SE128991C1

SE128991C1 -

Info

Publication number: SE128991C1
Authority: SE
Publication date: 1950-01-01

Description

Uppfinnare: G. Aue. Inventor: G. Aue.

Prioritet begard frcin den 5 mars 1945 (Schweiz). Priority requested on 5 March 1945 (Switzerland).

FOreliggande uppfinning har avseende ett sadant lophjul eller en sadan rotor for turbomaskiner, vilket är forsett med en eller flera rotationskroppar med ett eller flera nay och en vid detta lostagbart f5st axeltapp. Uppfinningen kannetecknas i huyndsak darigenom, att axeltappen ãr genomborrad i axiell led och genom en vid navet fast, genom axeltappens urborrning ford bult under forspanning är pressed mot navet. The present invention relates to such a flywheel or a rotor for turbocharged machines, which is provided with one or more rotating bodies with one or more nays and a shaft pin which can be detachably attached thereto. The invention can be characterized in particular by the fact that the shaft journal is drilled in the axial direction and through a bolt fixed to the hub through the bore of the shaft journal and is pre-tensioned against the hub.

Lampligen är navel tatt intill rotationskroppen forsett med ett koaxiellt hâlrum, varigenom vid navet uppstar ett detta Hiram omgivande rorformigt parti, vilket är i stand att giva efter i radiell riktning och darigenom forhindrar, att radiella utvidgningar av rotationskroppen i storande utstr5.ckning overfilres till de partier av navet yid vilka bultens faste och/eller en centreringsdel aro anbragta. Den axiella bulten kan vara ingangad i hjulets eller rotorns nay. I andamal att forhindra axeltappens snedstallning relativt navet under dritten är det fordelaktigt att valja den axiella bultens tvarsnittsyta mindre an axeltappens tvarsnittsyta samt att forspanna den axiella Millen upp till atminstone 50 % av dennas strackgrans. For att forspanningen i den axiella bulten och i axeltappen skall f5rhliva konstant, kan den axiella bultens skaft vara atminstone lyre ganger sa tang som detsammas diameter. Den i den axiella bulten erforderliga forspanningen kan astadkommas genom en olikhet i stigningen, med vilken gangorna aro utbildade. Dimensioner Oro harvid valda pa sadant satt, att kvadraten av de hada pa batten anordnade gangornas diametrar Oro onryant proportionella mot utmattningshallfastheten hos det pa bulten yerkande mutterrnaterialet. Yid en speeiell utforingsform kan en eller flera ringformiga mellankroppar vara inspanda mellan axeltappen och rotationskroppen, varyid det blir mOjligt att astadkomma fastandet av den axiella bulten vid navet och centreringen av axeltappen vid ett mitt emot rotationskroppen belaget stalle av metallkroppen, vid vilket stalle inflytandet ay de p0 rotationskroppen upptradande ut- vidgningarna uppga till det minsta mojliga vardet. For det fall rotationskroppen. Or utford i form ay en skiya pa sadant salt, att denna i forhallande till de genom centrifugalkrafterna uppkommande spanningarna oyerallt uppvisar konstant hallfasthet Or lampligen det kdaxiella halrummet i navel yid den ena sidan begransat genom den med konstant hallfasthet utforda skivans omkrets. Lamply, the navel taken adjacent to the rotating body is provided with a coaxial cavity, whereby at the hub a tubular portion surrounding this Hiram arises, which is able to yield in the radial direction and thereby prevents radial extensions of the rotating body to be enlarged to a large extent to the portions of the hub yid to which the bolt fasteners and / or a centering member are located. The axial bolt can be inserted into the nay of the wheel or rotor. In order to prevent the shaft pin from tilting relative to the hub under the cradle, it is advantageous to select the cross-sectional area of the axial bolt smaller than the cross-sectional area of the shaft pin and to prestress the axial mill up to at least 50% of its yield strength. In order for the preload in the axial bolt and in the shaft journal to remain constant, the shaft of the axial bolt can be at least lyre times as pliers as its diameter. The prestress required in the axial bolt can be achieved by a difference in the pitch with which the passages are formed. Dimensions Oro have been chosen in such a way that the square of the diameters of the aisles arranged on the batten Oro is unreasonably proportional to the fatigue strength of the nut material acting on the bolt. In a particular embodiment, one or more annular intermediate bodies may be clamped between the shaft journal and the rotating body, it being possible to effect the attachment of the axial bolt to the hub and the centering of the shaft pin at a stall of the metal body located opposite the rotating body, in which they influence p0 the expansions occurring on the rotating body amount to the smallest possible value. In that case the rotating body. Or challenge in the form of a disc on such a salt that it, in relation to the stresses arising by the centrifugal forces, generally exhibits constant half-strength, Or suitably the cadaxial cavity in the navel yid on one side bounded by the circumference of the disc with constant half-strength.

Det Or kant att framstalla ogenomborrade ltiphjul i ett stycke mod axeltappen. Olagenbeten hari linger dart, att man vid valet av material maste rakna sued en kompromiss Indian de erforderliga egenskaperna for lophjulet och for lagertappen. Det Or darfOr att foredraga alt framstalla flerdelade 15phjul, varigenom de olika delarna kunna framstallas av ett mot anyandningsandamalet aypassat material. Svarigheten ligger harvid i de olika delarnas forbindning med varandra och centrering relatiyt varandra pa sadant satt, att delarna yid alla under driften upptradande pakanningar och de darvid uppkommande utvidgningsskillnaderna, sarskilt vid hoga hastigheter och/eller hoga temperaturer, yerka som en enda enhet. It Or edge to produce un pierced ltip wheels in one piece against the axle pin. Inaccuracies have led to the fact that in the choice of material a compromise must be made with the necessary properties for the impeller and for the bearing journal. It is therefore preferable to produce multi-part 15-wheel wheels, whereby the various parts can be made of a material suitable for the breathable purpose. The responsibility then lies in the connection of the various parts to each other and centering relative to each other in such a way that the parts in all packages appearing during operation and the resulting expansion differences, especially at high speeds and / or high temperatures, act as a single unit.

Vid en redan hand utforingsform Or rotorn filr hoga periferlhastigheter utbildad sons en icke genomborrad skiva med konstant hallfasthet och fOrsedd med nay, sons Oro utformade med eii syagt konisk, axiell urborrning, i vilken de flansformigt fortjoekade, koniska andarna ay rotoraxeln Oro inskjutna och medelst rotoraxeln parallella skru-var under forspanning, inpressade i navurborrningarna. Det Or forenat med stora syarigheter och forutsiitter en synnerligen noggrann bearbetning att med derma kanda utforingsform under konstant drift bibehalla den for centreringen ay axeln och rotorn erforderliga fOrspanningen, emedan eentrifugalkrafterna icke utsatta navet och axelanden for like stora pakanfinger och darfOr fororsaka omsesidig fOr- skjutning. Besta rotorn och axeln dessutom ay olika material med fran varandra avvikan- de utvidgningskoefficienter, sasom t. ex. staloch lattmetallegeringar, eller Oro rotorns och 2— — navets driftstemperaturer hogre an axelns, upphaves f8rspanningen och darmed centreringsverkan meIlan axel och rotor. Darigenom kunna obalanserna verka ofordelaktigt och aventyra fOrbindningen Indian rotor och axel. In an already hand embodiment Or rotor fils high peripheral speeds formed son a non-drilled disc with constant half strength and provided with nay, son Oro formed with a sewn conical, axial bore, in which the flange-shaped, conical spirals ay the rotor shaft Oro inserted and by means of the rotor shaft parallel screws during pretensioning, pressed into the hub bores. It is combined with great sutures and requires a very careful machining to maintain with this known embodiment under constant operation the preload required for centering on the shaft and rotor, since the centrifugal forces do not subject the hub and shaft lands to equally large packing fingers and shafts. In addition, the rotor and shaft consist of different materials with different expansion coefficients, such as e.g. steel and light metal alloys, or the operating temperatures of the rotor and the two-hub above the shaft, cause the biasing and thus the centering effect between the shaft and the rotor. As a result, the imbalances can seem unfavorable and adventurous the connection Indian rotor and shaft.

Genom foreliggande uppfinning undanrOjas de ovan anforda svarigheterna vid framstallningen och driften av sammansatta lophjul. De under driften upptradande, radiella utvidningarna av rotorn paverka icke namnvart navet och de till detta anslutna elementen, varfor en for en st8rningsfri drift erforderlig bojningsstyv fiirbindning och god centrering konstant astadkommes mellan rotationskroppen och axeln. The present invention eliminates the above-mentioned responsibilities in the manufacture and operation of composite impellers. The radial extensions of the rotor which occur during operation do not have a significant effect on the hub and the elements connected to it, for which a bending rigid connection and good centering required for trouble-free operation are constantly achieved between the rotating body and the shaft.

Uppfinningen koinmer i det foljande att narmare beskrivas i saraband med tvenne bifogade ritning askadliggjorda utforingsformer av uppfinningsforemalet. The invention will hereinafter be described in more detail in conjunction with the two accompanying drawings as embodied embodied embodiments of the object of the invention.

Fig. 1 fortydligar den forsta och fig. 2 den andra utfOringsformen i axiell langdgenonhskarning. Fig. 1 illustrates the first and Fig. 2 the second embodiment in axial longitudinal cutting.

Vid utforingsformen enligt fig. 1 ãr rotationskroppen 1, exempelvis rotorskivan i en kompressor, en gas- eller angturbin eller liknande, utbildad utan axiell urborrning och som skiva av i det narmaste konstant hallfasthet saint vid ena sidan forsedd med navet 2. For att kunna driva denna rotationskropp 1 med hoga periferihastigheter av exempelvis 850 m/sek. eller mera bestar denna av ett material med stor hallfasthet, t. ex. av en statelier alminiurnlegering. Xr rotationskroppen 1 utsatt for hoga driftstemperaturer, sasom fallet fir vid gas- och angturbiner, bestar rotationskroppen lampligen av ett varmebestandigt, legerat slat. In the embodiment according to Fig. 1, the rotating body 1, for example the rotor disk in a compressor, a gas or steam turbine or the like, is formed without axial bore and as a disk of almost constant half-strength saint on one side provided with the hub 2. To be able to drive this rotating body 1 with high peripheral speeds of, for example, 850 m / sec. or more this consists of a material with high hall strength, e.g. of a statelier alminiurn alloy. When the rotating body 1 is exposed to high operating temperatures, as is the case with gas and steam turbines, the rotating body is suitably composed of a heat-resistant, alloy slat.

Taft intill rotationskroppen 1 Or navel 2 sâ forsett med ett koaxiellt halrum 3, att vid navet uppstA ett detta halrum omgivande rot.- formigt parti, vilket är i stand att giva efter i radiell riktning och darigenom forhindrar, att radiella utvidgningar av rotationskroppen i storande utstrackning overfOras till navet 2. Taft adjacent to the rotating body 1 Or the hub 2 is provided with a coaxial cavity 3, so that a rotatable portion is formed at the hub surrounding this cavity, which is able to yield in the radial direction and thereby prevents radial extensions of the rotating body in a large extent transferred to the hub 2.

I navet 2 fir inskruvad en axiell bult 4. Denna hult Or omsluten av en i axiell led genomborrad axeltapp 5 som anligger mot det med en centreringskant 6 fiirsedda navet, med vilket tappen 5 Or ovridbart forbunden medelst ett eller Hera sfikringsstift 9. Axeltappen 5 Or anordnad i ett icke visat lager, t. ex. ett tryckoljeglidlager eller ett kullager. Den ur axeltappen 5 framskjutna delen 7 av den axiella bulten 4 Or forsedd med gangor, ph vilka muttern 8 Or paskruvad. Genom tilldragning av muttern 8 pressas axeltappen 5 mot navet 2, sh att den axiella bulten 4 bibringas en daremot sl'arande forspanning. Denna for-spanning kan exempelvis bestammas med tillhjalp av elasticitetslagen (Hook's lag) darigenom, att langdfOrandringen mellan den spanningsfria och dn forspanda bulten 4 faststalles medelst en for detta andamal utfOrd matt-stock, som intores i den axiella urborrningen 11 i bulten. P0 detta salt blir det mojligt att avpassa fOrspanningen till ett ph forhand beraknat varde. Screwed into the hub 2 is an axial bolt 4. This hollow Or is enclosed by a shaft pin 5 pierced in axial direction which abuts against the hub provided with a centering edge 6, to which the pin 5 Or is inextricably connected by means of one or Hera securing pin 9. The shaft pin 5 Or arranged in a layer (not shown), e.g. a pressure oil plain bearing or a ball bearing. The part 7 of the axial bolt 4 Or projecting from the shaft pin 5 Or is provided with passages, ph which the nut 8 Or is screwed on. By tightening the nut 8, the shaft pin 5 is pressed against the hub 2, so that the axial bolt 4 is provided with a counter-tensioning preload. This prestress can be determined, for example, by means of the law of elasticity (Hook's law) in that the longitudinal change between the stress-free and the prestressed bolt 4 is determined by means of a mat stock made for this purpose, which is inserted into the axial bore 11 in the bolt. With this salt, it becomes possible to adjust the bias voltage to a pH calculated in advance.

Det storsta vardet av den yttre diametern hos den i ett lager lopande axeltappen 5 Or Legransat genom den tillatna lagerperiferihas- tigheten, varf Or det Or av -vikt, att utnyttja detta begransade tvarsnitt, som Or fordelat pa axeltappen 5 °eh den axiella batten 4, ph sadant salt, att storsta majliga axiella for-spanning uppnas, varigenom en snedstallning as axeltappen 5 relativt navet 2 fOrhindras under driften och en storsta mojliga driftssakerhet sakerstalles. Detta Or fallet, om den axiella bultens 4 tvarsnittsyta ar mindre On axeltappens 5 tvarsnittsyta, varvid den axiella bulten med tillhj alp av muttern 8 skall forspannas upp till atmistone 50 % av bultens sirackgrans. For att oskadliggiira kvarstaende deformationer i den axiella bulten 4 och forhindra en smaningom forsiggaende reduce-ring av forspanningen, Or bulten utford som en tanjbar bait, vars skaftlfingd uppgar till atminstone fyra ganger diametern. Gangytornas tryck mellan navet 2 och muttern 3 Or anpassad efter utmattningshallfastheten hos dessa material pa sadant salt, att kvadraten av den gangade delens 7 diameter och ganghuvudets 10 diameter Oro omvant proportionella mot utmattningshallfastheten hos de pa dessa verkande muttermaterialen. The largest value of the outer diameter of the axial pin 5 running in a bearing or limited by the permissible bearing peripheral speed, where it is important to use this limited cross-section, which is distributed on the shaft pin 5 ° eh the axial bat 4 salt so that the largest axial axial pre-tension is achieved, whereby an inclination of the shaft pin 5 relative to the hub 2 is prevented during operation and a maximum possible operational reliability is ensured. This is the case if the cross-sectional area of the axial bolt 4 is smaller than the cross-sectional area of the axle pin 5, the axial bolt with the aid of the nut 8 being prestressed up to at least 50% of the syrup boundary of the bolt. In order to neutralize residual deformations in the axial bolt 4 and to prevent a gradual gradual reduction of the prestress, the bolt is challenged as a stretchable bait, the shaft finger of which amounts to at least four times the diameter. The pressure of the gangway surfaces between the hub 2 and the nut 3 is adapted to the fatigue strength of these materials on such a salt that the square of the diameter of the gangway 7 and the diameter of the gangway 10 are proportionally proportional to the fatigue strength of the nut materials acting on them.

Vid utforingsformen enligt fig. 2 Or den for upptagande av storre centrifugalkrafter avsedda rotationskroppen 34 forsedd med skovlar 12. Vid rotationskroppen 34 Oro anordnade de med ett koaxiellt hatrum 13 forsedda naven 14, 15. I navet 14 Or ganghuvudet 16 till den sasom utvidgningsskruv utbildade, axiella bulten 17 ingangat. Den axiella bultens 17 andra Linde Or fOrsedd med ett gangat parti 18, varvid stigningen hos dettas gangor Or mindre On hos gangorna pa. ganghuvudet 16. Den -yttre anden av partiet 18 Or utbildad till ett sexkantshuvud 19, vilket kan tjana som faste for en skruvnyckel eller liknande. In the embodiment according to Fig. 2, the rotating body 34 intended for receiving larger centrifugal forces is provided with vanes 12. At the rotating body 34 axial bolt 17 engaged. The second Linde Or of the axial bolt 17 is provided with a passage portion 18, the pitch of its passages being less On of the passages pa. the aisle head 16. The outer spirit of the portion 18 is formed into a hexagon head 19, which can serve as a fastener for a wrench or the like.

Ph det gangade partiet 18 Or den axiellt genomborrade axeltappen 21 paskruvad och ford till anliggning mot passkanten 20 pa navet 14, vilken axeltapp 21 Or ovridbart forbunden med navel formedelst ett eller flera medbringarstift 22. Axeltappen 21 Or forsedd med en fla.ns 23, medelst vilken axeltappen kan fOrbindas med en icke visad drivande elkr driven axel. Det tryck, som under driften forhindrar en upplyftning av axeltappen 21 Iran navet 14, astadkommes genom vridning av den axiella bulten 17, -vilken till foljd av de olika stora stigningarna pa gangorna 16 och 18 framkallar en mot detta anpressningstryck svarande dragforspanning. Ph the threaded portion 18 Or the axially pierced shaft pin 21 is screwed on and fastened to abut against the fitting edge 20 of the hub 14, which shaft pin 21 is inextricably connected to the hub by means of one or more carrier pins 22. The shaft pin 21 Or is provided with a flap 23, by means of which shaft pin can be connected to a drive shaft (not shown). The pressure which during operation prevents a lifting of the shaft journal 21 from the hub 14 is achieved by turning the axial bolt 17, which, as a result of the various large rises on the passages 16 and 18, produces a tensile bias corresponding to this pressing pressure.

PA den pa ritningen sett hogra sidan Or rotationskroppen 34 forsedd med en centreringslist 25, mellan vilken och navet 15 den navet 15 ringformigt oingivande, med skovlar — — 32 forsedda mellankroppen 24 ar insatt. For att erhalla en i sin helhet stel kropp diger centreringen mellan axeltappen 29 och rotationskroppen 34 ruin under formedling av den en storre diameter an navet 15 uppyisande mellankroppcn 24. On the right side shown in the drawing, the rotating body 34 is provided with a centering strip 25, between which and the hub 15 the hub 15 is annularly provided, with vanes 32 provided with the intermediate body 24 is inserted. In order to obtain a completely rigid body, the centering between the shaft pin 29 and the rotating body 34 is ruined while forming the intermediate body 24 having a larger diameter than the hub 15.

For att centreringen mellan rotationskroppen 34 och mellankroppen 24 awn skall bibe- hallas under driften Sr den ringformiga mel- lankroppen med ayseende pa vaggtjockleken dimensionerad pa sadant satt och framstalld air ett sadant material, att mellankroppen vid med rotationskroppen 34 Overensstammande varytal utsattes for samma eller nagot stOrre utvidgning an centreringslisten 25. Dessutom är mellankroppens 24 elastieitet sà stor, att under driften de radiella utvidgningarna vid den vanstra anden ph grund ay den axiella utstrackningen och vaatjockleken ham bona fran den hogra Auden och pa grund darav icke inverka pa centreringen relativt axeltappen 29. In order for the centering between the rotating body 34 and the intermediate body 24 to be maintained during operation, the annular intermediate body with reference to the rock thickness is dimensioned on such a set and produced in such a material that the intermediate body at the rotating body 34. Greater expansion of the centering strip 25. In addition, the elasticity of the middle body 24 is so great that during operation the radial expansions at the left ventricle due to the axial extent and water thickness reside from the right eye and therefore do not affect the centering relative to the shaft journal 29.

I navet 15 Sr den axiella bultens 27 gangbuyud 26 inskruvat, medan axeltappen 29 Sr paskruyad pa bultens andra, mitt emot belagna gdngor och centrerad mot mellankroppens 24 passkant 30. Axeltappen 29 är med tillhjalp ay ett eller flera passtift 31 ovridbart forbunden med mellankroppen 24 och navet 15. Genom yridning ay skruvbulten 27 me-deist en yid flerkantskroppen 33 anbringbar skruynyckel drages till foljd ay stigningsskillnaden mellan gangorna 26 och 28 axeltappen 29 mot mellankroppen 24 och denna mot rotationskroppen 34, varvid bulten 27 erhaller en daremot svarande dragforspanning, vars storlek Sr sd avpassad, att en ensidig upplyftning av mellankroppen 24 och axeltappen 29 frail sina resp. anliggningsytor forhindras under driften. 1.7-tformningen och dimensioneringen av bultens 27 olika delar aro ay hallfasthetstekniska skill desamma som vid bultarna 4 och 17. Saval axeltappen 21 sorn axeltappen 29 kunna vara lagrade i lager och utnyttjas for effektoverfOring frau eller Lill rotationskroppen 34, utan aLt darf Or de axiella bultarna 17 och 27 utsattas for ytterligare pakanningar. The axle bolt 26 of the axial bolt 27 is screwed into the hub, while the shaft pin 29 is screwed onto the other, opposite threaded threads of the bolt and centered against the fitting edge 30 of the intermediate body 24. The axle pin 29 is inextricably connected to the intermediate body 24 and hub 15. By screwing on the screw bolt 27 by means of a wrench which can be attached to the polygonal body 33, the pitch difference between the passages 26 and 28 is tightened to the shaft pin 29 towards the intermediate body 24 and this towards the rotating body 34, the bolt 27 receiving a corresponding tensile bias, size Sr sd adapted, that a one-sided lifting of the middle body 24 and the shoulder pin 29 frail their resp. abutment surfaces are prevented during operation. The 1.7-shaping and dimensioning of the different parts of the bolt 27 are in the same strength technical differences as at the bolts 4 and 17. Saval shaft pin 21 so that the shaft pin 29 can be stored in bearings and used for power transmission from the or small rotating body 34, without all the axial bolts 17 and 27 are subjected to further package searches.

Claims

Patent claim:

1. Flywheel or rotor for turbomachines, each rotor Sr provided with one or more rotating bodies with one or more nay and a yid this resp. these 18-piece fixed shaft journals, characterized in that the shaft journal (5, 21 or 29) is drilled in the axial direction and through a fixed at the hub (2, 14 and 15, respectively) through the bore of the shaft journal ford butt (4, 17 and 27, respectively) under bias pressed against the hub.

Device as claimed in patent claim 1, characterized in that the hub (2, 14 and 15, respectively) tans next to the rotating body (1) Sr provided with a coaxial cavity (3 or 13), whereby at navel a cavity surrounding this cavity arises, tubular portion, which is capable of yielding in the radial direction and thereby prevents radial extensions of the rotating body (1 or 34) from being transmitted to a large extent to those portions of the hub at which the bolt (4, 17 and 27, respectively) are fixed (10). , 16 and 26, respectively) and / or a centering part are arranged.

Device according to claim 1, characterized in that the axial bolt (4, 17 and 27, respectively) is tightened in the nay of the rotor.

Device according to claim 1, characterized in that the cross-sectional area of the axial bolt is smaller than the cross-sectional area of the axle pin (5), yaryid the axial bolt Sr prestressed up to at least 50% of its yield strength.

5. A device according to claim 1, characterized in that the shaft of the axial bolt is at least four times as long as its diameter.

Device according to claims 1 and 3, in the case of the bolt in addition to the hub also being inserted into the shaft pin, characterized in that the preload Sr required in the axial bolt (17 and 27, respectively) is arranged to be provided by a difference in the pitch, in these passages (16 and 18 and 26 and 28, respectively).

7. Device according to patent claim 6, characterized in that the diameters of the diameters (16 and 18, respectively 26 and 28 and 28, respectively) of the two ph bolt (17 and 27, respectively) are inversely proportional to the fatigue strength of the nut acting as the bolt.

Device according to claim 1, characterized in that one or more annular intermediate bodies (24) are clamped between the shaft pin (29) and the rotating body (34).

Device according to claim 8, characterized in that the centering of the shaft pin (29) takes place at a position of the intermediate body (24) located opposite the rotating body (34), in which case the influence of the enlargements occurring on the rotating body amounts to the smallest possible vardet.

Device according to claim 2, in case the rotating body Sr is challenged in the form of a disc p5 in such a way that in relation to the stresses arising by the centrifugal forces it has a constant half-strength everywhere, the ddrigenor can be characterized in that the coaxial cavity (3 or 13) in the hub (2 or 14) Yid one side Sr bounded by the circumference of the disc (1 or 34) challenging with constant half-strength.