EP2362070A1 - Drive device for pivoting adjustable vanes of a turbomachine - Google Patents

Abstract

The drive device has an annular flow channel section (23) surrounded by a blade carrier (22), where the section is extended along a center line (24) of the blade carrier. The blades (19) are provided in the section in a ray-like manner for forming a ring. Each of the blades is pivoted about a longitudinal axis (31) and has a pin (26) which extends into the blade carrier. The pin is coupled to an adjustment ring (28) which encloses the blade carrier and is driven by a motor.

Description

The invention relates to a drive device for pivoting adjustable blades of a turbomachine, comprising an annular flow channel section enclosed by a blade carrier, which extends along the central axis of the blade carrier and in which blades are provided in a radiating manner to form a ring, wherein the blades each pivot about their longitudinal axis and each having a at least in the blade carrier extending pins which are coupled to a rotatable adjusting ring in the circumferential direction.

A device of such type is for example from the US 5,549,448 out. In order to adjust the radially extending blades of a blade ring of a compressor, a concentric to the central axis of the compressor collar surrounds the inner housing. Each blade of the blade ring rotatable about its longitudinal axis has a pin which extends through the blade carrier and which is connected to the adjusting ring outside the housing via a pivot lever. The adjusting ring is rotatable in the circumferential direction. The rotation of the adjusting ring, the pivot lever are moved, whereby the blades are pivoted about their respective longitudinal axis. The adjusting ring is moved by a drive in the circumferential direction, which also supports the adjusting ring at the same time.

Likewise is from the EP 1 524 413 A2 a circumferentially rotatable adjusting ring for adjusting the blades of a ring known.

From the GB 1 466 613 is also known that instead of a Schwenkhebelankopplung also a toothed coupling between adjustable bucket and collar is possible. The adjustment of the adjusting ring successes via a push rod, which introduces a hydraulically generated driving force tangentially into the adjusting ring.

Here are the from the US 5,549,448 and EP 1 524 413 A2 known drives consuming in construction, as many components are required and interpreted. The large number of components in production lead to a complex assembly, which is also still time-consuming due to the required accuracy of the position of the angle of rotation of the individual blade.

If such drive devices used in stationary gas turbines, the collars are also extremely massive. During operation, temperature differences between the adjusting ring and the blade carrier have an influence on the angle of attack of the compressor blades in the flow channel. These temperature differences can lead to unevenly set angles of attack of the blades of the blade ring, so that it must always be ensured that the adjusting ring and the blade carrier are mounted coaxially or concentrically to a common central axis. In addition, the tangential introduction of force via push rods can cause an equally disadvantageous decentering of the adjusting ring.

Also, the storage of the known collars can be polluted and prone to failure, which limits reliable and safe operation. In particular, foreign bodies in the embodiment according to GB 1 466 613 in the field of gearing or in the embodiment of the US 5,549,448 respectively. EP 1 524 413 A2 cause in the worst case a blocking of the drive device in the region of the lever, which then significantly limits the operating range of the turbomachine.

Accordingly, the object of the present invention is to provide a wear-free, reliable drive device for temperature-independent adjustment of itself radially in an annular channel extending, rotatable about their respective longitudinal axis blades.

The object is achieved with a drive device for pivoting adjustable blades of a turbomachine, which is equipped according to the features of claim 1.

The generic drive device for pivoting adjustable blades of a turbomachine comprises a blade carrier, which encloses an annular flow channel section. The flow channel section extends along the centerline of the blade carrier. In this are radiant, with respect to the machine axis, to form a ring blades provided which are pivotable about the longitudinal axis for adjustment. The blades each have a pin which extends at least into the blade carrier and which are respectively coupled to at least one adjusting ring rotatable in the circumferential direction, which is drivable via at least one motor. According to the invention, it is provided that the drive shaft of the motor or the motors is or are coupled to the adjusting ring or the adjusting rings via a toothed drive.

The invention is directed from previous designs, in which the rotation of the adjusting ring is effected by tangentially engaging push rods. The introduction of force for rotating the adjusting ring takes place according to the invention instead of via push rods via at least one pinion. The toothed drive is preferably designed as a crown gear or a bevel gear, wherein the drive shaft of the motor are simultaneously formed as the drive shaft of the pinion and the adjusting ring as the output shaft of the pinion. This makes it possible to obtain a much improved application of force for rotating the adjusting ring, which reduces the unwanted decentering of the adjusting ring. To provide sufficiently large forces for rotation of the adjusting ring or for redundancy reasons, some motors are preferably distributed over the circumference of the adjusting ring, which each have a Pinion, which are all identical, are coupled to the collar. To adjust the motors are of course controlled synchronously. All blades are then pivoted from the collar to the desired position.

This type of force application offers itself regardless of the type of coupling pin and collar. It can therefore be used for a lever coupling, but also for a gear-like coupling.

Advantageous embodiments are specified in the subclaims.

According to a preferred embodiment, one of the pins may be part of one of the drive shafts, so that the axis of rotation of drive shaft and coincides with the axis of rotation of the respective pin. Alternatively, drive shaft and pin can be rigidly connected together. In both cases, the blade corresponding to the respective pin is directly drivable by the motor. For adjustment, the motor consequently drives the blade connected to its drive shaft and the adjusting ring simultaneously. If several equally distributed over the circumference of the adjusting ring motors are provided, so each of these motors drives the collar and one of the adjustable blade directly. The not directly driven (remaining) blades are then pivoted by means of the adjusting ring in the desired position. The use of multiple motors also allows distributed over the circumference of force for adjusting the blades. The more motors are used, the lower are the forces to be introduced by each of these, which enables smaller tooth drives or toothings.

According to a further advantageous embodiment, two adjusting rings per drive device are provided in order to drive the pins free of transverse forces.

According to a further advantageous development, a circumferential groove is provided in the blade carrier or in the housing surrounding the blade carrier shell in which the pins end and in which the adjusting ring is arranged, wherein for shielding pin, collar and their coupling to the outside, the circumferential groove by a cover at least mostly closed. The coupling of adjusting ring and pin is thus embedded in the blade carrier and sunk in the circumferential groove, which - viewed in longitudinal section of the turbomachine - results in a shield on both sides. In this advantageous embodiment, averted from the prior art, in which the adjusting mechanism was previously arranged unprotected outside the housing of the turbomachine. It is now provided that the adjusting mechanism is at least covered, if not hermetically sealed, whereby the drive is largely (ie except for the implementation for the drive shaft of the motor) is displaced into the wall of the blade carrier. This requires that the blade carrier in the region in which the pins protrude into it, there has at least such a large wall thickness that there can be introduced from the outside, for example by mechanical machining a circumferential groove for receiving pin ends and collar. The cover of the circumferential groove by a plurality of cover segments is easy to accomplish, the attachment of the cover or cover with the usual means such as fittings is feasible. Hereby, a simple construction is specified, which is comparatively simple and inexpensive to implement.

Preferably, the coupling between the adjusting ring and the respective pin is in each case designed as a toothed drive, wherein the toothed drive is preferably designed as a crown gear. In this case, the collar is a crown wheel and the pin is at least over a portion of its circumference, if not interlocked over its full circumference. The toothing of the crown wheel and the toothing of the pin engage each other, so that rotation of the adjusting ring in the circumferential direction the blades are turned. With the help of Kronenradgetriebes a low-wear, temperature-independent coupling of adjusting ring and the respective pin can be made, which is also able to reliably transmit the large forces required for adjustment. If all blades are pivoted by means of the adjusting ring in the desired position, the required backlash of each pinion is irrelevant. All blades are then pivoted to the same extent. If some of the blades of engines directly and the remaining blades are adjusted by means of the adjusting ring and the coupling is done by toothed drives, the immediately driven blades can be slightly pivoted back by a predetermined angle of rotation after adjusting all blades to compensate for any existing backlash, so all blades have the same angle of attack.

A particularly simple and reliable mounting of the adjusting ring can be achieved if this - relative to the central axis of the blade carrier - is guided radially outwardly from the cover of the circumferential groove and radially inwardly from the groove bottom of the circumferential groove. The cover then serves as a guide for the adjusting ring, since this slidably, but without play abuts both the cover and the groove bottom. This avoids the use of other construction elements such as support rollers for the central bearing of the adjusting ring relative to the machine axis. Also, this embodiment allows a comparatively slim collar because its inherent rigidity can now be lower than before.

Another advantage of the cover is the leadership of the adjusting ring along the entire circumference, since this is composed of at least two segments. The segments of the adjusting ring can be connected or screwed together due to the proposed outer guide through the cover in a comparatively simple manner. An evasion of the principle Rod-shaped adjusting ring is not possible by the full-length guidance.

In order to prevent divergence of the teeth, the adjusting ring of a side wall of the circumferential groove, based on the center line of the blade carrier - guided axially. Alternatively or additionally, it can be provided that means for pressing the adjusting ring are provided on the pins in the side wall and / or between the side wall and adjusting ring. For example, can lead to the supply of hydraulic fluid in the side wall channels. It is also possible that equally distributed between the side wall and the adjusting ring over the circumference spring elements are provided which exert a force acting in the axial direction of the adjusting ring. By using a toothing of the collar can be made slimmer than the stationary gas turbine for comparatively massive collar from the prior art. By pressing the adjusting ring on the pin and the elimination of the backlash can be done so as to keep the adjustable blade clearance in its predetermined position during operation of the turbomachine. Optionally, the contact pressure can be reduced during the adjustment process, which is readily possible in particular when using a hydraulic fluid as a contact pressure. In this case, the adjustment process can be effected with comparatively small forces.

The drive device according to the invention can be used both for adjusting inlet guide vanes of a compressor, but also for adjusting guide vanes of a compressor, which are mounted in a manner analogous to the inlet guide vanes about their longitudinal axis extending in the radial direction of the machine axis.

FIG 1

eine Gasturbine in einem Längsteilschnitt;

FIG 2

das Detail X aus dem Längsteilschnitt gemäß FIG 1 in einer ersten Ausführungsvariante;

FIG 3

die Draufsicht auf das Detail X gemäß FIG 2;

FIG 4

die Befestigung des Motors am Fundament;

FIG 5

das Detail X gemäß einer dritten Ausführungsvariante und

FIG 6

das Detail X gemäß einer zweiten Ausführungsvariante.

The further explanation of the invention will be made with reference to the embodiments illustrated in the drawings. In detail, show schematically:

FIG. 1

a gas turbine in a longitudinal section;

FIG. 2

the detail X from the longitudinal section according to FIG. 1 in a first embodiment;

FIG. 3

the top view of the detail X according to FIG. 2 ;

FIG. 4

the attachment of the motor to the foundation;

FIG. 5

the detail X according to a third embodiment and

FIG. 6

the detail X according to a second embodiment.

FIG. 1 shows a trained as a gas turbine 1 turbomachine in a longitudinal partial section. It has inside a rotatably mounted about a rotation axis 2 rotor 3, which is also referred to as a turbine runner. Along the rotor 3 successive an intake 4, a compressor 5, a toroidal annular combustion chamber 6 with a plurality of rotationally symmetrical to each other arranged burners 7, a turbine unit 8 and an exhaust housing 9. The annular combustion chamber 6 forms a combustion chamber 17 which communicates with an annular hot gas channel 18. There four successive turbine stages 10 form the turbine unit 8. Each turbine stage 10 is formed of two blade rings. When viewed in the direction of flow of a hot gas 11 produced in the annular combustion chamber 6, the hot gas channel 18 is followed by a row of blades 13, a row 14 formed of blades 15. The stator blades 12 are fixed to the stator, whereas the blades 15 of a row 14 are attached to the rotor 3 by means of a turbine disk are. On the rotor 3, a generator or a working machine (not shown) is coupled.

At the intake housing side entrance of the compressor 5 adjustable inlet blades 19 are provided. The inlet blades 19 are arranged radially in the annular flow channel of the compressor 5 and can be rotated about their respective longitudinal axis by a drive device 21, for example, the gas flow flowing through the gas turbine 1 mass flow adjust. Depending on the angle of attack of the blades of the inlet guide vanes, a particularly large or a small mass flow can flow through the gas turbine 1 as needed. In order to reduce flow losses in the intake ambient air and to prevent vibration excitation from immediately downstream of the inlet blades 19 rotating blades 15, which takes place at a circumferentially uneven flow of the blades 15, all inlet blades 19 are synchronously adjusted while maintaining the same angle of attack ,

The drive device 21 is provided outside the flow channel and will be described in detail in the following figures.

This shows FIG. 2 this in FIG. 1 X marked detail. First, a blade carrier 22 is shown, which is also configured in the concrete embodiment as a housing component of the compressor 5 of the gas turbine 1 at the same time. The vane carrier 22 is also referred to as a vane carrier. In a section 23 of the compressor 5 that flows inward for the intake air, the guide blade carrier 22 has an increased wall thickness. In this axial portion 23 are provided with respect to the central axis 24 of the gas turbine 1 in an identical number as adjustable blades 19 holes 25 for receiving pins 26 which are each arranged on one of the adjustable blades 19. In section 23, an endless circumferential groove 27 is also provided on the shell side, in which the pins 26 end. The axial position of the holes 25 is chosen so that they do not open completely in the circumferential groove 27, but only partially such that only a small circular portion of the bore 25 is located in the groove 27 in order to ensure sufficient teeth (see FIG. 3 ). The required for the rotatable mounting of the pin 26 in the vane support 22 bearing (not shown) are provided for circumferential groove 27 radially inwardly adjacent in a known manner.

In the groove 27, an example of two segments existing collar 28 is arranged. The adjusting ring 28 has - viewed in longitudinal section of the turbomachine - a rectangular sectional contour. Each pin 26 has at least over part of its circumference a toothing in the manner of a gear. In a corresponding manner, an end wall of the adjusting ring 28 is also toothed, both gears are in the manner of a crown gear engaged with each other. The side wall teeth 30 of the adjusting ring 28 extends for each pin 26 along such an arc length ( FIG. 3 ) that the blade 19 can be safely pivoted over the entire Verstellwinkelbereich. The side wall teeth 30 may also be arranged endlessly over the circumference of the adjusting ring 28 as in a crown wheel. The adjusting ring 28 thus forms with each pin 26 a crown gear teeth, with which the rotational movement of the adjusting ring 28 is converted to the machine axis 24 in a rotary movement of the blade 19 about its longitudinal axis 31.

To guide the adjusting ring 28 and to avoid deposits and contamination in the respective crown toothing, the groove 27 is shielded by a cover 32. In this respect, the toothed drives and the adjusting ring 28 are in principle not accessible from outside the gas turbine 1.

In order to supply the required adjusting forces to the adjusting ring 28, at least one motor 33 is provided. The motor 33 can be designed as a hydraulic motor, but also as an electric motor or as a servomotor. The drive shaft 35 of the motor 33 extends through an opening provided in the cover 32 for opening 37 and is rigidly connected to one of the pins 26. Both are rotatable about a common axis of rotation, which coincides with the longitudinal axis 31. The motor 33 serves on the one hand for driving the adjusting ring 28 and for the direct drive of one with its drive shaft 35 via the pin 26 rigidly connected blade 19. It can also be several of the in FIG. 2 shown motors 33 distributed over the circumference of the adjusting ring 28 to its rotation be. The motor or motors 33 are then fastened via brackets not shown either on the guide vane or on the foundation of the gas turbine.

The attachment of one of the motors 33 on the foundation 40 is in FIG. 4 sketched, in which the rigid connection between the drive shaft 35 and pin 26 is indicated only schematically. For the sake of clarity, only the vane 19 of the vane ring and the adjusting ring 28, which can be directly driven by the motor 33, are shown.

Next is in FIG. 2 in a side wall 34 of the circumferential groove 27, a channel opening 38 is provided, via which a hydraulic means of the drive device 21 for pressing the adjusting ring 28 to the pin 26 is possible. The required connection cables are in FIG. 2 not shown. Of course, several channels for hydraulic fluid are distributed along the circumference to achieve a uniform contact pressure.

The plan view of an uncovered crown toothing in section 23 shows FIG. 3 , wherein identical features are provided with identical reference numerals.

According to one FIG. 2 alternative embodiment, which in FIG. 6 is shown, instead of a unilaterally arranged adjusting ring 28, a further adjusting ring 28 may be provided, such that between two belonging to a drive device adjusting rings 28, the pins 26 of the blades 19 are arranged and thus toothed on both sides. In this case, two grooves 27 are provided on both sides of the bores 25, in each of which one of the two adjusting rings 28 is arranged. Instead of two circumferential grooves 27 with holes 25 arranged therebetween, the bores 25 and thus also the pins 26 can be arranged centrally in only then a wider circumferential groove. For turning or pivoting of blades 19, the two associated to a drive device 21 adjusting rings 28 are simultaneously rotating in opposite directions.

Instead of the FIG. 2 known hydraulic contact pressure of the adjusting ring 28 to the pin 26 are according to FIG. 6 between the side wall 34 of the circumferential groove 27 and the adjoining thereto adjusting ring 28 evenly distributed over the circumference spring elements 36, for example in the form of disc springs, provided that cause a steady contact pressure.

Of course it is possible the in FIG. 6 shown spring elements 36 to be arranged even with a drive device 21 with only one adjusting ring 28. Conversely, it is equally possible to apply the hydraulic contact pressure for each adjusting ring 28 of a drive device 21, in the two oppositely rotatable adjusting rings 28 according to FIG. 6 are provided.

The preferred embodiments of the invention show the Figures 2 and 6 , The basic embodiment is in FIG. 5 shown, according to this the direct drive of one or more blades 19 is not mandatory. The motor 33 is then used solely for adjusting the adjusting ring 28, which for pivoting all blades 19 its rotational movement over the FIG. 2 described tooth drives between them and the pin 26 of the blades 19 transmits to the latter. Also in FIG. 5 embodiment shown may be slightly modified with respect to the number of collars 28 and the choice of the means for pressing the collars 28 to the pin 26th

The drive device shown in the figures is not only suitable for adjusting inlet guide vanes 19 of a compressor 5, but of course also for adjusting guide vanes of subsequent compressor stages which in modern gas turbines also about their longitudinal axis 31, which with the radial direction with respect to the machine axis 24th coincides, are pivotally mounted.

Overall, the invention relates to a drive device 21 for pivoting adjustable blades 19 of a turbomachine, with one of a guide vane carrier 22 enclosed annular flow channel portion 23 which extends along the central axis 24 of the vane support 22 and are provided in the radiating manner to form a ring blades 19, wherein the blades 19 are each pivotable about its longitudinal axis 31 and in each case at least in the guide vane carrier 22 extending pin 26th have, which are coupled to at least one the guide pad carrier 22 encompassing adjusting ring 28. To provide a particularly low-wear and reliable drive, it is proposed that the drive shaft 35 of the motor 33 and the motors with the adjusting ring 28 and the adjusting rings 28 is coupled via a toothed drive or are.

Claims (12)

Drive device (21) for pivoting adjustable blades (19) of a turbomachine,
with an annular flow channel section (23) enclosed by a blade carrier (22), which extends along the central axis (24) of the blade carrier (22) and in which blades (19) are provided in a radiating manner to form a ring,
wherein for adjustment, the blades (19) each about its longitudinal axis (31) are pivotable and each having at least in the blade carrier (22) extending pins (26) which are coupled to at least one circumferentially rotatable adjusting ring (28), which via at least one motor (33) is drivable,
characterized,
that the drive shaft (35) of the motor (33) or the motors with the adjusting ring (28) and the adjusting rings (28) is coupled via a toothed drive or are. Drive device (21) according to claim 1,
in which each drive shaft (35) respectively
one of the pins (26) comprises or
rigidly connected to one of the pins (26),
wherein the respective toothed drive in each case on the pin (26) of the thus directly driven blade (19) is arranged. Drive device (21) according to claim 2,
in which some of the blades (19) can be driven directly by a respective motor (33) and the remaining blades (19) can be driven via the at least one adjusting ring (28). Drive device (21) according to claim 1, 2 or 3, in which two adjusting rings (28) are coupled to the pin (26) and are drivable by the motor (33) or the motors. Drive device (21) according to one of the preceding claims,
in the casing (22) or in the blade carrier (22) surrounding a circumferential groove (27) is provided, in which the pins (26) terminate and in which the adjusting ring (28) or the adjusting rings (28) is arranged, wherein for shielding to the outside, the circumferential groove (27) is closed by a cover (32). Drive device (21) according to one of the preceding claims,
in which the coupling between adjusting ring (28) and all pins (26) is in each case designed as a toothed drive. Drive device (21) according to one of the preceding claims,
in which the toothed drives are designed as crown gear. Drive device (21) according to one of the preceding claims,
wherein each adjusting ring (28) - relative to the central axis (24) of the blade carrier (22) - radially outwardly of the cover (32) of the circumferential groove (27) and radially inwardly of the groove bottom of the circumferential groove (27) is guided. Drive device (21) according to one of the preceding claims,
wherein each adjusting ring (28) of a side wall (34) of the circumferential groove (27) - relative to the central axis (24) of the blade carrier (22) - is axially guided. Drive device (21) according to claim 9,
in which in the side wall (34) and / or between the side wall (34) and adjusting ring (28) means are provided for pressing the adjusting ring (28) on the pins (26). Drive device (21) according to claim 10,
in which open in the side wall (34) channels for supplying a hydraulic medium. Drive device (21) according to claim 10,
in which between the side wall (34) and collar (28) over the circumference uniformly distributed spring elements (36) are provided.

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