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. 30, 1991
Filed:
Aug. 30, 1989
Mark S Stroze, Rockford, IL (US);
William G Durtschi, Rockford, IL (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
In order to eliminate leakage and provide a more efficient system, a variable displacement hydraulic apparatus (10) includes a cylinder block (12) having a plurality of hydraulic cylinders (14) therein. Each of the cylinders (14) has a hydraulic piston (16) disposed therein for reciprocating movement relative thereto. The cylinders (14) and pistons (16) are disposed about an axis (18) of the hydraulic apparatus (10). The hydraulic apparatus (10) also includes a shaft (20) operatively associated with the pistons (16) for relative driven movement therebetween and a valve block (22) having a hydraulic fluid inlet port (24) for supplying hydraulic fluid to the cylinders (14) together with a hydraulic fluid outlet port (26) for returning hydraulic fluid from the cylinders (14). The inlet and outlet ports (24 and 26) communicate with the cylinders (14) through a port plate (28) having at least one port slot (30) therethrough. The port plate (30) is variably angularly positionable relative to the inlet and outlet ports (24 and 26) for varying displacement of the hydraulic apparatus (10). For this purpose, an electrically driven displacement device (32) is directly coupled to the port plate (30) to rotate it upon demand.