Bucket for the last stage of a steam turbine

• US 5,267,834 A
• Filed: 12/30/1992
• Issued: 12/07/1993
• Est. Priority Date: 12/30/1992
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Dinh, Cuong V., Ruggles, Stephen G.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Lee, Michael S.
• Application Number:
  US07/996,926
• Time in Patent Office: 342 Days
• Field of Search: 416/191, 416/193 R, 416/223 A, 416/DIG. 2
• US Class Current: 416/223.00A
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• CPC Class Codes: F01D 5/22 Blade-to-blade connections, e.g. for damping vibrations
• CPC Class Codes: F05D 2240/301 Cross-sectional characteristics
• CPC Class Codes: Y10S 416/02 Formulas of curves

Abstract

A last-stage steam turbine bucket having a profile according to Charts II-XIII, XV-XXVII and XXIX of Table I.

Claims

1. A bucket for a steam turbine having a profile in accordance with Charts II-XIII, XV-XXVlI and XXIX inclusive of Table I.

2. A plurality of buckets constructed in accordance with claim 1 spaced circumferentially about an axis of a turbine wheel and having tips, and means for continuously coupling said tips one to the other about said axis.

3. The buckets according to claim 2 wherein said coupling means includes a tip trapezoid for each bucket and a cover intermediate the tip trapezoid of next adjacent bucket tips, and means for connecting the tip trapezoid and the intermediate covers one to the other.

4. A plurality of buckets according to claim 3 including a sealing rib projecting radially from each said tip trapezoid and intermediate cover forming an annular sealing ring about the tips of said buckets.

5. A bucket according to claim 4, wherein said connecting means between adjacent tip trapezoid and intermediate covers is loose, enabling relative movement between adjacent buckets.

6. A bucket according to claim 3, wherein said connecting means includes a first loose connection between each said tip trapezoid and an adjacent intermediate cover in one direction about the turbine wheel enabling relative movement between adjacent buckets and a second rigid connection between each said tip trapezoid and an adjacent intermediate cover in the opposite direction about the turbine wheel.

7. A bucket according to claim 6, wherein said first connection includes an opening in each said tip trapezoid and a tenon carried by an adjacent intermediate cover for reception in said opening, said second connection including an opening in each said tip trapezoid and a tenon carried by another next adjacent intermediate cover for reception in said second connection opening.

8. A bucket according to claim 2 including means along intermediate portions of the lengths of aid buckets for loosely coupling adjacent buckets one to another.

9. A bucket according to claim 8 wherein said coupling means includes projections on opposite sides of each bucket and a sleeve between each bucket and engageable with said projections.

10. A bucket for a steam turbine having a profile in accordance with the Charts II-XIII and XVI-XXVII inclusive of Table I.

11. A bucket according to claim 10 having a profile in accordance with Chart XV.

12. A bucket according to claim 10 having a profile in accordance with Chart XXIX.

13. A bucket according to claim 10 having a profile in accordance with Charts XV and XXIX.

14. A bucket according to claim 10 having a profile in accordance with Chart I.

15. A bucket according to claim 14 having a profile in accordance with Chart XV.

16. A bucket according to claim 14 having a profile in accordance with Chart XXIX.

17. A bucket for a steam turbine having a profile in accordance with Charts I-XIV and XVI-XXVIII inclusive of Table I.