Dual valve systems for actuator control
AssigneeHamilton Sundstrand Corporation
InventorTimothy Maver
Life of this patent
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Abstract
A system for controlling propeller pitch in the event of electro-hydraulic servo valve (EHSV) failure can include an actuator and a selection valve in fluid communication with the actuator. The selection valve can be fluid communication with a first EHSV having a first null state bias configured to bias the actuator to an increased-pitch position, and a second EHSV having a second null state bias configured to bias the actuator to a decreased-pitch position. The selection valve can be configured to selectively allow fluid communication between one of the first EHSV and actuator and/or the second EHSV and the actuator.
Claims17
An actuator system, comprising:
- a pressure actuator having a piston, at least a first port and second port, wherein the first port is on a first pressure side of the piston and the second port is on a second pressure side of the piston;
- a first valve and a second valve in selective fluid communication with the first port and the second port of the pressure actuator via at least one first port line and at least one second port line,
- each of the first and second valve having a first open state, a second open state, and a closed state such that the first open state allows a pressure differential between the first port and the second port such that the actuator is biased to an extended position when one of the first and second valves is in fluid communication with the actuator and in the first open state, wherein the second open state allows a pressure differential between the first port and the second port such that the actuator is biased to a retracted position when one of the first and second valves is in fluid communication with the actuator and in the second open state,
- wherein the first valve includes a first null state in the event of a failure of the first valve such that first null state allows a pressure differential between the first port and the second port such that the actuator is biased to a first direction when the first valve is in fluid communication with the actuator and is in the first null state,
- wherein the second valve includes a second null state in the event of a failure of the second valve such that second null state allows a pressure differential between the first port and the second port such that the actuator is biased to a second direction when the second valve is in fluid communication with the actuator and is in the second null state;
- and
- a selection valve in fluid communication between the actuator and the first and second valves, wherein the selection valve is configured to move between at least a first selection state to select the first valve to fluidly communicate with the actuator and a second selection state to select the second valve to fluidly communicate with the actuator.
A system for controlling propeller pitch in the event of electro-hydraulic servo valve (EHSV) failure, comprising:
- an actuator;
- and
- a selection valve in fluid communication with the actuator, a first EHSV, and a second EHSV, the first EHSV having a first null state configured to bias the actuator toward an increased-pitch position, and the second EHSV having a second null state configured to bias the actuator to a decreased-pitch position,
- wherein the selection valve is configured to selectively allow fluid communication between one of the first EHSV and actuator and/or the second EHSV and the actuator.
A method, comprising:
- operating an actuator in an actuator control valve failure mode to control a position of the actuator by controlling a selection valve disposed between the actuator to select between a first actuator control valve and a second actuator control valve to select between an actuator extend bias of the first actuator control valve and an actuator deploy bias of the second actuator control valve.
Dependencies are inferred from the claim text.