The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1988
Filed:
Jun. 05, 1985
Mathias Maul, Elchingen, DE;
Wilhelm Appel, Ulm-Donaustetten, DE;
Hydromatik GmbH, Elchingen, DE;
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 hydraulic connection of the relevant working space of the adjustment device with a pressure line.