Piston pump

US6109896A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Wolfgang Schuller · Cleebronn, DE
• Norbert Alaze · Markgröningen, DE

Key dates

• Filing date: May 18, 1998
• Grant date: Aug 29, 2000
• Expiry date: May 18, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/7873
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A piston pump for pumping hydraulic fluid, especially for vehicle brake systems having a stepped piston axially displaceable in a pump space. The stepped piston in order to reduce the production costs comprises a cylinder of substantially constant outer diameter and a bush which is held axially nondisplaceably on the cylinder, by being press-fitted onto the cylinder. An elastomer seal is slipped onto a cylinder portion defined by the bush seals off the cylinder from the wall of the pump space and divides the pump space into two pump chambers of variable chamber volume.