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:
Jul. 12, 1988
Filed:
Oct. 03, 1986
Wilhelm Appel, Ulm-Donaustetten, DE;
Hydromatik GmbH, Elchingen, DE;
Abstract
A drive system having two hydrostatic gears (1, 2) driven by a common driving motor or by a plurality of driving motors having a fixed speed ratio, each having a pump (5, 6) and a hydraulic motor (7, 8) and in which the delivery or intake volume setting of the pumps (5, 6) and/or the hydraulic motors (7, 8) is performed by hydraulic servomechanisms (13, 14) of which the control pressures in the control pressure lines (23, 24) can be varied as desired either independently or together by means of pressure indicating valves (26) connected to each of the gears (1, 2) and supplied by an auxiliary source of pressure (9, 10) is arranged so that, at least on starting, the outputs of the gears (1, 2) are as nearly as possible equal. This is done by means of an adjustable differential pressure valve (41) connected to the control pressure lines (23, 24, 25) which is set to compensate for differences in output values of the gears (1, 2) arising from departures from the intended values by a corresponding pressure change in at least one of the control pressure lines.