US973705A - Governing mechanism for mixed-pressure turbines. - Google Patents

Description

F. -SAMUELSON GOVBBNING MECHANIBM FOB MIXED PRESSURE .TURBINES. APPLIUATIGF FILED IAB. 16, 1910.

973,705. l Pantea ot.25,191o.

2 BKEETHHEET 2.

; u l:V Y W n VM*- Figs.

go; Inventor-z F'redercKSamuelsorl b9 /ZMQM fUNiTEDsTATEs PATENT OFFICE.

FREDERICK SAMU-ELSON, OF RUGBY.- ENGLAND, ASSIGNOR T0 GENERAL ELEC'JIRICl COMPANY.' A CORPORATION OF NEW YORK..

GOVERNING MEOHANISM FOR MIXED-PRESSURE TURBINES.

To. all whom t may concern: A

Be it known that-I. FiucunlneleSurfin.- S'ON, 4a vsubject of the King of Sweden, residing at Rugby. England` have invented certa-in. new and useful Improvements in. Governing'-Mechanisms for Mixed-Pressure Turbines. of which the followingis a .specification.

The presentinventionrelates to governing mechanisms for minted pressure tur! b1nes, and-has for its object tOv nnprove their construction whereby. th'e57 are ren- .de1ed more certain -and reliable in Opera-- '-tlontjboth under normal and einerg'encjY conditions,

For a consideration of'what I conslder to 'b e novel .and my '-invention. attention is. di

rented -to the accompanying descriptions 4A.and claims appended hereto.

lIn tlie acco 1npanyin'g drawings. which illustrate one-of the-'embodiments Of-my in'- vention'jf F igure "1 is an e-nd'view of a tur- `bine -Sh'oi'vixng, certain "of the valve parts in section-[Fig. and-'theeam sh-af-tfor .actuating the high l,pressurex1ozzle val ves: Fig. 3 is a detailed viewshowing the pllot valve-for' controllingr theadinissiom of motive fluid to the motorl that. act'uates'the cani-shaft; Figjiis a de' `which i s"indic@ated at 12.'

tailed v-ieW showing a'part of the follow-up- .devicei Fi-gs. 5.and'0 are detailed views of the locking lever 'o t"4 the butterfly valve: Fig. Tis across section ofthetmotor that tnatefsi .the-camshaft., and Fig.' S ade- .tailedve-.w vof the emergency governor'.

10. indicates" the base of the machiue. vand mounted thereon is' a. turbinerasing 11. which contains as; vmany .rows of wheel` bueket's 'or 'vanesand as 1nany,nozzles or Huid dischnrgingdevlces as are'i'iecessary toV extractthe energv from the steam'or 'ed .onV a suitable shaft.. lthe reduced end, of This shaft ,is ymountedfin bearings 13,0111)Y one of which is. shown tgures.

twoindependent sources o f, the fluidl sup ply.

v'High pressulfesstealn is, admitted by thecon-l duit ll'to thehighpxessure-va-lve'chest 15.

- Low pressuie'steam 'lis' 4admitted tothe tur-1 bine byfthe conduiig *that communicates' Specification of Letters Patent.

Application filed March 1(1'` on account of the character Of the Steam, is admitted to `tlie turbine 'front utented Ovt. 55,

1910. Serial No. 549,747.

with the low pressure valve chest 1T. Steam for the high pressure service muv be received. from a boiler or other suitable source. and the steam for low' pressure niav be received from the exhaust ot'- a reciprocating engine or from an aceunmlator. or any other' suitablesource. As arrangedthe high pressure steam passes through nozzles or directing devices that are separated from the nozzles lor directing devices through .which the low'pressure steam passes.` Owing to the diference'in the volume ofthe high and low lin'essnre steam, the noz'zles for the latter-must have. -a greater cross see-- tional area in Order to' convey it.

One speed governor is employed'for eontrolling the admission of steam from both high and low pressure sources. By reason of this arrangement the apparatus is simplified and the proper sequence of operation of the various valves can be insured.' This governor. which mavbe of any suitable type.

comprises in the present instance. weightsv y,reasoi'i'that.it seems unnecessary to' a proper -understandln-gA of' 'my invention.

The speed governor-is provided with -a collar-.Q0 that moves up and. down as the weights move in and out. This collar-actuates the governor lever 2l that is pivoted toa suitable support." To the opposite end tains the adjustable coupling Q53 whereby -the length of the rod-can be adjusted. The

upper end ofthe rod is connected to the lever 2J: that actuates the pilot. 'valve'. ,-'The latter is moi-ei partieularh1 shown' inv yFig.

"of the lever is connected a rod 252. which conf' This pilot valve controls the adltnission of motive- Huid. (which may be "liquid for elastic fluid under pressure) `tothe -niotor andA is .moreparticularlyivherein' 26 is the cylinder, 27 the piston',

and 28 the fixed abutment that en ages the hub 29 of the piston. Fluid is admitted and `exhausted from ports 30 and 31, as 'will apy 36.. gt

is' admitted by the. ipe 42 to the lports 43 ton1is free 'to' escape 'through port 31 and ear later. The` piston of the motor is iieyed to the cam shaft32, the `latter heilig best shown .in Fig. 2. Formed directly on the.shaft or secured thereon is a plurality of cams 33, which are adapted to actuate fthe high pressure nozzle valves by means of the stems '134, Fig. 1. lFor thejfpurposes of description, these cam's may be termed the main'.- cams'.4 The stems 34 are suitably piclr'ed at 35 to prevent the escape of steam. The cam shaft is supported in ball bearings its ends and also at. intermediate points.'

A, Mounted on theileft-hand end of the. cam

shaft is a .pinion 3T-that meshes with a' rack 3.8,"'the latter beingsuitably guided lin its movements by the walls of the/"casing 39. Theupper end of the rack'is pivotally con'- -ne'cted to the lever 24. 'This lever is connectedby a pin with the stem 40 of the -balan'ced pilot valve 41. 'Fluid' under pressure situated between the ea'ds of the pilot valve.

The headsv o'f the valvenox'm'ally cover the .ports 44 and-.45 which communicate .with

.the ports 30 and 31 ofthe motor, Fig. 7. Assume that the governor, due to a decrease in speed of the turbine, moves the' pilot 'valve upward. This results' inopening the` port 44 and. ad1nitting high pressure fluid thereto and to the port 30, Fg.j 7, and to 4the upper side of the piston-27. The piston thenmoves in the direction indicated bythe arrow. The same movement. of. the pilot valve o ns the'port 45,-a'nd the fluid contained m the motor cylinder under the pis! i "port 45 into the passage 46, the latter be- 45. 44 when the pilot valve' is moveddownwa-rdly and the direction of-movement of g the lston 27'is opposite to thatindicatedv hy/tg I I Amg in constant communication with the ex-` haust pipe 47. AThe passa e 46A also' servesto 'convey the exhaust fluir `from' the port earrow.A Referring-again tothe movement of the pilot' 'valve rstfreferred to, z'. e., moving upward. t'- expose-the port 44 to high pressure, .the cam shaftstarts into operation and' i wardly. Since the governor has moved the- Vin'so doing, turns vthe inion 37. This move- -ment'is'communic'ate to'the jrack 3S, which under the' conditions described moves downs rodf22 to a position corresponding to the speed of the turbine,the p1vot'48F1g. 4.

now becomes the fulcrum andthe pinion 3T :moves .the left-'hand end, of .the lever 24 downwardly by` an' amount suiigient to -rel.store the "cveri' .tie ports 44 and 45."Tl1is movemeut o` the cam shaftwillopen one' or more llot valve to its norma-l position of the nozzle valvesto a greater or less extent, .de ending upon the load thrown on the tur ine. Conversely, if the load decreases -and the speed .ot the turbine increases, the .pilot valve moves in the opposite direction to'decrease the number of opennozzle valves, and the pinion 3T' moves in the. opposite ,direction tores-tore the pilot -valve'. 41 to its normal-position, where it closes the ports leading to the motor.'

The mechanism for controllingr the admission of low pressure steam from an engine, accumulator, or .other sources will now be described: Mounted lon the right-hand' end of the .cam shaft 32 and located within the housing is a cam 50 that has a cam groove 51, a portion of which is arranged 1n the form'ofa spiral, and another portion 52 is arranged in a plane perpendicular y to thev axis of the cam shaft.- For thepurpose of this description the 'cam' 50 may be termedA .the auxiliarycam.'l The reasonI or this peculiar arrangement is that for certainspeed' changes the low pressure valve only should-.move away from its seat-'nntl the maximum valve opening 'is reached, and' thereafter said low-pressure valve should be' heldstat-ionary, while'the. cam shaftcon, -tinues 'it'smovement to open the high pres. sure -nozzle 'valves one after the other. to admit high pressure steam, the latter being necessary when .the/supply of low-` pressure steam -is inadequate-' In order to-transmit the movements of the spiral cam to=-the low pressure valve an' arm '53, Fig. 2, isl pro-4 vided, having at its lower end a` pm or roller 54 that makes a snug fit with-the Walls of the groove of the spira] cam. The upper end of the arm is mounted oii fa' rock-'shaft To this rock shaft is also.' attached a'rm bell-crank lever.' The outerv end of the arm ,56 is connected byan adjustable connectingrod withV the balanced low pressure. double vseated valve '5.8, the latter being' mounted upon the stem 59.. The stem 'is provided with a long bearing surface to prevent the entrance of air or the escape of steam. The valve is provided with seats 60 and 61 that. are engaged by the upper andl lower heads of the'valve.' As the speed of Vi'oxi '56'. -F ig. 1, said arms 53 and 5(5 f6rming'a the turbine changes,due to changes in the load, valve 58 rises and falls in accordancelonger suficient to satisfy therequirements,

the. high pressure' valves begin- -to open. one

'with ythe amplitude -of-'the changes ot the speed andload, thereby hrottling the low pressure steam from the conduit 16 to va ,las

I "afteranoth'er until a balance effected betiveenth'e load requirements and thel admission ofhlgh andlow pressure steam.

lln a governing ni'echanism of this ki'nd.'it

isf essential to provide meansl for shutting vdownl the turbine when tor any reason' its act on the latch Fig'. 1. which latch engages 'a shoulder -on the. rod' (32%.' The right-hand end vof' the rod provided with alfork'ed arm G4 that is mounted on a rock shaft (35. ythc latter being "supported by'a bracket from the 'main bearing of the turbine. On theleftflia-ndend of' rod- 63 is a handle GG.' so that it can be rotated.. to free the shoulder from engagement with the llatcliT'VZ. On the roclrleliaftf is also mounted vertical rod (5S with vthe valve lever .69. The said arms'64 and 67 and shaft form fa bell-crank lever.

ofthe. high pressure emergency 'valve 72.

Between the lever 69 ano the spinoie 71 is av lcertain"tn nount off' lost motion, so'that 'a lnrmmerblow willlvbe imparted to thevalve vfor the purpose of startingit in the closing direction. Mounted on the verticalrod G8 is Van emergency motor. in this case ayveight .73, .thatutends at 'all times to close the.

.emergency valve. which tendency is 4resisted by.. the latch G21 etlects of .thesho'ek due tothe falling weight when the. .latch 69. isv released a compresfsion spring 74 isprovided thatuests at one 'and moving the rod (i3 to a ,end on a shoulder on the rod (58 and the other fend engages iveiglit.` This iveight is. intended to be resetjhyh-and. i; r. raising the rod (3S, weight. 3,lturn1ngarm (7..roek shaft (i5. arm4 G4,

the'. ,latch (Si). 'will engage the right by a spring. v The low pressure .emergency-mechanism be described :4 Mounted on'the rockv shaftis an' arm'. located .directly backlof connected toa horizontal rod 75.'. The. outerv endof this-rod is'slotted' 'to receive lthe lock.-

is 'providedon' the lever,'whereby'theklatter lever 76.

anal-111167 which is connect-ed by a The right-hand end of y the valve lever AG9 is supported 'by a link` and' attached to said lever is the-stem 71' ln order to decrear'se the may be actuated by hand if desired. lnthc4 sliding;r and swinging bar is a slot S0 to receive a pin carried by the arm 81, the latter beingr rigidly secured to .the spindle 82 of the l'mtterfly valveS-B.' On' the lower end of the bar 77- is an emergency'weight; '84, which normally tends to 'close the valve and which 'is prevented from so doing byithe locking The bar 77 is made in two parts, an upper and lower7 which are connected by the pivot that also forms a handle, Fig. The weight. H4 is spring-supported in the same manner and for the same reason as Weight 7?). Owingr to the fact. that there is a .pin and slot connection between the sliding and swinging bar 77' and the 'arm S41, when the weight 84 is released. it. will -inipart 'a hammer" blow to the butterfly valve and cause. the same to start from its position ot" rest and close promptly'.

In Fig. 5' and Fig. 6' the details o'f the locking lever 76 are more clearly. illustrated. `The Alever 7G is connected at itsright--hand a. lost-motion connection. The reason for providing the slot is to permit of resetting',r t'he bar 77 bythe handle S5, ,and also the valve 83 withoutbeingoblged tofactuate lthe rod 75 or any of the parts beyond it.. 'In other v'vords` the weight 73 is reset. by one operation, Weight 84 by another operation,-

.one .Weight is to be moved at a time. Saidpin and slot'connection also insures a. hammer lolo'v'sr for starting the parts into opera-- tion. The :locking lever 76 normally held in the position shown in-Fig. 5. by the spring 87 that isflocated'within the slot. in [Which .the left-hand end of the lever moves.

In the event of'an emergency condition, and assuming` that theemergencyugovernor. releases the latch 62, Vthe -weight 73 in falling closes the high pressure -valve 'and also :moves the' rod. 75, which in turn moves the locking. .lever 76 in the .direction to' release the emerf' the'fxvalled recess vin the' position where 4 shoulder of the' ...rod.. l'I he rod (3.is normally moved to the I gency Weighty S4, that Aactuates' the-butterflyl valve 83.

It' is to be noted that. Weights or motons are provided for each o f control ott-he weight. 73, and that both `Weights Yare controlled .by-the same einen gency governor. In "order to restore'. the.

'parts into position after the emergency op# eration. the butterfly valve is first: restored by raisingthe weight. 84 and peri'iiitng'tlie. locking lever 7.6 to snap into `place: Vthen the high pressure emergency valve' is restored -raising the Iweilgrhi; 4latch (32 to engage -thfe shoulder in' the rod 63.'

-and then Vthe high; but under cert-ain condi` .tionsthis order -inay be reyersed.

the valvesthev ,ive-ight Slis under the direct.;

I prefer 'to restore first thef-lowp1ess11'1e.\alve' end by a pin and slot with the rod 75' to form which operations' are independent, so that'v ioo whereas 'independent i .73j4 and permitting" the mechanism which is exceedinglysimple and =reliable operation.' Thefparts are very compact and relatively4 small. Each pai-t is so located tha .t.it is entirely accessibleand one part can be `adjustedor removed without` disturbing the whole' mechanism. I anialsoableto a'void.- lost motion inA those. parts whereit Would bev an undesirable factor.A

The joints between the arts are'of the sirnples't character, .and the caring surfacesamlple to prevent excessive Wear or strain.

-Byjarran 'ng'the weights 7.3'and 84 as de- I o tamthe great'advaiitage that the -governor'latcli '62 only has to support one` of...the in. VWhen' 4the weight '73 isfreleased 'it, .not", only 'closes its own valve, but, supplies 4the necessary force' to trip the locking'device of the-second weight 84. This. i .insures prompt, action 'of both emergency valvesj '.with a.' relatively .small load on the 'emergency overnor, so. that the latter will operatie wi certainty at exactlylthe'predetripping speed;

In. accordance with tlij provisionsfo'f the patent'-A statutes, 1 have described the tprinciple of operation Aof my -invention,. together Athe invention can be carried out' by other'.V

the admission of loiv pressure' tiuic 1 turbine', aniotor for actuating both of said valve means, -a speed governor' that 'controls withthe-'apparatus which I no i'v consider to paratis fSliOwn is only illustrative and 4that What I4 by Letters .Patent of the United States, is-

1.A turbine having -afconduitforsup-n plyin high4 pressure niot'ive iiuid'aiid a conduit vorsupplying low pressure motive fluid,

-.in.conibination with a. valve meansfor regu.Y

-lating the admission of high pressure iuid to the turbine, valve' means ffor regulating said valve means vandis driven by the tur- "isi,

bine,'emergency valves-'independent in action of said'regulating valves, independent motors for 'operating the emergency valves',

A4latchesfor revent'ing' both motors fr oni operatii'ig an a speed governor, 'also dri'ven by the 'tu"bine, that trips one-'latijn the other A being tripped'by one of the motors.

' supplying 2.LA turbine iaving av conduit. for supplying high 'prssure fluid. und a Aconduit for low pressure motive huid, in. combination 1with valves'for regulating. thc acl- 'missionfof high pressure fluid to lthe tur."

bine,v ac'am shaft for moving the valves, a

"motor mounted on one'cnd of the shaftfor actuating it, a low' pressure valve- 'nieclia-- nism, a' bell-crank leverandi-cd for trans .-l'nitt-ingniotion from Vthe ca ui' shaftj, to the .lowf pressure l valvemechanism, emergency yvalv'esforthe high and-low pressure. sources that are 'ar ranged. t-o close independently 'ofl re Vresent the embodiment thereof "but I have it understood that' the :ip-

to the'- .evenos the regulating valves, and an emergency 4governor that controls the emergencyvalves.

3.. A turbine having a conduit. for supplybiiiation with valve nieans for regulating the admission .of lh1 'h pressure fluid to-the a in otor mounted on' vthe shaft for' actuating Vit directly, a low'pressure valve mechanism,

`an rod actuated by the-spiral' cam for movmg the low pressure valve mechanisnn. a

gencv val-ve,- a sliding and.swinginvr rod` a weigl'iton the rod forclosing the va ve, and means' foi-'releasing thea-od and'iveight..

4. A turbine having high and-'lowpressure supply conduits, a v alve for each of the a motorl mounted 'directly on -th e', shaft-r. f or moving it, a governor or controlling' the 1 ently -of'the regulating valve', a means for imparting a ,hammer blow to said- 4valve to 'releas'in said" atcli.

' -5. ti rb'ne having high and low pressurev supply co duits, a plurality of high ressure valve's, a low pressure' valve,said va ves ac tcams for .actuating the'. high pressure'valves successively, 'an auxiliary cam which pre- 'cedesntlie in in. 'ca 'mfin its operation under conditions ci i creasing load on the turbine,` ashaft for th' camsg a.powertransmittin' the low pressure va'l've, a motor mounted directly on' the shaft that drives Iall of the ca'ins,- a spe d-igovernor forcontrolling the motor, a lov -slidin -rod'or actuating it, a locking lever. theieor,lnieans tending to hold the .locling "a s'4 iral cam driven bv the 'c'am shaft, a lever governor for the -i'notor,' abuttertiy enier vclose it suddenly,'a restraining-'latch foi-:said` means, and a' ove'rno'i" controlledf motor for' U connection between the auxiliary cam and .pi'essure' emergency valve, a'

lever inenga ement. with the' rod, and means lt e lever against tli'e-acticiiiof ves .regulatingtlicfsupply of fluid4 sure .valve or 'valves start'iiito operation uning high. pressure.4 fluid and a conduit .foi' supplying loiv pressure 'motive fiuid, incomturbine, a cam lshaft .for actuating thevalves,

'1notor, means actuated 4by. tliehcamthat is gencyl low g pressure valveactingv independin g' on the supplies from the conduits, maindeico'nditions lof' increasing load, andreas- Ato a`ii 'd, drives all of 'the cams, a governorcontrolled means .for regulating l'the action tfof the motor, 'high and' .sume its'ivork after thehigh pressure 'valve or valves are closed, a motor'that is common,

gency valves, a closing 'weight tor each valve, means actuated by one weight for releasing the other, and a governor for conti'olling the action ot' said weights.

T. A turbine having high and low pressure supply conduits, high and low pres- -sure regulating valves, means for actuating them, high and lou' pressure emergency valves, means for actuating them, and a sing'le emergency governor. that controls, the closing of both emergency valves.

8. A turbine having high and low pressure supply conduits, high and low pressure regulating valves, `means for actuating them, high and low pressure emergency valves, a'motor for each emergency valve for closin it, an emergency governor, means actuated )y the governor for releasing one of said motors, and a device actuated by'one motor for releasing the other.

SLA turbine havinghigh and low pressure supply conduits, high and low pres-A sure regulating calves, high and low pressu're emergency valves, motors tor actuating them that tendat all times to move thevalves, a governor controlled latch that 'preventsI one of the. motorsfrom operating. a

governor forreleasin'g said latch which is responsive to an al'mormal condition of op?.

eration. and a lostanotion device operated lh v..tv|;\e til-st motor for releasing the second.

lt). A turbine having high and low pressure supply conduits, vhigh and low pressure regulating valves, high and loiv pres sure emergency valves therefor, a means for holding the high pressure emergency valve in its open position, a means for holding 'the lovv pressure emergency valve in its -open said device.

close the en'rergency valves, a locking device' for the motors,

and a -governor foractuaf ing sure supply conduits, high and low pres` sure ,emergency valves therefor, a motor for actuating the high pressure valve, a motor for actuating the low .pressure valve, a lock restraining the low pressure valve from operating, a `power transmitting agent between the motor that operates the high pressurel valve ,and the lock, and a lost-motion device insaid agent. i

13'. In a governor mechanism, the combination .of a motor, a -shatt'-drivtn thereby, a. pilot valve ior controlling.,r the movements of the motor piston, a governor, a .lever that is attached to the pilotl valve and is vmoved by t'he governor. and a follow-up device .'for the pilot valve comprising a pinion driven by the motor` and afrack meshing therewith which is attached toithe lever andauider certain conditions holds one end ot' the lever stationary and at other times moves it.

, In witness whereof, I have hereunto set my hand this 10th day of )'Iarch,15)10.l

FREDERIC-K SAIUELSOX.

BENJAMIN B. HULL, HELEN ORFORD.

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