Engine and rotatable proprotor configurations for a tiltrotor aircraft

Patent metadata

Field	Value
Publication number	US-11148798-B2
Application number	US-201816015760-A
Country	US
Kind code	B2
Filing date	Jun 22, 2018
Priority date	Jun 22, 2018
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located on the top surface of the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is also 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 on a wing, wherein the engine comprises 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; a rotatable proprotor assembly disposed on the top surface of the wing, wherein the proprotor assembly comprises a proprotor pylon, a rotor mast, a plurality of rotor blades coupled to the rotor mast, and a proprotor input operable to accept a drive force generated by the output shaft, and wherein the rotor mast and plurality of rotor blades are disposed around a common proprotor longitudinal axis; a first gearbox disposed in a drive path between the output shaft and the proprotor input, wherein the first gearbox is operable to transfer a drive, force from the output shaft to the proprotor input; and a wing extension attached directly to the wing, below the proprotor assembly and engine, wherein the engine longitudinal axis is above, and substantially perpendicular to, the central axis of the wing, wherein the proprotor pylon contains the engine, and wherein a wing interconnect included at a center of the wing allows the wing to be removably attached to a fuselage of the tiltrotor aircraft such that the wing to 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 proprotor pylon is disposed on the top surface of the wing and 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.

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

4. The propulsion system of claim 3 , further comprising an interconnect drive system, the interconnect drive system comprising:
an interconnect gearbox disposed between the engine reduction gearbox and the proprotor gearbox;
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 3 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.

5. The propulsion system of claim 4 , wherein the interconnect gearbox transfers at least a portion of the drive force from the engine reduction gearbox to the proprotor gearbox.

6. The propulsion system of claim 5 , wherein:
the engine generates an output drive along the engine axis;
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.

7. The propulsion system of claim 6 , wherein the rotating engine output is directed to the rotor mast and rotor blades along the proprotor longitudinal axis.

8. The propulsion system of claim 7 , wherein the proprotor longitudinal axis and the engine longitudinal axis are substantially parallel when the tiltrotor aircraft is operating in an airplane mode.

9. The propulsion system of claim 7 , wherein the proprotor longitudinal axis and the engine longitudinal axis are substantially normal when the tiltrotor aircraft is operating in a helicopter mode.

10. The propulsion system of claim 7 , 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.

11. A tiltrotor aircraft, comprising:
a fuselage having a longitudinal axis, a tail section, at least two wings, and at least two propulsion systems, wherein the at least two propulsion systems are disposed opposite each other relative to 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; and
wherein the at least two propulsion systems comprise, respectively:
an engine having an engine longitudinal axis, the engine disposed above the central axis of the wing, wherein the engine longitudinal axis is substantially normal to the central axis of the wing;
a proprotor assembly having 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, and 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, wherein the proprotor assembly comprises a rotor mast and a plurality of rotor blades mounted thereon;
an engine reduction gearbox disposed between an engine output shaft and a proprotor input, the at least one gearbox operable to transfer the drive force generated by the engine to the proprotor assembly to turn the rotor mast;
wing extensions attached directly to the wings below the proprotor assembly and engine; and
a wing interconnect disposed between the two wings,
wherein the wing interconnect is operable to removably attach the wings to the fuselage,
wherein the pylon contains the engine, and
wherein the wing interconnect allows the wings to be removed or rotated to allow the tiltrotor aircraft to be stored or shipped in a shipping container.

12. The tiltrotor aircraft of claim 11 , further comprising an 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 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.

13. The tiltrotor aircraft of claim 12 , further comprising a proprotor gearbox operable to change the direction of the output drive at the proprotor input to the longitudinal axis of the proprotor.

14. The tiltrotor aircraft of claim 11 , wherein the at least two wing extensions are operable to removably couple to each of the respective wings.

15. The tiltrotor aircraft of claim 11 , wherein the proprotor assembly is positioned distal the fuselage to maximize a turn radius of the rotors disposed on the rotor mast, wherein the engine is positioned directly below the proprotor assembly to maximize the lift area of the wing.

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

• 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

• B64D35/00

  Transmitting power from power plants to propellers or rotors; Arrangements of transmissions · CPC title