Fuel pump assembly

US6142747A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernd Rosenau · Asperg, DE
• Gerd Loesch · Stuttgart, DE
• Markus Rueckle · Stuttgart, DE

Key dates

• Filing date: Mar 12, 1999
• Grant date: Nov 7, 2000
• Expiry date: Mar 12, 2019

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F04B2205/15
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a fuel pump assembly having a low-pressure region (ND) with at least one low-pressure pump-and a high-pressure region (HD) with at least one regulated-quantity high-pressure pump, which pumps a quantity of fuel required to compensate for the quantitative balance in the high-pressure region, the quantity regulation being effected via a metering unit which is disposed between the low-pressure pump and the high-pressure pump. In order, by simple and sturdy means with high availability and a long service life, to prevent the fuel quantity in correctly pumped by the metering unit at certain operating points from reaching the high-pressure region, the invention proposes that the pumping flow of the low-pressure pump is greater than the pumping flow of the high-pressure pump; that a fuel return line branches off between the metering unit and the high-pressure pump and discharges into the inlet of the low-pressure pump; and that a control element is disposed in the return line.