US980563A - Turbine-bucket. - Google Patents

Description

E. w. RICE, 1. TURBINE BUCKET.

APPLICATION FILED J'U'IE 28, 1909.

Patented m 3,1911

Inventor-z -WiLn eases:

,& .m a 9km .m R w.

- character of the turbine and the buckets to ceases.

' illustrative of my invention,

view in s1de elevation of a bucket segment;

both types.

STAT.

EDWIN W. RICE, JR., SCI-IENECTAIJY, NEW YORK,ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TURBINE-BUCKET.

Specification of Letters Patent.

To all whom it may concern: Be it known that I, EDWIN W. Rice, Jr., a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Turbine-Bucket Construction, of which the following is a specification. i

The present invention relates to turbine bucket construction and has for its object to provide an improved means for securing a cover orshroud to the free ends of the buckets.

For a consideration of what I believe to be novel and my invention, attention is di: rooted to the accompanying specification and the claims appended thereto. 1

In the accompanying drawing which is Figure 1 is a Fig. 2 is a'detail view showing the means for'uniting the buckets and the cover or shroud Fig. 3 is a detail view partly in section of a slightly modified form of cover securing means; and Fig. 4 is a sectional view of the structure shown in-Fig. 3, the section being taken at right angles thereto.

My invention is applicable to impulse and reaction turbines or to 'a combination of It is applicable also to the stator as well as the rotor buckets, The buckets may be mounted on a wheel, disk, drum, casing or other part. The particular means whereby they are secured. at their roots is immaterial so long as theyare securely anchored in place.

Referring to the drawing,

1 indicates a support or carrier having a plurality of radial buckets 2, whose outer or free ends are covered by the sectional cover. or shroud 3. This cover or shroud will ordinarily be made in relatively short lengths although this is a matter that depends somewhat upon the be covered.

Ihave shown the buckets occupying radial positions for use inan axial flow. machine, but where the invention .is used in avradial flow machine they would extend parallel to the shaft.

Referring to Fig. 2,2 indicates one of the buckets which at its outer or free end is provided with recess comprising an enlarged portion 4: and a restricted portion 5. By reason of this arrangement a shoulder is formed to anchor the cover securing device. The said recess, where the buckets are separate and individually applied,'will be machined before the buckets are mounted in place. lVhere the buckets are formed inte-' gral with the support or carrier, it may be formed either before or after the buckets are out. In either event the recesses extend from side to side or in other words from the front to the back face ofthe buckets. The. retaining devices will referably present smooth surfaces that lie in and form a con tinuation of the bucket'surfaces acted uponby the steamer other 'motive fluid. Mounted on the top or free ends of the buckets is a perforated cover or shroud 6 which in addition to forming one-wall of the steam space between the buckets, acts to tie the buckets together and increase their rigidity. Locaed within each recess and extending through a registering opening in the cover or shroud is a retaining device 7 vice has an enlarged head and, preferably, completely fills the recess and makes a tight fit therein. It Qis finished on the front and back and is fiush with the bucket surfaces so that in effect it forms a part of the bucket surface. The outer end of the retaining device is riveted or headed over at 8 to hold the bucket cover in place. In those cases where the centrifugal stresses are high, it is preferable to provide each of the buckets with a recess and cover or shroud retaining device, but where the centrifugal stresses are relatively' low, I may omit the recess and retaining device from a portion of the buckets. It is preferable, however, to make all of the buckets alike.

In assembling. the buckets ifmade separately are mounted on the support 1, one after the other, with suitable space blocks between them, and the buckets and blocks are retained by any suitable means. Previous to inserting the buckets in the support, each will usually be provided with a cover or shroud securing device 7 After the Patented Jan. 3, 1911.

This debuckets are mounted in place with the said fication of my invention wherein the shown a modi-. shape oftherecess in the bucket for receiving the retaining device 7 is changed. The lower 9 portion of, the recess is approximately rec: tang'ular' and shoulders 9 are provided to sesses certain a "Fig. 2 in that less depends upon the relative ,skill of the workman, it being an easy matprevent-the' retaining device from beingwithdrawnjin the'direction ofits length.

Where the buckets are relatively long and thin andthey have a tendency to spring or move sidewise in the plane of the row,-1t is necessary to provide means to tendency. Such means is foun eled projections 10 that are formed on the free. end of the bucket. These projections will'be mad evat the time the free end of therevent such bucket is machined or dressed. -'Insteadof riveting over theouter end of the retaining device as in Fig. 2, I'split it approximately in its center'so as to form two lugs 11 and 12. 'Afterthe cover or shroud 6 ismounted in place, one of the-lugs is bent in one d1rec tion and .the other in the' opposite direction as shown in Fig. 4. This arrangement posvantages over that shown in .ter to-seewhether or not the lugs properl engage the surface of the, cover or shrou .Further, the amount of stock turned over will be determined by calculation and test and little or nothing will be left to the judg- -ment of the Workman. In this case, the

cover. or shroud is'provided with openings 13 that in one dimension correspond to'that of .the retaining devices'7 ,as shown. in Fig. 4,

but in ,the'otherdimension are made somewhat longer to receive the beveled or ingclined projection or shoulders 10 of the bucket. When the lugs are properly over by hammering or otherwise to o head, the cover or shroud will be seated on g the ends of the buckets and the'projections .10 will engage the side walls of the recess in rm a ' the bucket which arrangement prevents the bucket from moving in any -direction from the normal. I

In carrying out my invention the ends of the buckets and the recesses therein will be made byspecial machinery and the retainmay also be similarly made,

ing devices thereby dispensing with hand work as far as I possible. This hasgthe advantage of reducmg the cost. and also of making the partsin- The bucket covers will be made 0 relatively thin sheet metal cut to terchan' cable.

or approximately the proper width after. which the openings to receive thesecuring device will be made by a punch-press operation. If for any'reason it becomes desirable to remove a section of the cover or shroud, it can readily" be'done by cutting off the lugs 11 and 12 with a cold chisel, after which the retaining devices 7 may be removed and new ones substituted. The old cover section or a new section can then be applied in the manner set forth above. This is of matein the bevbent tending through" the rial advantage in case the bucket cover has beenpermitted to rub .on some stationary part and has. been thereby injured. By making shoulders on the retaining devices the centrifugal strains are transmitted by them to. the buckets, the whole resulting in a strong and substantial construction. r In accordance with the provisions ofthe patent statutes, I-have described the principle of operation ofmy invention,

ratus shown is only illustrativd, and that the invention can be carried out by other means. What I claim as new'and desire to secure by Letters Patentof the United States, is

1. In a turbine the combination ,of a plurality of buckets a cover or shroud therefor, and shouldered devices separate from the buckets and anchored in their recesses for securing the cover to the buckets. I

the combination of. a pluhavmg recessed ends, a or shroudtherefor, the registering with said reretaining devices-eachoffwhich'fits into a recess and conf tends throught'a perforation and. is headed at its outer end to secure the cover'in place.

together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have itunderstood that theappa having shouldered recesses,

and means separatefrom the buckets,

orms in shape thereto, ex-

4. In a'turbine, the'com ination of a lurality of buckets having. r

w h cessed outer ends, the said recesses ber-mg shouldered and exside, a perforated cover or. shroud, retaining devices that are located in'the recesses and-.extend'through the said perforations, I each of said devices being rovidedwith a head that en ages theshoul er of the recess and is headed at its outer end to secure the cover in place.

5. Inaturbine, rality of buckets recess in its outer end, a perforated cover or shroud therefor, and retaining devices that are located in, the said recesses and-are,

'anchoredb'y the shoulders, the outer 'ends of said devices extending through the said perforations and .being bent over to secure the cover in place.

rality of buckets that have'shouldered reuckets from side 'to the combination of a plu-. each having a shouldered cesses in their outer ends, a perforated cover or shroud, and retaining devices that extend through the perforations, each of which has .7 v 1'25 6. In a turbine, the combination of a plua head on its inner end that engages the shoulder and a split outer end, the parts of which are bent over to engage and secure the cover in lace.

7. In a tur ine, the combination of a plurality of buckets that have shouldered recesses in their outer ends, a perforated cover or shroud, means for preventin the buckets and cover from moving in ependently, and cover securing means having heads at their inner ends that engage the shoulders and heads at their outer ends to engage and hold the cover.

8. In a turbine, the combination of a plurality of buckets arranged in a row and havin shouldered recessed ends, a cover or shrou therefor, devices separate from the buckets and anchored in the said recesses for securing the cover, and means for interlock ing the buckets and shroud to revent the buckets from movin in the p ane of the row independently o thecover.

9. In a turbine, the combination of a plurality of buckets, a cover or shroud therefor,

and devices for securing the cover to the buckets, each of said devices comprising a double-headed member arranged in line with the bucket, one of said heads being embedded in the body of the bucket and the other being outside of and engaging the surface of the cover.

10. In a turbine, the combination of'a plurality of buckets, a cover or shroud therefor, and devices which are anchored in the buck ets and hold the cover in place, the said devices forming a part of the surface of the bucket upon which the motive fluid acts.

In witness whereof, I havehereunto set my hand this 26th day of June, 1909.

.EDWIN W. RICE, JR.

Witnesses:

- BENJAMIN B. HULL,

HELEN Onrom).

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