Title of Invention

FASTENING OF THE BLADING OF A TURBO MACHINE

Abstract

FASTENING OF THE BLADING OF A TURBOMACHINE The present invention relates to blades (1, l1, 12, I3, ln) of a turbine or compressor are fastened into a groove (8) on the rotor (6) or stator of the turbine or compressor by means of the blade roots (4), there being no play or a prestress prevailing between the root plate (3) and/or the blade root (4), and adjacent blades (1, l1, 12, 13, ln) thereby being supported relative to one another with respect to torsional moments (12) and not or only slightly on the rotor (6) or stator. This is possible, for example, by means of a bevel (9). (Fig. 4)

Full Text

SUMMARY OF THE INVENTION - The aim of the invention is to avoid the disadvantages mentioned. The object on which the invention is based is to provide a fastening for blades of a turbomachine to a. rotor or stator, by means of which fastening the torsional moments can be absorbed to an increased extent by the blade root or the root plate of the blade, while at the same time the rotor/stator and the AMENDED SHEET blade root are relieved. Moreover, the overall length of the rotor/stator is to be shortened or, for the same length, the number of blade rows is to be increased and/or the use of cost-effective root connections is to be made possible. According to the invention, the object is achieved by means of a fastening of blades according to the preamble of claim 1, in that, after the installation of all the blades, the blades are contiguous to one another on the rotor or stator at the root plate and/or at the blade root without play or with a prestress and are therefore supported relative to one another with respect to torsional moment sj) the torsional moments which act at the root plates /Mid/or at the blade roots being opposite to 'the tors.'ip&al moments which act at the cover plate or at the supporting wing. This embodiment has the advantage that torsional moments are no longer or only marginally absorbed by the rotor, but, instead, by the root plates and/or blade roots contiguous to one another, since a twisting of these two structural elements is prevented. By virtue of this measure, the blade root and also the rotor (or stator) can have a correspondingly smaller .dimensioning, since relatively high forces no longer f-have to be absorbed at the rotor (stator)/blade-root V- ■ /contact face. Overall, therefore, the length of the rotor can be reduced. With the length of the rotor .(stator) being the same, the number of blade rows and consequently also the efficiency can be increased. Moreover, it is possible to use other.root connections which could not be used with, the previous technique. For example, a single-prong insertion root, a hammerhead -root or an equivalent simple blade root can advantageously be employed. Such blade roots can be manufactured in a simple way and without great difficulty by means of known milling methods. The root plate and possibly also the blade root have a bevel which is advantageously contiguous to a bevel of an adjacent moving blade, and therefore torsional moments are absorbed mutually at this point. BRIEF DESCRIPTION OF THB DRAWINGS A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by • reference to the following detailed description when considered in connection with the accompanying drawings, wherein: Fig. 1 shows a turbine blade of a steam turbine with a single-prong blade root and cover plate/supporting wing,-Fig. 2 shows a turbine blade of a steam turbine with a supporting plate (supporting wing) within the blade, Fig. 3 shows a top view of an exemplary embodiment according to the invention with the cover plates of the turbine blades, and Fig. 4 shows a section through an exemplary embodiment according to the invention of turbine blades which are arranged in a groove on the rotor or stator of the turbomachine, the root plates being visible. Only the elements essential for the invention are illustrated. Identical elements are given the same reference symbols in the various figures. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referrring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, figure 1 shows a blade 1 of a turbomachine, that is to say, for example, of a ; steam turbine or of a compressor. The blade 1, which may be a moving blade or a guide vane, consists of a blade root 4, of a root plate 3 adjoining the blade root 4, of a cover plate 2 or supporting wing or supporting plate and of a blade 5 located between the root plate 3 and the cover plate 2. The blade root 4 is designed, in figure 1, as a single-prong insertion root 4a. It serves for fastening the blade 1 to the rotor 6, not illustrated in figure 1, or to a stator. Both the root plate 3 and the cover plate 2 of the blade 1 are equipped with a bevel 9. The bevel 9 is located on the one side of the cover plate 2 or root plate 3, that is to say the bevel 9 is to be understood as being on both plates 2, 3 in terms of a top view, as also becomes clear in figures 3 and 4. It is also possible for a bevel 9 likewise to be formed on the blade root 4. The blade 1 may also be a blade with a multi-prong insertion root. As is evident from figure 2, the cover plate 2 can be mounted on the blade 5 between the blade tip 14 and the root plate 3. This applies in general to all blade types capable of being used. In the blades, which are shown in figure 1 and in figure 2, there are additionally in the blade root 4, 4a holes 11 which serve for fastening the root to the rotor or stator by means of bolts. When the blades llf 12/ I3, ln are being installed in a groove 8 on the rotor 6 or else on a stator, torsional moments 13 acting in' the direction of the bevel 9 are applied at the cover plate 2. The contact point 7 at which the torsional moments 13 are absorbed occurs in this case. This is illustrated in - the blade row of figure 3 which shows a top view of the various blades lx, 12/ I3, ln- The blades llt 12, I3/ In thereby acquire some prestress. A gap 10 is thus formed between the other part of the cover plate 2 at which the cover plates 2 are not contiguous to one another. The blade leaves 5, which may be arranged below the cover plate 2, can also be seen in figure 3. In the case of an intermediate arrangement of the cover plate 2 on the blade 5, as illustrated in figure 2, this is above and below the cover plate l2<.> Figure 4 shows i/a section through a blade row, the root plates 3 of .-the bladesPli, 12, I3, In being 'visible 'in this figure.. ■ .' , /['v Once again, adjacent root plates 3 butt directly, free of play, against one another at the contact points 7. The contact points 7 between adjacent plates 3 are in the region of the bevels 9. A gap 10 is formed in the other part of the root plates 3. The torsional moments 12 acting on the root plates 3 are, however, opposite to the torsional moments 13 shown in figure 3, so that the bevels 9 are also arranged at another corresponding end of the respective plate 2, 3. According to the invention, it is also possible to provide a prestress between the individual root plates 3. The contact point 7 may also relate, overall, to the contiguous root plates 3, without a gap 10 being formed. As already illustrated in figure 1, the bevels 9 may also relate to regions of the blade root 4. However, this is not shown in any more detail in figure 4. Since adjacent moving blades llf 12/ 13, in are contiguous' to one another at the bevel 9 and the torsional moment 12 acts in this direction, the moving blades llf 12, I3, ln are supported relative to one another. Twisting no longer takes place or takes place only to a very slight extent, so that the force has to be absorbed by the moving blades li, 12, 13/ In themselves and no longer by the rotor 6 (or the stator) or by the groove 8- The load on the rotor 6 is advantageously reduced by means of this type of arrangement of the moving blades li, 12/ I3, In. This takes place primarily as a result of the play-free or prestressed mounting at the root plates' 3 and/or at the blade roots 4. The bevel 9 must- then, of course, also be present on the blade root 4, in order to take ■ account of the existing effect. The single-prong insertion root illustrated in figure 1 is, however, selected only as an example. Various types known per se from the, prior art, such>'as, for example, a hammer root or rider root, may ' be used as a blade root 4. It is particularly noteworthy, however, that even blade roots 4 which have hitherto been incapable of being used or been capable of being used only under difficult conditions can be employed- This is possible due to the reduced transmission of force from the blade root 4 to the rotor 6 or to the stator. Since the blade roots 4 and also the rotor 6 or the stator can have smaller dimensioning (for example, in width), the overall length of the rotor 6 can be reduced or, for the same length of the rotor 6 (stator) , the efficiency of the turbomachine can be increased by means of additional blade rows. Existing rotors 6 (stators) can also easily be converted to the new type of fastening of the moving blades 1. This is an advantage, since simpler blades 1 which can- be manufactured more cost-effectively can now be used. For example, the insertion root shown in figure 1 or else a hammer root can be produced in a simple way by means of known milling methods. Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. New patent claims 1. A fastening of blades (1, l1; i2, 13/ ln) of a turbomachine to a rotor (6) or stator, the blades (1, li, la, I3, ln) being fastened to the rotor (6) or stator by means of blade roots (4) , and the blades (1, l1# l2/ 13/ In) having a root plate (3), a cover plat (2) or a supporting wing above the blade root (4) and a blade (5) , and a torsional moment (13) acting on the cover plate (2) or on the supporting ring as a result of the installation of the blades (1, llt l2, 13/ ln) , characterized in that, after the installation of all the Mades (1, llt 12, 13, ln) , the blades (1, li, l2,;,(111 In) are contiguous to one another on the rotor, |;6) or stator at the root plate (3) and/or at the", blade root (4) without play or with a prestress and are therefore supported relative to one another with respect to torsional- moments (12) , the torsional moments (12) which act at the root plates (3) and/or at the blade roots (4) being opposite to the torsional moments (13) which act at the cover plate (2) or at the supporting wing > '2. The fastening of blades (1, li, I2, I3* In) as :: claimed in claim 1, characterized in that both the root plate (3) and/or the blade root (4) and the cover plate (2) or the supporting wing have a bevel (9) which is arranged at the point at which the applied torsional moments (12, 13) act and at which the blades (l, llf 12, 13, In) are supported relative to one another. 3 . The fastening of blades (1, li, I2, I3/ in) as claimed in claim 1 or 2, characterized in that the cover plate (2) or the supporting wing is arranged f on the blade (5) between the root plate (3) and the blade tip (14). 4 . The fastening of blades (1, li, I2, 13, ln) as claimed in claim 1, 2 or 3, characterized in that a single-prong (4a) or multi-prong insertion root or a hammerhead root is used as the blade root (4) . 5. The fastening of blades (1, li, 12, I3/ In) as claimed in claim 4, characterized in that in the blade root (4) there are additionally holes (11) through which the blade root (4) can be fastened ho the rotor (6) or stator by means of bolts. 6. The fastening of blades (1, li, I2, I3/ In) as claimed in claim 4 or 5, characterized in that the blades (1, llt l2, 13, ln) are guide vanes or moving blades of a turbine or compressor. 7. A fastening of blades substantially as herein described with reference to the accompanying drawings.

Documents:

in-pct-2002-1485-che-abstract.pdf

in-pct-2002-1485-che-assignment.pdf

in-pct-2002-1485-che-claims duplicate.pdf

in-pct-2002-1485-che-claims original.pdf

in-pct-2002-1485-che-correspondence others.pdf

in-pct-2002-1485-che-correspondence po.pdf

in-pct-2002-1485-che-description complete duplicate.pdf

in-pct-2002-1485-che-description complete original.pdf

in-pct-2002-1485-che-drawings.pdf

in-pct-2002-1485-che-form 1.pdf

in-pct-2002-1485-che-form 26.pdf

in-pct-2002-1485-che-form 3.pdf

in-pct-2002-1485-che-form 5.pdf

in-pct-2002-1485-che-form 6.pdf

in-pct-2002-1485-che-pct.pdf