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US 7,251,934 B2Granted
Work vehicle hydraulic system
AssigneeCNH America LLC
InventorsRichard J. Lech, Matthew J. Hennemann
Life of this patent
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Abstract
A hybrid hydraulic system for a work vehicle is provided that includes a first fixed displacement hydraulic pump whose outlet is connected to a priority valve. The priority valve, in turn, directs the pump's flow to a first group of closed center backhoe valves on a primary circuit and a second group of open center loader valves on a secondary circuit. A second hydraulic pump is provided with independent load sensing capability to supplement fluid flow provided by the first pump.
Claims8
A hydraulic system for a work vehicle, comprising:
- a first hydraulic pump configured to generate a first flow of hydraulic fluid;
- a priority valve in fluid communication with the pump, said priority valve being configured to distribute the first flow to a primary outlet and to a secondary outlet:
- a plurality of open center hydraulic valves coupled to the secondary outlet;
- a hydraulic reservoir coupled to the plurality of open center hydraulic valves to receive the first flow after passing through the plurality of open center valves:
- a plurality of closed center hydraulic valves coupled to the primary outlet;
- a second hydraulic pump configured to generate a second flow of hydraulic fluid;
- and a reloader valve in fluid communication with the secondary pump, the reloader valve configured to distribute the second flow to the plurality of closed center valves, and further configured to prevent the secondary flow to the closed center valves when no demand signal is sensed;
- wherein the first flow passes directly to the fluid reservoir from the plurality of open center valves.
5 more elements
Dependencies are inferred from the claim text.