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:
Aug. 27, 1991
Filed:
Aug. 23, 1988
Heinz Berthold, Horb, DE;
BrueninghausHydraulik GmbH, , DE;
Abstract
A hydrostatic driving gear is described comprising a primary unit rotationally driven by a driving engine and a secondary unit rotationally driving an actuator. Each unit comprises a variable displacement hydraulic engine, in particular an axial piston engine. They cooperate in an open circuit. The primary unit and secondary unit each have a displacement adjusting device and can be continuously adjusted in respect of their direction of displacement through a zero displacement center position in two directions of displacement. The displacement adjusting device of the primary unit has associated with it a pressure flow controller which holds the working pressure at a constant presettable value. The displacement adjusting device of the secondary unit has associated with it a speed of rotation detecting device, having a position sensor to detect the flow setting. The secondary unit also has associated with it a speed detecting device and an electronic controller is provided which detects the displacement setting of the secondary unit and its actual speed of rotation and compares it with a predetermined desired actual speed of rotation and adjusts the controller correspondingly. A secondary controlled hydrostatic driving gear in an open circuit is provided which makes four-quadrant operation possible.