Actuator system

Patent metadata

Field	Value
Publication number	US-9657756-B2
Application number	US-201414460055-A
Country	US
Kind code	B2
Filing date	Aug 14, 2014
Priority date	Aug 14, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An actuator system having various features is disclosed. An actuator system may have a first and a second electrohydraulic servo valve. A control selector may connect one of the electrohydraulic servo valves to a cylinder and may isolate the other electrohydraulic servo valve to ameliorate leakage in response to a switching solenoid valve operating. In this manner, one electrohydraulic servo valve may be connected to a cylinder to operate the cylinder, and the other electrohydraulic servo valve may be isolated from the cylinder, for example, to provide a standby electrohydraulic servo valve.

First claim

What is claimed is:

1. An actuator system comprising:
a first electrohydraulic servo valve comprising a four-port valve comprising a first fluid supply port, a first fluid return port, a first extension port, and a first retraction port,
wherein one of the first retraction port and the first extension port is connectable to the first fluid supply port in response to a first electrohydraulic servo valve control signal, and wherein another of the first retraction port and the first extension port is connectable to the first fluid return port in response to the first electrohydraulic servo valve control signal;

a second electrohydraulic servo valve comprising a four-port valve comprising a second fluid supply port, a second fluid return port, a second extension port, and a second retraction port,
wherein one of the second retraction port and the second extension port is connectable to the second fluid supply port in response to a second electrohydraulic servo valve control signal, and the other of the second retraction port and the second extension port is connectable to the second fluid return port in response to the second electrohydraulic servo valve control signal;

wherein the first fluid supply port and the second fluid supply port are in fluid communication with a hydraulic supply;
a switching solenoid valve comprising a return input, a fluid supply input, a selection control output, and a solenoid plunger,
wherein the solenoid plunger connects one of the return input and the fluid supply input to the selection control output in response to a switching solenoid valve control signal;
a control selector whereby one of the first electrical hydraulic servo valve and the second electrohydraulic servo valve is connected to a cylinder in response to the switching solenoid valve connecting one of the return input and the fluid supply input to the selection control output, wherein the control selector comprises:
a cavity; and
a piston disposed within the cavity and comprising:
a retraction selector;
an extension selector; and
an isolation selector,

wherein the piston is movable within the cavity,
whereby the first extension port and the second extension port are alternately connected to the extension selector,
whereby the first retraction port and the second retraction port are alternately connected to the retraction selector, and
whereby the first fluid return port and the second fluid return port are alternately connected to the isolation selector.

2. The actuator system of claim 1 , wherein the fluid supply input is in fluid communication with an aircraft hydraulic source.

3. The actuator system of claim 1 , wherein the return input is in fluid communication with an aircraft hydraulic sink.

4. The actuator system according to claim 1 , wherein the hydraulic fluid comprises fuel.

5. The actuator system according to claim 1 , wherein the isolation selector is in fluidic communication with an aircraft hydraulic source.

6. The actuator system according to claim 1 , wherein the control selector further comprises:
a seal disposed annularly about the piston between the retraction selector and the isolation selector;
a seal disposed annularly about the piston between the isolation selector and the extension selector.

7. The actuator system according to claim 1 , further comprising:
an isolation valve in fluid communication with the first fluid return port and the second fluid return port,
whereby the first fluid return port is fluidically isolated from an aircraft hydraulic sink in response to the second electrohydraulic servo valve being connected to the cylinder, and
whereby the second fluid return port is fluidically isolated from the aircraft hydraulic sink in response to the first electrohydraulic servo valve being connected to the cylinder.

8. The actuator system according to claim 7 ,
wherein the control selector comprises:
a cavity; and
a piston disposed within the cavity and comprising:
a retraction selector;
an extension selector; and
an isolation selector,

wherein the piston is movable within the cavity,
whereby the first extension port and the second extension port are alternately connected to the extension selector,
whereby the first retraction port and the second retraction port are alternately connected to the retraction selector,
whereby the first fluid return port and the second fluid return port are alternately connected to the isolation selector, and
wherein the isolation selector is in fluidic communication with an aircraft hydraulic sink.

9. The actuator system according to claim 7 , wherein the isolation valve comprises:
a first cavity portion;
a second cavity portion;
a piston comprising a first face seal and a second face seal;
wherein the piston is movable within the first cavity portion and the second cavity portion and alternately occupies the first cavity portion and the second cavity portion;
wherein the first face seal fluidically isolates a channel in fluid communication with the first fluid return port in response to the piston occupying the first cavity portion;
wherein the second face seal fluidically isolates a channel in fluid communication with the second fluid return port in response to the piston occupying the second cavity portion.

10. The actuator system of claim 9 , wherein the cylinder comprises:
a retraction input in fluidic communication with the retraction selector; and
an extension input in fluidic communication with the extension selector.

11. The actuator system according to claim 10 , wherein the cylinder further comprises:
a main body comprising an actuator piston cavity; and
an actuator piston rod disposed partially within the actuator piston cavity,
wherein the actuator rod is translatable axially into the actuator piston cavity in response to hydraulic fluid at least one of flowing into the extension input or out of the retraction input, and
wherein the actuator rod is translatable axially out of the actuator piston cavity in response to hydraulic fluid at least one of flowing into the retraction input or out of the extension input.

12. A method of actuator system control comprising:
receiving, by a switching solenoid valve, a switching solenoid valve control signal;
operating the switching solenoid valve to select a selected electrohydraulic servo valve in response to the switching solenoid valve control signal,
wherein the selected electrohydraulic servo valve comprises one of:
a first electrohydraulic servo valve; and
a second electrohydraulic servo valve;
providing, by the switching solenoid valve, selection control information to a control selector;
operating the control selector in response to the selection control information;
connecting the selected electrohydraulic servo valve to a cylinder in response to the operating the control selector; and
operating an isolation valve in response to the operating the control selector; and
isolating an isolated electrohydraulic servo valve,
wherein the isolated electrohydraulic servo valve comprises the one of the first electrohydraulic servo valve and the second electrohydraulic servo valve that is not the selected electrohydraulic servo valve.

13. A method of actuator system control according to claim 12 , further comprising:
operating the cylinder by the selected electrohydraulic servo valve,
wherein the cylinder comprises an actuator piston rod disposed partially within an actuator piston cavity,
wherein the operating comprises at least one of extending and retracting the actuator piston rod axially with respect to the actuator piston cavity.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Bostiga Richard H
• Reuter Charles E

Classifications

• F15B20/005

  Leakage; Spillage; Hose burst · CPC title

• F15B2211/30565

  having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve · CPC title

• F15B18/00 Primary

  Parallel arrangements of independent servomotor systems · CPC title

• F15B2013/0428

  with switchable internal or external pilot pressure source · CPC title

• F15B13/042

  operated by fluid pressure {(F15B13/0401, F15B13/0416 take precedence)} · CPC title