Turbine segmented cover plate retention method

Patent metadata

Field	Value
Publication number	US-9803485-B2
Application number	US-201314103106-A
Country	US
Kind code	B2
Filing date	Dec 11, 2013
Priority date	Mar 5, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

An improved gas turbine cover plate assembly is disclosed for use in connection with segmented cover plates in turbine configurations where it is not possible to stagger the blades to create assembly clearance. The improved turbine assembly also avoids cover plate loading slots in the disc which can cause high stress features. The improved system also includes a method to axially retain segmented cover plates in relation to a turbine disc using a segmented retainer ring.

First claim

What is claimed is:

1. A gas turbine engine disc and cover plate assembly comprising:
a turbine disc having a first groove and a retaining arm including a radially extending portion;
a turbine blade having a second groove;
at least one segmented cover plate having an upper end and a lower end, the at least one segmented cover plate dimensioned such that when the upper end is positioned within the second groove the lower end clears the first groove;
at least one retainer member positioned within the first groove of the turbine disc below the lower end of the segmented cover plate such that the at least one retainer member is positioned against the bottom of the first groove and the radially extending portion, the retainer member having a contact surface comprising a notched portion for retaining the lower end of the segmented cover plate in place relative to the turbine disc such that the segmented cover plate is secured between the first groove and the second groove; and
at least one smash plate positioned within the first groove of the turbine disc;
wherein axial retention of the turbine blade relative to the turbine disc is aided by the smash plate; and
wherein the notched portion is configured to force the at least one segmented cover plate into the second groove and inwards against the turbine blade.

2. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the turbine disc includes an axially extending groove, said axially extending groove extends axially and is operable to receive a portion of the turbine blade.

3. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the first groove extends circumferentially substantially around a perimeter of the disc.

4. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the retainer member extends below the lower surface of the segmented cover plate such that the segmented cover plate and the retainer member consume substantially all of the space that exists within the first groove of the turbine disc.

5. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the smash plate is collapsible between a first position and a second position.

6. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the retaining member is a segmented ring, the segmented ring and cover plate operate to secure the blade and disc relative to one another.

7. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein a plurality of retaining members are positioned a various locations about a circumference of the assembly.

8. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the notched portion is arcuate shaped.

9. The gas turbine engine disc and cover plate assembly as claimed in claim 1 , wherein the upper end of the at least one segmented cover plate comprises an arcuate portion positioned within the second groove, the arcuate portion cooperating with the at least one retainer member to generate the inward force.

10. A disc and cover plate assembly for a turbo machine comprising:
a turbine disc having a first groove and a retaining arm including a radially extending portion;
at least one cover plate having an upper end and a lower end;
a turbine blade having a second groove; and
at least one segmented retainer member positioned within the first groove of the disc and extending below the lower end of the cover plate such that the at least one segmented retainer member is positioned against the bottom of the first groove and the radially extending portion, the segmented retainer member having a contact surface comprising a notched portion for retaining the cover plate in place relative to the turbine disc;
wherein a combined dimension of the cover plate and the at least one segmented retaining member comprise a length between a first groove and the second groove; and
wherein the notched portion is configured to force the at least one cover plate into the second groove and inwards against the turbine blade.

11. The disc and cover plate assembly as claimed in claim 10 , further comprising a smash plate that is positioned within the first groove of the disc.

12. The disc and cover plate assembly as claimed in claim 10 , wherein axial retention of the turbine blade relative to the turbine disc is aided by a smash plate.

13. The disc and cover plate assembly as claimed in claim 10 , wherein the segmented retaining member is a ring.

14. The disc and cover plate assembly as claimed in claim 10 , wherein the segmented retaining member is L-shaped in the end view.

15. The disc and cover plate assembly as claimed in claim 10 , wherein the cover plate is segmented.

16. The disc and cover plate assembly as claimed in claim 10 , further comprising a plurality of cover plates and segmented retaining members that are positioned around the perimeter of the assembly.

17. The disc and cover plate assembly as claimed in claim 10 , further comprising a gas turbine engine.

18. A method of assembling a cover plate to a gas turbine engine disc comprising the steps of:
a. providing a disc including a disc groove and a retaining arm including a radially extending portion;
b. providing at least one segmented cover plate;
c. providing a blade including a blade groove;
d. providing at least one segmented retainer ring;
e. providing at least one smash plate;
f. inserting one segmented cover plate into place within the blade groove, the segmented cover plate dimensioned to clear the disc groove;
g. inserting a segmented retainer ring into the disc groove adjacent to the segmented cover plate such that the segmented retainer ring is positioned against the bottom of the disc groove and the radially extending portion;
h. sliding the segmented retainer ring into a position beneath a lower end of the segmented cover plate such that the segmented cover plate is secured between the disc groove and the blade groove by engaging a notched portion of the segmented retainer ring, the notched portion configured to force the segmented cover plate into the blade groove and inwards against the blade;
i. continuing inserting segmented cover plates and segmented retainer rings until a predetermined number of spaces for segmented cover plates remain;
j. arranging the cover plates and segmented retainer rings such that the predetermined number of open spaces that remain are located to a preferred location; and
k. inserting a smash plate in each open space.

19. The method of assembling a cover plate to a gas turbine engine disc as claimed in claim 18 , further comprising the step of removing smash plates, removing the segmented retainer ring and removing the cover plate.

Assignees

• Rolls Royce Nam Tech Inc

Inventors

• Snyder Brandon R

Classifications

• B23P15/04

  turbine or like blades from several pieces · CPC title

• F05D2230/60

  Assembly methods · CPC title

• Y10T29/49321

  Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member · CPC title

• F01D5/326

  Locking of axial insertion type blades by other means · CPC title

• F01D5/3015 Primary

  with side plates · CPC title