US1188197A - Governing mechanism for turbines. - Google Patents

Description

APPL-'lcmn mfp MAY 9. 19143.

yPaten@ Juge 29,1916.'

Witnesses UNITED STATES f PAgENT CFFIGEv i linnn n NORTON, or WORCESTER. M'AssoHUsnrrs, AssIGNOn 'ro GENERAL ELnc'rnIc COMPANY, A CORPORATION or New romeP Applicationled May 9, 1918. Serial NO.'766,575.

all idiom. may concern Be 1t knownthat I. FRED- E. Xonrox, a citizen of the i= United States. .residing at Worcester. infthe county of Worcester and State of Massachusetts, have invented cer` tain newv andl useful lImprovements in Gov; erning Mechanism for. Turbines, of which the following is a specification.

. .The common practice of' today with turbine builders is to provide each turbinejwith .a-speed governor driven by its rotor and to vut-ilize'this governor to control the opening and closing of an admission valve means as the load changes. pSuch an arrangement lgives a speed range of say three to four per cent. from no load to full load. Often the limits of the speed' range are fixed once for all but in some cases adjusting means are provided for changing the tension of the `20 governor spring so that the range of speed of. the turbine is a little higher or a little lower as occasion' re uires. Such adjustingl means are commonly own as synchronizing dances. For many purposes, notably where the turbines ldrive electric generators, this 'arrangement is satisfactory, butfor other purposes`^'-'"'otably where the turbines drive centriu al"- compressors for blast furnacesand Vgas'zfgg:en erators, which compressors Vare called onto deliver widely di'ering amounts of 'air under varying pressures," it is insulticient or defective.. In blast furnace and gas generator work particularly the condi- I tions change very greatly from time to time according to the amount and character' of the ore in'the furnace and to the amount of gas taken from lthe generator.- Briefly stated, the-principal distinction between turl bine vdriven electric vgenerators and turbine driven air compressors is that the former operate as constant-speed units and thelat- I ter as variable speed units.

' My invention has .forits object-to over-` come the objections above stated yand to provide a-n imprved governing mechanismefOvEnNINe. MECHANISM ron TUnBrNEs.

Specicat'ion Of Letters Patent.'

.tained below normal.

aientedauiie 2o, 1916.

vided that is also responsive to speed changes of the turbine and which 'is .put intoservice when the speed 'is tobe main- This acts "on v`sa'id regulator' either directly, or- 'indirectly through s oinel intermediary, such as the pilot Vvalve of the motor which adjusts the regulator vwith respect to its seat or seats. This secondary oi'lvariable speed governor may with advantage take the form of a movable member which is acted upon by fluid from a pump driven by t-he turbine. This governor can readily'be adjusted to meet new speed conditions by changing the tension of va spring whichopposes said member, by

passing .a partof the fiuid from the pump, or by adjusting both the spring and the bypass.

- In the accompanying diawing which illustrates oneof the embodiments of my inventiomFgure 1- is a somewhat diagram-l matic view illustrating in v improved governor mechanism: F ig. 2 is a viewof the needle valve and its casing: Fig. 3 is a sectional view' of a fluid retarding device; and Fig. 4 isa plan view of a turbine driven compressor showing the regulating mechanisinA in position.

' 10 indicates a turbine of any suitable construction having a suitable speed responsive Adevice 11 comprising the usual weights and. an opposing spring. This primary gevernor controls the opening andclosing of-a valve means or regulator 12 through a system of levers. Driven by the turbine is a` compressor or equivalent 'apparatus 13- whoseloa'd i`s liable to change over a wide range` requiring different speeds :of rotation. The governor is'adapted for a speed regulation vof about 2% over or 'under a pre determined speed `and .may for convenience be designated as a constant speed governor. Attached to a movable member ofv the governor is a lever 14, Fig. 1. tothe free end of which is attached a link 15'. 4To the lower end of the link is pivotally attached a floating lever 16 which is connected by a link 17 with the lever 18, the latter being connected to the pilot valve 19 and to the rod 20 of the motor 2-1 which actuates the valve, means` 'les or regulator 12. The motor comprises a cylinder and a 'piston 22, the rod 20 of which is connected to the valve or valves ad mitting fluid to the turbine 1,0. As 'the load' n'n thehirhiun changes `a slight but lever 1i to.change the position of'the pilot valve 19,'

to the turbine.' By connectingthe lever 18 connected by Sie vpin 31 connecting'the rod pump to the piston '2O the movement ofthe latter will restore thepilotivalve to its initial position. This; arrangement of the lever 18 forms vvhatis commonly termed a follow# up device. The motorl maybe actiuated' by any suitablefmbtive uid,'such` for example as steam, water, oil or compressed air as desired. 'g

'I he secondaryv or variablespeed governor comprises a' movable-g abutment or member, such for vexample asthe '.siphon diaphragm 2 3. This diaphragm is connected'to the rod.

"2t and its outward movement 1s opposed by a coiled extension spring 25. Whose tension canbe adjusted bv the harid vvheel '26. the latter being attached to 'a nut Q7 that is threaded to thel rod Q4. ,Theupper end of the s rin is attached to a boss .on the frame '28. o t le lower end of the rod is attached a lever 29.

the 'rod 30 with the floating" lever 16.5 Whenl the primarv governor- 11 is controlling the operation o the turbine the and the lever 16 acts as the. jf'ulcrum and is stationary,but when the secondary governor is in control the fulcrum 31 is adjusted up and down and the pin 32 becomes the ulcrum. The lever 29 may be pivotally supported byany smtable. means. As shown it -is'mounted on the :framel :28 which carries/the diaphragm.

35indicates a tank or casin'gat one end of the turbine Aand located therein iS, a gear 36 of ordinary construction for' s\1p plying Huid to the goternor 'and lubricant to the hearings. shaft 3T of the pump is a gear 38 that meshes with a Worm llmounted on the end of Athe -turbine shaftor otherwise driven thereby/so that as the speed of the turbine 4`vchanges the speed .of the pump will corre p ,the pipe or conduit -regards the discharge o spondingly ciange and 'in l like manner; Fluid from the pump is discharged through 40 leading to the diaphragm 23. and through the pipe or conduit 41 to the bearings ofthe apparatusorto any other point that lmay be desired.v The ,conduits 4.0 and 41' are arranged in multiple as t vduid from the pump tor a purpose to be described later At some suitable point'in the conduit 411s arranged a needle valve t2; st shown in Fig. 2, ,whiclit controls the amount ot fluid passing through the pipe. 41 and hence the pressure in the pipe or conduit/t0 leading to or agiven speed ofthe Connected to the conduit 41 is a conduit 43 that leads back to the supply the latter to admit fluid under pt'essure to one side or the other of the '.1 piston 22 and thus admit more orless steam 14. onk the pilot valve o rordinary manner lncreasin the ri llt-hand end of which isu -cmnparatively small',y Aernor is putinto service `by vand takes control.- said primary governor remaining idle in-so-far as any controlling-- .0n the upper end of the l 'maaier sureis exceeded vfluid is by-passedtrom the 7o 'conduit .41- to the-tank.. As it isr generally desirable lto maintain a higher pressureY in the conduit Ll1 than in the conduit leading to the bearings,.a` perforated disk al?, l"ig..3, lis interposed between them -aiid atl'w `a )ointbeyond the conduit 43. *f

Vhenthe.turbinejsmto be o erated at,

constant speed within t-linliiiits of VtheA speed. governor llit acts through the lever the motor in. the a0 and ldecreasing L the amount ofsteam admitted to the tur-i bine, by the regulator 12.4 f During the time that this primary govf,

`ernor is in service the secondaryr governor is so 4 inactive, the fluid ressure from the pump distending the-diaphragm :23 and causing its outer end to rest on the frame 28. This hay'theeffgct ofvi'vin the position of the fulcrum 31. /The lubricant delivered by? the @o pump novv'passes from thelconduit 4l 'partly -1 to the bear-lugs by the conduit 45 and the remainder through the conduit 43. and-relief valve it back td the'supply tank. rThe lubricant. after passing through-the bearno ings is also returned to the tank-torturther use. v Assuming now that the `character of the load on the turbine, as determined by suitable indicatorse4 is such that its s @edito w@ attain the best results should be be ow the working ranoeof the main or primary gov ernor 11. wliich range as before stated is the secondary govthe operator N5 justed by changing' the tension-or. the 130' spring 25, and also by himging the opening of the needle valve 42.; As an example ofthe requirements of air 'compressor'serv- Y ice it is not unommontohavetochange the speed from 2,500' RL" E. M, to 1,5%"34355 R. P. M. Ait. times the-'com ressor mav,

tor example. be calledon to eliver 40,0 0

cubic feet of free air per minute and at other;. gv

times only 15.000 feet. .c Assunung that theload conditions mathe 10.0

turbine require, it. to. operate ut half its normal'speed for example, which is far below the workin range-of tlie'primary gov- P.ei-nor, the liant -wlieel 2G is'so adjusted as 5 to cause the spring to oppose the necessaryf resistance. to the. outward movement of the diaphragm to render it active and the valve -lQ is set to properly restrict the` passage of fluid to the conduit l1. Under this condition the pump 36 may, as iin-example. be called upon' to deliveniluid at 100 lbs. er square inch to balance' .the spring. s the speed changes up -or down with load variations thelever 29 willraise 16 or lower the'pivot 31 of the' floating lever 16 and in sol doing cause it to inove about the fixed fulc'rum '3:2 and adjust the lpilot valve to admit more o r less steam to the turbine, the action of the motor v21 and regulator being lthe same as before but in a diliereiit speed range. T he pivot 3:2 remains fixed under these conditions because the weights of the governor 1-1- are against theirstops and for all practical purposes the' lever 1-1'is fixed.

As before stated, I prefer to use, the pump 35 to supply lubricant to the bearings ofy the apparatus thereby utilizing it-foi: a double iuriose;v 2'.. e., or governing and for 'lubricating purposes. To prevent the flow of lubricant to lthe, bearings fromv interfering with the proper action of the secondary governorfby taking more fluid than they should, the adjustable needle valve 42 .is interposed in the conduit 41 beyond the conduit 40. This may, for example, be so adjusted that for a given speed of the turbine a pressure-of 100 lbs; per square inch is maintained in the lconduit -10 and dia.- phragm and a pressure of 35 lbs in the conduit 41. It is important also to maintain an approximately constant bearing pressure so the ielief valve is also sct ffor 35 lbs. Before the .lubricant can pass to the bearings it has to flow through the rela.- tively small perforation in the .disk 47 and in so doing its pressure s'further reduced, say t-o 30 lbs. per square inch for example, which remains substantially .constant-at a l times The apuount of fiuid'discharged by the pump is always suiiicent to cause some fluid to flow through thereliet` valve, the amount bei-ng ldetermined by the speed of' vthe turbine and pump. But'whetherthe' amount be small'f or large a substantially constant pressure is always maintained in the conduit -ll'so that the diaphragm will quickly respond to any increase in pump pressure due-to a change in speed of the 6 turbine. To state the matter in another f way the pump delivers Huid to two conduits "jin'multiple and in oneof which a constant pressure' ismainta'ined as nearly as possible. 'My improved governing mechanism has 65 the'afdvantage of` enabling the .user to op- I ing lever;

1 Tn "other words -ran'ge of operation,

regulator. a

can ben-eadily adapted for varying speed.

coiiditibns by the addition of the diaphragm and associated parts. Generally speaking,

4the only addition to the regulator 12 is the floating lever 16 and link 15. Ordinarily they link 17 would be directly connected to the y"governor lever 14 insteadfof to the {loat- As turbines are usually provided with gearl pumps for lubricating purpose, no change is reqi-ired in this particular.

"heii-the'tur ine is being controlled by the.' secondary governor the primary goveriior although not taking part in thenormal regulation of the turbine stands ready to do so' in case of accident to the former. the primary governor will prevent excess s eed of the apparatus, without, however, siiitting it down,'when for anyr reason the 4operator makes an' incorrectv adpistment of the secondary governor.

I have illustrated a siphon diaphragm as the secondary governor, but it is evident that other devices of an equivalent character can be, employed. Care should of. course be exercised to select -a device which is freely responsive to pressure changes and can be ke it tight;

n accordance with the provisions of the patent statutes, I have described the princile of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it .understood that the apparatus shownis onl illustrative and that the invention can e carried o iit by other means. A

Y What I claiin as new and desire to secure 'by Letters Patent of 'the United States, is:

1, In combination,- a motor, a vregulator therefor. afgovernoi which is responsive to the shaft speed of the motor and has a liniited range of operation',

of the motor and has a different and wider means connecting both of said governors to the regulatoi, and means enabling tl4 trolled b v one governor the othei. In combination, a prime in over. a reguto the ,exclusion of lator for varying the amount of energy admitted thereto. a motor for actuating the pilot valvetheiefor, a primary a second governor` l which is also responsive to the shaft speed ie regulator to be' con-l governor which has a limited range of operation andjis responsive tochanges in the load of the prime mover :for moving the pilot valve. a secondary governor that has a different and wider range of operationthan the rst, which is responsive to changes in fload on' the prime mover and which also acts to move the pilot valve, and means enabling v the regulator to'be controlled by one gov- Edt ernorto the exclusion of the other.

3. In combination, a..motor, a regulator therefor, a speed governor for controlling the' regulator, a pump for creating a fluidl pressure which varies with changes in speed of the motor, a member responsive to the fluid pressure that acts on the regulator, and

a-valvemeans for controlling the pressure ernor,a spring acting Lon the diaphragm in opposition to the pump pressure, and means vforrchanging the tension'oi the spring.

5. 1n combination, a motor, a regulator for the motor, a speed governor for controlling .the regulator, a second speed governor comprising a-pump for creating a fluid pressure which varies with changes in speed of the motor, am a movable abutment sensitive to the pressure l'created' b abutment to the'4 regulator, so that said regulator may be controlled by either to the exclusion of the other.

6. In combination, a motor, a regulator .for the motor, a speed governor for controlling the regulator, a second' speed governor comprising a pump for creating a fluid pressure which varies with changes in speed of the motor, and a movable abutment sensitive to the 'pressure created by the pump;v

and a oating lever which is connected to the speed governor, to the abutment and to the re ulator.

In combination, a motor, La. regulator for the motor, al speed governor for controlling the regulator, a pump for creating a duid pressure which varies with changes in speed of the motor, conduits connectedl in multiple relation to the pump, a device sensitive-to the pressure created by the pump f and located in one of the conduits, and means 'nterposed in another of the conduits for qm intaming a substantially constant .pressure therein.

' 8. In combination, e motor, a regulator therefor, a speedgovernor for controlling i the regulator, `a pump for creating a fluid pure weh varies vvlth changes in speed 'd interposed between of 'the motor, said pum discharging YHuid intmnltiple pa a aphragm and o posin mi upon by theuid iPn rin-g one o t e paths, an adjable valve and a- .restrictedorice leent/ed inthe other path, and a valve opeg m the adjustable valve the pump; and means connecting the spee governor and the v onse topressure maaier and the restricted orifice for maintaining a substantially constant pressure 1n the second path.

9. In combmation, a motor, a regulator.

for the'motor, a pump for creating a luid pressure which varies with change in speed lont the motor, said pump discharging uid regulator, a pilot valve therefor, a' governor responsive to changes inl load on the prime mover for moying the pilot valve, a secondary governor v`that hasa different'and Wider range of operation than the irst'which also acts to mm'e the' pilot valve, and means for adjusting the secondary governor so that it will control the pilot "alve when the speed of the prime mover is outsideof the operative working range of the first-named governor. f J

11. In combination, a prime mover, a regulator for admitting motive fluid thereto, a primary and a secondary governor, a member that is connected to both governors and to the regulator, a fulcrum for the member which is fixed in position bythe secondary governorl when the primary governor, `1s v1n operatlon, a second fulcrum, for the member `whichl is fixed in position bythe primary governor when the secondary governor is in operation, and. means for adJusting one of the governors so that the prime mover will have an operativeA speed that is outside of the range of control of the other governor. v

12. In combination, a prime mover, a. regulator foradmitting motive fluid thereto, a primary speed governor, a secondary governor lthat is responsive to fluid pressure, a pump lresponsive to speed of the prime mover that supplies fluid to the secondary governor, a member for transmitting movements of both of the governors to the regulator, fulcrums for the member only one of which is active at a time. said fulcrums being positioned byl thegovernors, and means forl opposing a greater or less resistance to the 'action of the secondary governor l to cause it to assume control of the regulator to the exclusion ot the primary regulator.

13. ln combination, a turbine, a regulator-- therefoiga governor comprising one element that is movable in response to pressure changes and acts to adjust the regulator, a .pump drivenl by the turbine which supplies luid under pressure to the governor and .to a bearing of the turbine, conduits connected in multiple-relation to the governor and the bearing, that. to the governor ineens? being unrestrite-d, nndmenns'for maintain-l ing n substantmlly constant pressure inthe' conduit len'di'nr to the bem-ing.

14. In combination, u turbine, f'regulntor therefor, a motor forl actuating the regullator, a pilot valve'for the motor, and means delivered by. the pump," and meansl lconn'ect- -1 "ing the member with the lpilot valve.

In witness whereof, vI, have liereuntoiset my hand' this t\\'en ty.nintl1 day of- April, 19.13.

NORTON.

i Witnesses: y E l CHARLES L. PUTNAM, FRED L. Bmzoxs.

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