Spline alignment

Patent metadata

Field	Value
Publication number	US-10302140-B2
Application number	US-201615380193-A
Country	US
Kind code	B2
Filing date	Dec 15, 2016
Priority date	Dec 15, 2016
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A gas turbine shaft assembly comprises first and second axially mating shafts. The first shaft has a circumferential array of splines configured to mesh with a corresponding circumferential array of splines on the second shaft. The first shaft defines at least one axially extending slot aligned with one of the splines on the first shaft. The second shaft has at least one radial projection aligned with one of the splines on the second shaft. The engagement of the radial projection with the slot provides angular correspondence between the splines of the first and the second shafts prior to axial engagement of the splines.

First claim

The invention claimed is:

1. A turbine shaft blind assembly comprising:
first and second axially mating turbine shafts,
the first turbine shaft having a circumferential array of splines configured to mesh with a corresponding circumferential array of splines on the second turbine shaft,
the first turbine shaft defining at least one axially extending slot aligned with one of the splines on the first turbine shaft,
the second turbine shaft having at least one radial projection aligned with one of the splines on the second turbine shaft, the engagement of the at least one radial projection with the at least one slot providing angular correspondence between the splines of the first and the second turbine shafts prior to axial engagement of the splines,
wherein the at least one axially extending slot has an axially converging entry segment merging into an axially extending alignment segment aligned with the one spline of the splines of the first turbine shaft, the axially converging entry segment having a width in a circumferential direction that tapers as the axially converging entry segment extends towards the axially extending alignment segment, the axially extending alignment segment having a width in a circumferential direction corresponding to that of the at least one radial projection.

2. The turbine shaft blind assembly defined in claim 1 , wherein the axially extending alignment segment of the at least one slot opens up on an enlarged end segment sized to provide a clearance in a circumferential direction with the at least one radial projection, the at least one radial projection being axially positioned on the second turbine shaft to fall into the enlarged end segment of the at least one slot once the splines of the first and second turbine shafts are axially engaged.

3. The turbine shaft blind assembly defined in claim 1 , wherein the axially converging entry segment is configured as a triangular slot.

4. The turbine shaft blind assembly defined in claim 1 , wherein the first turbine shaft is a male member, wherein the second turbine shaft is a female member, the male member being axially insertable into the female member, and wherein the at least one radial projection extends radially inwardly from an inner diameter of the female member.

5. The turbine shaft blind assembly defined in claim 4 , wherein the male member has a lead end, the circumferential array of splines of the male member being axially inward of the lead end, the at least one slot being defined axially along the lead end.

6. The turbine shaft blind assembly defined in claim 5 , wherein the at least one axially extending slot comprises at least two circumferentially spaced-apart slots along the lead end of the male member, the at least two circumferentially spaced-apart slots defining fingers therebetween, and wherein holes are defined in the fingers.

7. The turbine shaft blind assembly defined in claim 5 , wherein the lead end has an inner circumferential surface, and wherein said inner circumferential surface tapers in an axial direction towards the circumferential array of splines on the male member.

8. The turbine shaft blind assembly defined in claim 7 , wherein the at least one axially extending slot comprises at least two circumferentially spaced-apart slots along the tip of the male member, the at least two circumferentially spaced-apart slots defining fingers therebetween, and wherein holes are defined through the fingers.

9. The turbine shaft blind assembly defined in claim 4 , wherein the male member is a low pressure compressor shaft and the female member is a power turbine shaft of a gas turbine engine.

10. The turbine shaft blind assembly defined in claim 1 , wherein the at least one radial projection comprises a pin mounted in a radial hole defined through the second turbine shaft.

11. A gas turbine engine comprising:
a male member having a circumferential array of axially oriented splines configured to mesh with a corresponding circumferential array of axially oriented splines defined in a female member,
the male member having a lead end defining at least one slot for receiving at least one corresponding projection extending radially inwardly from the female member, the lead end of the male member projecting axially forward of the circumferential array of splines of the male member,
the at least one slot having a converging entry segment leading to an axial segment aligned with one of the splines on the male member, the converging entry segment of the at least one slot tapering towards the axial segment, the axial segment having a width in a circumferential direction corresponding to that of the at least one radial projection,
the at least one projection being aligned with one of the splines on the female member,
the at least one projection and the at least one slot being axially positioned relative to the splines of the male and female members so that the at least one projection is guided by the converging entry segment into the axial segment of the at least one slot prior to the splines on the male member engaging the splines of the female member when the male and female members are axially brought together.

12. The gas turbine engine defined in claim 11 , wherein the at least one slot further comprises an enlarged end segment providing clearance with the at least one projection in a circumferential direction, the enlarged end segment being disposed axially inward of the axial segment.

13. The gas turbine engine defined in claim 11 , wherein the male member is a low pressure compressor shaft and the female member is a power turbine shaft.

14. A method to provide self-alignment between splines of first and second axially mating turbine shafts of a gas turbine engine, the method comprising:
providing an alignment slot and a guide pin in respective ones of the first and second axially mating turbine shafts, the alignment slot having an axially converging entry segment followed by an axial segment, the axial segment being angularly aligned with one of the splines of the first turbine shaft, the guide pin being angularly align with one of the splines of the second turbine shaft, the axially converging entry segment of the at least one slot tapering towards the axial segment, the axial segment having a width in a circumferential direction corresponding to that of the at least one radial projection;
axially advancing the first and second turbine shafts towards each other so as to cause the guide pin to engage the converging entry segment of the alignment slot, wherein continued advancement of the guide pin in the converging entry segment of the alignment slot causes the first and second turbine shafts to rotate relative to each other until the guide pin engages the axial segment of the alignment slot, thereby angularly aligning the splines of the first and second axially mating turbine shafts; and further axially drawing the first and second axially turbine shafts towards each other so as to cause the splines of the first turbine shaft to engage the splines of the second turbine shaft.

15. The method defined in claim 14 , wherein providing an alignment slot comprises providing an enlarged end segment to loosely receive the guide pin after the splines of the first and second mating turbine shafts have been engaged.

16. The method defined in claim 14 , further comprising providing a lead end on the first turbine shaft, the lead end extending axially forwardly of the splines of the first turbine shaft, and wherein the alignment slot is defined in the lead end.

17. The method defined in claim 14 , wh

Assignees

• Pratt & Whitney Canada

Inventors

• Vinski Johnny
• Durocher Eric

Classifications

• F16D2001/103

  the torque is transmitted via splined connections · CPC title

• Y10T29/49895

  Associating parts by use of aligning means [e.g., use of a drift pin or a "fixture"] · CPC title

• F05D2250/11

  triangular · CPC title

• F02C7/36

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• Y10T403/7032

  including a means, e.g., spring biased portion, for misalignment correction · CPC title