Plug-in pump

Patent metadata

Field	Value
Publication number	US-9951733-B2
Application number	US-201314403649-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 21, 2012
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A plug-in pump includes a cylinder and a pump housing, wherein the cylinder has a cavity in which a movable piston is accommodated, wherein a first end of the piston delimits a pump chamber, and a second end of the piston is connected to a drive device for the piston. An inlet valve is arranged in the cylinder, which inlet valve connects the pump chamber to a feed line for a first fluid, and an outlet valve connects the pump chamber to an outlet. The pump housing has a cavity that forms a first chamber connected to a feed line for the first fluid, and at least one second chamber which is separated from the first chamber and which is connected to a fluid system of a second fluid. The first chamber is fluidically sealed off with respect to the second chamber.

First claim

The invention claimed is:

1. A plug-in pump comprising:
a pump housing defining a cylinder cavity,
a movable piston arranged in the cylinder cavity, wherein a first end of the piston delimits a pump chamber within the cavity, and a second end of the piston is connected through an intermediate piece to a slide comprising a roller tappet moving along a shared axis with the movable piston within a guide bushing,
the roller tappet riding along a drive device for the piston,
an inlet valve arranged in the pump housing, wherein the inlet valve connects the pump chamber to a feed line for a first fluid, and
an outlet valve that connects the pump chamber to an outlet,
wherein the cylinder cavity includes (a) a first chamber surrounding the second end of the piston and a first portion of the intermediate piece, the first chamber fluidly connected to a fluid system of the first fluid, and (b) at least one second chamber surrounding a exterior perimeter of a second portion of the intermediate piece and sealed off from the first chamber and connected to a fluid system of a second fluid, wherein the intermediate piece extends from the first chamber to the second chamber through a sealing element separating the first chamber from the second chamber.

2. The plug-in pump of claim 1 , wherein the second end of the piston is connected to or formed integrally with the intermediate piece that transmits a movement of the drive device to the piston.

3. The plug-in pump of claim 2 , wherein the intermediate piece includes a first section that projects into the first chamber, a third section that projects into the second chamber, and a second section that connects the first section and the third section and projects through a connecting region formed in the cavity between the first chamber and the second chamber.

4. The plug-in pump of claim 3 , wherein:
the connecting region has a shape of a hollow cylinder having an inside diameter that corresponds substantially to an outside diameter of the second section, and
at least one of the inner wall of the connecting region and the second section has a sealing element that prevents the first and second fluids from mixing with each other.

5. The plug-in pump of claim 1 , comprising at least one spring element arranged in at least one of the first chamber and the second chamber, wherein the at least one spring element moves the piston and the intermediate piece in a direction in which the inlet valve connects the feed line to the pump chamber.

6. The plug-in pump of claim 1 , comprising a spring element in the first chamber, wherein the spring element moves the piston and the intermediate piece in a direction in which the inlet valve connects the feed line to the pump chamber, and wherein the spring element is supported on an underside of the cylinder head and on a spring holder connected to an end of the intermediate piece facing the second end of the piston.

7. The plug-in pump of claim 1 , comprising a spring element in the second chamber, wherein the spring element moves the piston and the intermediate piece in a direction in which the inlet valve connects the feed line to the pump chamber, and wherein the spring element is supported on an underside of the connecting region and on a spring holder connected to an end of the intermediate piece facing the drive device.

8. The plug-in pump of claim 1 , wherein:
the first fluid is carried by the feed line and a connecting line in the pump housing into an annular passage,
the annular passage is formed in a connecting region between the cylinder and the housing, and
at least one side wall of the annular passage is formed by an outer side of the cylinder and at least one side wall of the annular passage is formed by an outer side of the housing.

9. The plug-in pump of claim 1 , wherein:
the drive device is a camshaft, and
a cam of the camshaft acts on the roller tappet to convert a rotary motion of the camshaft into a linear motion of the piston.

10. The plug-in pump of claim 1 , wherein the inlet valve is a digital inlet valve.

11. The plug-in pump of claim 1 , wherein the first fluid is a fuel and the second fluid is a lubricating oil.

12. The plug-in pump of claim 1 , wherein the cylinder is formed from steel and the pump housing is formed from cast steel or sintered steel.

13. A fuel injection system, comprising:
a plug-in pump comprising:
a pump housing defining a cylinder cavity,
a movable piston arranged in the cylinder cavity, wherein a first end of the piston delimits a pump chamber within the cavity, and a second end of the piston is connected through an intermediate piece to a slide comprising a roller tappet moving along a shared axis with the movable piston within a guide bushing,
the roller tappet riding along a drive device for the piston,
an inlet valve arranged in the pump housing, wherein the inlet valve connects the pump chamber to a feed line for a first fluid, and
an outlet valve that connects the pump chamber to an outlet,
wherein the cylinder cavity includes (a) a first chamber surrounding the second end of the piston and a first portion of the intermediate piece, the first chamber fluidly connected to a fluid system of the first fluid, and (b) at least one second chamber surrounding a exterior perimeter of a second portion of the intermediate piece and sealed off from the first chamber and connected to a fluid system of a second fluid, wherein the intermediate piece extends from the first chamber to the second chamber through a sealing element separating the first chamber from the second chamber.

14. The fuel injection system of claim 13 , wherein the second end of the piston of the plug-in pump is connected to or formed integrally with the intermediate piece that transmits a movement of the drive device to the piston.

15. The fuel injection system of claim 14 , wherein the intermediate piece includes a first section that projects into the first chamber, a third section that projects into the second chamber, and a second section that connects the first section and the third section and projects through a connecting region formed in the cavity between the first chamber and the second chamber.

16. The fuel injection system of claim 15 , wherein:
the connecting region has a shape of a hollow cylinder having an inside diameter that corresponds substantially to an outside diameter of the second section, and
at least one of the inner wall of the connecting region and the second section has a sealing element that prevents the first and second fluids from mixing with each other.

17. The fuel injection system of claim 13 , wherein the plug-in pump comprises at least one spring element arranged in at least one of the first chamber and the second chamber, wherein the at least one spring element moves the piston and the intermediate piece in a direction in which the inlet valve connects the feed line to the pump chamber.

18. The fuel injection system of claim 13 , wherein the plug-in pump comprises a spring element in the first chamber, wherein the spring element moves the piston and the intermediate piece in a direction in which the inlet valve connects the feed line to the pump chamber, and wherein the spring element is supported on an underside of the cylinder head and on a spring holder connected to an end of the intermediate piece facing the second end of the piston.

19. The fuel injection system of claim 13 , wherein the plug-in pump comprises a spring element in the second chamber, wherein the spring element moves the piston and the

Assignees

• Continental Automotive Gmbh

Inventors

• Vu Ngoc-Tam
• Nigrin Uwe

Classifications

• F04B53/18

  Lubricating · CPC title

• F04B53/16

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

• F04B53/10

  Valves; Arrangement of valves · CPC title

• F04B17/05

  driven by internal-combustion engines · CPC title

• F04B9/042

  the means being cams · CPC title