Tiltrotor outboard fixed engine configuration with offset rotation spindle and interconnect drive shaft
The present invention includes a rotorcraft drive system, method, and aircraft comprising a fixed engine; a rotating spindle that rotates a proprotor gearbox and rotor pylon between a hover and forward flight position, wherein the rotating spindle rotates about a rotation bearings on two inboard ribs of a wing member; and an interconnect drive shaft connected to the fixed engine, wherein the interconnect drive shaft passes through an aft cove of the wing member and connects to the engine via a forward-aft drive shaft, wherein the forward-aft drive shaft is connected to the proprotor gearbox to provide power to a proprotor.
1. A rotorcraft drive system comprising:
one or more fixed engines;
a wing member comprising two inboard ribs and an outboard tip rib connected between a forward wing spar and an aft wing spar, and an aft cove positioned aft of the aft wing spar;
a rotating spindle that rotates a proprotor gearbox and rotor pylon between a hover and forward flight position, wherein the rotating spindle rotates about a rotation bearings on the two inboard ribs of the wing member;
an interconnect drive shaft connected to the one or more fixed engines, wherein the interconnect drive shaft passes through the aft cove of the wing member and connects to a forward-aft drive shaft located outboard of the outboard tip rib, wherein the forward-aft drive shaft is connected to the proprotor gearbox to provide power to a proprotor; and
the forward wing spar of the wing member comprises a U-shaped extension between one of the inboard ribs and the outboard tip rib that is sized to allow space for and provide support of the rotor pylon in a forward position.
2. The rotorcraft drive system of claim 1 , wherein the one or more fixed engines are positioned at least one of: at an end of a first wing member, at an end of a second wing member opposite the first wing member, or centrally in, at, or about a fuselage.
3. The rotorcraft drive system of claim 1 , wherein the interconnect drive shaft connects to the one or more fixed engines by a spiral bevel gear.
4. The rotorcraft drive system of claim 1 , wherein the one or more fixed engines connects to the forward-aft drive shaft via one or more reduction gears.
5. The rotorcraft drive system of claim 1 , further comprising a bevel gear connected to the forward-aft drive shaft that connects at a spindle center of rotation.
6. The rotorcraft drive system of claim 1 , wherein the interconnect drive shaft is positioned aft from the aft wing spar of the wing member.
7. The rotorcraft drive system of claim 1 , wherein the rotating spindle is positioned immediately aft from the forward wing spar.
8. The rotorcraft drive system of claim 1 , wherein the rotating spindle is positioned forward from the aft wing spar.
9. The rotorcraft drive system of claim 1 , wherein the rotating spindle is offset from the interconnect drive shaft.
10. The rotorcraft drive system of claim 1 , wherein the outboard tip rib supports a non-rotating portion of the drive system and provides attachment for the one or more fixed engines.
11. The rotorcraft drive system of claim 1 , wherein the wing member comprises swept wings.
12. A method of providing power to a proprotor comprising:
providing one or more fixed engines;
providing a wing member comprising two inboard ribs and an outboard tip rib connected between a forward wing spar and an aft wing spar, and an aft cove positioned aft of the aft wing spar;
positioning a rotating spindle that rotates a proprotor gearbox and rotor pylon between a hover and forward flight position, wherein the rotating spindle rotates about two rotation bearings on the inboard ribs of the wing member;
connecting an interconnect drive shaft to the one or more fixed engines, wherein the interconnect drive shaft passes through the aft cove of the wing member and connects to a forward-aft drive shaft positioned outboard of the outboard tip rib, wherein the forward-aft drive shaft is connected to the proprotor gearbox to provide power to the proprotor; and
forming the forward wing spar of the wing member to comprise a U-shaped extension between one of the inboard ribs and the outboard tip rib that is sized to allow space for and provide support of the rotor pylon in a forward position.
13. The method of claim 12 , wherein the one or more fixed engines are positioned at least one of: at an end of a first wing member, at an end of a second wing member opposite the first wing member, or centrally in, at, or about a fuselage.
14. The method of claim 12 , further comprising connecting the interconnect drive shaft to the one or more fixed engines by a spiral bevel gear.
15. The method of claim 12 , further comprising connecting the one or more fixed engines to the forward-aft drive shaft via one or more reduction gears.
16. The method of claim 12 , further comprising connecting a bevel gear to the forward-aft drive shaft at a spindle center of rotation.
17. The method of claim 12 , further comprising positioning the interconnect drive shaft aft from the aft wing spar of the wing member.
18. The method of claim 12 , further comprising positioning the rotating spindle immediately aft from the forward wing spar.
19. The method of claim 12 , further comprising positioning the rotating spindle forward from the aft wing spar.
20. The method of claim 12 , wherein the rotating spindle is offset from the interconnect drive shaft.
21. The method of claim 12 , wherein the outboard tip rib supports a non-rotating portion of the drive system and provides attachment for the one or more fixed engines.
22. The method of claim 12 , wherein the wing member comprises swept wings.
23. An aircraft comprising:
a fuselage connected to a wing member, wherein the wing member comprises two inboard ribs and an outboard tip rib connected between a forward wing spar and an aft wing spar, and an aft cove positioned aft of the aft wing spar;
one or more engines;
a rotating spindle that rotates a proprotor gearbox and rotor pylon between a hover and forward flight position, wherein the rotating spindle rotates about rotation bearings on the two inboard ribs of the wing member;
an interconnect drive shaft connected to the one or more engines, wherein the interconnect drive shaft passes through the aft cove of the wing member and connects to a forward-aft drive shaft positioned outboard of the outboard tip rib, wherein the forward-aft drive shaft is connected to the proprotor gearbox to provide power to a proprotor; and
the forward wing spar of the wing member comprises a U-shaped extension between one of the inboard ribs and the outboard tip rib that is sized to allow space for and provide support of the rotor pylon in a forward position.
24. The aircraft of claim 23 , wherein the one or more engines are positioned at least one of: at an end of a first wing member, at an end of a second wing member opposite the first wing member, or centrally in, at, or about the fuselage.