Hydrodynamic torque-transfer unit, especially a hydrodynamic brake

US4421213A · kind A · utility

Assignee

• Voith Getriebe KG · DE

Inventors

• Klaus Brosius · Heidenheim an der Brenz, DE
• Berthold Herrmann · Heidenheim, DE

Key dates

• Filing date: Oct 29, 1981
• Grant date: Dec 20, 1983
• Expiry date: Oct 29, 2001

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16D57/04
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

The invention concerns a hydrodynamic torque transfer unit, particularly in the form of a hydrodynamic brake. Flow to the inlet of the working chamber of the transfer unit is controlled by an inlet valve movable between a closed, partially open and fully open position. A first piston moves the valve between its positions. A change over device cooperates with the first piston. The change over device includes a second piston. A first pressure chamber is defined between the first and second pistons. A second pressure chamber is defined behind the second piston. Initially, the first pressure chamber is pressurized, driving the first piston and thus the inlet valve to the fully open position. The second piston is moved by pressurization of the second pressure chamber to cut off pressure to the first pressure chamber and to instead cause communication between the first pressure chamber and the working chamber. Typically, the working chamber is at reduced pressure which thereby permits depressurization of the first pressure chamber. A spring then returns the inlet valve back toward the intermediate open position. The second piston has been shifted by pressurization of the second pressure …