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:
Nov. 06, 2007
Filed:
Apr. 21, 2004
Rodney V. Singh, Savage, MN (US);
Rodney V. Singh, Savage, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A hydraulic drive system () of the type including a hydrostatic pump-motor unit () having a pumping mode in which the unit pressurizes, from its port (A), a high pressure accumulator (), and a motoring mode, in which the unit is driven by pressurized fluid from the high pressure accumulator. The system also includes a low pressure accumulator () in communication with the opposite port (B) of the pump-motor unit (), and a filter circuit () disposed therebetween. The filter circuit () defines an unrestricted first flow path from the low pressure accumulator to the port (B) when the unit is in the pumping mode, and a second flow path from the port (B) to the low pressure accumulator when the unit is in the motoring mode. The second flow path comprises one path portion () through a filter shut-off valve () and a filter () in series, and in parallel therewith, another path portion through a controlled flow restriction (). Thus, filtration occurs during only the motoring mode, and the percentage of fluid being filtered can be predetermined.