EP3495626B1 - Lever connection and corresponding turbomachine - Google Patents

Description

The invention initially relates to a lever connection for the rotationally fixed connection of a guide vane to a lever of a guide vane adjustment of a turbomachine, the guide vane having a vane shaft extending along a vertical axis.
In addition, the invention has a turbomachine with a plurality of lever connections for producing a rotationally fixed coupling of the guide blades to a guide blade adjustment.

Compressors in axial turbomachines, for example aircraft engines, generally comprise a guide vane adjustment in the area of the front compressor stages or in the high-pressure compressor. Due to the guide vane adjustment, the guide vanes of the relevant row of guide vanes are adjusted depending on the speed around their vertical axis, so that an absolute stator outflow angle can be changed. This can prevent a stall when starting up the turbomachine or at low speeds. A step load is reduced. Alternatively, a stall could also be achieved by adjusting the blades of the compressor stages, but this is technically much more complex, so that the adjustment of the guide vanes has become established.

The adjustment of the guide vanes of a row of guide vanes is conventionally carried out mechanically by actuating an actuator. The actuator usually acts on the guide vanes via an adjusting ring and a lever. The adjusting ring is arranged outside the turbomachine and is usually positioned behind and coaxial to the guide vane row, viewed in the direction of flow. It can be rotated in the circumferential direction and displaced in the axial direction of the turbomachine. If there are several compressor stages to be adjusted, the adjusting rings are controlled simultaneously via an actuating lever of the actuator which is rotatably mounted on the compressor housing and which extends in the axial direction of the turbomachine and is connected to the adjusting rings.

In known guide vane adjustments, the lever is inserted in the radial direction of the turbomachine onto a blade shaft extending in the vertical direction of the guide vane. Then the lever on a generally small-area contact area of the blade shaft positively fixed and secured with a screw. The screw connection can be done by an internal thread or by an external thread. This type of lever connection requires a sufficiently thick shovel shaft for the design of the contact surfaces. Since the interlocking connection is only realized at the ends and with relatively small contact areas, locally higher mechanical stresses can arise, among other things.

WO 2014/158455 A1 discloses an exemplary variable wing actuation system, which includes, among other things, a wing arm with a wing shaft contact surface and a radially outwardly facing surface. The wing handle contact surface is intended to touch a wing handle of a variable wing and thereby actuate the variable wing about a radially extending axis. The contact surface of the wing stem is angled both with respect to the radially extending axis and with respect to the radially outwardly facing surface.

WO 2015/026420 A1 discloses an arrangement for operating a device, such as a variable blade, having an arm, a shaft to which the arm is connected, the shaft having a slot, and an element having a tab that fits into the slot, Has.

GB 2 412 947 A. discloses a variable vane assembly having two inclined engagement surfaces provided on the top of the upper vane shaft. A few protrusions with inclined surfaces are provided on the underside of a lever arm. The surfaces can only be brought into engagement if the surfaces 30 are in an axial alignment, otherwise the lever arm is raised relative to the guide vane in order to clearly indicate an incorrect mounting thereon.

DE 603 04 908 T2 discloses a rotary attachment for stator blades of a TL engine, consisting of a pivot pin of the blade with an end protruding from the stator and with a section with flat sides, and a control connecting rod, which extends through a bore which is delimited by flat sides, which connected to the flat sides of the trunnion, at which end of the blade trunnion is engaged.

DE 195 37 784 A1 discloses an adjustable vane that includes a wing portion with an integral outer pivot with a seat integrally extending therefrom. A threaded shaft extends from the seat and has a coextensive alignment surface that cooperates with a complementary mounting hole in a lever arm that inhibits rotation of the lever arm about the shaft during assembly to ensure a predetermined rotational position between the lever arm and the wing portion.

DE 699 22 382 T2 discloses a variable vane that includes an airfoil with a threaded pin, a lever with a mounting hole that receives the pin, and a nut that is threadedly engaged with the pin to hold the lever on the airfoil. A space is provided during alignment between the seat and the lever to provide sufficient threaded connection between the nut and the shaft to allow engagement therebetween, and insufficient threading during misalignment to provide a threaded connection therebetween prevent.

The object of the invention is to provide a lever connection of a guide vane adjustment of a turbomachine for establishing a rotationally fixed connection between a guide vane and a lever, which avoids the disadvantages mentioned above. It is also an object of the invention to provide a turbomachine with lever connections according to the invention.

The object is first achieved by a lever connection with the features of claim 1.

In the case of a lever connection for the rotationally fixed connection of a guide vane to a lever of a guide vane adjustment of a turbomachine, the guide vane having a vane shaft extending along a vertical axis, the lever is formed in one piece at a radially outer end of an essentially hollow cylindrical clamping sleeve that coaxially encloses the vane shaft in sections the blade shaft and the clamping sleeve are coupled via a longitudinal positive connection or a frontal positive connection and the blade shaft can be clamped with the clamping sleeve along the vertical axis by means of a fastening element, in particular a threaded nut.

This results in a separation of the power flows, since the blade shaft is essentially only subjected to tension and the clamping sleeve by means of the lever integrally formed thereon is at least essentially only acted upon by bending moments when adjusting the guide blade. Compared to a traditional lever connection, the risk of local increased mechanical stresses is reduced and overall a more even load distribution is achieved. The longitudinal positive connection also extends parallel to the vertical axis of the blade shaft. The threaded nut is usually self-locking executed. Instead of a threaded nut, for example, a threaded bolt can be used as a tensioning or fastening element.

The clamping sleeve preferably has a collar for radially securing the guide vane in a housing of the turbomachine, with a defined gap between the collar and the housing. As a result, smooth storage is possible.

In accordance with a technically advantageous development, a cylindrical bearing section for the pivotable mounting of the guide vane in the housing is formed between a radially inner end of the clamping sleeve and the collar of the clamping sleeve. As a result, there is a particularly large contact area between the adapter sleeve and the housing of the turbomachine, which results in a robust and durable bearing.

At least one bushing is preferably arranged between a bore in the housing and the bearing section of the clamping sleeve. As a result, in the case of a suitable material selection of the clamping sleeve, the at least one at least approximately hollow cylindrical bushing and the housing of the turbomachine, low-wear storage is possible in this area. In addition, tolerance compensation can be implemented by means of the at least one socket.

A threaded section for the threaded nut is preferably formed on a radially outer end of the blade shaft. As a result, there is a mechanically reliable and, if necessary, releasable connection between the blade shaft and the clamping sleeve.

The radially outer plate of the guide vane preferably forms a contact surface for the radially inner end of the clamping sleeve. This provides a one-sided abutment for the clamping sleeve on the blade shaft.

In the case of a first embodiment variant of the lever connection, the shovel shaft has a longitudinal outer toothing with a first recess below the threaded section and the clamping sleeve has a longitudinal inner toothing with a second recess in the region of the lever to create the longitudinal positive connection, the two recesses being designed such that an in The cut-outs of the cutouts, which can be precisely fitted, can be clamped between the blade shaft and the lever for their play-free connection when the blade shaft is clamped with the clamping sleeve. This provides a permanently play-free, non-rotatable connection between the clamping sleeve with the lever and the shovel shaft. The adjustment torques are transmitted by means of the long side Form-fit connection, while the transmission of bending moments via the clamping sleeve with the lever happens, which causes a distribution of these different power flows. The locking plate also serves to secure the position of the preferably self-locking threaded nut.

In the case of a second embodiment of the lever connection, the form-fitting connection on the end face is formed with a first end toothing directed towards the outer radial end of the blade shaft on the radially outer plate and with a second end toothing directed towards the first end toothing at the radially inner end of the clamping sleeve. Due to the oppositely oriented spur toothing, which is at least partially positively engaged with each other, there is a permanently play-free connection between the clamping sleeve with the lever and the blade shaft. In addition, the two spur gears ensure perfect centering of the adapter sleeve in relation to the blade shaft. As a result, the blade shaft remains completely free of bending or torsional moments and is therefore only subjected to tension, which results in a strict force flow separation, which largely prevents the occurrence of local mechanical stresses within the guide blade.

The two spur gears each have an irregular tooth pitch. As a result, there is a clear angular position between the blade shaft and the clamping sleeve to facilitate the assembly of the lever connection.

In the case of a technically advantageous embodiment, a recess for a locking plate for securing the position of the threaded nut is provided in the area of the clamping sleeve and / or the lever. In addition to the preferably self-locking threaded nut, this further secures the threaded nut against unintentional loosening.

The blade shank preferably has an at least approximately cylindrical centering collar, which at least in sections abuts an inner centering section in the region of the radially outer end of the clamping sleeve. This ensures reliable guidance of the blade shaft in the adapter sleeve.

A turbomachine according to the invention is equipped with a plurality of lever connections according to one of claims 1 to 10 for producing a rotationally fixed coupling of guide vanes to a guide vane adjustment. As a result, the force flows are decoupled, which avoids the risk of local mechanical stress peaks.

Figur 1:

eine perspektivische Ansicht einer Leitschaufel für eine erste Ausführungsvariante einer Hebelanbindung,

Figur 2:

eine perspektivische Ansicht einer Spannhülse mit einem einstückig seitlich daran ausgebildeten Hebel für die erste Ausführungsvariante der Hebelanbindung,

Figur 3:

eine Draufsicht auf die erste Ausführungsvariante der Hebelanbindung in einem montierten Zustand,

Figur 4:

einen Längsschnitt der montierten Hebelanbindung von Fig. 3 entlang der Schnittlinie IV-IV,

Figur 5:

einen Querschnitt der Hebelanbindung von Fig. 4 entlang der Schnittlinie V-V,

Figur 6:

einen Querschnitt der Hebelanbindung von Fig. 4 entlang der Schnittlinie VI-VI,

Figur 7:

eine perspektivische Ansicht einer Leitschaufel für eine zweite Ausführungsvariante einer Hebelanbindung,

Figur 8:

eine perspektivische Ansicht einer Spannhülse mit einem einstückig seitlich daran ausgeformten Hebel für die zweite Ausführungsvariante der Hebelanbindung,

Figur 9:

eine schematische Seitenansicht auf die zweite Ausführungsvariante der Hebelanbindung in einem montierten Zustand,

Figur 10:

eine Draufsicht auf die montierte zweite Ausführungsform der Hebelanbindung von Fig. 9,

Figur 11:

einen Längsschnitt durch die montierte Hebelanbindung von Fig. 10 entlang der Schnittlinie XI-XI.

They show schematically:

Figure 1:

1 shows a perspective view of a guide vane for a first embodiment variant of a lever connection,

Figure 2:

2 shows a perspective view of a clamping sleeve with a lever which is integrally formed on the side for the first embodiment variant of the lever connection,

Figure 3:

2 shows a top view of the first embodiment variant of the lever connection in an assembled state,

Figure 4:

a longitudinal section of the assembled lever connection of Fig. 3 along the section line IV-IV,

Figure 5:

a cross section of the lever connection of Fig. 4 along the section line VV,

Figure 6:

a cross section of the lever connection of Fig. 4 along the section line VI-VI,

Figure 7:

1 shows a perspective view of a guide vane for a second embodiment variant of a lever connection,

Figure 8:

2 shows a perspective view of a clamping sleeve with a lever integrally formed on the side for the second embodiment variant of the lever connection,

Figure 9:

2 shows a schematic side view of the second embodiment variant of the lever connection in an assembled state,

Figure 10:

a plan view of the assembled second embodiment of the lever connection of Fig. 9 ,

Figure 11:

a longitudinal section through the mounted lever connection from Fig. 10 along the section line XI-XI.

In the context of the present description, terms such as "radial", "radially outer", "radially outer", "radially inner" and "radially inner" - unless expressly indicated otherwise - refer to a machine longitudinal axis X of the turbomachine according to the invention , which embodies the axis of rotation of a rotor of the turbomachine.

Information such as "laterally" and "transversely" refer to a vertical axis H of a guide vane of the turbomachine, which runs essentially radially to the longitudinal axis X of the machine.

Figure 1 shows a perspective view of a guide vane for a first embodiment of a lever connection. A guide vane 10 shown in the installed position has, among other things, a vane shaft 12 which extends along a vertical axis H and has a vane blade 14. The guide vane 10 can be received pivotably about the vertical axis H in a housing (not shown here) of a turbomachine (also not shown). The machine longitudinal axis X of the turbomachine runs perpendicular to the vertical axis H. A radially outer plate 18 with a larger diameter is formed on a radially inner end 16 of the blade shaft 12. A threaded portion 22 is provided on a radially outer end 20 of the blade shaft 12. A radially inner airfoil root 24 of the airfoil 14 merges into a smaller-diameter, radially inner plate 26, while a radially outer airfoil root 28 merges into the larger-diameter plate 18.

At least in sections, longitudinal external toothing 30 running parallel to the vertical axis H is formed on the blade shaft 12. The longitudinal external toothing 30 can be designed as a uniform involute, trapezoidal, triangular toothing or the like. Between the threaded section 22 and the longitudinal external toothing 30 there is a fillet-like annular groove 32 or a constriction of the blade shaft 12. In the blade shaft 12 there is an approximately cuboidal recess 34 which runs parallel to the vertical axis H and which starts from the annular groove 32 via a small one Length L extends in the direction of the radially inner end 16 of the blade shaft 12. The recess 34 completely occupies at least one tooth 36 of the longitudinal external toothing 30 and here, for example, partially a further tooth 38 that is directly circumferentially adjacent to this tooth 38, only a narrow side wall 40 remaining from the tooth 38. The recess 34 serves to receive a locking plate, not shown here (cf. esp. Fig. 3 , 4th , 6 ). The plate 18 also has an approximately annular contact surface 42 for an adapter sleeve of the lever connection (cf. esp. Fig. 2 ).

Figure 2 shows a perspective view of a clamping sleeve with a one-piece laterally formed lever for the first embodiment of the lever connection. In the area of a radially outer end 46 of an essentially hollow cylindrical base body 48 of an adapter sleeve 50 there is a lever 52 of a guide blade adjustment which is only indicated in the drawing 54 of the turbomachine formed in one piece. The clamping sleeve 50 has an approximately disk-shaped collar 56 for the radial securing of the position of the guide vane in a housing of the turbomachine, not shown here. The clamping sleeve 50 has a longitudinal internal toothing 58 which corresponds to the longitudinal external toothing of the blade shaft (cf. in particular Fig. 1 ) and which extends from the radially outer end 46 to a radially inner end 60 of the clamping sleeve 50 parallel to the vertical axis H. The vertical axis H in turn runs orthogonal to the longitudinal axis X of the machine. A recess 62 for the locking plate is provided on the radially outer end 46 of the clamping sleeve 50 in the area of the base body 48 of the clamping sleeve and in the lever 52. The recess 62 has a first and a second side wall 64, 66 and a base 68, the side walls 64, 66 being oriented perpendicular to the base 68.

Figure 3 illustrates a plan view of the first embodiment variant of the lever connection in an assembled state. In an assembled state of a lever connection 80 according to the invention, the threaded section 22 on the blade shaft 12 of the guide blade 10 is connected to the clamping sleeve 50 by means of a preferably self-locking threaded nut 82 as a fastening element 84 and is pivotably received in a housing 86 of the turbomachine by means of the lever 52. The collar 56 of the clamping sleeve 50 secures the guide vane on one side in the radial direction. A locking plate 88 has two at least substantially triangular tabs 90, 92, which are brought to bear against the threaded nut 82 by appropriate bending. The securing element 88 lies at least in sections in the cutout 62 of the lever 52 of the clamping sleeve 50. When the lever connection 80 is installed by tightening or tightening the threaded nut 82, the locking plate 88 is at least in sections between the latter and the clamping sleeve 50 and the cutout 62 in the lever 52 and the concealed recess in the shovel shaft 12 are clamped.

Figure 4 shows a longitudinal section of the assembled lever connection of Fig. 3 along the section line IV-IV. The guide vane 10 has the vane shaft 12 and the vane blade 14 as well as the radially outer and the radially inner plate 18, 26. The vane 10 is in the installed position with respect to the longitudinal axis X of the machine. The blade shaft 12 of the guide vane 10 is inserted into the clamping sleeve 50 to form the lever connection 80 and clamped by means of the threaded nut 82 screwed onto the threaded section 22, a narrow gap 96 remaining between the collar 56 of the clamping sleeve 50 and the housing 86. Between The longitudinal external toothing 30 of the blade shaft 12 and the longitudinal internal toothing 58 of the clamping sleeve 50 thus have a positive connection 98 on the longitudinal side.
Between the radially inner end 60 of the clamping sleeve 50 and the collar 56, a cylindrical bearing section 100 for the pivotable mounting of the guide vane 10 is formed in a stepped bore 102 of the housing 86. Between the bearing section 100 and the stepped bore 102, three at least approximately hollow cylindrical bushes 104, 106, 108 are arranged here by way of example, a collar 110 directed vertically away from the vertical axis being integrally formed on the bushing 108, which is between the plate 18 and a shoulder 112 the stepped bore 102 is. The plate 18 also has the contact surface 42 as an abutment of the guide vane 10 braced against one another along the vertical axis H and the clamping sleeve 50.

By means of the lug 90 and the second lug of the locking plate 88, which is not visible here, additional locking of the preferably self-locking threaded nut 82 takes place. The locking plate 88 furthermore has a bore section 118 for the passage of the threaded section 22 of the blade shaft 12, one adjoining it vertically , that is to say parallel to the vertical axis H back section 120 and a parallel to the machine longitudinal axis X oriented clamping section 122 which lies in the recess 34 of the longitudinal external toothing 30 of the blade shaft 12 and in the recess 62 of the lever 52 of the clamping sleeve 50. The two recesses 34, 62 are designed according to the invention in such a way that at least the clamping section 122 of the locking plate 88 wedges between the blade shaft 12 and the lever 52 in a wedge-like manner when the blade shaft 12 is clamped with the clamping sleeve 50 in order to connect them without play. A cross-sectional geometry of the bore section 118, the back section 120 and the clamping section 122 of the locking plate 88 are approximately U-shaped.
The inventive design of the lever connection 80 ensures a separation of force flows acting on the guide vane 10 for protection against local load peaks, since adjusting moments are transmitted via the longitudinal positive connection 98 and bending or torsional moments through the lever 52 and the clamping sleeve 50 to the guide vane 10 .

Figure 5 shows a cross section of the lever connection of Fig. 4 along the section line VV. The lever connection 80 is formed, among other things, with the longitudinal outer toothing 30 of the blade shank 12, which is in engagement with the longitudinal inner toothing 58 of the clamping sleeve 50 and here represents the longitudinal positive connection 98. The clamping sleeve 50 with the blade shaft 12 coaxially and sectionally positively received therein is received in the housing 86 so as to be pivotable about the vertical axis H, in order to enable different angles of attack of the blade of the blade shaft 12, not shown here. The centering of the blade shank 12 in the clamping sleeve 50 is preferably carried out on an outer diameter 124 of the longitudinal positive connection 98. The bushing 104 ensures, among other things, that the clamping sleeve 50 can be pivoted smoothly and with little friction in the housing 86.

Figure 6 illustrates a cross section of the lever connection of FIG Fig. 4 along the section line VI-VI. The blade shaft 12 is connected in a rotationally fixed manner to the clamping sleeve 50 and the lever 52 integrally formed thereon by means of the longitudinal positive connection 98 of the lever connection 80 and is pivotably received in the housing 86 about the vertical axis H. The clamping section 122 of the locking plate 88 lies in the cutout 62 of the lever 52 and in the cutout 34 of the longitudinal outer toothing 30 of the blade shaft 12. The clamping section 122 is left between the side wall 40 of the remaining one by tightening the threaded nut (not shown here) during assembly of the lever connection 80 (Remaining) tooth 38 and the opposite side wall 66 of the recess of the lever 62 clamped like a wedge. As a result, any circumferential play of the longitudinal positive connection 98 in relation to the vertical axis H is permanently and reliably eliminated. The clamping section 122 is connected to the bow-shaped or clamp-like locking plate 88 by means of the back section 120 running parallel to the vertical axis H. By means of the locking plate 88, both the redundancy of the position securing of the threaded nut and the freedom from play of the lever connection 80 are brought about by way of example.

Figure 7 shows a perspective view of a guide vane for a second embodiment of a lever connection. A guide vane 200, again shown in its installed position, comprises an at least substantially cylindrical vane shaft 202 and an airfoil 204. To illustrate the spatial position of the components within the turbomachine, the vertical axis H and the longitudinal axis X of the machine are again shown. The blade shank 202 has a radially inner end 206, in the area of which a radially outer plate 208 with a larger diameter is formed analogously to the first embodiment variant. A threaded section 212 is provided at a radially outer end 210 of the blade shaft 202. A radially inner blade root 214 of the The airfoil 204 merges into a smaller-diameter radially inner plate 216, while a radially outer airfoil root 218 connects to the plate 208. As a difference to Fig. 1 instead of a longitudinal external toothing of the blade shaft 202 on the plate 208, a first end toothing 220 pointing in the direction of the threaded section 212 or the radially outer end 210 of the blade shaft 202 is provided with an irregular tooth pitch. The front toothing 220 can have teeth with a practically any geometry that deviates from the usual involute shape. Along the vertical axis H in the direction of the plate 208, an annular groove 222 and a cylindrical centering collar 224 adjoin the threaded section 212 of the blade shaft 202. The centering collar 224 has a diameter D _{2 which is} at least slightly larger in comparison to a diameter D _{1 of} the blade shaft 202. A contact surface 234 facing the radially outer end 210 of the blade shaft 202 is also provided peripherally to the spur toothing 220 for the clamping sleeve of the lever connection for adjusting the guide blade (cf. Figure 2 , Reference number 54).

Figure 8 illustrates a perspective view of an adapter sleeve with a lever integrally formed on the side for the second embodiment variant of the lever connection. At a radially outer end 236 of an at least approximately hollow cylindrical base body 238 of a second embodiment variant of an adapter sleeve 240 drawn in the installed position, a lever 242 is again preferably formed in one piece for coupling the guide vane adjustment, not shown here (cf. Figure 2 , Reference number 54). Corresponding to the variant of Figure 2 In turn, a circumferential collar 246 or a flange is integrally formed on the base body 238 of the clamping sleeve 240 and extends radially outward perpendicular to the vertical axis H. Deviating from the longitudinal internal teeth of the first variant of the adapter sleeve (cf. Figure 2 ), the base body 238 of the clamping sleeve 240 has a cylindrical through bore 248 which runs concentrically to the vertical axis H. The vertical axis H is in turn oriented at right angles to the longitudinal axis X of the machine. At a radially inner end 250 of the clamping sleeve 240, a second face toothing 252 with an irregular tooth pitch is provided as a further structural difference, which corresponds to the face toothing of the blade shaft of Figure 7 is designed. In a fillet-like transition zone 254 between the radially outer end 236 of the clamping sleeve 240 and the lever 242, a bore 256 or a recess is made for at least partially receiving a locking plate, not shown here.

Figure 9 shows a schematic side view of the second embodiment of the lever connection in an assembled state. The blade shaft 202 with the blade blade 204, which is only indicated in the drawing, is inserted into the clamping sleeve 240 to create the second embodiment variant of a lever connection 270. The blade shank 202 and the clamping sleeve 240 with the lever 242 and the flange-like collar 246 are mechanically braced against one another along the vertical axis H by means of a threaded nut 272 screwed onto the threaded section 212 and preferably designed to be self-locking as a fastening element 274. Between the threaded nut 272 and the radially outer end 236 of the clamping sleeve 240 there is also a locking plate 276 for the redundant rotation of the threaded nut 272 against uncontrolled loosening. The clamping sleeve 240 coaxially encloses the blade shaft 202 of the guide blade 200 in sections in the assembled state. The spur toothing 220 of the plate 208 is in the assembled state of the lever connection 270 shown here in a form-fitting engagement with the correspondingly shaped spur toothing 252 of the clamping sleeve 240 with the creation of a form-fitting connection 278 according to the invention, which at the same time acts centering. The radially inner blade root 214 merges into the smaller-diameter plate 216. The second embodiment variant of the lever connection 270 likewise enables an effective separation of the force flows or moments acting on the guide vane 200, since in order to minimize local mechanical stresses of the vane shaft 202, only tension and the clamping sleeve 240 are only subjected to bending or torsional moments.

Figure 10 shows a top view of the assembled second embodiment of the lever connection of FIG Fig. 9 . The clamping sleeve 240 of the fully assembled lever connection 270 is fixed at least on one side radially in the housing 86 of the turbomachine by means of the collar 246 and is pivotably received about the vertical axis H by means of the lever 242. For this purpose, the blade shank 202 is clamped in the direction of the vertical axis H with the clamping sleeve 240 by means of the threaded nut 272 screwed onto its threaded section 212. To secure the position of the threaded nut 272, the locking plate 276, which has a first and a second tab 280, 282, is inserted between the latter and the clamping sleeve 240. Furthermore, the locking plate 276 has an engagement section 284 running parallel to the vertical axis H, which is received at least in regions in the bore 256 of the lever 242.

Figure 11 illustrates a longitudinal section through the mounted lever connection of Fig. 10 along the section line XI-XI. The blade shaft 202 of the guide blade 200 is connected to the Clamping sleeve 240 is clamped along the vertical axis H by means of the threaded nut 272 screwed onto the threaded section 212 to produce the lever connection 270, a defined gap 290 remaining between the housing 86 and the collar 246 of the clamping sleeve 240. This ensures smooth pivoting of the guide vane 200 about the vertical axis H by actuating the lever 242 formed integrally with the clamping sleeve 240 by means of the guide vane adjustment of the turbomachine, not shown here (cf. Figure. 2nd , Reference number 54). The non-rotatable and at the same time permanently backlash-free connection between the blade shaft 202 of the guide blade 200 and the clamping sleeve 240 is ensured by the frontal positive connection 278 clamped along the vertical axis H, which is connected to the radial toothing 220 of the plate 208 and the radial toothing 252 engaging with it inner end 250 of the clamping sleeve 240 is formed. The blade 204 is integrally formed between the plate 208 and the smaller-diameter plate 216.

Between the radially inner end 250 of the clamping sleeve 240 and its collar 246, a cylindrical bearing section 292 is formed for the pivotable mounting of the guide vane 200 in a stepped bore 294 of the housing 86. Between the bearing section 292 and the stepped bore 294, four exemplary at least approximately hollow-cylindrical bushings 296, 298, 300, 302 are arranged here by way of example, whereby between the bushing 302 located furthest in the direction of the plate 208 and the annular contact surface 234 of the plate 208 and a hollow cylindrical intermediate layer 306 lies on a shoulder 304. The contact surface 234 serves as an abutment of the guide vane 200 and clamping sleeve 240 braced against one another along the vertical axis H to create the lever connection 270. The centering collar 224 of the vane shaft 202 also bears against an inner centering section 308 of the clamping sleeve 240 for further optimization of the guidance.

The hook-like locking plate 276 comprises two triangular tabs, of which only the tab 282 is visible, to which a bore section 310 connects, to which the engagement section 284 is connected at right angles. The threaded nut 272 is redundantly secured in position by means of the locking plate 276, through the central bore section 310 of which the threaded section 212 of the blade shaft 202 runs and which is clamped between the tightened threaded nut 272 and the radially outer end 236 of the clamping sleeve 240. The two triangular tabs of the locking plate 276 can be used to ensure the security purpose by bending to the system Threaded nut 272 or be brought to at least two of their hexagonal surfaces. The bore section 310 of the locking plate 276 is received in the bore 256 of the lever 242 of the clamping sleeve 240 to complete the securing of the position of the threaded nut 272.

The invention relates to two design variants of a lever connection for pivoting guide vanes in a compressor part of a turbomachine, in which a separation of the acting force and moment flows is realized by a clamping sleeve, such that the blade shaft essentially only with tensile forces and the clamping sleeve primarily with bending or torsional moments is applied. As a result, local mechanical load peaks are significantly reduced. In addition, the lever connection is permanently free of play and redundantly secured against uncontrolled loosening. Also disclosed is a turbomachine with a plurality of lever connections according to the invention for adjusting guide vanes in a compressor part by means of the guide vane adjustment.

Reference numerals

10th

Guide vane (1st variant)

12th

Shovel shaft

14

Airfoil

16

radially inner end (blade shaft)

18th

radially outer plate

20

radially outer end (blade shaft)

22

Thread section

24th

radially inner airfoil root

26

radially inner plate

28

radially outer airfoil root

30th

Longitudinal external toothing (blade shank)

32

Ring groove

34

Recess (longitudinal external toothing)

36

tooth

38

tooth

40

Side wall (tooth)

42

Contact surface (plate)

46

radially outer end (adapter sleeve)

48

Basic body (adapter sleeve)

50

Adapter sleeve (1st variant)

52

lever

54

Guide blade adjustment

56

Federation

58

Longitudinal internal teeth (adapter sleeve)

60

radially inner end (adapter sleeve)

62

Recess (adapter sleeve, lever)

64

first side wall

66

second side wall

68

ground

80

Lever connection (1st variant)

82

Threaded nut

84

Fastener

86

Housing (fluid machine)

88

Lock washer

90

Tab

92

Tab

96

gap

98

longitudinal positive connection

100

cylindrical bearing section (adapter sleeve)

102

stepped bore (housing)

104

Rifle

106

Rifle

108

Rifle

110

collar

112

Shoulder (stepped bore)

118

Bore section (locking plate)

120

Back section (locking plate)

122

Clamping section (locking plate)

124

Outer diameter (longitudinal positive connection)

200

Guide vane (2nd variant)

202

Shovel shaft

204

Airfoil

206

radially inner end (blade shaft)

208

radially outer plate

210

radially outer end (blade shaft)

212

Thread section

214

radially inner airfoil root

216

radially inner plate

218

radially outer airfoil root

220

first spur toothing (plate)

222

Ring groove

224

Centering collar (shovel shaft)

232

Side wall (tooth)

234

Contact surface

236

radially outer end (adapter sleeve)

238

Basic body (adapter sleeve)

240

Adapter sleeve (2nd variant)

242

lever

246

Federation

248

Through hole

250

radially inner end (adapter sleeve)

252

second spur toothing (adapter sleeve)

254

Transition zone

256

Bore (lever)

270

Lever connection (2nd variant)

272

Threaded nut

274

Fastener

276

Lock washer

278

Form-fit connection on the front

280

Tab

282

Tab

284

Engaging section

290

gap

292

cylindrical bearing section (adapter sleeve)

294

stepped bore (housing)

296

Rifle

298

Rifle

300

Rifle

302

Rifle

304

shoulder

306

Intermediate layer

308

Inner centering section (adapter sleeve)

310

Bore section (locking plate)

312 D _1.2

diameter

H

Vertical axis

L

Length of recess (longitudinal toothing)

X

Machine longitudinal axis (fluid machine)

Claims (11)

1. Lever connection (80, 270) for connecting a guide vane (10, 200) to a lever (52, 242) of a guide vane adjustment (54) of a turbomachine for conjoint rotation, the guide vane (10, 200) having a vane shaft (12, 202) that extends along a vertical axis (H), characterized in that the lever (52, 242) is formed in one piece at a radially outer end (46, 236) of a substantially hollow-cylindrical clamping sleeve (50, 240) that coaxially encloses the vane shaft (12, 202) in portions, and the vane shaft (12, 202) and the clamping sleeve (50, 240) are coupled via a longitudinal form-fitting connection (98) or an end-face form-fitting connection (278) and the vane shaft (12, 202) can be clamped by the clamping sleeve (50, 240) along the vertical axis (H) by means of a fastening element (84, 274), in particular a threaded nut (82, 272).
2. Lever connection (80, 270) according to claim 1, characterized in that the clamping sleeve (50, 240) has a collar (56, 246) for radially securing the guide vane (10, 200) in place in a housing (86) of the turbomachine, there being a defined gap (96, 290) between the collar (56, 246) and the housing (86) and/or a cylindrical mounting portion (100, 292) for pivotably mounting the guide vane (10, 200) in the housing (86) being formed between a radially inner end (60, 250) of the clamping sleeve (50, 240) and the collar (56, 246) of the clamping sleeve (50, 240).
3. Lever connection (80, 270) according to claim 2, characterized in that at least one bushing (104, 106, 108, 296, 298, 300, 302) is arranged between a bore (102, 294) of the housing (86) and the mounting portion (100, 292) of the clamping sleeve (50, 240).
4. Lever connection (80, 270) according to any of claims 1 to 3, characterized in that a threaded portion (22, 212) for the threaded nut (82, 272) is formed on a radially outer end (20, 210) of the vane shaft (12, 202).
5. Lever connection (80) according to claim 4, characterized in that the vane shaft (12) has a longitudinal external toothing (30) having a recess (34) below the threaded portion (22) and the clamping sleeve (50) has a longitudinal internal toothing (58) having a recess (62) in the region of the lever (52) in order to produce the longitudinal form-fitting connection (98), the two recesses (34, 64) being designed such that a locking plate (88), which can be received in the recesses (34, 64) with an exact fit, can be clamped between the vane shaft (12) and the lever (52) for zero-backlash connection thereof when the vane shaft (12) is clamped by the clamping sleeve (50).
6. Lever connection (80, 270) according to any of claims 1 to 5, characterized in that a radially outer disk (18, 208) of the guide vane (10, 200) forms a contact surface (42, 234) for the radially inner end (60, 250) of the clamping sleeve (50, 240).
7. Lever connection (270) according to any of claims 1 to 4 or 6, characterized in that the end-face form-fitting connection (278) is formed by a first end toothing (220), directed toward the outer radial end (210) of the vane shaft (202), on a radially outer disk (208) and by a second end toothing (252), directed toward the first end toothing (220), at the radially inner end (250) of the clamping sleeve (240).
8. Lever connection (270) according to claim 7, characterized in that the two end toothings (220, 252) each have an irregular tooth pitch.
9. Lever connection (270) according to either claim 7 or claim 8, characterized in that a bore (256) is provided in the region of the clamping sleeve (240) and/or the lever (242) for a locking plate (276) for securing the threaded nut (272) in place.
10. Lever connection (270) according to any of claims 7 to 9, characterized in that the vane shaft (202) has an at least approximately cylindrical centering collar (224) which rests at least in portions on an inner centering portion (308) in the region of the radially outer end (236) of the clamping sleeve (240).
11. Turbomachine having a plurality of lever connections (80, 270) according to any of claims 1 to 10 for coupling guide vanes (10, 200) to a guide vane adjustment (54) for conjoint rotation.

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