Pumps – Three or more cylinders arranged in parallel – radial – or... – Radial cylinders
Patent
1999-05-28
2000-10-31
Walberg, Teresa
Pumps
Three or more cylinders arranged in parallel, radial, or...
Radial cylinders
F04B 2704, F04B 104
Patent
active
061392847
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The invention relates to a radial piston pump for high-pressure fuel delivery in fuel injection systems of internal combustion engines, including a common rail injection system, with a drive shaft that is supported in a pump housing and is embodied as eccentric or has a number of cam-like projections in the circumference direction. The system includes a number of pistons that are disposed radially with regard to the drive shaft, each in a respective cylinder chamber, and can be set into a reciprocating motion in the radial direction in the cylinder chamber upon rotation of the drive shaft. Check valves on the intake side and the high-pressure side are provided for each piston. A metallic housing part, which constitutes the respective cylinder chamber, is provided with a fuel inlet opening and a fuel outlet opening.
In radial piston pumps of this kind, the housing part is supported and sealed in relation to other housing regions by a number of elastomer sealing elements. This leads to an indefinite arrangement of the components of the pump.
Based on this, an object of the current invention is to produce a radial piston pump that is a high-pressure-type up to 2000 bar. The high-pressure-affected components and their sealing points uncoupled from each other and in the assembled state, are exactly defined statically.
This object is attained with a radial piston pump of the type described at the beginning, by virtue of the fact that the housing part rests with a flat contact surface against a metallic housing base body from the radial outside with regard to the drive shaft. A projecting section of the housing part, which is concentric to the cylinder chamber and is oriented toward the drive shaft, extends through a radial opening of the housing base body in the direction toward the drive shaft. The fuel inlet opening and a fuel outlet opening discharge into the flat contact surface and are flush with other inlet and outlet openings in the housing base body. The housing part is tightened against the housing base body by way of screws in such a way that the high-pressure side is sealed through the clamping of the high-pressure sealing element.
Whereas in the previously known radial piston pump, the high-pressure seal was also achieved by way of interposed elastomer sealing elements, and the assembly of the components adjoining the high-pressure side--as mentioned at the beginning--included a flux of force over a number of components which led to a static indeterminacy. The invention proposes producing the seal by way of flat metallic contact surfaces of the respective radially outer housing part and the housing base body are tightened against each other. The fuel delivery and the fuel discharge to and from the cylinder chamber occurs by means of the respective fuel inlet opening and the fuel outlet opening, which discharge on the one end, into the intake or compression chamber and on the other end, into the contact surface of the housing part oriented toward the housing base body. The housing part can rest in a statically defined manner against the housing base body without the interposition of any sealing element. When the housing part is tightened against the housing base body, a so-called hard seal is produced by the metallic contact surfaces of the radially outer housing part and the housing base body.
Preferably, all high-pressure-affected sealing points of metallic components that are tightened against one another are embodied without the interposition of additional sealing elements.
To this end, the surfaces of the metallic components that rest against each other in a sealed fashion are machined, in particular lapped, in order to produce a desired surface roughness. If the lapping can only be carried out with difficulty or is altogether impossible because a relevant component has a protruding pin or the like, then a surface quality that is sufficient for producing a hard seal (metal against metal) can also be produced by means of hard turning, i.e. metal-removing machining, after the heat harden
REFERENCES:
patent: 2271570 (1942-02-01), Pardee
patent: 2621607 (1952-12-01), Trapp
patent: 4363607 (1982-12-01), Eichele et al.
patent: 4983100 (1991-01-01), Budecker
patent: 5382140 (1995-01-01), Eisenbacher
patent: 5626466 (1997-05-01), Ruoff et al.
patent: 5647729 (1997-07-01), Jong et al.
patent: 6003430 (1999-12-01), Lang
Greigg Edwin E.
Greigg Ronald E.
Patel Vinod D
Robert & Bosch GmbH
Walberg Teresa
LandOfFree
Radial piston pump for high pressure fuel delivery does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radial piston pump for high pressure fuel delivery, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radial piston pump for high pressure fuel delivery will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2044792