EP3667020A1 - Turbo machine blade assembly - Google Patents

Abstract

The invention relates to a blade arrangement for a turbomachine, in particular a gas turbine, with a first blade (10-12), which has a first blade (10) and a first platform (11), and a second blade (U) which is adjacent in the circumferential direction (U). 20-22), which has a second blade (20) and a second platform (21), a first wall (12) of the first blade and a second wall (22) of the second blade delimiting a blade cavity in which a damper ( 30) is arranged with a wall-side contact surface (31, 32), this contact surface having at least a first surface section (31) which is convexly curved in a first direction (K) in at least one contact position in which the first surface section contacted the first wall, is parallel to at least a portion of an edge (k) of the first platform facing the second platform.

Description

The present invention relates to a blade arrangement for a turbomachine, in particular a gas turbine, a turbomachine, in particular a gas turbine, with the blade arrangement and a method for reducing vibrations of the blade arrangement.

Turbomachinery blades can have different vibration modes during operation. In particular, so-called flap modes ("F mode") of the blades can cause the blades or platforms to tilt about the main or rotational axis of the turbomachine, and so-called couple disk modes ("CD mode") can nod of the blades or platforms in the direction of a dividing line between the platforms.

An object of an embodiment of the present invention is to reduce blade assembly vibrations.

This object is achieved by a blade arrangement with the features of claim 1 and a method with the features of claim 11. Claim 10 provides a turbomachine with one or more blade arrangements described here under protection. Advantageous embodiments of the invention are the subject of the dependent claims.

According to an embodiment of the present invention, (at least) one blade arrangement for a or a turbomachine, in one embodiment a gas turbine, in particular an aircraft engine, has a blade with an airfoil and at least one platform, as well as one adjacent (arranged) in the circumferential direction. e further blade with an airfoil and at least one platform, these two blades being referred to as the first and second blades without restriction of generality, their airfoil and their platform accordingly as the first airfoil or first platform (the first blade) or second Blade or second platform (the second blade).

In one embodiment, the blades are rotor blades and / or blades of a compressor or turbine stage of a gas turbine, in particular an aircraft engine, and / or have blade feet which, in particular releasably and / or positively and / or frictionally, in a carrier, in particular a rotor the turbomachine, attached or provided for this purpose, in particular set up, are or are used.

Because of the conditions of use, the present invention can be used here with particular advantage.

According to an embodiment of the present invention, a wall of the first blade ("first wall") and a wall of the second blade ("second wall") delimit a blade cavity in which a one-part or multi-part damper is arranged, which is a wall-side damper Has contact surface, which during operation contacts the first and second wall at least temporarily or is provided for this, in particular set up, is or is used.

According to one embodiment of the present invention, this contact surface has a surface section, which in the present case is referred to as the first surface section without restriction of generality and is convexly curved (seen) in a first direction, in at least one contact position in which this first surface section has the first wall contacted, parallel to at least a portion of an edge, in particular a blade edge or flow channel side or upper edge, of the first platform, which faces the second platform. In other words, the contact surface has a first surface section which is convexly curved in the direction of at least a section of an edge (facing the airfoil or flow channel or upper) of the first platform or a dividing line between the first and second platforms, when the damper or its first surface portion is in the contact position.

In one embodiment, this section of the edge is at least 10%, in particular at least 25%, in one embodiment at least 50% of a (total) length of the edge or dividing line, it can in particular also be 100%. The dividing line can be in the form of a gap, in particular in order to compensate for tolerances, thermal expansions, movements or the like. Correspondingly, the edge of the first platform (facing the second platform) does not touch the second platform in one embodiment (in (normal) operation) or is provided for this, in particular set up. In another embodiment, the edge of the first platform (s) facing the second platform and the second platform can touch at least temporarily, so that the dividing line forms a contact line between the first and second platforms. Thus, in an embodiment in the at least one contact position in which the first surface section contacts the first wall, the first direction is parallel to at least a section of a dividing line between the first and second platforms, in particular a section of an edge (through the edge facing the second platform) of the first platform) temporary or only virtual or theoretical contact line between the first and second platforms, this section in one embodiment at least 10%, in particular at least 25%, in one embodiment at least 50% of a (total) length of the separation or (temporary or (only) virtual or theoretical) contact line, in particular can also be 100%.

As explained in the introduction, couple disk modes can cause the blades or platforms to nod in the direction of the dividing line. Because the damper or its contact surface in the first surface section is convexly curved parallel to at least a section of the edge of the first platform facing the second platform or the dividing line defined thereby between the first and second platforms, in one embodiment, a (thereby favored) ) Relative movement of the first and second blades relative to one another is advantageously dissipated by a (thereby favored) frictional sliding movement of the damper or its contact surface and thus corresponding vibrations of the blade arrangements are reduced.

In one embodiment, the first surface section is also convexly curved in the circumferential direction (seen) when the damper is in the contact position.

As explained in the introduction, flap modes can cause the blades or platforms to tilt about the main or rotational axis or in the circumferential direction. Since the damper or its contact surface in the first surface section is also convexly curved in the circumferential direction, in one embodiment, as a result of a (thereby favored) relative movement of the first and second blades relative to one another, advantageously (due to this) frictional sliding movement of the damper or its contact surface Vibration energy is dissipated and corresponding vibrations of the blade arrangements are reduced.

In an alternative embodiment, the first surface section is straight (seen) in the circumferential direction when the damper is in the contact position.

As a result, in one embodiment, a sliding movement between the first surface section and the first wall can be made more difficult or a contact surface can be enlarged and the damper can thereby be better supported on the first wall.

In particular, in particular with regard to the above-mentioned flap modes or the tilting of the blades or platforms about the main or rotational axis or in the circumferential direction, it can advantageously be provided that the contact surface has a further surface section, which is present is referred to without limitation of generality as the second surface section, contacts the second wall when the damper is in the contact position, or is provided for this, in particular is set up, is used, and then or in the contact position in the circumferential direction (viewed) is convexly curved.

As a result, tilting of the blades or platforms about the main or rotational axis or in the circumferential direction can be favored in this embodiment and thus advantageously vibrational energy can be dissipated from flap modes by a frictional sliding movement of the damper or its contact surface (thereby favored) and so corresponding Vibrations of the blade arrangements can be reduced.

As explained, the damper can advantageously be supported on the first wall by the first surface section that is straight in the circumferential direction (seen), the second surface section convexly curved in the circumferential direction (seen) in the contact position is not limited to this, but also in combination with a first surface section which is convexly curved in the circumferential direction (seen) in the contact position, can advantageously reduce vibrations.

Additionally or alternatively, in particular in the case of the first surface section convexly curved in the contact position both in the first direction and in the circumferential direction (as seen), it can be advantageous to provide one or the (second) surface section of the contact surface which in the contact position has the second wall contacted and is straight (seen) in the first direction and / or in the circumferential direction. This second surface section can in particular be flat or planar.

As a result, in one embodiment, a sliding movement between this second surface section and the second wall can be made more difficult and the damper can thereby be better supported on the second wall.

In one embodiment, the damper has one or more damper cavities in which (in each case) at least, in a preferred embodiment (in each case) exactly one, in one embodiment spherical, shock body is or will be arranged, which during operation has butt contacts executes the damper cavity wall or provides for this, in particular is set up or used.

That is a matter of principle from the WO 2012/095067 A1 Known, concept for reducing blade vibrations by means of butt contacts, by means of which in particular resonance frequencies of blades (arrangements) can be detuned. In addition, the above mentioned WO 2012/095067 A1 Reference and their content expressly included in full in the present disclosure.

As has surprisingly been found, in combination with impulses between shock bodies, dampers and blades can be transmitted in a particularly advantageous manner in combination with the contact surface described above, and blade vibrations can thereby be particularly advantageously reduced. It is assumed that this is particularly favored by the sliding movements in the corresponding directions which are thereby favored or made more difficult, without being bound to this assumption.

In one embodiment, the or one or more of the shock bodies is / are / are arranged airtight or gas-tight in the (respective) damper cavity.

As a result, blade vibrations can be reduced particularly advantageously due to impact contact.

In one embodiment, the or one or more of the damper cavities is / are / are closed (in each case, in particular together) by an airtight cover, which is arranged on a side of the damper opposite the contact surface.

As a result, the impulse transmission between shock bodies, dampers and blades can be (further) improved in one embodiment.

In one embodiment, the first and second platforms are platforms on the blade root side, in particular thus radially inward and / or sub-platforms.

Additionally or alternatively, the blade cavity is arranged in one embodiment on a side of the first and / or second platform facing away from the blade, in one embodiment entirely or partially in the first and / or second platform.

It has surprisingly been found that blade vibrations are particularly advantageously reduced in this way.

In one embodiment, an axial direction is parallel to a rotary or (main) machine axis of the turbomachine, corresponding to a circumferential direction a direction of rotation about this axis, a radial direction perpendicular to the axial and circumferential direction.

Fig. 1

eine Schaufelanordnung nach einer Ausführung der vorliegenden Erfindung in radialer Draufsicht;

Fig. 2

eine Schaufel der Schaufelanordnung in perspektivischer Ansicht;

Fig. 3

einen Dämpfer der Schaufelanordnung in vergrößerter perspektivischer Ansicht;

Fig. 4

einen Schnitt längs der Linie A-A in Fig. 1;

Fig. 5

den Dämpfer aus einer anderen Perspektive; und

Fig. 6

einen Schnitt längs der Linie VI-VI in Fig. 4.

Further advantageous developments of the present invention result from the subclaims and the following description of preferred embodiments. Here shows, partly schematically:

Fig. 1

a blade assembly according to an embodiment of the present invention in a radial plan view;

Fig. 2

a blade of the blade arrangement in a perspective view;

Fig. 3

a damper of the blade assembly in an enlarged perspective view;

Fig. 4

a section along the line AA in Fig. 1 ;

Fig. 5

the damper from a different perspective; and

Fig. 6

a section along the line VI-VI in Fig. 4 .

Fig. 1 shows a blade arrangement according to an embodiment of the present invention in a radial plan view, Fig. 2 one of the two identical blades of the blade arrangement in a perspective view.

Both blades each have an airfoil 10 or 20 and a platform 11 or 21 on the blade root side.

In a blade cavity in the two platforms, which are separated by corresponding walls 12 and 22 (cf. Fig. 4 ) is limited, a damper 30 is arranged, on the wall-side contact surface one in Fig. 3 looks.

This contact surface has a first surface section 31 which is convexly curved in a first direction K, which is in a contact position in which the first Surface section contacts the wall of a blade (cf. Fig. 4 ), parallel to the edge k of the first platform 11 facing the second platform 21 or dividing line between the first and second platforms. Fig. 6 shows a section along the in Fig. 4 dash-dotted line VI-VI.

In the exemplary embodiment, the first surface section in the contact position is also convexly curved in the circumferential direction U, and the contact surface has a second surface section 32, which contacts the wall of the other blade in the contact position and is straight in the first direction K and in the circumferential direction U.

In a modification not shown, conversely, the first surface section 31 is straight in the contact position in the circumferential direction U and the second surface section 32 is convexly curved in the circumferential direction.

As in the rear view (from radially below) of the Fig. 5 recognizable, the damper 30 has a plurality of damper cavities 33, in each of which one (in Fig. 5 hidden) shock body is arranged for butt contact with the respective damper cavity wall.

The damper cavities are or are defined by a (in Fig. 5 hidden) cover airtight.

Although exemplary embodiments have been explained in the preceding description, it should be pointed out that a large number of modifications are possible. It should also be pointed out that the exemplary embodiments are only examples that are not intended to restrict the scope of protection, the applications and the structure in any way. Rather, the person skilled in the art is given a guideline for the implementation of at least one exemplary embodiment by the preceding description, with various changes, in particular with regard to the function and arrangement of the described components, can be made without leaving the scope of protection resulting from the claims and these equivalent combinations of features.

Reference symbol list

10th

first airfoil

11

first platform

12

first wall

20th

second airfoil

21st

second platform

22

second wall

30th

mute

31

first surface section

32

second surface section

33

Damper cavity

k

Edge

K

first direction

U

Circumferential direction

Claims (11)

Blade arrangement for a turbomachine, in particular a gas turbine, with a first blade (10-12), which has a first blade (10) and a first platform (11), and a second blade (20-22) adjacent in the circumferential direction (U), which has a second blade (20) and a second platform (21), a first wall (12) of the first blade and a second wall (22) of the second blade delimiting a blade cavity in which a damper (30) with a wall side Contact surface (31, 32) is arranged, said contact surface having at least a first surface section (31) which is convexly curved in a first direction (K), which is parallel in at least one contact position in which the first surface section contacts the first wall to at least a portion of an edge (k) of the first platform facing the second platform. Blade arrangement according to claim 1, characterized in that the first surface section in the contact position is also convexly curved in the circumferential direction. Blade arrangement according to the preceding claim, characterized in that the contact surface has at least one second surface section (32) which contacts the second wall in the contact position and is planar and / or straight in the first and / or circumferential direction. Blade arrangement according to claim 1, characterized in that the first surface section (31) in the contact position is straight in the circumferential direction. Blade arrangement according to one of the preceding claims, characterized in that the contact surface has at least one second surface section (32) which in the contact position contacts the second wall and is convexly curved in the circumferential direction. Blade arrangement according to one of the preceding claims, characterized in that the damper has at least one damper cavity (33), in which at least, in particular precisely, a shock body for shock contact with the damper cavity wall, in particular airtight, is arranged. Blade arrangement according to the preceding claim, characterized in that the damper cavity is closed by a cover, in particular airtight, which is arranged on a side of the damper opposite the contact surface. Blade arrangement according to one of the preceding claims, characterized in that the first and second platforms are platforms on the blade root side. Blade arrangement according to one of the preceding claims, characterized in that the blade cavity is arranged on a side facing away from the blade, in particular at least partially in, the first and / or second platform. Turbomachine, in particular gas turbine, with at least one blade arrangement according to one of the preceding claims. Method for reducing vibrations of a blade arrangement according to one of the preceding claims, characterized in that the damper is arranged in the blade cavity in such a way that it can assume the contact position.

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