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:
Jan. 07, 1992
Filed:
May. 04, 1990
Wolfgang Kauss, Lohr-Wombach, DE;
Mannesmann Rexroth GmbH, Lohr/Main, DE;
Abstract
Disclosed is a preferably electrohydraulic control for a load-dependently operating variable displacement pump, which is equipped with a differential pressure control device for ensuring a predetermined pressure drop at the control edge of a directional valve integrated into the consumer supply line. The differential pressure control device has a servo valve, the valve spool of which can be brought out of a first position, increasing the output volume of the variable displacement pump, against the compressive force of a spring and of a control pressure led off from the supply pressure upstream of the directional valve, by the pump pressure into a second position, reducing the output volume. In order to be able to adapt the volume flow control to the different requirements of various consumers, in particular of a mobile piece of equipment, such as for example a farming tractor, and thereby improve the quality of the control, the control pressure effective at the servo valve is arbitrarily influenced by means of a separately controllable actuating device, preferably designed as a servo valve.