US1081443A

US1081443A - Elastic-fluid engine.

Info

Publication number: US1081443A
Application number: US69134212A
Authority: US
Inventors: William A Godfrey
Original assignee: BF Sturtevant Co
Current assignee: BF Sturtevant Co
Priority date: 1912-04-17
Filing date: 1912-04-17
Publication date: 1913-12-16
Anticipated expiration: 1930-12-16

Description

W. A. GODFREY. ELASTIC FLUID ENGINE. AYPLIOATION FILED APR.17, 1912.

Patented Dec. 16, 1913.

2 SHEBTS-SHEBT 1.

ww M W. A. GODFREY. {ELASTIC FLUID ENGINE.

APPLIOATION FILED APR.17, 1912.

- Patented Dec. 16, 1913.

Wa'imecsaecs.

WILLIAM A. GODFREY, 0F BOSTON, MASSACHUSETTS, ASSIGNOR TO B. F. STURTEVANT COMPANY, 015 BOSTON, MASSACHUSETTS, -A CORPORATION OF MASSACHUSETTS.

ELASTIC-FLUID. ENGINE.

Specification of Letters i 'atent.

Patented Dec. 16, ia1a.

To all whom it may concern.-

Be it known that I, WILLIAM A. GODFREY,

a citizen of the United States, residing at through the Wall of the casing which holds the elastic fluid under pressure.

One object of the present invention is to produce a stufiing box surrounding the shaft where it emerges from the engine casing which will follow the lateral movements of the shaft relatively to the casing.

Another object of the present invention is to so mount the stufling box on the engine casing that, the stuffing box will act as a relief valve when the pressure in the casing becomes excessive.

With the above objects in view, the present invention relates to the elastic-fluid engine hereinafter described and particularly pointed out in the claims.

Referring to the drawings; Figure 1 is a vertical sectional view of an elastic-fluid engine of the steam turbine type in which is embodied the preferred'form of the present invention; Fig. 2 is an enlarged vertical section showing the stuffing box and its mountings in more detail, and Fig. 3 is a view taken on the line 33 of Fig. 1 showin the outer efid of the stufling box.

eferring to the. drawings, the elasticfluid engine is a steam turbine of the impulse type in which steam is expanded in nozzles, is delivered at high velocity to the turbine buckets and then escapes at low velocity and pressure into an exhaust chamber surrounding the bucket wheel. The turbine comprises a rotor and a stator. The rotor comprises a bucket wheel 4 and a supporting shaft 6. The stator comprises a casing indicated generally by reference numeral 8 forming an exhaust chamber 10 around the bucket wheel 4. The casing 8 is made up of two castings 12 and 14 respectively, which are bolted together around 3 her 10.

their peri heries to form the exhaust chamhe steam from the boiler passes throu h the throttle and emergency valves 16 an 18 respectively which are controlled by governor mechanism 20, and enters an annular steam chamber 22, which distributes the steam to the nozzles 24. The steam is expanded in the nozzles 24 and is delivered at high velocity and low pressure to buckets milled in the periphery of the bucket wheel 4 and return buckets formed integral with the nozzle members. The steam is discharged from the buckets at exhaust pressure into the'exhaust chamber 10 from which it passes through an exhaust opening 26 to a condenser or the like. The shaft 6 is supported in bearings 30 and 32 which are mounted on brackets 34 and 36 which are cast integral with the side plates 12 and 14 respectively of the turbine casing. The center parts of the side plate castings 12 and 14 are somewhat concave to reduce the size of the exhaust chamber near the center of the bucket wheel. Openings 40 are left through the side plates for the passage of the rotor shaft 6. Over the mouths of the openings 40- are secured, by means of screws 42, flatannular metal plates 44 which have openings 46 therein ofa diameter less than the diameter of the openings 40 but somewhat greater than the diameter of the shaft 6. Rings 48 of suitable packing interposed stufling box 50 has a laterally extending flange 54 on its inner end. The inner face of the flange 54 is cut away somewhat at 56 so that an annular bearingfsurfacei58 is left to bear against the face of the plate 44. The annular bearing surface 58 is ground againstthe plate 44 with emery to form a steam tight ground joint 59-between the stufling box 50 and the outer surface of the plate 44.

The packing 52 is compressed by means of.

a gland which comprises a follower 60 and ring, the two halves of which are held assembled by means of a spring wire clip a screw cap 62. The follower 60 is a split 64.' The screw cap 62 is formed in two parts held to ether by bolts 66. The screw cap.

. the shaft.

Holdin means is provided for seeuring each stu 'ng box to the casing 8.- The holding means has provision for permitting the stuifing box 50 to float or slide laterally on the plate 44, so that the stuflin box may follow the lateral movements of t e shaft 6 relative to the casing 8, and also has provision for permitting the stuflingbox to be moved outward against a yielding tension so that it may act as a relief valve in case the steam pressure in the exhaust chamberbecomes excessive. The holding means comprises studs 70 screw-threaded into the casin and passing through stud-receiving ho es in the flange 54, and helical compression springs 72 surroundin the studs 70 and acting to hold the stufling li against the plate 44. The stud receiving holes in :the flange 54 are provided with cupped. bushings openings there n somewhat larger than the diameter of the studs so that the stuffing box 50 is allowed a limited lateral sliding movement with relation to the casing, and the ground joint 59 forms a sliding joint be- '78 respectively which form a ments for the outer ends of the'springs 72. The springs 72 hold each stuflin box 50 'tween the stuffing box .and casing. The

outer cuppedends of the bushings 74 form abutments for the springs '72. The outerends of the studs 70 are screwrthreaded-to receive adjusting and locking nutil76 I:nd

jus'ta e'a utyieldingly against the casing so t at when there is suflicient steam pressure against the inner end of the stufling box, the spring 72 will yield and the two faces of the ground joints will separate, allowing the steam to escape betweenthe outer face of the annular plate44 and the inner face of the flange 54. In this connection it is to be noted that the openings 46 through the plates 40 are somewhat smaller than the openings 40 through the casting pieces .12 and 14. The effective pressure of steam against the stuflingl boxes is therefore reduced, so that the tota pres-- sure at any time against either one of the stuflingboxes is equal to the pressure of steam'per unit area times the area of the opening 46.v B making the area 46' (30111, paratively smal the springs 72 which hold the two faces of the ground joint together need not be made very stiff. If for any reason the pressure in the exhaust chamber 10-becomes abnormally great, the pressure of the steam through the annular openings 46 against the stufling boxes will be suificient to overcome the springs 72 and thestuflingox 50 yieldingly' 74 having stud receivingg small boxes 50 will act as relief valves for the exhaust chamber 10.

Since the two surfaces of the ground joint 59 between each late 44-.and stufling box 50 have a limited s ding movement, it is evident that the stufling box will follow any lateral movements of the shaft 6, whether caused by bodily displacement of the shaft 6 due to a shifting'in position of the bearings 30, or to any eccentricity in the shaft itself.

ticularly important when a metallic packing is used. In steam turbines similar to'the turbine illustrated in Fig. 1, and provided with stufiing boxes rigidly bolted to the ,cas-- ing it has been found that, when steam the parts of the castings 12 and 14 which made up-t he side plates of the casing 8, ex-

panded more rapidly than the brac ets 34 and 36 which held the shaft bearings 30 and- 32. The result was that the stufling boxes.

metallic packing were lifted relatively to the shaft 6. The metallic packcontaining the ing is sufliciently unyielding so'that a'small leakage space was left between the top of the packing and the shaft through which the exhaust steam escaped, and the shaft ground against the bottom of the packing. After the turbine had been running for some time the brackets 34 and 36 became heated by conduction and in expanding lifted the shaft 8 was first admitted in starting the turbine,

The use of the floating stuifing box is parbearings 30'and 32 so that the shaft 6 was lifted to approximately the same position relative to the stuflingboxes as it had when thegtu'rbine-was cold. It was found, however,- that the shaft 6 grinding against the bottom of the packing during the startof the turbine was suflicient to wear a leakage space in'the packing, so that the exhaust steam escaped between the bottom of the shaft and the packing. The above mentioned difficulty has been entirely obviated by the floating stufling box 56 of the resent invention, which allows the packlng 52 to follow the shaft 6 as it moves relatively to the side plates of the turbine casing dce either to the unequal expansion of'the parts of the stator or .to any other cause. Moreover, it is found "that if the shaft 6 is slightly eccentric, the stuflin' box 50 will float relatively to the casing and follow the eccentricity of the shaft. The floating stufling box greatly lengthens the life of the metallic packing and insures that a steam-tight packing around the shaft is maintained very much longer than it has been found possible to maintain a steam tight packing with a stufling box bolted rigidly to the casing.

While in the preferred embodiment of the present invention, annular bearing plates 44 are interposed between the stufing boxes 50 and the casingcastings 12 and 14, it will be evident that the stufling'boxes may be mamas 1 held to form a sliding joint directly against the casing castings without the mterposi tion of an intermediate plate or plates. or may be mounted in any other suitable manner, so that they may follow-the lateral movements of the shaft relative to the easing. While the present invention has been illustrated as embodied in a steam turbine, nevertheless it is evident that thefioating stufiing box of the present invention may be employed to pack a shaft extending through any diaphragm or partition upon opposite sides of which a difference of pressure'is maintained, and the term elastic-fluid-engine as used in the specification and claims, is intended to define any apparatus in which an elastic fluid is employed and is confined within a chamber through the wall or walls of which is passed a movable member or 'shaft capable of either rotary or reciprocapresentinvention has-been specifically illus-f trated and described it is to be understood, however, that the present invention is not limited. to the details of construction hereinbefore set forth, but may be embodied in other structures within the purview of the following claims.

I claim- 1. An elastic-fluid engine having, in combination, a casing for'holding fluid under pressure, a. movable member extending through an opening -in the casing, and means for forming a fluid-tight joint around the movable member including a stufing box mounted on the casing, and means for. supportingthe 'stufing box so as to-permit 'it to move bodily with respect to the casing,

substantially as described.

2. An elastic-fluid engine, having, in combination, a movable shaft, a casing for holding the elastic fluid underpressure having in one ofvits walls an opening for the passage of the shaft, a stuffing box forholding a fluid-tight packing around the shaft, and

means for securing the stufling box to the casing haying provision for a limited lateral bodily movement of the stufling box relatively to the casing so that the stuflingbox may follow the lateral movements of the shaft relative to the casing, substantially "as described. I a Y 3. An elastic-fluid engine, having,in co bination, a movable shaft,;acasing for bolding theielastic fluid under,- j ressure having one of its. walls an opening for the pasa sage of the shaft and having a smooth surface around the mouth of the opening, a stufling box for holding a fluid-tight packing around the'shaft having a cooperating smooth surface adapted to fit agamst and form a fluid-tight sliding joint with the surface around the opening, and means for securing the stuifing box to the casing with the two smooth surfaces in sliding contact to permit the stufiing box to follow the lateral movements of the shaft relative to the casing, substantially as described.

4. An elastic-fluid engine, having, in combination, a movable shaft, a casing for holding the elastic fluid under ressure having in one of its Walls an opening for the passage of the shaft and having a smooth surface around the mouth of the opening, 'a stuffing box for holding a fluid-tight packing around the shaft having a cooperating smooth surface adapted to fit against and form a fluid-tight sliding joint with the surface around the opening, and means, including a spring, for securing the stuffing box to the casing with the two smooth surfaces in sliding contact to permit the 'stufing box tofollow the lateral movements of the shaft relative to the casing, substantially as de scribed. 7

. '5. An elastic-fluid engine, having, in com bination, a movable shaft, a casing for holding the elastic-fluid under pressure having in one of its walls an opening for the passage of the shaft and having a bearing surface around the mouth of the opening, a stuffing box for holding a fluid-tight packing around the shaft having a cooperative bearing surface adapted to fit against and form a fluid-tight joint with the bearingsurface on the casing, and means for securing the stufiing'box to the casing with the two ed on the casing and acting as a relief valve 1 when the pressure in the casing becomes excesslve, substantially as described.

bina'tion, a movable shaft, a casing for holding the elastic fluid under pressure having in one of' its walls an opening somewhat larger than the sh'aftfor the passage of the shaft, a stufling box for holding a fluid-tight packing around the shaft, including aspring .and means for securing the stufiing box to 7. An elastic-fluid engine, having, in com- .5

the casing'having provision for a relative relative to the casing and having provision I for a movement of the stufling box away from the casing against the force of. the spring so that the stufling box may act as a relief valve when the pressure in the casing becomes excessive, substantially as described.

8. elastic-fluted engine, having, in 'cc-mbinatlon, a movable. shaft, a casing for holding the elastic fluid under pressure having in one of its walls an opening for'the passage of' the shaft somewhat larger than the shaft andhaving a smooth substantially plane surface around the mouth of the openin one of its walls an opening somewhat s5, ing, a stuffing box Ior holding a fluid-tight- Iceived through openings, in the stufling boxspring to oerinit the escape of the fluid ing, a stuffing box for holding a fluid-tight packing around the shaft, having a cooperating smooth surface adapted to fit against and form a fluid-tight sliding joint with the surface around the opening, and means, in-f eluding a spring, for securing the stufling box to the casing with the two smooth surfaces in sliding contact to permit the stuffingbox. to follow the lateral movements of the shaft relative to the casing and having provision for the separation of the faces of the sliding joint against the pressure of the from the casing when the ,pressure in the casing becomes excessive. v v

'9.- An elastic-fluid engine, having, incombination, a movable shaft, a casing-for holding the elastic fluid under pressure having larger than the shaft for the passage of the shaft and having a smooth substantially plane surface around the mouth of the openpacking around the shaft having a coiiperating smooth surface adapted to fit against and form a fluid-tight sliding joint with,v the surface around the pening, and means, in-y eluding studs secure to the casing,1and re-- of somewhat greater. diameter of the studs and springs,'for securing the stufling box-to the casing with the two surfaces of the joint in] 'sliding1- and, in: yielding engagement, whereby the vstufiing box may follow the lateral m'ovementsgof the shaft relative to the I described.

against the; pressure of as a. relief valve when;

combination, a movable shaft, ac

holding the elastic fluid under Pressillohfllcasing, and may move away. from the casing he' sprmgs to act casing becomes excessive, substantially as 1 An elastic fluiden'gm asingl for Y ingan opening in one of its wallsg forthe passage of the-shaft, a plate secured to the casing around I the mouth of said; opening having an opening therein, for the; passage 1 I of the shaft somewhat larger than the-shaft ing around he shaft having a smooth surand having a smooth outer bearingsurface, a ,stufling box for holding a fluid-tight packpressure 1n the the lateral movements of theshaft relative to the casing and to move away from the basing against the pressure of the springs in the casing becomes. excessive, substantially as described.

bination, a movable shaft,. a casing for holding the elastic fluid having in one'of its walls an opening for the passage of the shaft mouth of the opening, holding a fluid-tight packing around the face fitting against and forming a fluidtight sliding joint with-the the opening, I and meansfor securing the stufling box toqthe casing with the two smooth, fl

permit the stufling box to slide laterally shaft relative to the casing, substantially as described.-

binaticli, a movable sha t, a casing for hold-- ing the elastic fluid having in one of its walls an opening 1 having a smooth-, flat surface around the mouth of the opening, holding the fluid-tight packing around the face fitting against and forming a fluidtight sliding joint withits s urfacearound the opening, and means including a' spring for securing the stufling box to with'the twosmooth, flat surfaces in sliding contact to permit the stuffing box to move laterally and follow the lateral ovements ofthe shaft relative to the casin .tially as described.

a .a shaft, a-stufling boxfor hail ng-g; tight packing around-gj-the. sha ft,;'= and for securing the stu'fli'ng boxvjitoyth having provision {for holding th sufling box against rotation relatively to :the."casing ingjoint with the surface of the\ joint in sliding and yielding engagement so that the stufling box is permittedto follow and act as a relief valve when the pressure" and having a smooth, flat surface around the a stufling box for f s 12. An elastic-fluiden 'ne having, com- I of. a diameter somewhat greater than. the

strings surrounding the studs and pressing for securing the stufling "11 A nelastic-fluid engine having, in com- 7 shaft having-a coeperating smooth, flat sursurface around t surfacesin-sliding contactto v and. follow the lateral movements of the for the passageof the shaft'anda stufling box for r shaft having a cooperating smooth, flat sur-" the casing 11 ubstanif "13. An elastic-fluid enginehavingin com- I bina tion, a movable shaft, a casing forrfholding the elastic fluidhavin n zon'e ofqlt's walls -an'open'ing for, th e 'of".' he' 5 the fluid means asing.

but'permitting a li mite'd liltferal movem ent of the stuflingboxj' -relatively to; the casing 14. An elastic-fluid engine having, in combination, a movable Shaft, a casing-for holding the elastic fluid having in one of its walls an opening for the passage of the shaft and having a smooth surface around the mouth of the opening, a stuffing box for holding a fluid-tight packing around the shaft having a cooperating smooth surface adapted to fit against and form a fluid-tight sliding joint with the surface around the opening, and means for securing the stufling box to the casing with the two smooth surfaces in sliding contact having provision for holding the stuffing-box from rotation relative to the casing but permitting the stuffing box to follow the lateral movements of the shaft relative to the casing, substantially as described; a

15. An elastic-fluid engine having, in combination, a movable shaft, a casing for holding the elasticffluid having in one of its walls an opening for the passage of the shaft and having a smooth, flat surface around the mouth of the opening, a stufling box for holding a fluid-tight packing around the shaft having a cooperating smooth, flat surface fitting against and forming a fluidtight sliding joint with the surface around the opening, andfmeans for securing the stufling box to; the casing with the tWo smooth flat surfaces'in sliding contact hav-' ing provisional-for holding the stuffing box from rotation relative to the casing but permitting thestufling box to slide laterally on the casing and follow the lateral movements of the shaft relative to the casing, substantiallyas described.

'LWILLIAM A. GODFREY.

Witnesses:

' OLIVER D. BENTLEY,

LEO I. SMITH.