Piston fuel pump for an internal combustion engine
AssigneeRobert Bosch GmbH
InventorsSiamend Flo, Markus Hilligardt, Heiko Jahn, Franz Elischer, Cornelia Giessler, Bernd Koch
Life of this patent
Estimating the term…
Abstract
A piston fuel pump for an internal combustion engine includes a pump cylinder and a pump piston slidably accommodated in the pump cylinder. The piston fuel pump has a supporting and sealing assembly for the pump piston. The supporting and sealing assembly includes a guiding region configured to axially guide the pump piston in the pump cylinder and a sealing region having a sealing lip.
Claims18
A piston-type fuel pump for an internal combustion engine, the piston-type fuel pump comprising:
- a pump cylinder;
- a pump piston displaceably received in the pump cylinder, the pump piston including a shoulder having a circular ring-shape;
- and
- a mounting and sealing arrangement including:
- a guide region spaced apart from the pump cylinder by less than 0.1 mm and in direct contact with the shoulder of the pump piston, the guide region configured to axially guide the pump piston in the pump cylinder;
- and
- a sealing region axially spaced apart from the guide region, the sealing region including:
- a sealing lip in direct contact with the pump cylinder,
- a cylindrical section that is cylindrical in shape and is in direct contact with the pump piston, and
- a recess defined radially between the cylindrical section and the sealing lip,
- wherein the mounting and sealing arrangement is formed as a contiguous structure,
- wherein the guide region is radially interposed between the shoulder and the pump cylinder, and the sealing region is not radially interposed between the shoulder and the pump cylinder,
- wherein the cylindrical section and the sealing lip extend away from the shoulder in a first axial direction, and
- wherein the cylindrical section extends away from the shoulder by a greater axial distance than the sealing lip.
A piston-type fuel pump for an internal combustion engine, the piston-type fuel pump comprising:
- a pump cylinder formed within a pump housing;
- a pump piston configured to be displaceably received in the pump cylinder;
- a guide sleeve fixedly coupled to the pump housing, the guide sleeve having a cylindrical section arranged coaxially about the pump piston, the cylindrical section including an internal wall facing toward the pump piston, and the internal wall arranged nearest to the pump piston at an inwardly projecting portion of the guide sleeve;
- a mounting and sealing arrangement, including:
- a guide region configured to axially guide the pump piston in the pump cylinder, and
- a sealing region axially spaced apart from the guide region, the sealing region having a sealing lip in direct contact with the pump cylinder, a cylindrical portion that is cylindrical in shape and in direct contact with the pump piston, and a recess defined radially between the cylindrical portion and the sealing lip;
- and
- a second mounting arrangement configured to guide the pump piston, the second mounting arrangement arranged positionally fixedly relative to the pump cylinder, and the second mounting arrangement arranged in the inwardly projecting portion,
- wherein the mounting and sealing arrangement is formed as a contiguous structure,
- wherein the guide region is radially interposed between the shoulder and the pump cylinder, and the sealing region is not radially interposed between the shoulder and the pump cylinder,
- wherein the cylindrical portion and the sealing lip extend away from the shoulder in a first axial direction, and
- wherein the cylindrical portion extends away from the shoulder by a greater axial distance than the sealing lip.
Dependencies are inferred from the claim text.