Speed regulation device for a hydrostatic drive unit

US4722187A · kind A · utility

Assignee

• Hydromatik GmbH · DE

Inventors

• Mathias Maul · Burgthann, DE
• Wilhelm Appel · Laa an der Thaya, AT

Key dates

• Filing date: Jun 5, 1985
• Grant date: Feb 2, 1988
• Expiry date: Jun 5, 2005

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H61/433
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a speed regulating device for a hydrostatic drive unit comprising a pump of variable feed volume and a motor in a hydraulic circuit, wherein the pump is driven by a drive motor of variable speed, and there is provided a regulating valve which controls the loading of a hydraulic adjustment device on the pump in dependence on the pressure differential in front of and behind an adjustable throttle arranged in the hydraulic circuit, in such a way that the feed volume is changed in inverse proportion to a speed change in the drive motor. It is the aim of the invention to produce a simple construction for the speed regulating device which can also be easily controlled in reverse operation and can be easily operated. This is achieved by the fact that the hydraulic circuit is a closed circuit, the pump and the hydraulic motor are set-up for operation in both feed directions, the throttle can be adjusted out of a central zero position or a position of minimum feed volume in two opposite directions at maximum feed volume, and the adjustment movement of the throttle is mechanically coupled to the adjustment movement of a directional control valve which produces the hy…