Electromagnetically activated piston pump

US4743179A · kind A · utility

Assignee

• Webasto-Werk W. Baier GmbH & Co. · DE

Inventors

• Peter Waas · Munich, DE
• Bernhard Matschull · Munich, DE
• Wolfgang Baeuml · Eichenau, DE
• Wolfgang Beck · Schwabsoien, DE
• Siegfried Piegsa · Munich, DE

Key dates

• Filing date: Feb 13, 1986
• Grant date: May 10, 1988
• Expiry date: Feb 13, 2006

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F04B53/1032
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A piston pump, in accordance with several embodiments, comprises a suction chamber into which fluid medium enters from an inlet line via a suction valve, beginning at the outset of a delivery stroke of the piston pump, without a build-up of intake negative pressure during the delivery stroke of the piston, and is particularly adapted to prevent vapor bubble formation. A reliable pump closure is ensured in the vicinity of the pump outlet, independent of the spring action of a return spring, which bears against the piston, in that any fluid medium entering the suction chamber of the pump contacts the piston in a direction producing reinforcement of the outlet closure pressure. In accordance with preferred embodiments, the piston may be a partially hollow or entirely hollow piston instead of a solid one. Variously designed connecting elements and relief valve arrangements for the conducting of the fluid medium from the suction chamber of the fuel pump to an armature compartment are provided, with the objective that the piston pump have a minimum inactive flow volume.