Bucket for the last stage of a steam turbine

• US 5,299,915 A
• Filed: 07/15/1992
• Issued: 04/05/1994
• Est. Priority Date: 07/15/1992
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Ruggles, Steven G., Dinh, Cuong V.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US07/913,352
• Time in Patent Office: 629 Days
• Field of Search: 415/181, 416/189 R, 416/190, 416/191, 416/192, 416/194, 416/195, 416/196 R, 416/223 A, 416/DIG. 2, 416/DIG. 5, 416/193 A
• 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 5/225 by shrouding
• CPC Class Codes: F01D 5/24 using wire or the like
• CPC Class Codes: F01D 5/3023 of radial insertion type, e.g. in individual recesses
• CPC Class Codes: Y10S 416/02 Formulas of curves

Abstract

A last-stage steam turbine bucket having a profile according to Charts I-XXXXI of Table I.

The bucket is divided into a number of profile sections each of which is a predetermined radial distance from the root section. Each point on a profile section at the predetermined radial distance from the root is defined by an X-Y coordinate and a radius R along the arc of a circle connecting adjacent points.

Claims

1. A bucket for a steam turbine having a profile in accordance with Charts I-XIX;

XXI-XXXIX; and

XLI inclusive of Table I.

2. The bucket according to claim 1 having a theoretical aerodynamic profile according to Chart XX of Table I.

3. The bucket according to claim 1 having a theoretical aerodynamic profile according to Chart XL of Table I.

4. The bucket according to claim 3 having a theoretical aerodynamic profile according to Chart XX of Table I.

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

6. The buckets according to claim 5 including a plurality of inner covers connecting the tips of adjacent pairs of buckets one to the other and a plurality of outer covers connecting adjacent ones of adjacent pairs of said buckets one to the other and in radially overlying relation to said inner covers.

7. A plurality of buckets according to claim 6 including a sealing rib projecting radially from said outer covers forming an annular sealing ring about the tips of said buckets.

8. A bucket according to claim 1 wherein said bucket has a root connected to a dovetail, said dovetail having a projection and a corresponding recess on circumferentially opposite sides thereof.

9. A bucket for a steam turbine having a profile in accordance with the Charts I-XVIII;

and XX-XL inclusive of Table 1.