Reversible gear pump with invariant flow direction

US4200427A · kind A · utility

Assignee

• Zahnradfabrik Friedrichshafen AG · DE

Inventors

• Bernhard Binger · Ravensburg, DE
• Anton Engstler · Friedrichshafen, DE

Key dates

• Filing date: Sep 19, 1978
• Grant date: Apr 29, 1980
• Expiry date: Sep 19, 1998

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F04C14/04
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A gear pump for unidirectionally transporting a fluid such as oil has a stationary housing with an inlet port and an outlet port on opposite sides of the axis of a cylindrical chamber in which a ring with an eccentric inner periphery is rotatable through an arc of 180.degree. between two limiting positions. Freely rotatable within the inner ring periphery is an annular outer rotor with internal gear teeth entrainable by a driven inner rotor with external gear teeth, the latter numbering one less than the internal gear teeth of the outer rotor. A face of the ring has one or more shallow depressions open toward the outer rotor, each depression being spanned by a leaf spring which is anchored to the ring and defines with the outer periphery of that rotor a wedge-shaped gap diverging symmetrically toward its ends to form alternate lodgments for a rotary coupling member such as a ball or a roller. With the ring in one of its limiting positions and the rotors being driven in a direction in which the pumping spaces formed between the coacting rotor teeth move the fluid from the inlet port to the outlet port, the coupling member lies free or under light spring pressure in the downstream lo…