The present application claims priority to Application No. 10 2004 051 116.0, filed in the Federal Republic of Germany on Oct. 20, 2004, which is expressly incorporated herein in its entirety by reference thereto.
The present invention relates to a rotor of a turbo engine, e.g., a gas turbine rotor.
Rotors of a turbo engine, e.g., gas turbine rotors, for example, have a rotor base member, as well as a plurality of rotor blades rotating with the rotor base member. The rotor blades may either be an integral component of the rotor base member, or may be anchored in one or more grooves of the rotor base member via blade roots. Rotors having integral blading are known as blisk or bling, depending upon whether the rotor base member is disk-shaped or ring-shaped. For rotors in which the rotor blades are anchored in a groove via blade roots, a distinction is made between rotors in which the blade roots of the rotor blades are secured either in so-called axial grooves of the rotor base member or in a circumferential groove of the same. An example embodiment of the present invention relates to a rotor of a turbo engine, e.g., a gas turbine rotor, in which the rotor blades are secured by their blade roots in a groove of the rotor base member extending in the circumferential direction, thus in a circumferential groove.
For rotors in which the rotor blades are secured by their blade roots in so-called circumferential grooves, the circumferential grooves have at least two diametrically opposed feed openings, in order to introduce the blade roots of the rotor blades into the corresponding circumferential groove. Conventionally, the feed openings may be formed by neckings in the region of groove-wall side pieces or limbs of the circumferential groove, the blade roots abutting with bearing flanks against the groove-wall side pieces during operation. Due to the feed openings, notch locations are formed on the groove-wall side pieces, which may be subject to a high level of stress during operation of the rotor. The service life of the rotor may thereby be reduced. Furthermore, conventionally, because of the design principle of rotor blades guided in circumferential grooves described above, the blade roots of the rotor blades, viewed in the circumferential direction, may have only approximately half the width of blade platforms of the rotor blades. Because of this, the forces which the blade roots are able to receive during operation of the rotor may be limited. The range of application of conventional rotors, in which the rotor blades are guided and secured via their blade roots in so-called circumferential grooves, may therefore be limited.
An example embodiment of the present invention may provide a rotor of a turbo engine in which the groove and the blade roots have a profile, such that the blade roots of the rotor blades are insertable into the circumferentially extending groove of the rotor base member by a tilting motion or swiveling motion, a width of the blade root corresponding approximately or roughly to a width of the blade platform of the specific rotor blade in the circumferential direction.
A rotor of a turbo engine may be provided, in which the rotor blades are guided and secured via their blade roots in a circumferential groove, but in which the groove, e.g., the groove-wall side pieces, have no feed openings minimizing mechanical strength. Rather, the groove and the blade roots have a profile which may allow the blade roots to be inserted into the groove by a tilting motion. Moreover, the blade roots may be dimensioned such that, in the circumferential direction, a width of the blade roots corresponds approximately to the width of the blade platform of the specific rotor blade. Therefore, strength-minimizing feed openings in the region of the groove may be avoided, and the blade roots may be able to take up greater forces because of their markedly greater extension in the circumferential direction. The range of application of rotors in which the rotor blades are guided in circumferential grooves may thereby be expanded.
In the radial direction, a relative position between the rotor blades and the rotor base member may be defined by spacers, the spacers being positioned between groove-wall side pieces of the groove extending in the circumferential direction and the blade platforms of the rotor blades.
The spacers may be in the form of hump-like projections, a plurality of hump-like projections being positioned at a distance from each other on both groove-wall side pieces of the groove in the circumferential direction. In each case, two rotor blades may be supported with their blade platforms on two opposing projections positioned on different groove-wall side pieces. A securing element, which defines a relative position between the rotor blades and the rotor base member in the circumferential direction, may extend through in each case two opposing, hump-like projections positioned on different groove-wall side pieces.
Formed as a spacer on one groove-wall side piece of the groove may be a projection that is closed in the circumferential direction of the groove, extends in the radial direction and is an integral component of the groove-wall side piece. Positioned as a spacer on the other groove-wall side piece of the groove may be a closure ring closed in the circumferential direction or a closure ring segmented in the circumferential direction, which is insertable between the groove-wall side piece and the platforms of the rotor blades and is fixed in position by a retaining ring.
Formed as a spacer on one groove-wall side piece of the groove may be a projection that is closed in the circumferential direction of the groove, extends in the radial direction and is an integral component of the groove-wall side piece. Formed as a spacer on the other groove-wall side piece of the groove may be a projection that extends in the circumferential direction of the groove, is interrupted by at least one opening and is an integral component of the groove-wall side piece.
According to an example embodiment of the present invention, a rotor of a turbo engine includes: a rotor base member including a groove extending in a circumferential direction of the rotor base member; and a plurality of rotor blades, each rotor blade including a blade, a blade root and a blade platform positioned between the blade and the blade root, the rotor blade anchored in the groove by the blade root. The groove and the blade root are profiled so that the blade root is insertable into the groove by one of (a) a tilt motion and (b) a swivel motion, in the circumferential direction, a width of the blade root corresponding approximately to a width of the blade platform.
The rotor may be arranged as a gas turbine rotor.
A relative position between the rotor blades and the rotor base member in a radial direction may be defined by spacers.
The spacers may be positioned between groove-wall side pieces of the groove and the blade platforms of the rotor blades.
The spacers may include projections positioned on at least one side of the groove.
The projections may include a plurality of projections positioned at a distance from one another in the circumferential direction on at least one groove-wall side piece of the groove, a recess formed between adjacent projections.
The projections may include a plurality of projections positioned at a distance from one another in the circumferential direction on both groove-wall side pieces of the groove, and two rotor blades may be supported with the blade platforms on each of two opposing projections positioned on different groove-wall side pieces of the groove.
The rotor may include securing devices that define a relative position in the circumferential direction between the rotor blades and the rotor base member, and the securing devices may extend through two opposing projections positioned on different groove-wall side pieces of the groove.
The securing devices may include rivets.
The projections may be integral to the groove-wall side pieces and may extend radially outwardly starting from the groove-wall side pieces.
The spacer on one groove-wall side piece of the groove may include a projection that is closed in the circumferential direction of the groove, extends in the radial direction and is integral to the groove-wall side piece.
The spacer on another groove-wall side piece of the groove may include one of (a) a closure ring that is closed in the circumferential direction and (b) a closure ring that is segmented in the circumferential direction, is insertable between the another groove-wall side piece and the platforms of the rotor blade and is immobilized by a retaining ring.
The spacer on another groove-wall side piece of the groove may include a projection that extends in the circumferential direction of the groove, is interrupted by at least one opening and is integral to the another groove-wall side piece.
According to an example embodiment of the present invention, a gas turbine includes at least one rotor as described above.
The gas turbine may be arranged as a gas turbine of an aircraft engine.
Exemplary embodiments of the present invention are explained in greater detail below with reference to the appended Figures.
A conventional gas turbine rotor having rotor blades guided in a circumferential groove is illustrated in
FIGS. 2 to 4 illustrate a gas turbine rotor 20 according to an example embodiment of the present invention, having a rotor base member 21 and a plurality of rotor blades 22. Rotor blades 22 each have a blade 23, a blade root 24 and a blade platform 25 arranged between blade 23 and blade root 24. Rotor base member 21 has a groove 26 extending in the circumferential direction and bounded by lateral groove-wall side pieces or limbs 27 and 28, respectively, rotor blades 22 being guided with their blade roots 24 in groove 26 extending in the circumferential direction. In the assembled state (see, e.g.,
Circumferential groove 26 and blade roots 24 have a profile, such that blade roots 24 of rotor blades 22 are insertable into circumferential groove 26 of rotor base member 21 by a tilting motion or swiveling motion, and e.g., without neckings or notches which may minimize mechanical strength being necessary in groove-wall side pieces 27 and 28, respectively. In
As already mentioned, after rotor blades 22 have been pivoted by blade roots 24 into circumferential groove 26 in accordance with double arrow 30, rotor blades 22 are aligned relative to rotor base member 21 such that blade roots 24 abut against groove-wall side pieces 27 and 28 of groove 26, forming bearing flanks 29. In this context, in the radial direction, a relative position between rotor blades 22 and rotor base member 21 is defined by spacers, the spacers being positioned between groove-wall side pieces 27 and 28 extending in the circumferential direction and blade platforms 25 of rotor blades 22.
As illustrated in FIGS. 2 to 4, the spacers may be in the form of hump-like projections 31 which extend on both sides of groove 26, and accordingly are positioned in the region of both groove-wall side pieces 27 and 28. Viewed in the circumferential direction, a plurality of hump-like projections 31 are formed with distance from one another on both sides of circumferential groove 26. Therefore, in each case, a recess 32 is formed between two hump-like projections 31 adjacent in the circumferential direction. Multiple hump-like projections 31 are accordingly positioned at a distance from one another in the circumferential direction in the region of both groove-wall side pieces 27 and 28. In each case, two rotor blades 22 are supported with their blade platforms 25 on two opposite, hump-like projections 31 positioned on different groove-wall side pieces 27 and 28. Thus,
Therefore, in the mounted state of rotor blades 22, the spacers, formed in the exemplary embodiment illustrated
In the circumferential direction, the relative position between rotor blades 22 and base member 21 of gas turbine rotor 20 is defined by securing elements 33 that, in each case, extend through two opposite, hump-like projections 31 positioned on different groove-wall side pieces 27 and 28. In the exemplary embodiment illustrated in FIGS. 2 to 4, securing elements 33 may be in the form of rivets supported in bore holes 34 of hump-like projections 31. In the exemplary embodiment illustrated in
In the exemplary embodiment illustrated in FIGS. 2 to 4, the gas turbine rotor includes a guidance of the blade roots of the rotor blades in a circumferential groove of the rotor base member, in which no strength-minimizing notches may be necessary in the groove-wall side pieces of the circumferential groove. Rather, the circumferential groove and the blade roots are profiled such that the blade roots may be introduced into the circumferential groove by a tilting motion, and the width of the blade roots in the circumferential direction corresponds approximately to the width of the respective blade platform, and therefore markedly larger bearing flanks may be made possible between the blade roots and the groove-wall side pieces compared to conventional systems. In the radial direction, the relative position between the rotor blades and the rotor disk base member is defined by spacers in the form of hump-like projections that may be an integral component of the groove-wall side pieces. In the circumferential direction, the relative position is defined by securing elements that extend through two opposite, hump-like projections positioned on different groove-wall side pieces.
An aspect of this design of a gas turbine rotor compared to conventional systems is that it may be possible to eliminate feed openings, required according to conventional systems, in the groove-wall side pieces which may reduce the mechanical strength and the service life of the blade/rotor connection. A further aspect is that markedly larger bearing flanks may be made possible between the blade roots and the groove-wall side pieces, which means the compressive load per unit area in the region of the bearing surfaces, and therefore the danger of so-called fretting, may be reduced. Gas turbine rotors hereof may be able to take up perceptibly higher forces during operation than conventional rotors, e.g., thereby increasing service life and enlarging a range of applications.
FIGS. 7 to 9 illustrate a gas turbine rotor 39 according to an example embodiment of the present invention. The same reference numerals are used in FIGS. 7 to 9 for the same or similar structural components, and in the following description, only those details are discussed which differentiate the exemplary embodiment illustrated in FIGS. 7 to 9 from the exemplary embodiment illustrated in FIGS. 2 to 4. Thus, the exemplary embodiment illustrated in FIGS. 7 to 9 again differs from the exemplary embodiment illustrated in FIGS. 2 to 4 due to the form of the spacers which define the relative position of rotor blades 22 with respect to rotor disk base member 21 in the radial direction. In the exemplary embodiment illustrated in FIGS. 7 to 9, on one groove-wall side piece 27 of circumferential groove 26, a first spacer is formed as a projection 43 closed in the circumferential direction of groove 26. Projection 43 is an integral component of groove-wall side piece 27 and, starting from groove-wall side piece 27, extends radially outwardly in the direction of platform 25 of rotor blade 22. As already mentioned, in the exemplary embodiment illustrated in FIGS. 7 to 9, projection 43 is closed in the circumferential direction. Used as a spacer in the region of opposite groove-wall side piece 28 is a projection 44 that extends in the circumferential direction of groove 26, is interrupted by at least one opening 45, and is an integral component of groove-wall side piece 28. In the region of each opening 45, the relative position in the circumferential direction between rotor blades 22 and base member 21 of gas turbine rotor 20 is defined by a securing element 46. Securing elements 46 are formed by a rivet 47 and a closure element 48 for opening 45, closure element 48 cooperating with rivet 47. As illustrated in
Number | Date | Country | Kind |
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10 2004 051 116.0 | Oct 2004 | DE | national |