US 2402418 A
Description (OCR text may contain errors)
June 18,1946. R. P.-KROON 2,402,418
' TURBINE APPARATUS Filed Jan, 20, 1943 -nt u- 2 WK 25 Her Morn/E 19 III FLUID JIZ I Z4 Jill Z! v Fig. 1
INVENTOR' W EEm/quT R KeooAf 1- BY whiz ATTORNEY Patented June 18, 1946 Application January 20, 1943, Serial No. 412.957
This invention relates to power plants and particularly to the stationary nozzle structure of a gas turbine and it has for an object to provide an improved device of the character described. It is desirable that gas turbines start quickly requiring high temperatures to bring the unit up is Claims. (o1. ease-1s) with and supports combustion ofa mu, tn hot to speed with theresult that the turbine issubjected to a rapid increase in temperature and attendant expansion or the turbine parts. In contrast to steam turbines, changes in load on gas turbines are normally accompanied by changes in temperature of the motive fluid entering the turbine.- Hence, sudden and largetemperature variations.
The blades'on the turbine rotor are, of course,
free to expand longitudinally into the clearance space provided in the casing. However, if the stationary guide vanes are welded or fixed to the turbine casing structure, rapid heating of the vanes and the surrounding parts may cause substantial differential expansion and set up very high stresses which may result in cracking of welds and rupture of the vanes or ofthe supporting structure.
It is, accordingly, a further object of the invention to provide an improved turbine in which stresses between the stationary guide vanes and compressed air and products of combustion serving to drive the turbine. A power plant of this character is shown in my copending application Serial No. 474,093, filed Januarylifl, 1943, and assigned to the assignee of the present invention.
The turbine, generally indicated ll, comprises an outer casing structure I I, which, wifli an inner supporting structure, generally indicated l2, provides an annular passage B for the flow of the heated motive fluid. The motive fluid is by nozzle vanes 14 against turbine blades Ii ofa turbine wheel IS. The turbine wheel is carried .on a shaft I! which is journaled inthe inner sup-' 15 porting structure l2, as by means of a hearing ll.
- The nozzle vanes II are supported in the turbine casing by means of concentric rings I! and 2| carrledby the structures H and i2, respee-. tively. These rings are provided with radially aligned holes 22 and 23 of a shape eorrupon l to the cross section oi the vanes. 'fiiese holes may be punched in the rings and serve as mortises .in which the ends of the guide vanes are slidably received. The vanes Il may be inserted their supporting structure, due to rapid temperature changes, is substantially eliminated;
These and other objects are effected by the invention as will be apparent irom the following description-and claims taken in connection with the accompanying'drawing, forming a part of this application, in which: 7
Fig; 1 is a longitudinal sectional view of the stator and rotor .section of a turbine in which thepresent invention has been incorporated;
Fig. 2 is an enlarged view of the stator shown in Fig. 1;
Fig. 3 is a view taken substantially on the line IIIIII of Fig. 2 and shown on an enlarged scale;
Fig. 4 is a sectional view taken on the line IVIV of 1; and,
Fig. 5 is an elevational view or an outer guide vane ring, as seen substantially on the line V-V of F18. 4.
The turbine shown in the drawing may be of any type, although the present invention is particularly suitable for use in a gas turbine wherein a heated motive fluid, suchas hot compressed air, serves to drive the turbine. For example, air may .be compressed in a compressor, driven by the turbine, and heated in a suitable combustion substantially in the rings i9 and 2| and the assemblyplaeed in the turbinewiththe rings seated in recesses 24 provided in the structures II and 2. The rings may then be fixed to the structure in any suitable manner as by welding or peening. The
'80 mortise openings 22 and 23 inihe ruins hold :the vanes at the proper angle to direct the hull! against the turbine blades "and substantially prevent lateral movement of the vanes. How- ,ever, the vanes are free to move longitudinally a5 in the openings. Thus, during rapid temperature apparatus in which the'compressed air is mixed 6 While the invention has been variations, the ends or the vanes may move, as shown by the broken lines 22 in Figs. 2 and 3, in'to clearance spaces 25 and 2! provided between the ends of the vanes and the structures II and I2 and prevent stresses from being developed between the vanes andtheir supporting structure.
A small clearance may be provided at 28 between the nomle vanes and the walls of the holes on the supporting n es. so that the vanes are able to distort in bending, without setting up end of the guide vanes in'the supporting rings.
if desired, the vanes may be fixed, as-hy'welding.
at one end to one of the rings llpr 2i, tlmspenmitting expansion and contractim of the vanes in the openings of the other ringr 1 shown in but 3 one form, it will be obvious to those skilled in the art that it isnot so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.
What is claimed is:
1. A turbine comprising an outer casing structure, an inner supportingstructure spaced from said casing and defining therewith a passage for the flow of motive fluid, a first ring member secured to the inside of said outer casing structure, a second ring member secured to said inner supporting structure and arranged substantially concentric with respect to said first ring member, said ring members having a plurality of circumferentially-spaced holes therein, and guide vanes extending across said passage for guiding said motive fluid through said passage, the end portions of said'vanes being received in said holes in said first and second ring members and both end portions of said vanes being free to move longitudinally in said holes.
2. A turbine nozzle ring comprising a. pair of ring members disposed in spaced, concentric. relation, a plurality of guide vanes carried by said ring members and extending between them, and means connecting the ends of said vanes to the rings, said connecting means fixing said vanes in definite circumferentially-spaced relation while permitting limited longitudinal movement of both ends thereof. Y
3. A supporting structure'for a nozzle vane for turbines or the like in which the-parts are subjected to temperature changes, comprising spaced supporting members fixed relative to each other, said members having holes therein, and vanes extending between said members with both ends of the vanes slidably received in said holes whereby said vanes and supporting members may expand or contract due to temperature changes therebetween a passage for the flow of motive fluid, vanes extending across said passage for guiding said fluid through said passage, said members having holes therein to slidably receive the end portions of said vanes, said holes being of a shape corresponding to the cross section of and receiving the ends of said vanes to substantially preventdateral motion while permitting longitudinal movement of each end of said vanes in said holes.
6. In a turbine, a casing, a rotor having a row 'of blades, said casing including inner and outer annular structures having exterior and interior cylindrical surfaces, respectively, at the inlet side of said blades and spaced radially to suit the height of the latter, a row of nozzle vanes extending radially between said surfaces and each having a length which is slightly less than the radial distance therebetween, means for retaining said vanes in circumferentially-spaced relation and comprising inner and outer rings having openings conforming to the section of and receiving the ends of the vanes so that such ends thereof without exerting excessive stresses beare capable of sliding in the openings; said outer ring fitting the interior cylindrical surface of the outer annular structure and said inner ring fitting the exterior cylindrical surface of the inner annular structure, and means for securing the rings in place with respect to the annular structure.
'7. A nozzle structure for turbines or the like comprising a pair of ring niembers disposed in spaced concentric relation, and a plurality of guide vanes carried by said members and extending between them, said pair of ring memfbers being formed with radially-aligned holes of a shape correspondingto the cross section of the end portions of said guide vanes, and said guide vane end portions being received in said holes for limited longitudinal movement of each end portion thereof.
8. A turbine or the like comprising an outer casing structure, an inner supportingstructure spaced from said casing and defining therewith a passage for the flow of fluid, a first ring member secured to the inside of said outer casing structure, a second ring member secured to said inner supporting structure and arran ed substantially concentric with respect to said first ring member, said ring members having a plurality of circumferentially-spaced holes therein, and guide vanes extending across said passage for guiding fluid through said passage, the end portions of said vanes being received in said holes in saidfirst and second ringmembers and both end portions being slidable longitudinally therein.
REDIOUT P. KROON.