LUBRICATING TRANSFER TUBE

• US 20120260769A1
• Filed: 04/14/2011
• Published: 10/18/2012
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX
• Original Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Rollins, Michael J., Bell, Melissa A.
• Granted Patent: US 8,944,216 B2
• Time in Patent Office: Days
• US Class Current: 74/606.R
• CPC Class Codes: F16H 57/0456 Lubrication by injection; Injection nozzles or tubes therefor oil mist or spray lubrication F16H57/0458
• CPC Class Codes: F16H 57/0495 with fixed gear ratio
• CPC Class Codes: Y10T 74/2186 Gear casings

Abstract

An example lubricating transfer tube assembly includes a transfer tube having a bore extending from a fluid inlet portion to a fluid outlet portion. The transfer tube is configured to communicate a fluid through the bore between the fluid inlet portion and the fluid outlet portion within a gearbox. The transfer tube defines a spray aperture extending from the bore to an outer surface of the transfer tube. The spray aperture is configured to communicate at least some of the fluid from the bore to an area of the gearbox.

Claims

1. A lubricating transfer tube assembly, comprising:

a transfer tube having a bore extending from a fluid inlet portion to a fluid outlet portion, the transfer tube configured to communicate a fluid through the bore between the fluid inlet portion and the fluid outlet portion within a gearbox,

the transfer tube defining a spray aperture extending from the bore to an outer surface of the transfer tube, the spray aperture configured to communicate at least some of the fluid from the bore to an area of the gearbox.

2. The lubricating transfer tube assembly of claim 1, wherein the bore extends along an axis from the fluid inlet portion to the fluid outlet portion.

3. The lubricating transfer tube assembly of claim 2, wherein the fluid outlet portion establishes an outlet axis that is spaced from the axis of the bore.

4. The lubricating transfer tube assembly of claim 1, wherein the gearbox includes a gearbox housing having a plurality of inwardly facing surfaces that establish a gearbox interior, the fluid inlet configured to receive fluid directly from a first position near a first one of the plurality of inwardly facing surfaces, and the fluid outlet is configured to communicate fluid directly to a second position near a second one of the plurality of inwardly facing surfaces.

5. The lubricating transfer tube assembly of claim 4, wherein the second one of the plurality of inwardly facing surfaces is an inwardly facing surface of a cover of the gearbox housing.

6. The lubricating transfer tube assembly of claim 4, wherein the fluid inlet portion is radially enlarged relative to the bore, and the fluid inlet portion is configured to be received within a recess established in the gearbox housing.

7. The lubricating transfer tube assembly of claim 6, including an o-ring secured around the fluid inlet portion, the o-ring configured to seal fluid flow at a radially outer interface between the fluid inlet portion and the gearbox housing.

8. The lubricating transfer tube assembly of claim 4, wherein the spray aperture is spaced from the inwardly facing surfaces.

9. The lubricating transfer tube assembly of claim 1, wherein the gearbox includes a gearbox housing having a plurality of inwardly facing surfaces that establish a gearbox interior, and the bore of the transfer tube spans across the gearbox interior from a first one of the plurality inwardly facing surfaces to an opposing, second one of the plurality of inwardly facing surfaces.

10. The lubricating transfer tube assembly of claim 1, wherein the fluid comprises a lubricant and coolant.

11. The lubricating transfer tube assembly of claim 1, wherein the outer surface is a radially outer surface relative to an axis of the bore.

12. The lubricating transfer tube assembly of claim 1, wherein the aperture is axially spaced from the fluid inlet portion and the fluid outlet portion.

13. A auxiliary power unit gearbox assembly, comprising:

a housing establishing a gearbox cavity configured to receive a plurality of gears; and

a transfer tube establishing a bore, the transfer tube configured to communicate a fluid from a first face of the housing to an opposing, second face of the housing,

the transfer tube defining a spray aperture extending from the bore to a radially outer surface of the transfer tube, the spray aperture configured to deliver a spray of the fluid to an area within the gearbox cavity.

14. The auxiliary power unit gearbox assembly of claim 13, wherein the housing comprises a housing cover, and one end of the transfer tube is received within a recess of the cover.

15. The auxiliary power unit gearbox assembly of claim 13, wherein the plurality of gears are configured to be driven by a rotatable input provided by a turbine engine shaft, and the axis of the bore is aligned with an axis of rotation of the turbine engine shaft.

16. The auxiliary power unit gearbox assembly of claim 13, wherein the first face and the second face are both inwardly facing surfaces of the housing.

17. The auxiliary power unit gearbox assembly of claim 13, including a first end portion configured to fluidly couple the transfer tube to the first face, and a second end portion configured to fluidly couple the transfer tube to the second face, at least one of the first end portion or the second end portion establishing an end portion axis that is aligned with and spaced from an axis of the bore.

18. The auxiliary power unit gearbox assembly of claim 17, wherein the first face establishes a conduit portion extending along a conduit axis and configured to deliver the fluid to the first end portion, wherein the conduit axis is spaced from the end portion axis of the first end portion.

19. A method of lubricating an auxiliary power unit gearbox assembly, comprising:

positioning at least a portion of a gearbox transfer tube within a gearbox cavity of a gearbox;

communicating fluid through a bore of a gearbox transfer tube from a first end portion to second end portion of the transfer tube; and

moving some of the fluid through an aperture in the transfer tube directly to a portion of the gearbox cavity.

20. The method of claim 19, including engaging a first wall of the gearbox with the first end portion, and engaging an opposing, second wall of the gearbox with the second end portion.

21. The method of claim 19, wherein the second wall is a cover of the gearbox.