External gear type fluid displacing machine with bearing gap

US4056337A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jürgen Zorn · Rossatz, AT
• Jan Vlemmings
• Karl-Heinz Muller · Wissen, DE
• Siegfried Mayer · Leinfelden, DE
• Wilhelm Dworak · Stuttgart, DE
• Eugen Hartmann
• Martin Fader
• Wolfgang Talmon · Rain, DE
• Claus Jons
• Ivan Sauer
• Paul Bosch · Ludwigsburg, DE

Key dates

• Filing date: Jul 17, 1975
• Grant date: Nov 1, 1977
• Expiry date: Jul 17, 1995

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F05C2225/04
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

An external gear type hydraulic pump or motor wherein the trunnions of gears in the chamber of the housing are surrounded by annular bearing members. The peripheral surface of each bearing member defines with the adjacent internal surface of the housing an arcuate gap whose width increases in a direction toward the respective end face of the corresponding gear. To this end, portions of or the entire peripheral surfaces of bearing members and/or portions of or the entire internal surfaces of the housing have a conical or spherical shape. The gaps are located in the low-pressure zone and reduce the likelihood of wear upon those end faces of bearing members which are adjacent to the end faces of the gears because the bearing members can tilt in response to increasing load without localized rubbing against the gears. Additional gaps can be provided between the end faces of the gears and the adjacent end faces of the bearing members to further reduce the likelihood of uneven wear upon the bearing members.