Autonomous Emergency Lubrication of Aircraft Gearboxes

Patent metadata

Field	Value
Publication number	US-2024166345-A1
Application number	US-202217989908-A
Country	US
Kind code	A1
Filing date	Nov 18, 2022
Priority date	Nov 18, 2022
Publication date	May 23, 2024
Grant date	—

Abstract

A drive system for an aircraft includes a first gearbox assembly and a second gearbox assembly that is in mechanical communication with the first gearbox assembly. A first pressurized lubrication system is configured to circulate a first lubricant through the first gearbox assembly. A second pressurized lubrication system is configured to circulate a second lubricant through the second gearbox assembly. An emergency lubrication system is configured to autonomously supply a portion of the first lubricant to the second gearbox assembly responsive to a loss of pressure in the second pressurized lubrication system. The emergency lubrication system is also configured to autonomously supply a portion of the second lubricant to the first gearbox assembly responsive to a loss of pressure in the first pressurized lubrication system.

First claim

What is claimed is:

1 . A drive system for an aircraft, the drive system comprising:
a first gearbox assembly; a second gearbox assembly in mechanical communication with the first gearbox assembly; a first pressurized lubrication system configured to circulate a first lubricant through the first gearbox assembly; a second pressurized lubrication system configured to circulate a second lubricant through the second gearbox assembly; and an emergency lubrication system configured to autonomously supply a portion of the first lubricant to the second gearbox assembly responsive to a loss of pressure in the second pressurized lubrication system.

2 . The drive system as recited in claim 1 , wherein the first gearbox assembly further comprises one of a proprotor gearbox and an interconnect gearbox; and
wherein, the second gearbox assembly further comprises the other of the proprotor gearbox and the interconnect gearbox.

3 . The drive system as recited in claim 1 , wherein each of the first and second pressurized lubrication systems further comprises a tank, a pump, a heat exchanger, a filter and at least one lubrication line.

4 . The drive system as recited in claim 1 , wherein the first pressurized lubrication system is independent of the second pressurized lubrication system during normal operating conditions.

5 . The drive system as recited in claim 1 , wherein the emergency lubrication system further comprises a valve assembly positioned between the first pressurized lubrication system and the second pressurized lubrication system.

6 . The drive system as recited in claim 5 , wherein pressure in the second pressurized lubrication system maintains the valve assembly in a closed position during normal operating conditions of the second pressurized lubrication system; and
wherein, responsive to the loss of pressure in the second pressurized lubrication system, the valve assembly shifts to an open position such that the portion of the first lubricant is autonomously supplied to the second gearbox assembly.

7 . The drive system as recited in claim 5 , wherein the valve assembly is maintained in an operating configuration to supply a portion of the second lubricant to the second gearbox assembly during normal operating conditions of the second pressurized lubrication system; and
wherein, responsive to the loss of pressure in the second pressurized lubrication system, the valve assembly shifts to an emergency position such that the portion of the first lubricant is autonomously supplied to the second gearbox assembly.

8 . The drive system as recited in claim 5 , wherein the valve assembly further comprises a spring biased differential pressure operated valve assembly.

9 . The drive system as recited in claim 1 , wherein the emergency lubrication system is configured to autonomously supply the portion of the first lubricant to the second gearbox assembly responsive to the loss of pressure in the second pressurized lubrication system for a predetermined period of time.

10 . The drive system as recited in claim 1 , wherein the loss of pressure in the second pressurized lubrication system further comprises the pressure in the second pressurized lubrication system falling below a predetermined threshold pressure.

11 . The drive system as recited in claim 1 , wherein the emergency lubrication system further comprises a sensor configured to detect when the portion of the first lubricant is autonomously supplied to the second gearbox assembly.

12 . The drive system as recited in claim 1 , wherein the emergency lubrication system is configured to autonomously supply a portion of the second lubricant to the first gearbox assembly responsive to a loss of pressure in the first pressurized lubrication system.

13 . The drive system as recited in claim 12 , wherein the emergency lubrication system further comprises a valve assembly positioned between the first pressurized lubrication system and the second pressurized lubrication system.

14 . The drive system as recited in claim 13 , wherein pressure in the first pressurized lubrication system maintains the valve assembly in a closed position during normal operating conditions of the first pressurized lubrication system; and
wherein, responsive to the loss of pressure in the first pressurized lubrication system, the valve assembly shifts to an open position such that the portion of the second lubricant is autonomously supplied to the first gearbox assembly.

15 . The drive system as recited in claim 13 , wherein the valve assembly is maintained in an operating configuration to supply a portion of the first lubricant to the first gearbox assembly during normal operating conditions of the first pressurized lubrication system; and
wherein, responsive to the loss of pressure in the first pressurized lubrication system, the valve assembly shifts to an emergency position such that the portion of the second lubricant is autonomously supplied to the first gearbox assembly.

16 . The drive system as recited in claim 13 , wherein the valve assembly further comprises a spring biased differential pressure operated valve assembly.

17 . The drive system as recited in claim 12 , wherein the emergency lubrication system is configured to autonomously supply the portion of the second lubricant to the first gearbox assembly responsive to the loss of pressure in the first pressurized lubrication system for a predetermined period of time.

18 . The drive system as recited in claim 12 , wherein the loss of pressure in the first pressurized lubrication system further comprises the pressure in the first pressurized lubrication system falling below a predetermined threshold pressure.

19 . A tiltrotor aircraft having a helicopter mode and an airplane mode, the tiltrotor aircraft comprising:
a proprotor assembly; a first gearbox assembly in mechanical communication with the proprotor assembly; a second gearbox assembly in mechanical communication with the first gearbox assembly; an engine in mechanical communication with the second gearbox assembly and configured to provide torque and rotational energy to the proprotor assembly via the first and second gearbox assemblies; a first pressurized lubrication system configured to circulate a first lubricant through the first gearbox assembly; a second pressurized lubrication system configured to circulate a second lubricant through the second gearbox assembly; and an emergency lubrication system configured to autonomously supply a portion of the first lubricant to the second gearbox assembly responsive to a loss of pressure in the second pressurized lubrication system and configured to autonomously supply a portion of the second lubricant to the first gearbox assembly responsive to a loss of pressure in the first pressurized lubrication system.

20 . An aircraft comprising:
a rotor assembly; a first gearbox assembly in mechanical communication with the rotor assembly; a second gearbox assembly in mechanical communication with the first gearbox assembly; an engine in mechanical communication with the second gearbox assembly and configured to provide torque and rotational energy to the rotor assembly via the first and second gearbox assemblies; a first pressurized lubrication system configured to circulate a first lubricant through the first gearbox assembly; a second pressurized lubrication system configured to circulate a second lubricant through the second gearbox assembly; and an emergency lubrication system confi

Assignees

• Textron Innovations Inc

Inventors

• Olson Eric Stephen
• Tiprigan Ezra Mike

Classifications

• F16H57/0442

  for supply in case of failure, i.e. auxiliary supply · CPC title

• B64C29/0033 Primary

  the propellers being tiltable relative to the fuselage · CPC title

• F16N2260/20

  Emergency · CPC title

• F16N25/02 Primary

  with reciprocating distributing slide valve · CPC title

• F16K99/0028

  Valves having multiple inlets or outlets · CPC title