US2143467A - Turbine diaphragm - Google Patents

Description

Jan. 10, 1939. A. R ALLARD TURBINE DIAPHRAGM Filed Jan. 26, 1938 Fig.2.. WITNESSES: FQYM INVENTOR ARTHUR R. HLLHRU.

cbl I ATTORNEY Patented Jan. 10, 1939 UNITED STATES PATENT OFFICE TURBINE DIAPHRAGM Arthur R. Allard, Drexel Hill, Pa., assignor to Westinghouse Electric & Manufacturing Com- D l-1y, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 26, 1938, Serial No. 188,951

4 Claims. (01. 253-78) My invention relates to fluid turbines and more particularly to an improved diaphragm construction therefor.

An object of my invention is to provide apparatus of this character fabricated from standard parts and welded together to form a unitary construction.

In accordance with the invention, there is provided a diaphragm comprised of an inner memher having grooves extending transversely of its periphery, blades mounted in the grooves and extending radially therefrom, and an outer member forming a ring-like structure at the outer ends of the blades.

This and other objects are eiiected by my invention as will be apparent from the following description and claims taken in accordance with the accompanying drawing, forming a part of this application, in which:

Fig. i is a perspective view of one form of my invention;

Fig. 2 is a similar view of another form thereof;

Fig. 3 is a perspective view of one of the elements forming the outer ring of the structure of Fig. 2;

Fig. 4 is a similar view of a blade;

Fig. 5 is a perspective view of the elements of Figs. 3 and 4 united as by tack welding;

Fig. 6 is a view similar to Figs. 1 and 2 but showing a further modification of the invention; and,

Fig. '7 is a sectional view showing a preferred manner of attaching the assembled diaphragm to a support, such as the casing of a turbine.

In the drawing, there is shown a diaphragm element ill or 20 having grooves II or 2i in its periphery, and in which are mounted blades i2 or 22. At the outer ends of the blades is a ringlike member [4 or 24 comprised by separate sections spacing the outer ends of the blades, and united in end-to-end arcuate relation to form a unitary outer member.

In the form of the invention shown in Fig. 1, an inner member ill of disk-like shape, and preferably of plate material, has provided in its periphery grooves l l extending entirely thereacross, and receiving the root portions of blade elements l2. Each groove has one side wall shaped to continguously engage the adjacent face of the blade therein, and the grooves are of a width greater than the width of the blade root portions, whereby spaces are provided between the other side walls of the grooves and the other faces of the blades, for the reception of weld metal l3, which weld metal, together with the blade root portions, completely fliis the grooves, and provides autogenous connections of the blades l2 and the inner disk-like member II).

An outer arcuate member ll of composite character is provided at the outer ends of blades 12. This outer member is comprised by spacing sections or blocks l6 of arcuate shape, each section being integrally formed at the outer end of a blade member. One end of each spacing section comprises, in effect, an unbroken continuation of a face of the blade with which it is integral. The opposite end of the spacing section is shaped to abut the end surface of the next adjacent spacing section. This opposite end of the section has its vertical edges beveled, as at H, and preferably, also has its upper horizontal edge beveled, as at [1a, to provide recesses for the reception of weld metal Hi, the weld metal autogenously connecting the spacing elements to one another to form the arcuate outer member i4 and to prevent leakage of steam at the joints.

In the construction shown in Figs. 2 to 5, the disk. member 20 has formed in its periphery grooves or recesses 2| corresponding generally to the grooves ii of Fig. 1, but differing therefrom in that they do not extend entirely across the periphery to the sides of the disk. The recesses 2i are of a shape similar to the section of the root portions of the blades 22 to be received therein, and the side walls of the grooves contiguously engage the faces of the blade root portions.

As best shown in Figs. 4 and 5, the thin tail edge portion of the blade root portion is relieved or cut away as at 22a whereby a root portion section is provided, for which the recess 2| can be satisfactorily machined.

The outer edge of one side wall of each recess 2! is beveled at 2i a to provide a groove for the recep'tion of weld metal 23, which weld metal autogenously connects the blades 2| to the disk member 20. The bevels at the outer edge of one of the faces of the recesses 2| extend beyond the tail end portion of the recesses, whereby the grooves provided for .the reception ofweld metal extend substantially the full width of the blade faces.

In this form of the invention, the outer ringlike member 24 is formed by separate spacing elements 26 located between and spacing apart the outer ends of the blades 22. Preferably, each element 26 is temporarily united with a blade element 22, as by tack welding, as at 21, prior' to assembly of the blades in the recesses. As best 6|- shown in Fig. 2, the blocks 26 extend transversely of the disk 20 and blades 22 such a distance that they project beyond the adjacent edges of the blades and preferably beyond the ends also, to provide recesses 28 and 28a at the vertical edge and at the top respectively of each bladefor the reception of weld metal 29, which weld metal forms autogenous connections, not only of the blocks to one another in end-to-end relation, but also of each block to its adjacent blades, and prevents leakage of steam at the meeting faces of the blocks and blades.

The form of my invention shown in Fig. 6 diners from that of Figs. 2 to 5 only in that the attachment of block 26 to the blade 22 prior to assembly vof the latter, is omitted and, instead, the blades are first assembled and afterwards the blocks are placed therebetween at the outer ends thereof. In this arrangement, the blocks may be temporarily held in position in any desired manner until the weld metal 29 has been applied. The blocks 26 may be of such dimensions that they will be held in place solely by friction with the adjacent blades, prior to final welding.

InFig. 7, I have shown one manner of attaching the completed diaphragm to the turbine casing. In this construction, a ring 3| is provided having an internal diameter such that the assembled diaphragm structure may be received therein with the outer periphery of the diaphragm outer member 24 closely fitting the inner surface of the ring 3|. This ring 3| is fixedly secured to the casing of the turbine in any well-known manner. The outer ring-like member 24 of the completed diaphragm and'the inner surface of the ring 3| may have the edges of their contacting surfaces-beveled to provide recesses 32 for the reception of weld metal 33, which weld metal autogenously connects the completed diaphragm assembly to the turbine casing.

From the foregoing, it will be seen that I have provided apparatus of the desired nature which may be easily and accurately assembledfrom standard parts.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. A turbine diaphragm construction comprising an inner disk-like member having an arcuate periphery and provided with grooves extending transversely of said periphery, blades extending radially outwardly from the periphery of the inner member and having root portions in the grooves, weld metal in the grooves adjacent the blade root portions for autogenously connecting radially outwardly from the periphery of the in-.

ner member and having root portions in the,

grooves, weld metal in the grooves adjacent the blade root portions for autogenously connecting the latter to the inner member, and an arcuate outer member comprised by arcuate sections integral with the outer ends of the blades and having radially extending end surfaces, one of said end surfaces constituting an unbroken continuation of a face of the blade with which it is integral, and the second end surface being shaped to abut the end surface of the next adjacent arcuate section, said second end surface being beveled at its vertical edges to provide channels for the reception of weld metal, and weld metal in the channels autogenously connecting the arcuate elements in end-to-end relation to form the arcuate outer member.

3. A turbine diaphragm construction comprising an inner disk-like member having an arcuate periphery and provided with grooves extending transversely of said periphery, blades extending radially outwardly from the periphery of the inner member and having root portions in the grooves, weld metal in the grooves adjacent the blade root portions'for autogenously connecting the latter to the inner member, and an arcuate outer member comprised by arcuate sections spacing apart the outer portions of the blades and weld metal between adjacent surfaces of said spacing sections autogenously connecting them to the blades and to one another.

4. A turbine diaphragm construction comprising an inner disk-like member having an arcuate periphery and provided with grooves extending transversely of said periphery, blades extending radially outwardly from the periphery of the inner member and having root portions in the grooves, weld metal in the grooves adjacent the blade root portions for autogenously connecting the latter to the inner member, an arcuate outer member comprised by arcuate sections positioned between the blades at the .outer ends of the latter with the sides of the arcuate sections contiguous to the faces of their adjacent blades and the ends of the arcuate sections projecting beyond the edges of their blades to provide recesses therebetween for the reception of weld metal, and weld metal in the recesses autogenously connecting the arcuate sections together and to the blades therebetween, to form the arcuateouter member.

' ARTHUR R. ALLARD.

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