Lubricating transfer tube

• US 8,944,216 B2
• Filed: 04/14/2011
• Issued: 02/03/2015
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Rollins, Michael J., Bell, Melissa A.
• Primary Examiner(s): Dondero, William E
• Assistant Examiner(s): TRUONG, MINH D
• Application Number:
  US13/086,464
• Publication Number:
  US 20120260769A1
• Time in Patent Office: 1,391 Days
• Field of Search: 184/6.12, 184/11.2, 184/6.17
• US Class Current: 184/11.2
• 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 including a bore extending continuously along a linear axis 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, a portion of the outer surface defining the spray aperture, the portion being open and exposed to an interior area of the gearbox, the spray aperture configured to communicate at least some of the fluid from the bore to the interior area of the gearbox, wherein the gearbox includes a plurality of gears and each of the gears within the gearbox is configured such that the transfer tube supports no gears. wherein the gearbox includes a gearbox housing including a plurality of inwardly facing surfaces that establish the interior area, and the bore of the transfer tube spans across the interior area from and through a first one of the plurality of inwardly facing surfaces to and through an opposing, second one of the plurality of inwardly facing surfaces.

2. The lubricating transfer tube assembly of claim 1, wherein the fluid outlet portion establishes an outlet axis that is spaced from a longitudinal axis of the bore.

3. The lubricating transfer tube assembly of claim 1, wherein the gearbox includes a gearbox housing including a plurality of inwardly facing surfaces that establish the interior area, 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.

4. The lubricating transfer tube assembly of claim 3, wherein the second one of the plurality of inwardly facing surfaces is an inwardly facing surface of a cover of the gearbox housing.

5. The lubricating transfer tube assembly of claim 3, 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.

6. The lubricating transfer tube assembly of claim 5, 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.

7. The lubricating transfer tube assembly of claim 3, wherein the spray aperture is spaced from the inwardly facing surfaces.

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

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

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

11. The lubricating transfer tube assembly of claim 1, wherein the linear axis of the bore is offset from an inlet axis of the fluid inlet portion, an outlet axis of the fluid outlet portion, or both.

12. An 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 bore extending continuously along a linear axis from and through the first face to and through the second face,

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 interior area within the gearbox cavity, the radially outer surface that provides an outlet of the spray aperture being open and exposed to the interior area, wherein the transfer tube supports no gears.

13. The auxiliary power unit gearbox assembly of claim 12, wherein the housing comprises a housing cover, and one end of the transfer tube is received within a recess of the cover.

14. The auxiliary power unit gearbox assembly of claim 12, wherein the plurality of gears are configured to be driven by a rotatable input provided by a turbine engine shaft, and an axis of the bore generally parallel to an axis of rotation of the turbine engine shaft.

15. The auxiliary power unit gearbox assembly of claim 12, wherein the first face and the second face are both inwardly facing surfaces of the housing.

16. The auxiliary power unit gearbox assembly of claim 12, including a first end portion of the transfer tube configured to fluidly couple the transfer tube to the first face, and a second end portion of the transfer tube 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 generally parallel to and spaced from a longitudinal axis of the bore, wherein a central portion of the transfer tube joins the first end portion to the second end portion.

17. The auxiliary power unit gearbox assembly of claim 16, 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.

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

communicating fluid through a bore of a gearbox transfer tube from a first end portion to second end portion of the transfer tube extending along a linear axis, wherein at least a portion of the gearbox transfer tube is within a gearbox cavity of the gearbox having gears;

moving some of the fluid through an aperture in the transfer tube directly to a portion of the gearbox cavity, wherein each of the gears within the gearbox is unsupported by the gearbox transfer tube within the gearbox cavity of the gearbox and the aperture in the transfer tube is uncovered by any of the gears within the gearbox; and

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 wherein the bore extends through the first wall and through the second wall.

19. The method of claim 18, wherein the second wall is a cover of the gearbox.

20. The method of claim 18, wherein a portion of the gearbox cavity to which the fluid through the aperture in the transfer tube is moved and sprayed by fluid moved through the aperture in the transfer tube is spaced from the gearbox transfer tube.

21. The method of claim 18, wherein a linear axis of the bore is offset from an axis of the first end portion, an axis of the second end portion, or both.