US874993A

US874993A - Bucket for turbines.

Info

Publication number: US874993A
Application number: US32521906A
Authority: US
Inventors: Walter F Rice
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1906-07-09
Filing date: 1906-07-09
Publication date: 1907-12-31
Anticipated expiration: 1924-12-31

Description

U'Niraiu srarns ienrnnr onnion,

WALTER F. RICE, OF QUINCY, IVIASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEWy YORK. v

BUCKET FOR TURBKN'ES.

specification of Letters Patent.

Patentecl Dec. 31, 1907.

i Application filed July 9` 1906. Serial No. 325.219'

chusetts, have invonted certain new and use-I ful' Improvements in Buckets for Elastic- Fluid Turbines, of which the following is a specification. I

This invention relates to elastic fluid turbines, and one object thereof is to provide an im roved mode of 'unitin separately forme buckets to a suitable ase or support, either movable or stationary.

A further object is to unite-said buckets to the cover, which incloses their outer ends to guide the motivefiuid and also to prevent leakage thereof. It has been proposed to connect buckets to their base or othei` su port by casting the latter about the shan s of the buckets, so that the two parts will be fused together.l By my invention I not only fuse the buckets to their base or other support, but I also connect them mechanically in order to guard against the possibilityi of a bucket. getting loos`e because it has been imerfectly fused.

Wing to the thinness of the cover, it is impracticable to effect a fusion with the buckets when it islcast thereon. I, therefore, provide for a mechanical interlock between the cover and the buckets when the casting is done. Thisis effected by grooving, slotting, recessing, perfo'rating, or otherwise treating the outer ends of the buckets so as to form Shoulders or abutments transverse to the longitudinal axi's of the bucket, whereby when the Icover is cast the molten metal will fiow under said Shoulders or abutments and form a mechanical interlock therewith when it cools.

In the aceompanying drawing, Figure 1 is a section of a portion of a bucket-wheel and buckets embodying my invention, taken in a plane of revolution on the line 1-1, Fig. 2; Fig. 2 is a 'section in an axial plane on the line'2-2, Fi 3; and Fig. 3, is a ``Vcross-section on the line 3-3, Fig. 2, the `cover bein absent.

The buclet wheel or other support carries one or more segmental bases 2, which have flanges 3 fitting against the'sides of the Wheel, and provided with lips and entering apropriate grooves in said wheel to resist t e centrifugal force ,develo ed at high speeds. The bases are secure to the Wheel by rivets 5 which pass through the fianges on the other whe counter-sunk 'lush with the surface of the flanges to reduc'e rotationlosses.

The buckets 6 are of the customary shape, being lune-shaped in cross-section and spaced apart to leave a passageway 7 between them for the steam ;to flow through. ends ofthe buckets are perforated or slotted, and the perforations or slots are all alined so that a connector, such as a rod or cable 8, canbe threaded through them. The outer ends of the buckets are provided with a shoulder, formed, for example, by a groove, slot or recess 9. The buckets are made of a selected alloy and preferably formed by extruding said alloy through a die. lAfter being cut to the proper length, lfinished, bored or slotted at the base, and. slotted or recessed or otherwise shouldered at the outer end, a plurality of them is threaded on a connector of suitable length and laced in a ,mold,

,where they are careful y and accurately spaoed by suitable devices. Molten metal, preferably an alloy similar to that from which the buckets are made, lis then oured into the mold, forming the segmental ase .or other support 2 and a cover 10. The metal of the base or support extends outwardly along the buckets to a point beyond the connector 8, enters the holes in the inner ends of the buckets and fillsithe s ace between the walls of said holes and t le connector. A.

and have their heads.

The innercable is preferred as a connector because the helical grooves between the strands afford an excellent opportunity for the inolten metal to pass through the holes. The ends of the buckets enveloped by the melted metal are fused so that when properly done a perfect union is formed between the buckets and the base or support. Should the fusion be faulty from some unforeseen or unpreventable reason, the connector will hold the 'bucket in place, its shearing strength being far in excess of any strain tending to pull the bucket from its place. As a usual thing, the connector itself .is partly or wholly fused to the base and to the buckets.

The metal forming the cover is not sufiicient in quantity to effect a complete fusion of the buckets therewith, but it enters the grooves, slots or other shoulder-forming portions of the bucket, and thus insures' a firm mechanical interlook between said cover and the buckets. The cover is made unusually thck and strong, .havingplenty of stock forf machining in the operation of truingupithel completed Wheel. The base a'nd the cover project slightly beyond the buckets, so as to protect the sharp edges of the latter When the parts are handled m assembling, and also v to guard them 'from rubbing against the intermediates or'other stationary elements of the machinevtwhen it is running. It is evi- 'buckets b dent that''the cover may bel secured to the a connector, in addition to'the shouldere interlock, if desired and also that .the shouldered interlock may be used to assist in holding the bucket to thebase, as an additional precaution in case of' faultyfusiom A cast-on cover affords several points of advantage in economy and ease of construction. When a 'separate cover strip is used,

'tenons must becut on the buckets, and the strip must be punched to receive these tenons, and this Work must be very accurately done to avoid' springing the buckets out of place whenthe cover 'strpis fitted on. 'The tenons'must be headed down, and it is diflicult to do this evenly and regularly.` Moreover, as above pointed out, the cast-on cover can bemade much thicker andstronger than the punched sheet metal cover.- The casting re resent t -ratus shown is only illustrative, and that the i invention can be carried out b other means. What I claim as new, andl esire to secure by Letters Patent of the United States,;is,-

1. In an elastic fluid turbine, the combination with separately formed buckets, of a connector passing throu h the same, and a mass of metal cast on sai buckets.

' 2. In an elastic fluid turbine, the combina- 'tion With separately formed buckets, of a connector passing throu h the same, and a mass of metal .cast on sai buckets and fused thereto., t

tion withseparately formed .buckets, of a .connector passing. through the same, and a mass of metal cast on said buckets and fused theretoand to said connector.

4. in an eiasac-fiuid turbine', the'mbination with separately-formedbuckets, of a'- connectorpassing through their ends, and a mass of metal cast thereon and extending beyond said-connector.

5. In an elastic fluid'turbine, the combina- 3. In an elasticfluid turbine, the 'combina-l tion With separately' formed buckets, of a v cable passing through their'ends, and a support cast thereon and enveloping said 'ends i a 765 6. In an elasticfluid turbine, the'combination with separately formed buckets, of' a. base and a cover both cast thereon, 'and a and said cable.

connector passing through said buckets.

7. In anelastic fluid turbine, the combination with separatelyformed bucket's, of a .base and a' cover both cast thereon,l and 'a connector passing through said buckets and enveloped by the cast metal;

8. In an elastic fluid turbine, the combina-v tion withl separately formed'buckets', of a cover cast thereon vand mechanically interlocked therewith. i

9; In an elastic fluid turbine, the combination withseparately formed buckets, of a cover cast thereon and mechanilly interlocked therewith,` and a base cast on and fused to said buckets. 1

10. In an elastic fluid turbine, the combination with separately formedv'buckets having shouldered ends, of a cover cast thereon and interlocking With said Shoulders;

11. In an elastic fluid ,turbine,` the combination with separately'formed buckets', of a connector 'passing through them near one end, a base cast on and 'fused to saidbuckets' and enveloplng said connector, and a covel` cast .on and mechanidally interlocked with said buckets.

In witness Whereof, I have hereunto set my handthis 5th day of July, 1906. t

- WALTER F. RICE Witnesses: (JARL l 0. THoMAs' SAMEL T. MAC UANIE.