cylinder with a piston bore and a piston reciprocally driven in the piston bore to pressurize fuel in the cylinder. The piston has an inner end located in the piston bore and an outer end outside the piston bore. A bellow having a first opening and a second opening is arranged between the piston and the pump body, wherein the piston extends through the first and second openings, wherein the bellow is connected to the pump body such that the first opening is sealed on the pump body and wherein the bellow is connected to the outer end of the piston such that the second opening is sealed on the piston. This arrangement prevents mixing of engine oil and fuel. The bellow may be connected to a drainage line via a one-way valve.

First claim

What is claimed is:

1 . A high pressure pump of a common rail pump system, the high pressure pump comprising:
a pump body having a cylinder with a piston bore, a piston reciprocally driven in the piston bore by an eccentric to pressurize fuel in the cylinder, the piston having an inner end located in the piston bore and an outer end outside the piston bore, and a bellow arranged between piston and the pump body and having a first opening and a second opening, wherein the piston extends through the first opening and the second opening, wherein the bellow is connected to the pump body such that the first opening is sealed on the pump body and wherein the bellow is connected to the outer end of the piston such that the second opening is sealed on the piston.

2 . The high pressure pump of claim 1 , comprising a back leak connection at the bellow, which is connected with a drainage line for draining leakage fuel off an interior space of the bellow.

3 . The high pressure pump of claim 2 , comprising a one-way valve arranged between the back leak connection and the drainage line.

4 . The high pressure pump of claim 2 , wherein the piston bore comprises a radially outwardly extending recess connected with the drainage line.

5 . The high pressure pump of claim 1 ,
comprising a back leak connection at the bellow, which is connected with a drainage line for draining leakage fuel off an interior space of the bellow, wherein the piston bore comprises a radially outwardly extending recess connected with the drainage line, and wherein the one-way valve is upstream of a connection of the recess in the piston bore and the drainage line.

6 . The high pressure pump of claim 4 , comprising a fuel inlet connected to the radially outwards extending recess.

7 . The high pressure pump of claim 1 , wherein a gap between the piston and the piston bore is greater than 0.008 mm.

8 . The high pressure pump of claim 1 , comprising a pressure dampening membrane supported in the bellow such that a permeable fluid receiving space is created in the bellow,
wherein a fuel inlet of the high pressure pump is connected with the fuel receiving space and a fuel inlet of the piston bore is connected with the fluid receiving chamber, wherein the pressure dampening membrane is configured to attentuate pressure peaks of incoming flow of fuel.

9 . The high pressure pump of claim 8 , wherein the membrane comprises a drainage port or pores or a gap to the bellow that provides a permeability.

10 . (canceled)

11 . A high pressure pump of a common rail pump system, the high pressure pump comprising:
a pump body having a cylinder with a piston bore, a piston reciprocally driven in the piston bore to pressurize fuel in the cylinder, a leakage gap between an outer surface of the piston and an inner surface of the piston bore, a bellow having a first end secured to the piston and a second end secured to the pump body, and defining a bellow internal volume within the bellow, wherein the bellow internal volume is communicatively coupled to both (a) the leakage gap between the outer surface of the piston and the inner surface of the piston bore and (b) a drainage line, wherein the bellow is coupled to the piston such that a reciprocal movement of the piston causes a corresponding reciprocal change in the bellow internal volume, and wherein during the reciprocal movement of the piston, fuel leaks through the leakage gap and into the bellow internal volume, and said fuel subsequently pumped from the bellow internal volume into the drainage line due to the reciprocal change in the bellow internal volume.

12 . The high pressure pump of claim 11 , comprising a one-way valve arranged between the in the drainage line or at a connection between the drainage line and the bellow internal volume.

13 . The high pressure pump of claim 11 , wherein the piston bore comprises a radially outwardly extending recess connected with the drainage line.

14 . The high pressure pump of claim 13 , comprising a fuel inlet connected to the radially outwards extending recess.

15 . The high pressure pump of claim 11 , comprising a one-way valve arranged between the in the drainage line or at a connection between the drainage line and the bellow internal volume,
wherein the piston bore comprises a radially outwardly extending recess connected with the drainage line, and wherein the one-way valve is upstream of a connection of the recess in the piston bore and the drainage line.

16 . The high pressure pump of one of the claim 11 , wherein the leakage gap between the piston and the piston bore is greater than 0.008 mm.

17 . The high pressure pump of claim 11 , comprising a pressure dampening membrane supported in the bellow such that a permeable fluid receiving space is created in the bellow,
wherein a fuel inlet of the high pressure pump is connected with the fuel receiving space and a fuel inlet of the piston bore is connected with the fluid receiving chamber, wherein the pressure dampening membrane is configured to attenuate pressure peaks of incoming flow of fuel.

18 . The high pressure pump of claim 17 , wherein the membrane comprises a drainage port or pores or a gap to the bellow that provides a permeability.

Assignees

• Continental Automotive Gmbh

Inventors

• Nigrin Uwe
• Vu Ngoc-Tam
• Ederer Andreas
• Bhat Uday
• Magadibyredevaru Thejesh Kumar
• Olik Marcin

Classifications

• F02M59/46

  Valves · CPC title

• F04B43/02 Primary

  having plate-like flexible members, e.g. diaphragms (F04B43/14 takes precedence) · CPC title

• F04B11/00

  Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation · CPC title

• F04B53/16

  Casings; Cylinders; Cylinder liners or heads; Fluid connections · CPC title

• F04B53/04 Primary

  Draining · CPC title