Dual pressure control for a rotor brake actuator for vertical lift aircraft

Patent metadata

Field	Value
Publication number	US-9676478-B2
Application number	US-201514684922-A
Country	US
Kind code	B2
Filing date	Apr 13, 2015
Priority date	Sep 25, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

In some aspects, a master cylinder assembly for vertical lift aircraft is configured to move pressurized fluid through a conduit in response to applied movement of an input lever. A low pressure relief valve can be connected to a first conduit to limit pressure to a low level. An isolation valve can be connected to the first conduit and configured to isolate the low pressure relief valve from the conduit when engaged. A high pressure relief valve can be connected to a second fluid conduit to limit pressure to a high level. In some aspects, a rotor brake actuator is fluidly connected to the first conduit and the second conduit and configured to engage a rotor brake in response to hydraulic fluid pressure.

First claim

The invention claimed is:

1. A rotor blade rotation control master cylinder assembly for vertical lift aircraft, the assembly comprising:
a master cylinder configured to be activated by movement of a rotor blade rotation control handle of a vertical lift aircraft to move pressurized hydraulic fluid through one or more conduits;
a rotor brake actuator connected to the master cylinder and configured to engage a rotor brake of the vertical lift aircraft in response to receiving hydraulic fluid at a hydraulic fluid pressure from the master cylinder;
a pressure relief valve fluidly connected in parallel to the master cylinder and the rotor brake actuator, and configured to transmit pressurized hydraulic fluid away from the rotor brake actuator in response to the hydraulic fluid pressure exceeding a pressure threshold of the pressure relief valve; and
an isolation valve connected in series with the pressure relief valve, the master cylinder configured to push the hydraulic fluid at a first pressure to the rotor brake actuator in response to the isolation valve being open wherein the first pressure is selected to slow the rotor of the vertical lift aircraft, and to push the hydraulic fluid at a second pressure that is higher than the first pressure in response to the isolation valve being closed wherein the second pressure is selected to hold the rotor of the vertical lift aircraft.

2. The rotor blade rotation control master cylinder assembly of claim 1 , wherein the pressure relief valve is a first pressure relief valve and the pressure threshold is a first pressure threshold, and wherein the rotor blade rotation control master cylinder assembly further comprises a second pressure relief valve connected in parallel to the master cylinder, the rotor brake actuator and the first pressure relief valve, wherein the second pressure relief valve is configured to transmit pressurized hydraulic fluid away from the rotor brake actuator in response to the hydraulic fluid pressure exceeding a second pressure threshold of the second pressure relief valve, the second pressure threshold higher than the first pressure threshold, and wherein the first pressure relief valve can be isolated from the second pressure relief valve.

3. The rotor blade rotation control master cylinder assembly of claim 2 , wherein the first pressure relief valve comprises a low pressure relief valve and the second pressure relief valve comprises a high pressure relief valve.

4. The rotor blade rotation control master cylinder assembly of claim 2 , wherein the rotor brake actuator is configured to hold the rotor of the vertical lift aircraft at or below the second pressure threshold when the isolation valve is closed.

5. The rotor blade rotation control master cylinder assembly of claim 4 , wherein the isolation valve is configured to be closed and the rotor brake actuator is configured to hold the rotor of the vertical lift aircraft when the vertical lift aircraft is starting.

6. The rotor blade rotation control master cylinder assembly of claim 1 , further comprising one or more stops to prevent an input lever from translating beyond a certain distance.

7. The rotor blade rotation control master cylinder assembly of claim 1 , wherein the hydraulic fluid in the rotor blade rotation control master cylinder assembly can provide a pressurized volume of fluid to engage the rotor brake in response to a single translation of the rotor blade rotation control handle.

8. The rotor blade rotation control master cylinder assembly of claim 1 , wherein the isolation valve includes a solenoid.

9. The rotor blade rotation control master cylinder assembly of claim 1 , wherein the rotor brake actuator is configured to slow the rotor of the vertical lift aircraft at or below the pressure threshold when the isolation valve is open.

10. The rotor brake actuator of claim 9 , wherein the rotor brake actuator is configured to slow the rotor of the vertical lift aircraft when the vertical lift aircraft is stopped.

11. The rotor blade rotation control master cylinder assembly of claim 1 , wherein the rotor blade rotation control master cylinder assembly is configured to maintain sufficient pressure to prevent rotor motion for a period of time after stopping.

12. A rotor blade rotation control master cylinder assembly for vertical lift aircraft, the assembly comprising:
a master cylinder configured to be activated by a pressure of a rotor blade rotation control handle of a vertical lift aircraft to move pressurized hydraulic fluid through one or more conduits, and configured to move pressurized fluid into a rotor brake actuator;
a pressure relief valve fluidly connected to the master cylinder and configured to transmit hydraulic fluid in response to the hydraulic fluid pressure exceeding a pressure threshold of the pressure relief valve; and
an isolation valve connected in series with the pressure relief valve configured to allow the master cylinder to move pressurized hydraulic fluid at a first pressure in response to the isolation valve being open wherein the first pressure is selected to slow the rotor of the vertical lift aircraft, and to move the pressurized hydraulic fluid at a second pressure that is higher than the first pressure in response to the isolation valve being closed wherein the second pressure is selected to hold the rotor of the vertical lift aircraft.

13. The rotor blade rotation control master cylinder assembly of claim 12 , wherein the pressure relief valve is a first pressure relief valve and the pressure threshold is a first pressure threshold and further comprising a second pressure relief valve connected in parallel to the master cylinder and the first pressure relief valve, wherein the second pressure relief valve is configured to transmit hydraulic fluid in response to the hydraulic fluid pressure exceeding a second pressure threshold of the second pressure relief valve, the second pressure threshold higher than the first pressure threshold.

14. The rotor blade rotation control master cylinder assembly of claim 12 , wherein the hydraulic fluid in the rotor blade rotation control master cylinder assembly can be pressurized to engage a rotor brake in response to a single translation of the rotor blade rotation control handle.

15. The rotor blade rotation control master cylinder assembly of claim 12 , wherein the volume of pressurized hydraulic fluid actuates the rotor brake actuator.

16. The rotor blade rotation control master cylinder assembly of claim 15 , wherein the rotor brake actuator is configured to slow the rotor of the vertical lift aircraft at or below the pressure threshold when the isolation valve is open.

17. The rotor brake actuator of claim 16 , wherein the rotor brake actuator is configured to slow the rotor of the vertical lift aircraft when the vertical lift aircraft is stopped.

18. The rotor blade rotation control master cylinder assembly of claim 13 , wherein the rotor brake actuator is configured to hold the rotor of the vertical lift aircraft at or below the second pressure threshold when the isolation valve is closed.

19. The rotor blade rotation control master cylinder assembly of claim 18 , wherein the isolation valve is configured to be closed and the rotor brake actuator is configured to hold the rotor of the vertical lift aircraft when the vertical lift aircraft is starting.

20. The rotor blade rotation control master cylinder assembly of claim 12 , wherein the rotor blade rotation control master cylinder assembly is configured to maintain suff

Assignees

• Bell Helicopter Textron Inc

Inventors

• Elving Carl T
• Sobel James E
• Pujol Michael

Classifications

• B60T15/02

  Application and release valves · CPC title

• B64C27/12 Primary

  Rotor drives · CPC title