EP2189664B1 - Multivane variable stator arrangement for turbomachine - Google Patents

Description

The invention relates to a multiblade adjusting stator unit of a fluid power machine according to the preamble of claim 1.

The aerodynamic load capacity and the efficiency of fluid flow machines, such as fans, compressors, pumps and fans, is limited in particular by the growth and detachment of boundary layers in the region of the radial gap between the blading and the housing or the hub which is structurally necessary at the annular channel edge.

The radial gaps, which can arise through free cuts in front of and behind the rotating spindle, are particularly pronounced on rotating adjustable stators and cause considerable flow losses. In order to limit these losses, turntables as large as possible are usually provided at the inner and outer ends of the adjusting stators in order to keep the extent of the cutouts in the flow direction small.

Now the turntables are usually completely round. Since the diameter is limited by the distance between two adjacent blades, only turntable, the diameter of which are significantly smaller than the profile length of the blade in the respective Hub- or especially with narrow blade pitches, as they are increasingly found in modern machines, are provided Housing area. There remains inevitably a considerable radial gap before and / or behind the turntable.

The Fig. 1 shows a part of a fluid flow machine in the region of one of its prior art Verstellstatorreihen 1, shown in the meridian plane. Apart from the adjustment stator row 1 itself, components in the hub area 3 and housing area 3 are indicated, which hold the adjusting stator 1 inside and outside.

On the right side of the image, the view AA is shown, showing the inner flow path boundary (hub 3) in the plane formed by the meridional direction m and the circumferential direction u. The construction shown here according to the prior art provides separate from each other in the hub 3 mounted turntable 5 of individual adjusting blades before. Each turntable 5 is connected to a single blade 1. The blade 1 protrudes significantly with its front and / or rear edge on the turntable 5 addition. The representation is made as an example for the hub 3, but there is a basically the same arrangement of the turntable 5 on the housing side boundary of the flow path of the fluid flow machine.

In detail, the invention relates to at least one adjustable unit of a stator blade row, optionally also as an element of an adjustable guide wheel, a fluid flow machine. The blading in question is arranged within a housing which limits the flow of usually at least one rotor blade row (rotor) and at least one row of stator blades (stator) with a fluid to the outside. While a rotor comprises a plurality of rotor blades attached to a rotating shaft and supplies energy to the working fluid, a stator consists of a plurality of stator blades usually mounted in the housing.

A disadvantage proves in the prior art that the corresponding arrangements of the blade and turntable lead to large radial part gaps at the blade ends and thus considerable pressure losses in the flow. The consequence are restrictions with regard to the achievable efficiency and the operating behavior of the fluid flow machine. Especially with adjustable stators arrangements of blades and turntables, which allow a substantial or even complete avoidance of the blade overhang and the associated radial partial gaps.

The US Pat. No. 3,069,070 shows a centrifugal compressor, in which two stator blades are arranged on a common turntable and are rotatable about a common axis of rotation.

Another centrifugal compressor is out of the CH 492 130 A known. In this two blades are mounted on a common turntable and also rotatable about a common axis of rotation.

The DE 28 35 349 B1 shows the arrangement of a respective stator blade on a turntable and the assignment of the adjacent turntable.

The present invention has for its object to provide an adjustable Statorschaufelanordnung of the aforementioned type, which achieved avoiding the disadvantages of the prior art, a substantial or complete avoidance of Radialteilspalten at the blade end by the provision of at least two stator blades on a turntable.

According to the invention the object is achieved by the combination of features of claim 1, the dependent claims show further advantageous embodiments of the invention.

The present invention thus relates to variable stator blade rows of fluid flow machines such as fans, compressors, pumps, and fans in axial, semi-axial, or even radial design. The working medium (fluid) can be gaseous or liquid.

Fig. 1

eine schematische Darstellung eines Verstellstators nach dem Stand der Technik in der Meridianansicht,

Fig. 2a

einen Verstellstator, Definition von Kenngrößen,

Fig. 2b

einen Verstellstator, Ansicht A-A, Dualkonfiguration, gleichmäßige Schaufelanordnung,

Fig. 3

einen Verstellstator, Ansicht A-A, Dualkonfiguration, unterschiedliche Schaufelteilung,

Fig. 4

einen Verstellstator, Ansicht A-A, Dualkonfiguration, unterschiedliche Schaufelteilung und meridionale Schaufelposition,

Fig. 5

einen Verstellstator, Ansicht A-A, Dualkonfiguration, unterschiedliche Schaufelteilung und meridionale Schaufelposition und drehtellerangepasste Profilgestalt,

Fig. 6a

einen Verstellstator, Ansicht A-A, Dualkonfiguration, unterschiedliche Schaufelteilung und meridionale Schaufelposition und drehtellerangepasste Profilgestalt, alternierend verkürzte Profiltiefe,

Fig. 6b

einen Verstellstator, Ansicht A-A, Dualkonfiguration in Auslegungsanordnung, weitere Kenngrößen,

Fig. 6c

einen erfindungsgemäßen Verstellstator, Ansicht A-A, Dualkonfiguration in Auslegungsanordnung, Engstellung zweier Profile,

Fig. 6d

einen Verstellstator, Ansicht A-A, Dualkonfiguration in Auslegungsanordnung, Engstellung zweier Profile, kurzes Frontprofil,

Fig. 6e

einen Verstellstator, Ansicht A-A, Triple-Konfiguration, Engstellung der Profile,

Fig. 7a

einen Verstellstator, Ansicht A-A, Dualkonfiguration, unterschiedliche Schaufelteilung, meridionale Schaufelposition, Profilgestalt und alternierend verkürzte Profiltiefe,

Fig. 7b

einen Verstellstator, Ansicht A-A, Dualkonfiguration in Auslegungsanordnung, weitere Kenngrößen,

Fig. 7c

einen Verstellstator gemäß Fig. 7a, Bauweise,

Fig. 7d

einen Verstellstator gemäß Fig. 7a in der Meridianansicht,

Fig. 8a

einen Verstellstator, Ansicht A-A, Triple-Konfiguration unterschiedliche Schaufelteilung, meridionale Schaufelposition und unterschiedliche Profiltiefe,

Fig. 8b

einen Verstellstator gemäß Fig. 8a, Bauweise,

Fig. 8c

einen Verstellstator gemäß Fig. 8a in der Meridianansicht.

The present invention relates to stators, which are rotatably mounted on at least one blade end and can be adjusted by a spindle about a rotation axis 4. As shown in all figures, the flow of the relevant row of blades 1, as indicated by the thick arrow, takes place from left to right. For use in a fluid flow machine, an adjustable stator blade row is provided which has at least one main flow path boundary, hub or housing, at least one arrangement of a turntable with at least two fixedly connected to the turntable stator blades, such that at least two stator blades in a rotational adjustment to rotate the same axis and be controlled by only one rotary spindle. According to the invention, the at least two stator blades are arranged offset to one another in the meridional direction and their profiles are designed in accordance with the characterizing part of the first claim. In the following, on the one hand, the invention will be described with reference to an exemplary embodiment (in FIG Fig. 6c ) and second, but not belonging to the claimed invention examples described in conjunction with the figures. Showing:

Fig. 1

a schematic representation of an adjustable stator according to the prior art in the meridian view,

Fig. 2a

an adjustable stator, definition of characteristic values,

Fig. 2b

an adjustable stator, view AA, dual configuration, even blade arrangement,

Fig. 3

an adjustable stator, view AA, dual configuration, different blade pitch,

Fig. 4

an adjustable stator, view AA, dual configuration, different blade pitch and meridional blade position,

Fig. 5

an adjustable stator, view AA, dual configuration, different blade pitch and meridional blade position and turntable-adapted tread shape,

Fig. 6a

an adjustable stator, view AA, dual configuration, different blade pitch and meridional blade position and turntable-adapted profile shape, alternately shortened tread depth,

Fig. 6b

an adjustable stator, view AA, dual configuration in design arrangement, further characteristics,

Fig. 6c

an adjustable stator according to the invention, view AA, dual configuration in design arrangement, constriction of two profiles,

Fig. 6d

an adjustable stator, view AA, dual configuration in design arrangement, narrowness of two profiles, short front profile,

Fig. 6e

an adjustable stator, view AA, triple configuration, constriction of the profiles,

Fig. 7a

an adjustable stator, view AA, dual configuration, different blade pitch, meridional blade position, profile shape and alternately shortened tread depth,

Fig. 7b

an adjustable stator, view AA, dual configuration in design arrangement, further characteristics,

Fig. 7c

an adjusting stator according to Fig. 7a , Construction,

Fig. 7d

an adjusting stator according to Fig. 7a in the meridian view,

Fig. 8a

an adjustable stator, view AA, triple configuration different blade pitch, meridional blade position and different tread depth,

Fig. 8b

an adjusting stator according to Fig. 8a , Construction,

Fig. 8c

an adjusting stator according to Fig. 8a in the meridian view.

Not explicitly shown, but also the subject of the present invention are Verstellstatoranordnungen in which a storage is provided solely in the housing or alone in the hub with full radial gap at the other end of the blade.

• a.) die Profiltiefe I, gemessen in Richtung der Profilsehne
• b.) die Profilwölbung f, gemessen als senkrechter Abstand des am weitesten von der Profilsehne entfernten Punkt der Skelettlinie zur Profilsehne
• c.) der Vorderkantenneigungswinkel β1, gemessen zwischen der Meridionalrichtung m und der Tangente an die Skelettlinie im Vorderkantenpunkt
• d.) der Hinterkantenneigungswinkel β2, gemessen zwischen der Meridionalrichtung m und der Tangente an die Skelettlinie im Hinterkantenpunkt
• e.) der Staffelungswinkel λ, gemessen zwischen der Meridionalrichtung m und der Profilsehne
• f.) der Drehtellerdurchmesser d
• h.) die Profilexzentrizität e, gemessen als senkrechter Abstand des Drehtellermittelpunktes M zu einer Parallelen zur Profilsehne durch den am weitesten von der Profilsehne entfernten Punkt der Skelettlinie
• i.) die Profilabdeckung n, gemessen zwischen den Schnittpunkten der Skelettlinie mit dem Drehtellerrandkreis in Richtung der Profilsehne (falls die Vorder- oder Hinterkante auf dem Drehteller angeordnet ist, bildet der Vorder- oder Hinterkantenpunkt den jeweiligen Bezugspunkt).
• j.) der meridionale Profilversatz a, gemessen zwischen den Vorderkantenpunkten zweier benachbarter Profile in der Meridionalrichtung m

The Fig. 2a shows the definition of the geometric parameters important for the invention in the plane formed by the meridional direction m and the circumferential direction u directly on the turntable 5. Here, by way of example, a turntable 5 is shown with two attached blades 1. The characteristics are shown on the upper of the two blades 1, but the parameters also apply to each further blade 1 connected to the turntable 5. Each blade 1 has a (usually concave) pressure side DS and a (usually convex) suction side SS. Each blade profile has a skeleton line that runs between the front edge VK and trailing edge HK centrally between the suction side and the pressure side through the profile. Another important reference line represents the profile chord, which is applied on the pressure side of the blade profile. The following parameters are in Fig. 2a Are defined:

• a.) The tread depth I, measured in the direction of the chord
• b.) the profile curvature f, measured as the vertical distance of the point furthest from the profile chord of the skeleton line to the chord
• c.) the leading edge tilt angle β1, measured between the meridional direction m and the tangent to the skeleton line in the leading edge point
• d.) the trailing edge inclination angle β2, measured between the meridional direction m and the tangent to the skeleton line in the trailing edge point
• e.) the stagger angle λ, measured between the meridional direction m and the chord
• f.) the turntable diameter d
• h.) The profile eccentricity e, measured as the vertical distance of the turntable center point M to a parallel to the chord by the furthest from the chord line point of the skeleton line
• i.) the profile cover n, measured between the intersections of the skeleton line with the turntable edge circle in the direction of the chord (if the front or rear edge is arranged on the turntable, the leading or trailing edge point forms the respective reference point).
• j.) the meridional profile offset a, measured between the leading edge points of two adjacent profiles in the meridional direction m

The Fig. 2b shows on its left side (a.) A series of uniformly at the same pitch t arranged stator blades 1 identical profile shape in the design position, ie in the nominal position. The conventional turntable conventional turntable are shown in dashed lines. The solution on which the invention is based, provides larger turntable 5, each of which is connected in the variant shown here with two blades 1 (dual configuration). The blades 1 are here largely on the turntable 5 and protrude only with the front and / or rear edge slightly beyond the turntable 5, both blades 1 have a relative coverage n / l greater than 0.5. The embodiment shown here even shows an advantageous relative coverage n / l of over 0.75. Also advantageous, but not graphically represented here, would be a different profile shape of the two blades 1 in the region of the turntable 5, if the two blades 1 have different relative covers of smaller n / l = 1.

The right half of the figure (b.) Shows the variable stator arrangement in a partial load operating point of the fluid flow machine, d. H. with an adjustment of the blades 1 towards larger stagger angles λ. For large amounts of λ there is a collision of two adjacent vanes 1 belonging to different turntables 5, so that this solution is only well suited for small adjustment ranges.

The Fig. 3 shows a similar Verstellstatoranordnung as Fig. 2b but here the blade pitch t alternates between two blades 1 in each case, that two blades 1 lying closer to one another are arranged on a turntable 5. In the nominal position of the turntable 5, see the left side of the picture (a.), The leading and trailing edges of the blades 1 continue to form a straight line. Here, regardless of the relative coverage n / l, it is in any case advantageous to design the profile shape of the two blades differently. The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the alternating blade pitch results in a larger possible adjustment range, before it comes to a collision of two adjacent to different turntables 5 belonging blades 1.

The Fig. 4 shows a similar Verstellstatoranordnung as Fig. 3 , however, additionally the meridional position of the blades 1 alternates such that on a turntable 5 the leading edge of a blade 1 is arranged farther downstream relative to the meridional direction m (meridional profile offset a> 0), the profile depths of two adjacent blades 1 are less than 10% and the stagger angle λ _{U of} the blade located farther downstream is smaller than the stagger angle λ _{D of} the blade further upstream, see the left side of the figure (a.). The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the different blade pitch and the meridional profile offset results in a streamlined configuration and a slightly larger possible adjustment range.

The Fig. 5 shows a similar Verstellstatoranordnung as Fig. 4 However, the two provided on a turntable 5 blades 1 with respect to the tread depth I, the staggering angle λ and the meridional profile offset a significant differences. The arrangement is particularly favorable here designed such that both blades 1 completely without overhang on the turntable 5 place, see left side (a.). The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the complete placement on the turntable 5 results in a streamlined configuration and an unlimited adjustment.

The Fig. 6a shows a similar Verstellstatoranordnung as Fig. 5 , in which also both blades 1 completely without overhang on the turntable. 5 Find a place. Here, however, a difference of the profile depths of the two blades 1 of at least 25% is provided in order to achieve improved utilization of the turntable 5. The shorter profile is arranged on the turntable 5 on the pressure side of the longer profile, see left image page (a.). The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the complete placement on the turntable 5 results in a streamlined configuration and an unlimited adjustment.

1. a.) der meridionale Profilversatz a, gemessen zwischen den Hinterkantenpunkten zweier benachbarter Profile in der Meridionalrichtung m
2. b.) die meridionale Überlappung b, gemessen zwischen dem Vorderkantenpunkt des kürzeren Profils und dem Hinterkantenpunkt des längeren Profils in der Meridionalrichtung m
3. c.) die meridionale Reststrecke c, gemessen zwischen dem Vorderkantenpunkt des längeren Profils und dem Vorderkantenpunkt des kürzeren Profils in der Meridionalrichtung m
4. d.) der druckseitige Abstand q, gemessen in der Umfangsrichtung u, zwischen dem Schnittpunkt der Linie durch die Hinterkantenpunkte der längeren Profile mit der Skelettlinie des kürzeren Profils und dem Hinterkantenpunkt des saugseitig vom kürzeren Profil angeordneten längeren Profils
5. e.) der saugseitige Abstand g, gemessen in der Umfangsrichtung u, zwischen dem Schnittpunkt der Linie durch die Hinterkantenpunkte der längeren Profile mit der Skelettlinie des kürzeren Profils und dem Hinterkantenpunkt des druckseitig vom kürzeren Profil angeordneten längeren Profils

The Fig. 6b shows the favorable dual arrangement with the definition of further characteristics that describe it. The arrangement is characterized by two blade profiles on a common turntable, wherein a shorter profile is arranged on the pressure side of the longer profile. Characteristic quantities are defined in the picture:

1. a.) the meridional profile offset a, measured between the trailing edge points of two adjacent profiles in the meridional direction m
2. b.) the meridional overlap b, measured between the leading edge point of the shorter profile and the trailing edge point of the longer profile in the meridional direction m
3. c.) the meridional residual distance c measured between the leading edge point of the longer profile and the leading edge point of the shorter profile in the meridional direction m
4. d.) the pressure-side distance q, measured in the circumferential direction u, between the intersection of the line through the trailing edge points of the longer profiles with the skeleton line of the shorter profile and the trailing edge point of the longer profile arranged on the suction side of the shorter profile
5. e.) The suction-side distance g, measured in the circumferential direction u, between the intersection of the line through the trailing edge points of the longer profile with the skeleton line of the shorter profile and the trailing edge point of the longer profile arranged on the pressure side of the shorter profile

$$0<\left(\mathrm{b}/\left(\mathrm{b}+\mathrm{c}\right)\right)<\mathrm{0,65}$$

$$\mathrm{0,3}<\left(\mathrm{q}/\left(\mathrm{g}+\mathrm{q}\right)\right)<\mathrm{0,7}$$

Particularly favorable are the following definitions: $$0<\left(\mathrm{a}/\left(\mathrm{b}+\mathrm{c}\right)\right)<0.25$$

$$0<\left(\mathrm{b}/\left(\mathrm{b}+\mathrm{c}\right)\right)<0.65$$

$$0.3<\left(\mathrm{q}/\left(\mathrm{G}+\mathrm{q}\right)\right)<0.7$$

The Fig. 6c shows a likewise advantageous according to the invention dual arrangement with the property that the front edge of the farther downstream profile is provided in the vicinity of the trailing edge and the pressure side of the further upstream profile, see left side (a.). The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. The narrowness of the profiles according to the invention is described by further variables identified in the picture. Here, l2 is the total profile depth, ie the length of the dual arrangement in the direction of the pressure applied to the entire arrangement tangent. The entanglement b2 is measured (positive as shown) in the direction of the total tread depth. Further characteristics are the total division w and the total height v, both are measured perpendicular to the total profile depth. For particularly favorable arrangements: $$-0.1<\left(\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="imgf0001.png,imgf0008.png"\; state="\{\{state\}\}">b</figure-callout>}2/\mathrm{I}2\right)<0.1\mathrm{and}\left(\mathrm{v}/\mathrm{w}\right)<0.3$$

According to the invention, it is particularly advantageous to dimension the relative curvature f / l of the profile arranged farther downstream significantly greater than the relative curvature f / l of the further upstream profile (f / l) _downstream > 1.2 * (f / l ) _upstream .

The Fig. 6d shows another favorable dual arrangement with bottleneck, here with a short front profile, see left image page (a.). The right-hand side of the picture (b.) Shows the variable stator arrangement at partial load operation.

The 6E shows a constriction arrangement in which three profiles are arranged in series, see left side of the image (a.). The right-hand side of the picture (b.) Shows the variable stator arrangement at partial load operation.

The Fig. 7a shows a similar Verstellstatoranordnung as Fig. 6 in which also both blades are completely without overhang on the turntable 5 place and a difference in the profile depths of the two blades of at least 25% is provided in order to achieve improved utilization of the turntable. The shorter profile is here, however, advantageously arranged on the turntable 5 on the suction side of the longer profile, see left side of the picture (a.). The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the complete placement on the turntable results in a very streamlined arrangement and an unlimited adjustment.

1. a.) der meridionale Profilversatz a, hier gemessen zwischen den Vorderkantenpunkten zweier benachbarter Profile in der Meridionalrichtung m
2. b.) die meridionale Überlappung b, hier gemessen zwischen dem Vorderkantenpunkt des längeren Profils und dem Hinterkantenpunkt des kürzeren Profils in der Meridionalrichtung m
3. c.) die meridionale Reststrecke c, hier gemessen zwischen dem Hinterkantenpunkt des kürzeren Profils und dem Hinterkantenpunkt des längeren Profils in der Meridionalrichtung m
4. d.) der druckseitige Abstand q, hier gemessen in der Umfangsrichtung u, zwischen dem Schnittpunkt der Linie durch die Vorderkantenpunkte der längeren Profile mit der Skelettlinie des kürzeren Profils und dem Vorderkantenpunkt des druckseitig vom kürzeren Profil angeordneten längeren Profils
5. e.) der saugseitige Abstand g, hier gemessen in der Umfangsrichtung u, zwischen dem Schnittpunkt der Linie durch die Vorderkantenpunkte der längeren Profile mit der Skelettlinie des kürzeren Profils und dem Vorderkantenpunkt des saugseitig vom kürzeren Profil angeordneten längeren Profils.

Besonders günstig sind folgende Festlegungen: $$0<\left(\mathrm{a}/\left(\mathrm{b}+\mathrm{c}\right)\right)<\mathrm{0,25}$$

$$0<\left(\mathrm{b}/\left(\mathrm{b}+\mathrm{c}\right)\right)<\mathrm{0,65}$$

$$\mathrm{0,3}<\left(\mathrm{q}/\left(\mathrm{g}+\mathrm{q}\right)\right)<\mathrm{0,7}$$

The Figure 7b shows the particularly favorable dual arrangement with the definition of further characteristics that describe it. The arrangement is characterized by two blade profiles on a common turntable 5, wherein a shorter profile is arranged on the suction side of the longer profile. Characteristic quantities are defined in the picture:

1. a.) The meridional profile offset a, measured here between the leading edge points of two adjacent profiles in the meridional direction m
2. b.) the meridional overlap b, measured here between the leading edge point of the longer profile and the trailing edge point of the shorter profile in the meridional direction m
3. c.) the meridional residual distance c, measured here between the trailing edge point of the shorter profile and the trailing edge point of the longer profile in the meridional direction m
4. d.) the pressure-side distance q, measured here in the circumferential direction u, between the intersection of the line through the leading edge points of the longer profile with the skeleton line of the shorter profile and the leading edge point of the longer profile arranged on the pressure side of the shorter profile
5. e.) The suction-side distance g, measured here in the circumferential direction u, between the intersection of the line through the leading edge points of the longer profiles with the skeleton line of the shorter profile and the leading edge point of the longer profile arranged on the suction side of the shorter profile.

Particularly favorable are the following definitions: $$0<\left(\mathrm{a}/\left(\mathrm{b}+\mathrm{c}\right)\right)<0.25$$

$$0<\left(\mathrm{b}/\left(\mathrm{b}+\mathrm{c}\right)\right)<0.65$$

$$0.3<\left(\mathrm{q}/\left(\mathrm{G}+\mathrm{q}\right)\right)<0.7$$

The 7c shows the Verstellstatoranordnung Fig. 7a , with different design solutions. In the left half of the picture, the turntable-blade arrangement is also shown in the mu-plane. Plotted there is the course of view BB.

1. (I) Mindestens zwei dem Drehteller 5 zugeordnete Schaufeln 1 besitzen jeweils einen Schaufelfuß 6, wobei die mindestens zwei Schaufelfüße 6 zur runden Form des Drehtellers 5 an der Strömungspfadberandung beitragen.
   Dabei ist mindestens ein Schaufelfuß 6 an der strömungspfadzugewandten Seite in einer Ausnehmung im Drehteller 5 vorgesehen. Dann bildet ein Schaufelfuß 6 einen flachen einschiebbaren Einsatz mit gegebenenfalls schräger Anlagefläche im Drehteller 5 und gegebenenfalls im Fuß einer anderen Schaufel 1.
   Die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Einzelschraub- oder Einzelstiftverbindung aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.
2. (II) wie (I) aber: die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Schweißverbindung an der Hauptströmungpfadberandung aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.
3. (III) Mindestens eine dem Drehteller zugeordnete Schaufel besitzt keinen ausgeprägten Schaufelfuß, wobei das Schaufelprofil direkt mit dem in seinem Bereich bereits vollständig kreisförmigen Drehteller verbunden wird.
   Das Schaufelprofil wird unmittelbar an der Strömungspfadberandung mit dem Drehteller durch eine Schweißnaht verbunden. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.
4. (IV) wie (III) aber: das Schaufelprofil wird gänzlich oder mit einer Zunge durch ein Loch im Drehteller gesteckt und an der der Strömungspfadberandung abgewandten Seite des Drehtellers (gegebenenfalls durch Materialstauchung, wie hier abgebildet, siehe Markierung St) eingeklemmt oder (wie hier nicht abgebildet) angeschweißt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.

On the right half of the image, the variable stator arrangement is shown in the view BB. Solutions relate to adjustable stators with at least one turntable 5 (on the hub 3 or on the housing 2). The Verstellstator shown here has for the purpose of illustrating many design solutions with two turntables 5 provided ends, where different possible constructions are. Of course, the variable stator can be produced in one piece by means of machining, chemical or deposition / build-up (welding / laser / sintering) processes. However, it is provided as a particularly favorable solution that the variable stator is designed and manufactured as an assembly of at least two components and then assembled into a Verstellstatoreinheit. For this purpose, different favorable concepts are presented below:

1. (I) At least two of the turntable 5 associated blades 1 each have a blade root 6, wherein the at least two blade feet 6 contribute to the round shape of the turntable 5 at the Strömungspfadberandung.
   In this case, at least one blade root 6 is provided on the flow path-facing side in a recess in the turntable 5. Then, a blade root 6 forms a flat insert insert with optionally inclined contact surface in the turntable 5 and optionally in the foot of another blade. 1
   The adjoining turntable parts (or blade feet) are by means of a Einzelschraub- or single pin connection together attached. This is particularly advantageous when the concept is used at both ends of the variable stator.
2. (II) as (I) but: the adjacent turntable parts (or blade feet) are fixed to each other by means of a welded joint at the main flow path boundary. This is particularly advantageous when the concept is used at both ends of the variable stator.
3. (III) At least one blade associated with the turntable does not have a pronounced blade root, the blade profile being connected directly to the turntable, which is already completely circular in its region.
   The blade profile is connected directly to the Strömungspfadberandung with the turntable by a weld. This is particularly advantageous when the concept is used at both ends of the variable stator.
4. (IV) as (III) but: the blade profile is inserted entirely or with a tongue through a hole in the turntable and on the side facing away from the Strömungspfadberandung turntable (possibly by material compression, as shown here, see mark St) or (as shown here not shown) welded. This is particularly advantageous when the concept is used at both ends of the variable stator.

The Fig.7d shows the Verstellstatoranordnung Fig. 7a in the meridian view. Concealed blade edges are dotted.

The Figure 8a shows an adjustable stator assembly as Fig. 6 in which three blades 1 find room completely without overhang on the turntable 5 and a difference of the minimum and maximum profile depth of the three blades 1 of at least 25% is provided in order to achieve improved utilization of the turntable 5. It is particularly advantageous to provide a longer profile between two shorter, the short suction side of the long profile arranged profile in Meridianströmungsrichtung m further upstream than the short pressure side of the long profile arranged profile, see left side (a.). It is also advantageous if the two short profiles have a lower relative curvature f / l than the long profile. It is furthermore advantageous if the long profile has a low relative eccentricity of 2 · e / d <0.15 and at least one of the short profiles has a high relative eccentricity of 2 · e / d> 0.35. It is also advantageous if the staggering angle decreases from the short suction-side-arranged profile to the long, centrally arranged profile and further to the short pressure-side profile: λ _U > λ _M > λ _D.

The right-hand side of the picture (b.) Again shows the variable stator arrangement in partial load operation. Due to the complete placement on the turntable results in a very streamlined arrangement and an unlimited adjustment.

The 8B shows the Verstellstatoranordnung Fig. 8a , with different design solutions. In the left half of the picture, the turntable-blade arrangement is also shown in the mu-plane. Plotted there is the course of view BB.

• (V) wie (I) aber: die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Schweißverbindung an der Seite des Drehtellers aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Endes des Verstellstators verwendet wird. an der Seite des Drehtellers (wie nicht im Bild gezeigt)
• (VI) wie (I) aber: mindestens ein Schaufelfuß bildet die volle Dicke des Drehtellers und grenzt stoßartig an einen anderen Teil des Drehtellers an.
  Die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Schweißnaht an der der Strömungspfadberandung abgewandten Seite des Drehtellers aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.
• (VII) wie (I) aber: mindestens ein Schaufelfuß ist an der strömungspfadzugewandten Seite in einer Ausnehmung im Drehteller vorgesehen. Dann bildet der Fuß einer Schaufel einen flachen einschiebbaren Einsatz mit gegebenenfalls schräger Anlagefläche im Drehteller und gegebenenfalls im Fuß einer anderen Schaufel.
  Die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Doppel-Schraub/-Stift-Verbindung aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.
• (VIII) wie (I) aber: mindestens ein Schaufelfuß grenzt mit einer Nut/Feder-Verbindung an einen anderen Teil des Drehtellers gegebenenfalls den Fuß einer anderen Schaufel an.
  Die aneinander grenzenden Drehtellerteile (beziehungsweise Schaufelfüße) werden mit Hilfe einer Einzelschraub- oder Einzelstiftverbindung von der der Strömungspfadberandung abgewandten Seite des Drehtellers aneinander befestigt. Dies ist insbesondere dann vorteilhaft, wenn das Konzept an beiden Enden des Verstellstators verwendet wird.

On the right half of the image, the variable stator arrangement is shown in the view BB. It is also provided here as a particularly favorable solution that the variable stator is designed and manufactured as an assembly of at least two components and then assembled into a Verstellstatoreinheit. For this purpose, different favorable concepts are presented below:

• (V) as (I) but: the adjacent turntable parts (or blade feet) are attached to each other by means of a welded joint on the side of the turntable. This is particularly advantageous when the concept is used at both ends of the variable stator. on the side of the turntable (as not shown in the picture)
• (VI) as (I) but: at least one blade root forms the full thickness of the turntable and abruptly adjacent to another part of the turntable.
  The adjoining turntable parts (or blade feet) are fastened to one another by means of a weld on the side of the turntable facing away from the flow path boundary. This is particularly advantageous when the concept is used at both ends of the variable stator.
• (VII) as (I) but: at least one blade root is provided on the flow path facing side in a recess in the turntable. Then the foot of a blade forms a flat retractable insert with optionally inclined contact surface in the turntable and possibly in the foot of another blade.
  The adjoining turntable parts (or blade feet) are fastened together by means of a double screw / pin connection. This is particularly advantageous when the concept is used at both ends of the variable stator.
• (VIII) as (I) but: at least one blade root adjoins, with a tongue and groove connection to another part of the turntable optionally the foot of another blade.
  The adjoining turntable parts (or blade feet) are fastened to each other by means of a Einzelschraub- or single-pin connection of the Strömungspfadberandung side facing away from the turntable. This is particularly advantageous when the concept is used at both ends of the variable stator.

• a) der meridionale Profilversatz a gemäß 0 < (a / (b+c)) < 0,25 ausgebildet ist
• b.) die meridionale Überlappung b gemäß 0 < (b / (b+c)) < 0,65 ausgebildet ist
• c.) der druckseitige Abstand q gemäß 0,3 < (q / (g+q)) < 0,7 ausgebildet ist

wobei c die meridionale Reststrecke und g der saugseitige Abstand sind.
wobei die Vorderkante mindestens einer auf dem Drehteller stromab angeordneten Statorschaufel in der Nähe der Hinterkante und druckseitig einer weiter stromauf angeordneten Statorschaufel vorgesehen ist, wobei für die Gesamtprofiltiefe l2, die Verschränkung b2, die Gesamtteilung w und die Gesamthöhe v der Anordnung der jeweils betroffenen zwei Statorschaufeln gilt: -0,1 < b2 /l2 < 0,1 und v / w < 0,3.
wobei bevorzugt auf einem Drehteller drei Schaufelprofile vorgesehen sind, wobei das mittlere Schaufelprofil bezüglich der Profiltiefe l einen Unterschied von mindestens 25% gegenüber den anderen zwei Schaufelprofilen aufweist,
wobei bevorzugt die mehreren mehrschaufeligen Verstellstatoreinheiten der Verstellstatorschaufelreihe um die Drehachse (Drehtellerachse) im vollen Bereich von 360° synchron verstellbar sind, derart, dass eine Kollision beziehungsweise eine Positionsüberschneidung benachbarter mehrschaufeliger Verstellstatoreinheiten nicht vorkommt,
wobei bevorzugt die mehrschaufelige Verstellstatoreinheit mindestens zwei Bauteile umfasst, die getrennt gefertigt und anschließend zusammengefügt werden, wobei an einem Drehteller mindestens Schaufeln jeweils einen Schaufelfuß besitzen, wobei die mindestens zwei Schaufelfüße zur runden Form des Drehtellers an der Strömungspfadberandung beitragen,
wobei bevorzugt mindestens ein Schaufelfuß die volle Dicke des Drehtellers besitzt und stoßartig an einen anderen Teil des Drehtellers angrenzt, wobei eine Verbindung der Schaufel mit dem Drehteller auf der dem Hauptströmungspfad abgewandten Seite des Drehtellers durch Schweißen vorgesehen ist,
wobei bevorzugt mindestens ein Schaufelfuß an der strömungspfadzugewandten Seite in einer Ausnehmung im Drehteller vorgesehen ist und auf diese Weise einen flachen Einsatz mit gegebenenfalls schräger Anlagefläche im Drehteller bildet, der mit Hilfe einer Schraub- Stift- oder Schweißverbindung befestigt ist,
wobei bevorzugt mindestens ein Schaufelfuß in Form einer Nut-Feder-Verbindung an einen anderen Teil des Drehtellers angrenzt, wobei eine Verbindung der Schaufel mit dem Drehteller durch Schraub- Stift- oder Schweißverbindung, bevorzugt auf der dem Hauptströmungspfad abgewandten Seite des Drehtellers, vorgesehen ist,
wobei bevorzugt die mehrschaufelige Verstellstatoreinheit mindestens zwei Bauteile umfasst, die getrennt gefertigt und anschließend zusammengefügt werden, wobei an einem Drehteller mindestens eine Schaufel keinen ausgeprägten Schaufelfuß besitzt und die Verbindung mit dem Drehteller durch Schweißen oder Fügen in unmittelbarer Nähe des Profils dieser Schaufel vorgesehen ist,
wobei bevorzugt eine mindestens teilweise Verlängerung des Schaufelprofils in eine Öffnung im Drehteller eingepasst ist und eine Verbindung der Schaufel mit dem Drehteller auf der dem Hauptströmungspfad abgewandten Seite des Drehtellers, gegebenenfalls auch durch Stauchen, vorgesehen ist.The 8c shows the Verstellstatoranordnung Fig. 7a in the meridian view. Concealed blade edges are dotted. Advantageous embodiments of the invention can be described as follows: Flow working machine according to claim 1, wherein preferably all arranged on the turntable blade profiles have a relative coverage n / l greater than 0.5,
wherein preferably at least one blade profile arranged on the turntable has a relative coverage n / l of greater than 0.75,
wherein preferably at least one blade profile arranged on the turntable has a tread depth of 0.8 <I / d <1.2 relative to the turntable diameter,
wherein preferably at least one of the blade profiles arranged on the turntable has no overhang (relative coverage n / l = 1),
wherein preferably all arranged on the turntable blade profiles have no overhang,
wherein preferably the spacing of adjacent blade profiles of the variable stator blade row in the circumferential direction of the turbomachine varies periodically,
wherein preferably in at least one position of the turntable at least one of the connecting lines of similar blade edge points (leading edge or trailing edge points) of the arranged on the Hauptströmungspfadberandung blade profiles Verstellstatorschaufelreihe along the circumference of the fluid flow machine varies periodically according to a different meridional positioning of similar blade edges,
wherein at least two of the arranged on the turntable blade profiles are provided with different shape with respect to at least one of the sizes tread depth l, relative curvature f / l and staggering angle λ,
wherein preferably the stagger angle λ of the blade profiles provided on a turntable, as the multi-blade variable stator unit progresses along the circumference of the turbomachine and progressing from a convex suction side to the concave pressure side of the next profile, progressively increases from blade to blade,
wherein on a turntable 5 two stator blades 1 are arranged, wherein with respect to the tread depth l is a difference and wherein the stator blade 1 is arranged with a smaller tread depth on the turntable 5 on the suction side of the stator blade 1 with a greater tread depth.
wherein on a turntable 5, two stator blades 1 are arranged, wherein with respect to the tread depth l is a difference and wherein the stator blade 1 is arranged with a smaller tread depth on the turntable 5 on the pressure side of the stator blade 1 with a greater tread depth.
wherein the center of the turntable 5 is provided with respect to the stator blade 1 with a greater profile depth on the same side as the stator blade with a smaller profile depth.
in which

• a) the meridional profile offset a is formed according to 0 <(a / (b + c)) <0.25
• b.) the meridional overlap b is formed according to 0 <(b / (b + c)) <0.65
• c.) the pressure-side distance q is formed in accordance with 0.3 <(q / (g + q)) <0.7

where c is the meridional residual distance and g is the suction-side distance.
wherein the leading edge of at least one arranged on the turntable downstream stator blade near the trailing edge and the pressure side of a further upstream stator blade is provided, wherein for the total profile depth l2, the Entanglement b2, the total division w and the total height v of the arrangement of the two stator blades concerned are: -0.1 <b2 / l2 <0.1 and v / w <0.3.
wherein three blade profiles are preferably provided on a turntable, wherein the mean blade profile with respect to the tread depth l has a difference of at least 25% compared to the other two blade profiles,
wherein the plurality of multi-vane Verstellstatoreinheiten the Verstellstatorschaufelreihe about the axis of rotation (turntable axis) in the full range of 360 ° are preferably synchronously adjustable, such that a collision or a position overlap adjacent multi-vane Verstellstatoreinheiten does not occur
wherein the multi-vane Verstellstatoreinheit preferably comprises at least two components which are manufactured separately and then joined together, wherein on a turntable at least blades each have a blade root, said at least two blade feet contribute to the round shape of the turntable at the Strömungspfadberandung,
wherein preferably at least one blade root has the full thickness of the turntable and abruptly adjacent to another part of the turntable, wherein a connection of the blade with the turntable is provided on the side facing away from the main flow path side of the turntable by welding,
wherein preferably at least one blade root is provided on the side facing the flow path in a recess in the turntable and in this way forms a flat insert with optionally inclined contact surface in the turntable, which is fastened by means of a screw pin or welded joint,
wherein preferably at least one blade root in the form of a tongue and groove connection adjoins another part of the turntable, wherein a connection of the blade with the turntable by screw pin or welded connection, preferably on the side facing away from the main flow path side of the turntable is provided
wherein the multi-vane Verstellstatoreinheit preferably comprises at least two components which are manufactured separately and then joined, wherein on a turntable at least one blade has no pronounced blade root and the connection to the turntable is provided by welding or joining in the immediate vicinity of the profile of this blade
wherein preferably at least a partial extension of the blade profile is fitted in an opening in the turntable and a connection of the blade with the turntable on the main flow path side facing away from the turntable, optionally also by upsetting, is provided.

In the flow machine according to the invention (fan, compressor, pump, or fan) according to claim 1, an improvement of the flow and in particular the edge flow is achieved, which can increase the efficiency of a stage with adjustable stator by more than 1% at a given aerodynamic load and the same stability , With today's usual aerodynamic loads, a reduction in the number of blades of up to 20% is possible. The concept according to the invention is applicable to different types of turbomachines and, depending on the degree of utilization of the concept, leads to reductions in costs and weight for the turbomachine of 2% to 5%. In addition, there is an improvement in the overall efficiency of the fluid flow machine, depending on the application, of up to 1.5%.

LIST OF REFERENCE NUMBERS

1

Stator blade / variable stator / variable stator / blade / blade / blade row

2

Housing / housing component

3

Hub / hub component

4

Turning spindle axis / rotation axis

5

turntable

6

blade

m

meridional

u

circumferentially

Claims (14)

1. Fluid-flow machine with a main flow path which is confined by a hub (3) and a casing (2) and in which at least one row of variable stator vanes (1) is arranged, wherein on at least one hub (3) or casing (2) at least one arrangement with at least two stator vanes (1) connected to a common rotary base (5) is provided, wherein the at least two stator vanes (1) are rotatable around a common rotary axis (4) when this multi-vane variable stator unit is varied, characterized in that the relative camber f/l of the centroidally further downstream profile, when seen in the meridional direction, is distinctly larger than the relative camber f/l of the centroidally further upstream profile, when seen in the meridional direction, according to (f/l)_downstream > 1.2 * (f/l)_upstream, wherein l is the profile depth, measured in the direction of the profile chord and f is the profile camber, measured as vertical distance of the furthermost point of the skeleton line from the profile chord relative to the profile line.
2. Fluid-flow machine in accordance with Claim 1, characterized in that all stator vanes (1) arranged on the rotary base (5) have a relative coverage n/l of more than 0.5, and/ or that at least one stator vane (1) arranged on the rotary base (5) has a relative coverage n/l of more than 0.75, wherein n is the profile coverage, measured between the intersecting points of the skeleton line of the stator vane (1) and the marginal circle of the rotary base (5) in the direction of the profile chord of the stator vane (1), and I is the profile depth, measured in the direction of the profile chord.
3. Fluid-flow machine in accordance with one of the Claims 1 or 2, characterized in that at least one stator vane (1) arranged on the rotary base (5) has a profile depth of 0.8 < I / d < 1.2 with reference to the rotary base diameter d, wherein I is the profile depth measured in the direction of the profile chord.
4. Fluid-flow machine in accordance with one of the Claims 1 to 3, characterized in that at least one of the stator vanes (1) arranged on the rotary base (5) has no overhang (relative coverage n/l = 1), wherein n is the profile coverage, measured between the intersecting points of the skeleton line of the stator vane (1) and the marginal circle of the rotary base (5) in the direction of the profile chord of the stator vane (1), and I is the profile depth, measured in the direction of the profile chord.
5. Fluid-flow machine in accordance with one of the Claims 1 to 4, characterized in that all stator vanes (1) arranged on the rotary base (5) have no overhang (relative coverage n/l = 1), wherein n is the profile coverage, measured between the intersecting points of the skeleton line of the stator vane (1) and the marginal circle of the rotary base (5) in the direction of the profile chord of the stator vane (1), and I is the profile depth, measured in the direction of the profile chord.
6. Fluid-flow machine in accordance with one of the Claims 1 to 5, characterized in that the distance of adjacent stator vanes (1) of the variable stator vane row varies periodically in the circumferential direction of the fluid-flow machine.
7. Fluid-flow machine in accordance with one of the Claims 1 to 6, characterized in that in at least one position of the rotary base (5) at least one of the connecting lines of similar vane edge points (leading edge or trailing edge points) of the stator vanes (1) of the variable stator vane row situated on the main flow path confinement extends periodically variably along the circumference of the fluid-flow machine, with a different meridional positioning of similar vane edges, wherein in particular at least two of the stator vanes (1) arranged on the rotary base (5) have different shape in terms of at least one of the quantities profile depth I, relative camber f/l and stagger angle A, wherein f is the profile camber, measured as vertical distance of the furthermost point of the skeleton line from the profile chord relative to the profile chord, and A is the stagger angle, measured between the meridional direction m and the profile chord, and I is the profile depth, measured in the direction of the profile chord, and/or a stagger angle A of the stator vanes (1) arranged on a rotary base (5) progressively increases from vane to vane, when viewing the multi-vane variable stator unit along the circumference of the fluid-flow machine and proceeding from a convex suction side to the concave pressure side of the next profile, wherein A is the stagger angle, measured between the meridional direction m and the profile chord, and/ or two stator vanes (1) are arranged in particular on a rotary base (5), with a difference existing in profile depth I, and with the stator vane (1) with smaller profile depth being arranged on the rotary base (5) on the suction side of the stator vane (1) with larger profile depth, and with the stator vane (1) with smaller profile depth being arranged on the rotary base (5) on the pressure side of the stator vane (1) with larger profile depth, wherein I is the profile depth, measured in the direction of the profile chord.
8. Fluid-flow machine in accordance with Claim 7, characterized in that the center of the rotary base (5), relative to the stator vane (1) with larger profile depth, is provided on the same side as the stator vane with smaller profile depth.
9. Fluid-flow machine in accordance with one of the Claims 7 or 8, characterized in that

   a.) the meridional profile offset a is provided as per 0 < (a / (b+c)) < 0.25

   b.) the meridional overlap b is provided as per 0 < (b / (b+c)) < 0.65, and

   c.) the pressure-side distance q is provided as per 0.3 < (q / (g+q)) < 0.7,

   with c being the meridional residual distance and g being the suction-side distance.
10. Fluid-flow machine in accordance with one of the Claims 1 to 7, characterized in that the leading edge of at least one stator vane arranged downstreamly on the rotary base is provided in the vicinity of the trailing edge and on the pressure side of a further upstream stator vane, with the following applying to total profile depth 12, overlap b2, total pitch w and overall height v of the arrangement of the respective two stator vanes: -0.1 < b2 / l2 < 0.1 and v / w < 0.3, wherein l2 is the total profile depth, measured as the length of the dual arrangement in the direction of the tangent applied to the total arrangement on the pressure side, b2 is the overlap in the direction of the total profile depth, w is the total pitch, measured vertically to the profile depth, and v is the overall height, measured vertically to the total profile depth.
11. Fluid-flow machine in accordance with one of the Claims 1 to 7, characterized in that, three stator vanes (1) are arranged on a rotary base (5), with the center stator vane (1) differing from the two other stator vanes (1) by at least 25 percent in profile depth I, wherein in particular at least one vane root (6) has the thickness of the rotary base and abuttingly adjoins another part of the rotary base (5), with an attachment of the stator vane (1) to the rotary base (5) being provided by means of welding on the side of the rotary base (5) facing away from the main flow path, or wherein at least one vane root (6) is provided on the flow-path facing side in a recess in the rotary base (5), thereby forming a flat insert with oblique mating surface in the rotary base (5), and wherein at least one vane root (6) is arranged on another part of the rotary base (5) in the form of a tongued and grooved joint, with an attachment of the stator vane (1) to the rotary base (5) being provided on the side of the rotary base (5) facing away from the main flow path.
12. Fluid-flow machine in accordance with one of the Claims 1 to 10, characterized in that the several multi-vane variable stator units of the variable stator vane row being synchronously variable around the rotary axis (4) throughout 360°, or that the multi-vane variable stator unit includes at least two components separately manufactured and then assembled, with at least one stator vane (1) on a rotary base (5) having no pronounced vane root (6) and the connection to the rotary base (5) being provided by welding or jointing in the immediate vicinity of the profile of this stator vane (1).
13. Fluid-flow machine in accordance with one of the Claims 1 to 10, characterized in that the multi-vane variable stator unit includes at least two components which are separately manufactured and then assembled, with at least two stator vanes (1) on a rotary base (5) having a vane root (6) each, with the at least two vane roots (6) contributing at least partly to the roundness of the rotary base (5) at the flow path confinement.
14. Fluid-flow machine in accordance with Claim 11, characterized in that an at least partial extension of the stator vane (1) is fitted in an opening in the rotary base (5) and a connection of the stator vane (1) to the rotary base (5) is provided on the side of the rotary base (5) facing away from the main flow path.

Images