US1998951A - Nozzle diaphragm - Google Patents

Description

A ril 23, 193 5. J. M. DOWNER 1,998,951

NOZ ZLE DIAPHRAGM Filed Nov. 15, 1955 lnvehtor: John M. Downer,

HIS ttcprney.

Patented Apr. 23, 1935 UNITED STATES NOZZLE DIAPHRAGM John M. Downer, Schenectady, N.

General Electric Company, a

New York 1, amino:- to corporation of Application November 15, 1933, Serial No. 898,089

The present invention relates to nozzle diaphragms such as are used in elastic fluid turbines for properly directing elastic fluid discharged from' the outlet side of one turbine wheel into the inlet of another turbine wheel. These nozzle diaphragms usually comprise an inner disk to which a plurality of blades, defining nozzle openings between them, are, fastened and an outer ring for holding the outer ends of the. blades.

together and for supporting the diaphragm on the stationary turbine casing.

One object of my invention is to provide an improved construction of nozzle diaphragms of the type above specified forming a rigid and safe structure which can be manufactured at comparatively low cost.

Another object of my invention is an improved method of manufacturing such nozzle diaphragms.

For a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto in connection with the accompanying drawing which forms apart of my specification.

In the drawing, Fig. 1 illustrates a perspective view of a nozzle diaphragm, partly broken away, in accordance with nrv invention; Fig. 2 is a development of a sectional view through the nozzles of the arrangement shown in Fig. 1; Fig. 3 shows a perspective view of the nozzle blade; and Figs. 4 and 5 show two steps in the manufacture of a modified form of my invention.

The nozzle diaphragm illustrated in Figs. 1 and 2 comprises an inner disk ill which may be made of rolled plate or other material and is provided with an annular projection or rim II. This projection may be formed by machining the circumferential portion of the disk or other desirable method. A plurality of blades i2 are fastened to the disk which at their outer ends are held together by means of an outer ring i3. The intermediate portions of the blades are s aced apart to define nozzle openings through which elastic fluid to be conducted from one turbine stage into a lower turbine stage passes. In the manufacture of the blades I form a bar of rolled material, as indicated in dotted lines I in Fig. 3. The front face ii of the block is curved in accordance with the curvature of the blade. The lower end of theblock is recessed to define two legs I 8 and I! which when assembled straddle the projection ii on the.,disk. The upper end of the blade is also recessed to define a central projection I! which when assembled enters an annular groove in the ring it. In addition, the upper portion is provided with grooves II and 2| adjacent the projection i8. Projections 2i formed adjacent the groove of the ring it enter the grooves I! and 20 respectively. A portion 5 '22 on the rear side of the block is removed to provide a nozzle opening. It will be readily seen that the recess and removed portions define lugs 23 and 24 at one side and lugs 23a and 24a at the other side. These lugs act as spacing mem- 10 bars between adiacent blades.

In the arrangement shown in Figs. 1 to 3 the blades are rigidly secured to the disk and the ring by means of rivets 25 and 20 respectively. Each inner rivet 25 projects through a rivet hole 18 25a of the lug 23, through the rim ll, through a rivet hole 251) of the lug 23a and finally through a rivet hole 250 in the forward edge portion of an adjacent partition. The rivets thereby do not only secure the blades to the rim of the disk 20 but they also fasten the blades directly to each other.

Whereas I have shown in Figs. 1 to 3 an arrangement in which the. blades are fastened to the disk and the rim illustrated in Figs. 4 and 5 another arrangement in which the blades are fastened to one of said members by another method which will be presently described. The arrangement in Figs. 4 and 5 comprises an inner disk 30, a plurality of blades 30 3| having projections 32 located in an annular. recess in the disk and fastened thereto by means of rivets 33, and an outer ring 34 having a recess 35 for receiving a projection 36 of each blade. Before assembly, as shown in Fig. 4, the outer 35 projections 36 have recessed or concave side faces 31 and 38 respectively,and the ring has outwardly curved or convex side faces 39 and 40 respectively. The ring is fastened to the projections 38 by forcing or pressing its sides inwardly into engagement 40 with the concave faces of the projections 31, as shown in Fig. 5. This process of uniting the parts is usually termed cold-pressing or forming.

Having described the method and the apparatus according to my invention, I wish to have it understood that changes may be made in both the apparatus and the method without departing from the spirit of my invention and the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a nozzle diaphragm, a disk, a plurality of blades defining nozzles and being fastened to the disk, each blade having inner and outer lugs integrally formed with the blade and engagin an by means of rivets, I have 25 i adjacent blade, an outer ring having a groove the blades to each other and to the disk, each receiving a projection oi each blade. and rivets blade having inner and outer lugs integrally for securing each blade to the disk and to an formed with the blade and enzaginz an adjacent adjacent blade, each rivet projecting through a blade, and an outer ring having a groove receiv- 5 lug o! a blade, 2. portion of the disk and a portion in: a projection of each blade and bein: Iastened 5 of an adjacent blade. to the blades by a forming process.

2. In a nozzle diaphragm, a diet, a plurality 0! blades defining nozzles, means to: fastening JOHN 1L DOWNIR.

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