Hook ring segment for a compressor vane

1. A compressor stator vane assembly comprising:

a plurality of vanes, each vane having an airfoil and an attachment wherein the attachment has a first surface and a second surface spaced a distance from the first surface, extending between the first surface and the second surface is a pair of generally parallel sidewalls and a forward wall and an aft wall, with the forward and aft walls generally perpendicular to the plurality of sidewalls, the forward wall having a forward channel and the aft wall having an aft channel;

a forward hook ring segment having a generally circumferential length and axially extending hook; and

an aft hook ring segment having a generally circumferential length and axially extending hook;

wherein the forward hook ring segment and aft hook ring segment are pressfit into the forward channel and aft channel of each vane attachment, respectively, so as to join the plurality of vanes together to form the vane assembly.

2. The vane assembly of claim 1 wherein the first and second surfaces of the attachment are generally parallel.

3. The vane assembly of claim 1 wherein the first and second surfaces of the attachment have a radius of curvature.

4. The vane assembly of claim 1 wherein the forward and aft channels have a generally “C” shaped cross section.

5. The vane assembly of claim 4 wherein the forward and aft channels are generally arc-shaped.

6. The vane assembly of claim 5 wherein the forward and aft hook ring segments are generally arc-shaped.

7. The vane assembly of claim 6 wherein the pressfit of the hook ring segments into the forward and aft channels creates 0.000-0.0005 inches of interference between the hook ring segments and the attachment.

8. The vane assembly of claim 1 wherein the hook ring segments dampen vibrations from the plurality of vanes.

9. The vane assembly of claim 1 comprising five individual vanes.

10. The vane assembly of claim 1 wherein a gap is maintained between adjacent attachments of the plurality of vanes.

11. The vane assembly of claim 1 wherein the forward hook ring segment and aft hook ring segment further comprise an Aluminum Bronze coating applied to a surface of the hook ring segment that contacts a compressor casing.

12. The vane assembly of claim 11 wherein the vane assembly is positioned within the compressor casing by the hooks on the forward hook ring segment and aft hook ring segment.

13. A method of forming a compressor stator vane assembly comprising:

providing a plurality of vanes, each vane having an airfoil and an attachment wherein the attachment has a first surface and a second surface spaced a distance from the first surface, extending between the first surface and the second surface is a pair of generally parallel sidewalls and a forward wall and an aft wall, with the forward and aft walls generally perpendicular to the plurality of sidewalls, the forward wall having a forward channel and the aft wall having an aft channel;

providing a circumferentially extending forward hook ring segment;

providing a circumferentially extending aft hook ring segment; and

inserting the forward hook ring segment into the forward channel and inserting the aft hook ring segment into the aft channel.

14. The method of claim 13 wherein inserting the hook ring segments into the channels of the attachment creates 0.000-0.0005 inches of interference between the hook ring segments and the attachment.

15. The method of claim 13 further comprising the step of coating at least one surface of the forward hook ring segment and aft hook ring segment, not in contact with the attachment, with an Aluminum Bronze coating.

16. The method of claim 15 further comprising inserting the vane assembly within a compressor casing by the hooks on the forward hook ring segment and aft hook ring segment.

17. A method of modifying individual vanes into a compressor stator vane assembly comprising:

providing a plurality of vanes, each vane having an airfoil and an attachment wherein the attachment has a first surface and a second surface spaced a distance from the first surface and generally parallel thereto, extending between the first surface and the second surface is a pair of generally parallel sidewalls and a forward wall and an aft wall, with the forward and aft walls and the side walls being generally perpendicular to the first surface and second surface, and having a forward hook and an aft hook that are generally parallel to the first and second surfaces;

providing a circumferentially extending forward hook ring segment;

providing a circumferentially extending aft hook ring segment;

machining the sidewalls of the attachment such that the sidewalls are oriented at an angle relative to the second surface, and removing the forward hook and aft hook by machining a forward channel having a radius of curvature into the forward wall and machining an aft channel having a radius of curvature into an aft wall; and

inserting the forward hook ring segment into the forward channel and the aft hook ring segment into the aft channel.

18. The method of claim 17 wherein inserting the hook ring segments into the channels of the attachment creates 0.000-0.0005 inches of interference between the hook ring segments and the attachment.

19. The method of claim 17 further comprising the step of coating at least one surface of the forward hook ring segment and aft hook ring segment, not in contact with the attachment, with an Aluminum Bronze coating.

20. The method of claim 17 further comprising inserting the vane assembly within a compressor casing by the hooks on the forward hook ring segment and aft hook ring segment.