US 11,852,232 B1
Persistent lubrication systems for aircraft gearboxes
Charles Hubert Speller, Flower Mound, TX (US); and Ezra Mike Tiprigan, North Richland Hills, TX (US)
Assigned to Textron Innovations Inc., Providence, RI (US)
Filed by Textron Innovations Inc., Providence, RI (US)
Filed on Nov. 1, 2022, as Appl. No. 17/978,919.
Int. Cl. F16H 57/04 (2010.01); B64C 29/00 (2006.01)
CPC F16H 57/0442 (2013.01) [B64C 29/0033 (2013.01); F16H 57/0436 (2013.01); F16H 57/0445 (2013.01); F16H 57/0453 (2013.01); F16H 57/0404 (2013.01); F16H 57/0417 (2013.01)] 20 Claims
OG exemplary drawing
 
17. 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 lubrication system associated with the first gearbox assembly, the first lubrication system including a bifurcated first tank configured to contain a lubricant in an operating chamber including a lower sump and in an emergency chamber including an upper sump, the first lubrication system including a first operating pump configured to supply the lubricant from the operating chamber to the first gearbox assembly;
a second lubrication system associated with the second gearbox assembly, the second lubrication system including a second tank configured to contain the lubricant and a second operating pump configured to supply the lubricant from the second tank to the second gearbox assembly; and
an emergency pump in fluid communication with the emergency chamber;
wherein, the emergency pump is configured to supply the lubricant to the first gearbox assembly from the emergency chamber responsive to a failure in the first lubrication system; and
wherein, the emergency pump is configured to supply the lubricant to the second gearbox assembly and to the operating chamber from the emergency chamber responsive to a failure in the second lubrication system.