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US 9,810,334 B2Granted
Pressure limited flow priority boost
AssigneeParker-Hannifin Corporation
InventorGregory T. Coolidge
Life of this patent
Estimating the term…
Abstract
A hydraulic valve assembly includes an inlet; an outlet; a pressure compensator upstream of the inlet; and a pressure limited flow priority boost valve spool movable between a first position and a second position and comprising an outer spool body and an inner spool body. The outer spool body includes deadhead meter notches disposed such that, in the first position, the spool closes fluid communication between the inlet and the pressure compensator, and such that, in the second position, the spool opens fluid communication between the inlet and the pressure compensator. The inner spool body is movable relative to the outer spool body and is configured to open fluid communication between the inlet and the outlet so as to bypass the compensator. The flow between the inlet and the compensator is a reduced pilot flow.
Claims15
A pressure limited flow priority boost valve comprising:
- an inlet chamber;
- a metering chamber;
- a spool bore fluidly connected between the inlet chamber and the metering chamber;
- a feed chamber opening to two longitudinally spaced locations of the spool bore;
- a compensator that fluidly couples the metering chamber to the feed chamber;
- a first workport chamber that fluidly couples a first workport to the spool bore;
- and
- a spool disposed in the spool bore and moveable from a neutral position to a first workport position,
- wherein the spool includes:
- an outer spool body having a first longitudinal side and a second longitudinal side, the first longitudinal side having a longitudinal bore and at least one radial bore in fluid communication with the longitudinal bore;
- an inner spool body disposed in the longitudinal bore and axially movable with respect to the outer spool body, the inner spool body being biased toward the second side, wherein a metering chamber bypass is formed in the longitudinal bore of the outer spool body between an exterior peripheral surface of the inner spool body and an interior peripheral surface of the outer spool body, the inner spool body including at least one longitudinal bore and at least one radial bore in fluid communication with the longitudinal bore of the inner spool body and the radial bore of the outer spool body,
- wherein, when the spool is in the neutral position, the metering chamber bypass is blocked and the inlet chamber is disconnected from the metering chamber, the feed chamber, and the first workport chamber, and
- wherein, when the spool is in the first workport position, (i) the inlet is fluidly connected to the metering chamber via a first fluid passageway, and the metering chamber bypass forms a second fluid passageway that fluidly connects the inlet to the workport chamber while bypassing the metering chamber and the compensator if a pressure at the workport chamber is below a predetermined value, and (ii) the inlet is disconnected from the workport chamber via the metering chamber bypass if the pressure at the workport chamber is above a predetermined value.
10 more elements
A hydraulic valve assembly comprising:
- an inlet;
- an outlet;
- a pressure compensator downstream of the inlet;
- and
- a pressure limited flow priority boost valve spool movable between a neutral position and a working position and comprising an outer spool body and an inner spool body,
- wherein the outer spool body includes deadhead meter notches disposed such that, in the neutral position, the pressure limited flow priority boost valve spool closes fluid communication between the inlet and the pressure compensator, and such that, in the working position, the pressure limited flow priority boost valve spool opens a first fluid passageway to allow fluid communication between the inlet and the pressure compensator, and
- wherein, in the working position, the inner spool body is movable relative to the outer spool body and is configured to form a second fluid passageway between the inlet and the outlet that bypasses the pressure compensator when a pressure at the outlet is below a predetermined value, wherein the second fluid passageway is blocked when the pressure limited flow priority boost valve spool is in the neutral position.
4 more elements
A pressure limited flow priority boost valve spool comprising:
- an outer spool body having a first longitudinal side and a second longitudinal side, the first longitudinal side having a longitudinal bore and at least one radial bore in fluid communication with the longitudinal bore;
- and
- an inner spool body disposed in the longitudinal bore and axially movable with respect to the outer spool body, the inner spool body being biased toward the second side, wherein a metering chamber bypass is formed in the longitudinal bore of the outer spool body between an exterior peripheral surface of the inner spool body and an interior peripheral surface of the outer spool body, the inner spool body including at least one longitudinal bore and at least one radial bore in fluid communication with the longitudinal bore of the inner spool body and the radial bore of the outer spool body,
- wherein the outer spool body includes deadhead meter notches on a radially outward and longitudinally central portion for providing a load sense signal and a reduced pilot flow,
- wherein when the outer spool body is in a neutral position, the metering chamber bypass is blocked, and
- wherein when the outer spool body is shifted from the neutral position, the inner spool body is movable relative to the outer spool body to allow the metering chamber bypass to open fluid communication between an inlet and an outlet so as to bypass a compensator disposed downstream from the inlet when a pressure at the outlet is below a predetermined value.
3 more elements
Dependencies are inferred from the claim text.