US2609255A

US2609255A - Steam turbine

Info

Publication number: US2609255A
Application number: US68494A
Authority: US
Inventors: Clarence E Kenney; Charles D Wilson
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1948-12-31
Filing date: 1948-12-31
Publication date: 1952-09-02
Anticipated expiration: 1969-09-02

Description

2 sl-IEETs-SHEET 1 Filed Deo. 51, 1948-l Sept. 2, 1952 C. E. KENNEY ETAL Sept. 2, 1952 STEAM TURBINE 2 SHEETS- SHEET 2 Filed Dec. 31, 1948 Patented Sept. 2, 1952 gUgllqziflgo STATES PATENT OFFICE Allis, Wis.; assignors to Allis-Chalmers Manu'- i'actulingl Company, Milwaukee, Wis., aY corporation of Delaware Application, December 31, 19.48,` SerialNo.. 68,494 1t claims. (chaos-166% The present invention relates to elastic fluid turbinesy and' hasfor a. principal object the pro.- vision. of new and' improved apparatus of this type.

A' more specific object of the' invention is to provide new and improved means for adjusting the rotating element of a turbine relative to the stationary element of the turbine in order to compensate for unequal relative longitudinal expansion and' contraction of these elements.

This invention contemplates the use of an adjustable, mechanism to connect the thrust bearing `supporting means with the turbine casing in s uclr a manner as to provide for more accurate adjustment than has been heretofore obtained.

Another object of the invention is to reduce the effectoflost motion inthe turbine adjusting mechanism to such an extent that the displacement of the rotor relative to. the casing resulting from `lost motion in the adjusting mechanism is negligible.

Another object4 is to provide` a. structure that will cooperate with thegturbine casing'and thrust bearing but will not transmit stressesto the thrustV bearing which are causedf by transverse expansion and contraction of the parts ofthe turbine casing. y

Still another object ofthe invention is to provide an adjusting means tol compensate for relativel longitudinal movement of a turbinecasing from this specification andV the accompanying drawing showing one embodiment of the'invention and'forming a part of this application, and all of these novel features are intended to be pointed out in theA claims. In the drawing:

Fig. 1 is a fragmentary plan view embodying this invention;

Fig. 2 is a section taken on line lII-II offFig. 1j lookingin the 'direction of the arrows; and` Fig. 3 is a section taken on line III-IIlof Fig. 2 looking in the direction ofthe arrows.

The turbineA herein illustrated as embodying thisinvention comprises a turbine casing I enclosing 'a turbine rotor'2. The rotor 2 has a shaft 3fwhich-isjournaled in bearings 4'.('one of the bearings being indicated) and is provided with of ia turbine 2.* a thrust bearing Svcarrled` by supporting means, herein shown asa yoke 6,connected tov the turbine casing I by anadjustable connecting mechanism, and slid'ablyrmounted on apedestal 8.y The adjustablev connecting mechanism mayv comprise two linkagesl 1A and 'IB as here shown. The pedestal Sis supported4 separately from the turbine casing I.

The rotor 21 of' the turbine carries rowsof'j bladingv 9' and dummy blading for the labyrinth seal IIIv which must bey rotated in planes which bear a definite relationship` to the stationary rows` of blading. II of the turbine casing I". Temperature changes willl produce unequal relative longitudinal expansion, andcontraction between the casing I' andi rotor 2; which willl destroy this relationship and may result in clearances between the fixed' and moving blades which. are. too. large for e'icient' operation or it may cause serious damagejby permitting the fixed and moving blades to come in contact with eachother. Therefore. provision must be made to compensate for this unequal relative longitudinal expansion and contraction while permitting free simultaneous longitudinal expansion and contraction. y

y Simultaneous longitudinalexpansion and contraction of'casing I and rotor 2 is; permittedV by virtue `ofthe slidable mounting of the yoke B on the pedestal 8th'e yoke 6 cooperating with the turbine. casing," I through the linkages IA and IB andwi'th the rotor 2 through the. thrust bearing 5.. The pedestal 8,is provided with a longitudinal recess" L3 with which a lug` I4,I formed on the bottom of thev yoke 6; coacts to maintain the center ofthe yoke 6 Within av vertical plane passing throughthe rotational axis of the rotor 2. The yoke 6 is supported by the pedestal 8 on bearing surfaces 12j. The yoke IiA is enclosed in a cover I5' secured. tothe pedestal 8 and provided with laterally extending lugsA I6 which coact with laterally extending lugs Il formed on the yoke 6.v Lugs YISa-nd Il are so disposed as to'V restrain the yoke Bfrom rotation about the, axis of rota,-`

tion o f the rotorv shaft 3butv do not oppose longitudinal movement of the; yoke drelative to the pedestal 8'.:

Compensationfor unequal' relative longitudinal expansionv and contraction of the casingv I and rotor 2` is accomplished'by adjusting thejeiective lengthof thelinkages 'I'A and. 1B, thus varying the relativel position of the yoke 6 andthe casing l'. l 'Since the relatively stationary part |18- of the thrust bearing 5 isf rigidly mountedv in' the yoke I 6 and cooperates with the relatively movable thrust bearing part I9 which is rigidly mounted fto the Shafts 24 by keys 21.

The connecting mechanism comprises mem-- bers connected to the casing I and engaging the eccentrics rotatably mounted on the yoke E. The connecting mechanism is shown here as comprising links 2| pivotally connected by pins 22 to laterally extending lugs 2.3.formedon the turbine casing l and engaging the eccentrics 20 rigidly The proportions of the worm 44, worm wheel 40, rod 436, levers 26 and eccentrics 20 should be such that there is a known relation between the angular displacement of the hand Wheel l45 and the relative movement of the turbine casing I and rotor 2. For example, the proportion might be such that the rotation of the.handwhee1 45 Athrough 360o` would cause a relative-longitudinal movement of the rotor 2 of 0.001. l It Will now be obvious that, with this invention, small relative movements between the turbine feasing I and rotor 2 may be produced by relamounted on rotatable shafts 24 journaled in the yoke 6.

The shafts 24 are adapted to be rotated simultaneously by levers 26 which are mounted on the shafts 24 and restrained from rotation relative The levers 26 are movable in a plane perpendicular to the longitudinal axis of the shafts 24 by a lever kactuating mechanism 28 which slidably engages slots 29 in the end portions of the levers 26. Movement of the levers 26 Will cause the shafts 24and the eccentrics 2B to rotate and the. rotation of the eccentrics 20 in the links 2l will move the Yoke 6 longitudinally relative to Ythe turbine casing I -thereby adjusting the relative positions of the `turbine casing I and rotor 2. Y

- It is desirable to limit the extent to which the relative positions of the turbine casing and rotor may .bevaried '.Iofaccomplishy this, the links 2| areprovided with radially extending flanges 3D disposed on opposite sides of the` yoke B and adapted to abut limit plates3l,fmounted on the yokeB, when the maximum and minimum displacement vof, therotor 2 islachieved. yIt is apparent that vthe thicknessof the limit plates 3l `Will determine the range of longitudinal adjustment.`

' The embodiment ofthe lever actuating mechanism 28 herein shown and described is illus- .trative `only and other means for actuating the lever 26 will. be apparent to those skilled inthe art. As here shown, theen'dsfof the lever 2liy are slotted at 29 to receive trunnions 33 extending from .opposite sides of a rectangular block. 3.4. The block 34 has a threaded opening- 35. extending through it parallel vto the yrotor shaft 3.

Through this openingy 35 is. disposed a threaded rod 36 the threads of which` cooperate Withthe threads of the threadedopening and the end portions of which 31 and are reduced in diameter. One end 31 is journaled in a bearing 39 supported by the yoke E. The other `reduced end portion 38 of the rod 35 is provided with the worm Wheel 4Q and is journaled ina bracket 4I which is rigidly mounted on the yoke 6. LSpacers 4.2 are mounted on the reduced end iportion- 38 rof'the rod y36 and bear .against opposite Asides ofthe bracket 4I. thereby preventing `longitudinal displacement of the rod 3S relative to the-yoke E. yOn one end of a -shaft 43 is secured a worm `44 which engages the Worm Wheel 4,0.. The other end ofthe shaft 43 .fcarries `a'handvvheel 45 for. turning `the shaft 431 It is apparent that the `turning of the handwheel 45 will cause the threaded rod 3B to rotate and the block 34 to run along the rod 36 thus displacing theplevers 26 and adjusting the relative positions ofthe turbine casing `I and rotor 2 ashereinbefore described. n Y Y The eccentrics 20 are restrained from rotation relative to the shafts 24 by keys 25.-

tivelylarge displacements of the actuating means (shown here ashandwheel 45) thus simplifying accurate adjustment. It will also be obvious that changes in the relative positions of the turbine casing I and rotor 2 resulting from lost motion in the lever actuating mechanism 28 Will be so small as to be negligible since the amplitude of such lost motion is greatly reduced through the actionof the levers26 'and eccentricsZl.v

The pivotalconnection of the links 2| to `the casing I by the' pins 22 is' such that lateral l,ex-

pansion and contraction of the casing will be unhampered and strains and accompanying stresses .of such expansion and contraction cannot be transmitted 'to the yoke 6 and thrust bearing 5.

From the foregoing, it Will be apparent tolthose skilled `in the art that the illustrated embodiment of the invention accomplishes the objects of the invention. It will also be obvious tothose skilled in theart that the invention is not limited to the form shownbut is susceptible of various other changes and modications Without departing from the .spirit of theinvention and that.' ac,- cordingly, the disclosure herein is illustrative only and the inventionlisfnot limited thereto...

)Itl is claimed and desiredto secure by Letters Patenti l l 1. In an elastic iiuid tiu'bine, thecombination comprising: a casing; a rotor Within said casing; a -thrust bearing for said rotor; a yoke carrying the relatively stationary part of said thrust bearing;` adjustable means for connecting said casing With said yoke,\said adjustable lmeans comprising at least oneeccentric rotatably mounted on said yoke, a lever secured to said at leastv one eccentric, and adjustable means for holdingthe movableend of said lever. Y v` 2. In an elastic iluid turbine, the combination comprisingz' a casing;. a rotor Within. said casing; .a thrust bearing for said rotor; 'supporting means for carrying the relatively stationary part of4 saidthrust bearing; and adjustable means for connecting said casing with said, supporting means, said, adjustable means comprising at least one eccentric rotatably mounted on said supporting means, at least one vmember carried by said casing and pivotally engaging said eccentric, and means for rotating said eccentric.v I 3. kIn an elastic fluid turbine, the combination comprising: la casing; a rotor .Within said casing; a thrust bearing for said rotor; supporting means for carrying the relativelystationary part of said thrust bearing; and adjustable means for connecting said casing with said supporting means, said adjustable means comprising atleast one eccentric rotatably mounted onfsaid supporting means, a1; least one link pivotally connectedto said casing and pivotally yengaging said eccentric, and means for rotating said eccentric.l ,4-1m an elastic-fluid turbine. the combination comprising: a casing, a rotor Within said casing; a thrust bearing for said-rotor; .a yoke carrying the relatively stationary part of; said thrust bearing; adjustable means for connecting said casing with said yoke, said adjustable means comprising eccentrics rotatably mounted on said yoke, members carried by said casing and engaging said eccentrics, levers secured to said eccentrics, and adjustable means for holding the movable ends of said levers.

5. In an elastic fluid turbine, the combination comprising: a casing; a rotor within said casing; a thrust bearing for said rotor; a yoke carrying the relatively stationary part of said thrust bearing; adjustable means for connecting said casing with said yoke, said adjustable means comprising eccentrics rotatably mounted on said yoke, links pivotally connected to said casing and engaging said eccentrics, levers secured to said eccentrics, and adjustable means for holding the movable ends of said levers.

6. In an elastic fluid turbine, the combination comprising: a casing; a rotor Within said casing; a thrust bearing for said rotor; a yoke carrying the relatively stationary part of said thrust bearing; and adjustable means for connecting said casing With said yoke, said adjustable means comprising eccentrics rotatably mounted on said yoke, members carried by said casing and engaging said eccentrics, levers secured to said eccentrics, adjustable means for holding the movable ends of said levers comprising a threaded rod held against longitudinal movement, a block having a threaded opening cooperating with said threaded rod, and means for slidably connecting said levers to said block.

7. In an elastic iiuid turbine, the combination comprising: a casing; a rotor within said casing; a thrust bearing for said rotor;v a yoke carrying the relatively stationary part of said thrust bearing; and adjustable means for connecting said casing with said yoke, said adjustable means comprising eccentrics rotatably mounted on said yoke, links pivotally connected to said casing and engaging said eccentrics, levers secured to said eccentrics, adjustable means for holding the movable ends of said levers comprising a threaded rod held against longitudinal movement, a block having a threaded opening cooperating with said threaded rod, and means for slidably connecting said levers to said block.

8. In an elastic fluid turbine, the combination comprising: a casing; a rotor Within said casing; a thrust bearing for said rotor; a yoke carrying the relatively stationary part of said thrust bearing; adjustable means for connecting said casing with said yoke, said adjustable means comprising eccentrics rotatably mounted on said yoke, links pivotally connected to said casing and engaging said eccentrics, levers secured to said eccentrics, and adjustable means for holding the movable free ends of said levers; and means for limiting the displacement of said yoke relative to said casing, said means comprising iianges on said links adapted to abut bearing surfaces on said yoke when displacement of said yoke relative to said casing is a predetermined maximum or minimum.

9. In an elastic iiuid turbine, the combination comprising: a casing; a rotor Within said casing; a thrust bearing for said rotor; supporting means for carrying the relatively stationary part of said thrust bearing, said supporting means being separate from said casing; and longitudinally adjustable means for connecting said casing with said supporting means, said adjustable means comprising at least one link connected at one end to said casing to pivot about a given axis; and an eccentric rotatably mounted on said supporting means and pivotally engaging the other end of said link, the axis of said eccentric being substantially parallel to said given axis to permit free lateral expansion and contraction of said casing.

10. In an elastic fluid turbine, the combination comprising: a -turbine casing; a thrust bearing; a rotor extending through said casing and guided in said thrust bearing; a bearing casing carrying said thrust bearing, said bearing `casing being 'separate from said turbine casing; and means adjustable longitudinally of said rotor and interposed between said casings for maintaining a preselected clearance between said rotor and said turbine casing, said adjustable means comprising a member, a first connecting means joining said member to said turbine casing and a second connecting means joining said member to said bearing casing, at least one of said connecting means comprising a pivotal structure having rotatable relatively eccentric portions engaging said member and one of said casings respectively and jointly rotatable to cause relative longitudinal movement of said casings.

CLARENCE E. KENNEY. CHARLES D. WILSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,168,273 Banner Jan. 18, 1916 2,263,9fl2 Allen g Nov, 25, 194:1l