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US 2026/0226922 A1Published application
Hydraulic actuator
AssigneeSVM Schultz Verwaltungs-GmbH & Co. KG
InventorPaul Philipp Herz
Life of this patent
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Abstract
A hydraulic actuator traversed by a longitudinal axis includes a housing with an inlet and an outlet, a first fluid path and a second fluid path extending from the inlet to the outlet, a main valve spool adjustable between open and closed positions, a pilot valve spool adjustable between an open and closed position, and an actuator piston movable between retracted and extended positions. A method of operating the hydraulic actuator is also disclosed.
Claims18
A hydraulic actuator, which is traversed by a longitudinal axis, comprising:
- a housing comprising an inlet and an outlet;
- a first fluid path extending from the inlet to the outlet;
- a second fluid path extending from the inlet to the outlet;
- a main valve spool;
- a pilot valve spool;
- and
- an actuator piston;
- wherein the main valve spool is adjustable along the longitudinal axis to a single open position or to a double open position;
- wherein the pilot valve spool is arranged coaxially with the main valve spool and is adjustable along the longitudinal axis between an open position in which the second fluid path is open, and a closed position in which the second fluid path is closed;
- wherein the actuator piston is arranged coaxially with the main valve spool and adjustable along the longitudinal axis by a fluid pressure from the inlet between a retracted position and an extended position.
7 more elements
A method of operation for a hydraulic actuator, comprising:
- from a basic state of the hydraulic actuator in which a first fluid path and a second fluid path are open, an actuator piston is in a retracted position, and a main valve spool is moved to a pre-closed position in which a volume flow of a first fluid path is greater than the volume flow of a second fluid path:
- moving a pilot valve spool from an open position to a closed position, thereby closing the second fluid path;
- moving the main valve spool to a closed position by means of a fluid pressure present at an inlet, thereby closing the first fluid path and the second fluid path;
- moving the actuator piston to an extended position by means of the fluid pressure present at the inlet;
- moving the pilot valve spool from a closed position to an open position, thereby opening the second fluid path;
- interrupting the fluid pressure on the main valve spool and moving the main valve spool from the closed position to a single open position or to a double open position;
- allowing a flow of a fluid through the hydraulic actuator from the inlet to an outlet along at least one of the two fluid paths;
- interrupting or reducing the volume flow at the inlet and moving the pilot valve spool from the open position to the closed position, thereby closing the second fluid path;
- and
- moving the actuator piston to the retracted position and thereby moving the main valve spool to the pre-closed position.
7 more elements
Dependencies are inferred from the claim text.