US843237A - Steam-turbine. - Google Patents

Description

PATENTED FEB. 5, 1907.

2 SHEETS-SHEET 1.

F. D. SHEPHERD. STEAM TUREINE.

APPLICATION FILED MAR. s1. 1906.

PATENTED FEB. 5, 1907.

F. D. SHEPHERD. STEAM TURBINE.

APPLIOATIQN FILED MAR. s1. 190e. A

2 SHEETS-SHEET 2.

I 5mm/woz @LLM/L i7 @MAQ/WM abbr/mwa:

UNrrED srAirEs PATENT OFFICE.

FRANK D. "sHEPHEFn-OF SALT LAKE eiTY, UTAH.

STEANIQTURBINE.

S'peeieation of Letters Patent.

Patented Feb. 5, 1907..

Application filed March 31, 1906'. Serial No. y309,219.

Be it known that I, FRANK D, SHEPHERD, of Salt Lake City, in the county of Salt-Lake and in thel Siate oiUr-ah, have invented a certain new and useful' Improvement in Steam-Turbines; and I do hereby declare that the following is a full, clear, and` exact description thereof, reference being had to the accompanyingy drawings, in Which-.

.i Figure-1 is a vertical longitudinal section4 of a steam-turbine embodying my invention; Fig. 2, a cross-section on Athe line 2 2 of Fig. 1,' Fig. 3, a detail view in lperspective of a "portion of one of the blade-carryingdisks and one of the `blades detached therefrom,

and Fig. 4 a siniilar view of a portion of one of the blade-carrying rings.

The object of myinvention is to so improve i the construction of steam-turbines as to en? able the utilization of the maximum proportion of the energyof the steam and to [simplify and cheapen the cost of building;

and to attain these objects'of efficiency and economy my invention consists in the turbine constructed substantially as hereinafter specified and claimed. l

In making my invention I have improved upon the turbine ol my Patent No.755,062,

Aissued March 22, 1904, and in the einbodiment of my invention which I have selected for illustration the turbine is a compound one of two main stages and comprising a shaft, tovvhich runs from the throttle-valve a port or passage d for the supply of steam to such annular channel for delivery to the'highpressure cylinder, and contiguous to and concentric with said ysteam-channel the steam- 4 chest has an annular groove or recess d in its side next the `higli-i ressure cylinder for the n reception ot' aj ring that contains the guide ports prnozzles for the delivery of steam into the .h1ghpressure cylinder. The ring conlar K screwed thereon.

forms in shape to the recess, and its lit is so close thereto thatuwhen it is pressed into thel cavity it will tit the same steam-tight, andit is Isecured in place therein by an inwardlyturned flange c on the-high-.pressur'e cylinder,

. which overlaps the outer side of thelring. The

ports or nozzles h of the ring H are made with square corners, and their'delivery ends are as Wide or substantially as Wide -radially as the Width radially ofthe blades 'i of the iirst disk I, into which said ports ornozzles discharge,

as a result of which construction there are no dead spaces and the formation of eddy-currents in the steam which results in friction and loss of energy. There is a series of disks Imounted side by side upon the shaft F and v i keyed thereto, and all except the last or outermost disk have a'` thickness axially double the length axially of their eripheral blades t, and by this construction avoid the use of separate blank or blinddisks7 such as I employed' in the turbineof my patent above referred to, this combining in asingle disk of the blade-carrying and blank or blind disks, not only resulting in a stronger construction, but one reducing the cost of construction. and assembling by reason of the reduction ofthe number of pa'rts. In like manner the rings J, which carry the guide-blades j, that project radiall r in alinement with theportion of the disk Ihaving no blades, comprise'in a single piece the blade-carrying member and the `blank or blind member opposite the diskblades 'i With the like advantage of economy of construction. The last or outermost disk .of the `series at its periphery is only wide enough in an axial direction to accommodate its blades i, and saiddisk is used as a rotorcap for the series of disks, the shaft contiguous to said last disk beingthreaded and a col- 'Ihat at one endengagessaid last diskand serves to clamp the series of disks against a shoulder f onthe shaft formed by the enlargement ofthe portion thereof Within the steam-chest. The

collar 'or nut K is prevented from becoming loose 'on the shaft byradial set-screws vc,

whose inner ends impinge on the thread and are of some soft vmetal to'prevent marring of the thread bycontact therewith, and between the collar or nut and theadjacent cylinder, head there is afriction-ring L, encircling the shaft which maintains the disks, and conse-` quently their blades inproper relative position, and' prevents the blades cutting into eachother. The use of the last disk of the series as a cap simplifies and cheapens the construction, and for a like reason the last ring Jyof the series is engaged by the inner ends of a ring-form flange e, projecting inward from the cylinder-head, said flange exteriorly fitting the cylinder. By making the flange integral With the head instead of separate therefrom the construction is cheapened and there is also the advantage that the shaftopening through the head .is accurately alined. Toprovide for-the expansion of the steam as it traverses the cylinder by increasing the length of the blades, which increase in length is from each velocity and pressure stage to`the next-succeeding one, the disks are successively reduced in diameter and the rings are successively increased in diameter, a seat for each ring being provided in the cylinder by boring the latter, and, as Icombme tWo rings in one, this expedient economizes in cost of construction by reducing the num- .ber of bores of the cylinder. Each ring is securely held in place against rotation by a radial screwl M,fastened to the cylinder-Wall from the outside thereof and entering at its inner end a recess or cavity in the ring.. The ring at the steam-inlet end of. the cylinder abuts against the cylinder-flange a.

The blades both for the disks andthe rings have each a shank or tenon 10 at the inner end ofwhich is a cylindrical enlargement 11, and in each disk or ring, as the case may be, there is a radially-extending slot 12, whose inner end is enlarged by a cylindrical opening, so that the slot conforms in shape and size to the shank o'r tenon of a blade, the

blade shank or tenon being vslid endWise into said slot. The advantage of this construction is cheapness of manufacture, because the cylindrical enlargements of the radial s'lots can be bored in. the disks and rings on a drilling-machine and the remainder of the slots cut out in a slotting-machine, and the shanks or tenons can be accurately and yet cheaply made by a punching-machine. It will thus be seen that :no hand-Work at all is required, and yet the bladeslare most accurately fitted to the'disks and rings.

The V-steam after passing the last disk in the series in the high-pressure cylinder enters a port N., that extends from that end of the high-pressure cylinder through the Wall of. the cylinder parallel With the cylinder- 'axis to and partially through the steamchest, Where it communicates with an annular channel or chamber O therein, concentric with the annular steam-chest channel or chamber G, but larger in diameter and in cross-section than the latter, but `otherwise sinilar thereto,v and delivering steam into thel low-pressure cylinder or the next main stage through a ring-P, having ports p, the

latter and the ring andthe manner of mount- 1 ing the latter being'sirrfilar ,in all respects to lthe ring II andtheconst-ruction of said next main `stage bein in all respects similar to that of thehig -pressure cylinder or the first main stage, already described, so that va specific description of said construction' is unnecessary. The form of the port' N in cross-section is, as best shown in Fig. 2, curvilinear, its curvature being concentric with. the'cylinder; and as it is contiguous to the 'steam-channel G in the steam-chest D the steam passing through said port N and into said channel O, having lost some of its temperature in its passage4 through the highpressure cylinder, will be slightly superheated as it approaches the high-pressure end of the cylinder and said steam-channel G and Will be further superheated as it passes around the steam-channel O, the Walls of the various passages referred to being kept at a high temperature by-the steam in the steam-channell G. i As Will be seen by reference to Fig. 1 of the drawings, there is an abrupt and comparatively great increase of diameter of the first disk, or the disk at the steam-inlet end of the second main stage, over the diameter of the disk at the outer or exhaust end of the first main stage, and I make this difference in diameter vbecause the velocity of the steam after it leaves the last disk of the first main stage is so great as to require thefirst disk of the second mainI stage to have such diameter as to give a substantial increase of peripheral speed to the blades thereof, such peripheral speed being a little less than the velocity of the steam impinging thereon, and the diameters o f the suceeding disks of the second main stage are such as to make the speed of the blades thereof just right with reference to the velocit of the steam, the speed of the blades of allythe disks being less than the Ivelocity of the steam. i It will be observed that the area of the blades of the first piston of the second main stage is lessA this relation of the blades of the-said first. and

last pistons I employ because thereby 'I am IOO.

les

able to utilize the steam to the best possible i advai'itagel The result is lthat the progressive changes of the pressure and velocity of the steam from the time it `enters the highpressure cylinder or the first main stage until it is readyv to leave 'the low-pressure cylinder or the last mainstage are so compensated for by changes in diameter, area, and peripheral speed of the blades' as to utilize all the energy of the steam in power ap' lied to the shaft less that lost in unavoi able friction, and loss by friction is reduced to a 1r. inirnumby giving the proper angles to the blades and by balancing the pisttns of one main stagagainst those of another. Be-

sides the waste of power, which would result by having the velocity of the-steam in excessl or' the peripheral speed of thel blades, there and provided with asuitable connection c for the attachment of an exhaust-pipe. Should I a condenser be used, it can be -built in the base, with the advantage of compactness, saving room, andalso the advantage of havingl the vacuum close tothe turbine.

.- Leakage of steam from thehigh-pressure c linder to the low-pressure cylinderthrough t e steam-chest where the shaft passes therethrough is prevented by a bushing,which for facility of construction is made of two pieces It and R,applicd to the enlarged portion of the shaft in the steam-chest, said bushing having at each of its outer ends an annular flange r, seated in an annular cavity in the side of the steam-chest provided for it, rIhe bushing tits the steain-chest'sufliciently close to have skin friction only, and when it is revolved with vthe shaft 'centrifugal force is` suflicient to maintain the joints between the bushing and the steam-chest steam-tight.

. Leakage of steam from each cylinder outward'along the shaft i'sfprovided against by the stuffing-boxes hereinbefore referred to.

vAny desired packing may be employed in these stu'fiingboxes; but I prefer thepacking shown, which consists of two sets or series of Cone packing-rings S in the stuffing .box or gland, between which is a perforated oilspool, and between the outermost cone-ring of one series and -the cap T of the gland or stuffing-box is interposed a collar U, which encircles the shaft and which by the screwing up ofuthe cap acts on the cones to expand' them, and thus tighten thepacking, as well as taking up wear and centering the shaft. I he cap T is held in the position to which it may be adjusted by a soft-pointed set-screw t, that passes radially through the cap and impinges on the thread of the gland or box on which the cap is screwed.

Each cylinder is surrounded by a jacket- U, vand they at their low-pressure ends-are provided with' vacuum *and low-pressure gages, respectively, of a very sensitive char-l acter to show theconditions of thecylinders at these points, and eachlsteam channel or chamber ofthe .steam-chest will be provided with a gage.-

A port W is provided inthe steam-chest for-the supply of steam at boiler-pressure to .the low-pressure cylinder for use in starting up the engine and also for use in' the Aemerl geney ofpan overload-being thrown on the engine, said port in the case of an overload being automatically openedthrough connections with the governor mechanism with which my4 engine isprovided, but which is not necessary to be described in this application, as it forms the subject of -a separate applicationfor patent, which I have liled.

I of course do not limit the scope of my invention to the details of construction which I illustrate and describe, as changes in' these respects may be made which will involve no departure from the scope of -my invention, nor do I limit myself to any particular number of main stages.'

Having thus described my invention, what I claimisl 1. In a turbine-engine, the combination of .a cylinder, .a piston therein having radiallyextending blades, a source of supply of'an operating fluid, such as a steam-chest, a ring having a seat in a cavityin said steam-chest concentric with the blades and provided with`ports whose dimensions at their ends adjoining or toward'the blades are the saine rings carrying guide-blades, said rings being I placed side by side in the cylinder, the series at one end abutting against `said cylinderflange, anda head at the other end of the cylinder .havin cylinder an engaging the other end of the series of rings.

3. In a turbine-engine, the combination of a cylinder, a series of blade-car@ ing disks therein, the blades occupying but a portion of each disk in an axial direction, aseries of rings in the cylinder having guide-blades that likewise extend over the respective ring only partially in an axial direction, the blades on thevrings being op osite the portions of the 4disks over which .t 1e disk-blades do not extend, and the blades of the disks being opposite the ortions ofthe rings over which the ring-bla es do not extend, a flange on thecylinder against which oneend of the series of rings abut, and a .cylinder-head havin an integral flange within the cylinder a utting against the other endof the series of rings.

4. In a turbine-engine, the combination of highpressurel and lowV pressure cylinders, and a steam-chest having an annular chamber or channel for the supply of steam tothe Ihigh-pressure cylinder,r and having an annular chamber or channel for Athe supply of an integral ilange within the steam to the low-pressure cylinder, said chambers or channels being side by side, whereby the steam in one may receive heat from the steam in the other.

' 5 5. In a turbine-engine, the combination4 of high-pressure and low-pressure cylindeis, a V steam-chest havingan annular chamber or channel for the supply of steam to the high pressure cylinder, and having an annular ro chamber or, channel for the supply of steam to the low-pressure,cylinden said chambers .Por channels being side by side, whereby the steam 'in one may receive heat froml the steam in .the other, and aport leading fiom f5 therhigh-pessure cylinder to the channel or chamber for the supply of steam to tlie.low-

pressure cylinder, said port passing contigu- Ous to the high-pressure channelaor chamber in the steam-chest.

- a plurality of main stages provided with rotating pistons, the first piston of a succeeding main stage being of substantially greater diameter than the last piston of the next pre- -.2 5 ceding stage, the pressure-receiving area of said first piston being substantially less than the pressure-receiving area of said last piston,

and a port leading fi om one stage to the neXt.

.7. In a turliine-engine, the combination of 3o a plurality of niain stages provided with r0-` ta'ting pistons, the fist'piston of a succeeding main stage being of substantially greater dianieter than the last piston of the-next pre-V ceding stage, a steam chest intermediate 3 5 the' different stages having contiguous chan? nels or chambers for the supply of steam to the respeetive stages, and a. port extending from one stage to the channel or chamber of the next stage.

8. In a turbine-engine, the combination of high-pnessure and low-pressure cylindeis, a

Wall'interposed between the cylindeis,a pis' ton carrying shaft passing through vsaid walls, and a bushing on the shaft having at 45 each end circumferential flanges engaging 6. In a turbine-engine, the combination of4 the wall, said bushing being mounted on the shaft to rotate therewith, the revolution. of the bushingl with the shaft resulting 1n the maintenanceof steam-tight joints between the bushing and the wall.

9.` In a turbineengine, the combination ofl high-pressure and low-pressure cylinders, a wall interposed between the cylinders, a piston-carrying shaft passing through said wall,

a piston-engaging shoulder on said shaft at each side of the wall, means for holding the pistons againstsaid shoulder and a bushing on said shaft having at each end circumferential flanges engaging the wall.

10. In a turbine-engine, the combination of high-pressure and low-pressure cylinders, a steam-chest between the two cylinders, a shaft passing ,through the cylinders and the stea1n-chest, -piston-disks on the portion of the shaft lin each cylinder, a bushing on the portion of the shaft within the stea1n-c`hest having circumferential flanges seated in cavities or recesses in the steam-chest, such poi'- tion of the shaftv being notched, and the shoulder formed thereby being engaged by 7o the end one of the disks in each cylinder, a

collar or nut on the shaft engaging the other end one of the disks in each cylinder, astufing-box for the shaft wherelit passes fifom v each cylinder, Contiguous, concentric chaii- 75 nels orchambers in the steam-chest for the supplyof steam t the cylinders, respectively, and a port leading. from the, high-pressure cylinder to the chamber or channel which supplies steam to the low-pressure cylinder, a base 'or bed on which the cylindeIs and steam-chests are mounted, and an exhaustport leading from' the' low-pressure ,cylinder to a chamber in said'base or bed.

In .testimony that I claim :the foregoing I 8 5 have hereunto set my hand.

, FRANK ns1-mennen `litnesses:

W. O. MQCLAIN, WILL Anims

Images