Engine and rotatable proprotor configurations for a tiltrotor aircraft

Patent metadata

Field	Value
Publication number	US-11338916-B2
Application number	US-201816014441-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Jun 21, 2018
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located below the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is mounted on the top surface of the wing. The engine and proprotor assembly are connected via a series of one or more gearboxes that route the engine output from the engine to the proprotor.

First claim

What is claimed is:

1. A propulsion system for a tiltrotor aircraft, comprising:
an engine disposed below a wing, wherein the engine comprises a first gearbox having an output shaft along an engine longitudinal axis, and wherein the wing comprises a leading edge, a trailing edge, a top surface and a bottom surface and a central axis that runs substantially parallel to the leading edge and the trailing edge, wherein the engine generates an engine output drive along the engine axis;
a rotatable proprotor assembly disposed on the top surface of the wing, wherein the proprotor assembly comprises a rotor mast, a plurality of rotor blades coupled to the rotor mast, and a second gearbox coupled to a proprotor input and operable to accept a drive force generated by the output shaft, wherein the rotor mast and plurality of rotor blades are disposed around a common proprotor longitudinal axis; and
an interconnect drive system coupled between the first and second gearboxes and configured to transfer drive force from the output shaft to a second propulsion system;
wherein the first gearbox is operable to transfer a drive force from the output shaft to the proprotor input; and
a wing extension coupled to a wing structure of the wing between the rotatable proprotor assembly and the engine,
wherein a wing interconnect allows the wing to be removably attached to a fuselage of the tiltrotor aircraft such that the wing can be removed or rotated to allow the tiltrotor aircraft to be stored or shipped in a shipping container.

2. The propulsion system of claim 1 , wherein the longitudinal axis of the engine is below, and substantially perpendicular to, the central axis of the wing.

3. The propulsion system of claim 1 , further comprising a proprotor pylon disposed on the top surface of the wing, wherein the pylon connects the proprotor assembly to the wing, and provides for at least a 90° rotation of the proprotor assembly about the central axis of the wing.

4. The propulsion system of claim 1 , wherein the first gearbox is an engine reduction gearbox, and the second gearbox is a proprotor gearbox.

5. The propulsion system of claim 4 , the interconnect drive system comprising:
an interconnect drive shaft coupled to the interconnect gearbox, wherein the interconnect drive shaft is operable to transfer drive force from the propulsion system of claim 4 to a second propulsion system disposed on one of the same wing or a second wing, wherein the interconnect drive shaft runs substantially along the longitudinal axis of the wing from the coupling of the interconnect drive shaft at the interconnect gear box, and
wherein the interconnect gearbox is operable to direct at least a portion of the drive force to the interconnect drive shaft.

6. The propulsion system of claim 5 , wherein the interconnect gearbox transfers at least a portion of the drive force from the engine reduction gearbox to the proprotor gearbox.

7. The propulsion system of claim 6 , wherein:
the engine reduction gearbox changes the direction of the output drive at least 90° so that the output drive is routed to the interconnect gearbox;
the interconnect gearbox routes output drive to a proprotor gearbox input; and
the proprotor gearbox converts the output drive to a rotating engine output along a longitudinal axis of the proprotor assembly.

8. The propulsion system of claim 7 , wherein the rotating engine output is directed to the rotor mast and rotor blades along the proprotor longitudinal axis.

9. The propulsion system of claim 8 , wherein the proprotor longitudinal axis and the engine longitudinal axis are substantially parallel when the tiltrotor aircraft is operating in an airplane mode.

10. The propulsion system of claim 8 , wherein the proprotor longitudinal axis and the engine longitudinal axis are substantially normal when the tiltrotor aircraft is operating in a helicopter mode.

11. The propulsion system of claim 8 , wherein the engine longitudinal axis is fixed and the proprotor longitudinal axis is rotatable from 0° to at least 90° relative to the engine longitudinal axis.

12. A tiltrotor aircraft, comprising:
a fuselage having a longitudinal axis, a tail section, at least two wings attached to the fuselage at a wing interconnect, and at least two propulsion systems, wherein the at least two propulsion systems are disposed at opposite sides of the fuselage, wherein the at least two wings comprise, respectively, a leading edge, a trailing edge, a top surface, a bottom surface, and a central axis substantially normal to the fuselage;
wherein the at least two propulsion systems comprise, respectively:
an engine having an engine longitudinal axis, the engine disposed below the bottom surface of the wing, and wherein the engine longitudinal axis of the engine is substantially normal to the central axis of the wing, wherein the engine generates an engine output drive along the engine axis;
a proprotor assembly having a proprotor input and a proprotor longitudinal axis disposed on a pylon mounted on the top surface of the wing, wherein the proprotor longitudinal axis is substantially normal to the central axis of the wing, wherein the proprotor longitudinal axis is rotatable in relation to the central axis of the wing from a position substantially parallel to the engine longitudinal axis to a position substantially normal to the engine longitudinal axis, and wherein the proprotor assembly comprises a rotor mast and a plurality of rotor blades mounted thereon; and
an engine reduction gearbox disposed between an engine output shaft and a proprotor input, the engine reduction gearbox operable to transfer a drive force generated by the engine to the proprotor input to turn the rotor mast;
a proprotor gearbox coupled to the proprotor input and operable to receive the drive force generated by the output shaft; and
an interconnect drive system coupled between the engine reduction gearbox and the proprotor gearbox and configured to transfer the drive force from the output shaft to a second one of the two propulsion systems,
wherein each of the at least two wings include a wing extension coupled to a wing structure of the wing disposed between the rotatable proprotor assembly and the engine,
wherein at least one wing interconnect allows the at least two wings to be removably attached to the fuselage of the tiltrotor aircraft such that the at least two wings can be removed or rotated to allow the tiltrotor aircraft to be stored or shipped in a shipping container.

13. The tiltrotor aircraft of claim 12 , the interconnect drive system, wherein the interconnect drive system is connected to the engine output shaft, and mounted in a position fixed relative to the engine, and comprises:
an interconnect gearbox disposed between the engine reduction gearbox and the proprotor input; and
an interconnect drive shaft coupled to the interconnect gearbox of each of the at least two propulsion systems along the longitudinal axes of the at least two wings, wherein the interconnect gearbox is operable to transfer at least a portion of an output drive generated by the engine to the interconnect drive shaft and the proprotor input of each of the at least two propulsion systems.

14. The tiltrotor aircraft of claim 13 , wherein the proprotor gearbox is operable to change the direction of the engine output drive at the proprotor input to the longitudinal axis of the proprotor.

15. The tiltrotor aircraft of claim 13 , wherein each of the at least two wing extensions respectively extend the two wings along the longitudinal axis of each respective wing.

16. The tiltrot

Assignees

• Textron Innovations Inc

Inventors

• Gilliland Colton
• Williams Jeffrey
• Rinehart Michael E
• Kooiman James
• Przybyla Mark
• Smith Clegg
• Olson Eric Stephen
• Decker George Ryan
• Bockmiller David Russell

Classifications

• B64D35/08

  characterised by the transmission being driven by a plurality of power plants (for hybrid-electric power plants B64D35/022) · CPC title

• B64D27/402

  comprising box like supporting frames, e.g. pylons or arrangements for embracing the power plant · CPC title

• B64C3/56

  Folding or collapsing to reduce overall dimensions of aircraft · CPC title

• B64C29/0033 Primary

  the propellers being tiltable relative to the fuselage · CPC title

• B64D27/26

  Operations & Transport · mapped topic