Reconfigurable lubrication system for tiltrotor transmission

Patent metadata

Field	Value
Publication number	US-10655728-B2
Application number	US-201514955987-A
Country	US
Kind code	B2
Filing date	Dec 1, 2015
Priority date	Dec 1, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

Reversely identical transmissions for a tiltrotor aircraft include reconfigurable gearbox lubrication systems to accommodate operation in either direction of propeller rotation, using common parts. In a typical installation, at least two separate winged tiltrotor transmissions operate with opposing propeller rotations. Common parts of the two transmissions include cast housings, rotor shafts, pinion gears, lubrication sump tanks, lubrication pumps, and lubrication filter manifolds including filters having reversible orientations. Either transmission configuration can be utilized on either the left or right side of a tiltrotor aircraft by swapping the lubrication sump tank and lubrication filter manifold locations on the gearbox. In addition, a plug is used to manually reconfigure an opposite lubrication oil path to accommodate first and second rotational directions of the lubrication pump.

First claim

What is claimed is:

1. A gearbox for a tiltrotor aircraft, the gearbox comprising:
a housing;
the housing including a gear rotatably supported within the housing, the gear being configured to rotate in opposite first and second directions of rotation;
the housing further including a lubrication system, the lubrication system having a reversely rotatable lubrication pump; wherein the rotation of the gear controls rotation of the pump in either the first or the second direction of rotation;
wherein the lubrication system includes a filter manifold, and the housing includes a first attachment interface and a second attachment interface; and wherein the filter manifold is configured to be coupled to the first attachment interface when the gear is rotating in the first direction, and wherein the filter manifold is configured to be coupled to the second attachment interface when the gear is rotating in the second direction; wherein the gearbox lubrication system is reconfigurable for accommodating propeller rotation in either direction.

2. The gearbox of claim 1 , wherein the first attachment interface and the second attachment interface have identical footprints.

3. The gearbox of claim 1 , being configured to have a vertical orientation, a horizontal orientation, and orientations between the vertical and horizontal orientations during operation on a first wing of the tiltrotor aircraft.

4. The gearbox of claim 1 , wherein the lubrication system includes a sump tank; and wherein the sump tank is configured to be coupled to the second attachment interface when the gear is rotating in the first direction; and wherein the sump tank is configured to be coupled to the first attachment interface when the gear is rotating in the second direction.

5. The gearbox of claim 4 , wherein the gear rotates in a direction corresponding to that of a first propeller on a first wing of the tiltrotor aircraft, the tiltrotor aircraft having first and second wings, the second wing having a second propeller, wherein each of the first wing and the second wing supports a different direction of rotation of each respective propeller.

6. The gearbox of claim 4 , wherein the filter manifold contains a filter, and wherein the filter is usable in either the first or second attachment interface upon a reverse orientation of the filter manifold to accommodate an oil flow direction within the gearbox.

7. The gearbox of claim 4 , wherein the lubrication pump is a positive displacement pump rotatable in either the first or second direction of rotation.

8. A tiltrotor aircraft having a left propeller on a left wing thereof, a right propeller on a right wing thereof, and a pair of oppositely rotating transmissions, each transmission respectively affixed to one propeller; the tiltrotor aircraft comprising:
each transmission including a lubrication system including a lubrication pump, a lubrication sump tank, and a filter manifold; wherein rotation of the lubrication pump is reversibly reconfigurable by switching positions of the lubrication sump tank and filter manifold to either the left or right wing in either of a first and a second direction of propeller rotation;
wherein rotation of the lubrication pump in the first or the second direction of propeller rotation is accommodated by reversing positions of the lubrication sump tank and the filter manifold on the transmission; and
wherein a filter is configured to be affixed to the filter manifold of each transmission, each filter being defined by a flat, circular body including a filter manifold orientation indicator to display orientation of the filter manifold on each of the pair of transmissions.

9. The tiltrotor aircraft of claim 8 , wherein each transmission is configured to have a vertical orientation, a horizontal orientation, and orientations between the vertical and horizontal orientations.

10. The tiltrotor aircraft of claim 8 , wherein each transmission comprises common parts irrespective of rotation of the lubrication pump of that transmission, wherein the common parts include a cast housing, a rotor shaft, a pinion gear, the oil sump tank, the filter, and the filter manifold.

11. The tiltrotor aircraft of claim 8 , wherein each lubrication pump of each respective transmission is a positive displacement pump rotatable in either of the first or second directions of propeller rotation.

12. The tiltrotor aircraft of claim 8 , wherein each transmission further comprising a rotatable gear, wherein one of the lubrication pumps interfaces with the rotatable gear of the one transmission for inducing rotation of the one lubrication pump, wherein the one transmission includes a first attachment interface and a second attachment interface; and wherein one of the filter manifolds is coupled to the first attachment interface of the one transmission when the gear is rotating in the first direction, and wherein the other of the filter manifolds is coupled to the second attachment interface of the one transmission when the rotatable gear of the one transmission is rotating in the second direction.

13. The tiltrotor aircraft of claim 12 , wherein one sump tank is coupled to the second attachment interface of the one transmission when the gear of the one transmission is rotating in the first direction; and wherein the other sump tank is coupled to the first attachment interface of the one transmission when the gear is rotating in the second direction.

14. The tiltrotor aircraft of claim 12 , wherein each of the first attachment interface and the second attachment interface have identical footprints.

15. The tiltrotor aircraft of claim 12 , wherein each filter is used on either of the first or second attachment interface by a reverse orientation of the filter manifold to accommodate an oil flow direction within the transmission.

16. A method of making a gearbox for a tiltrotor aircraft, the method including the steps of:
forming a pair of housings, each having a lubrication system and a gear rotatably supported within each housing, each gear being configured to rotate in opposite first and second directions of rotation;
configuring each lubrication system within each housing to include a reversely rotatable pump and a filter manifold attachable respectively to each housing, each filter manifold having a reversible orientation on each respective housing; wherein the rotation of each gear controls rotation of the pump in either the first or the second direction of rotation;
wherein the lubrication system includes a filter manifold, and the housing includes a first attachment interface and a second attachment interface; and wherein the filter manifold is configured to be coupled to the first attachment interface when the gear is rotating in the first direction, and wherein the filter manifold is configured to be coupled to the second attachment interface when the gear is rotating in the second direction; wherein the gearbox lubrication system is reconfigurable for accommodating propeller rotation in either direction.

17. The method of claim 16 , further comprising the step of providing the first attachment interface and the second attachment interface on each housing, and forming the interfaces to have identical footprints.

Assignees

• Boeing Co

Inventors

• Filter Evan J
• Robuck Mark J

Classifications

• B64C29/0025

  the propellers being fixed relative to the fuselage · CPC title

• F16H57/02 Primary

  Gearboxes; Mounting gearing therein · CPC title

• F16H57/0436 Primary

  Pumps · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• F16H57/0402

  Cleaning of lubricants, e.g. filters or magnets · CPC title