Lever for adjusting an adjusting blade

Abstract

The present invention relates to a lever for adjusting a variable displacement blade of a turbomachine (1), wherein the lever has a pivot point for rotatably mounting the lever about an axis of rotation, a first load arm with a first adjustment connection point for at least indirect connection with the variable displacement blade and a first force arm with a first actuating connection point for connection with an actuating device, wherein the lever further has a first strut which connects the first adjustment and first actuating connection points and extends in an arc shape about the axis of rotation.

Description

Technical field

[0001] The present invention relates to a lever for adjusting a variable vane of a turbomachine. State of the art

[0002] A turbomachine can be, for example, a jet engine, such as a turbofan engine. Functionally, a turbomachine is divided into a compressor, combustion chamber, and turbine. In the case of a jet engine, for instance, intake air is compressed by the compressor and then combusted with kerosene in the downstream combustion chamber. The resulting hot gas, a mixture of combustion gas and air, flows through the downstream turbine and expands. Both the compressor and the turbine are typically composed of several stages, each with a stator (guide vane assembly) and a rotor (rotor blade assembly).

[0003] Variable-pitch blade assemblies can be used in turbines and especially in compressors. An adjustment mechanism for the variable-pitch blades can include an adjustment ring that is rotatable about the longitudinal axis of the turbomachine, with this rotational offset then being transmitted to the individual variable-pitch blades of the assembly. Furthermore, the adjustment mechanism can also include a connecting rod that is axially displaced to generate the rotational offset of the adjustment ring, for example, as part of a gearbox that simultaneously actuates variable-pitch blades of different stages.

[0004] A lever, as discussed here, can be arranged between the connecting rod and the adjusting ring. An adjusting connection point on the lever's force arm is connected to the connecting rod, and an adjusting connection point on its load arm is at least indirectly connected to the adjusting blade. Specifically, a push rod, for example, can be mounted at the adjusting connection point, transmitting the lever's displacement to the adjusting ring (from where a further mechanism can then couple to the individual adjusting blades). Corresponding levers, optimized for conventional manufacturing processes, are known, for example, from US 2006 O 263 206 A. Description of the invention

[0005] The present invention is based on the technical problem of providing an advantageous lever for adjusting a variable vane of a turbomachine.

[0006] This is achieved according to the invention with the lever according to claim 1. In this lever, the adjusting and adjusting connection points are not only connected to the pivot point of the lever via the load and force arms, respectively, but a strut is also provided. This strut connects the adjusting and adjusting connection points directly to each other and extends in an arc around the axis of rotation of the lever. If, during operation, an offset is transmitted via the lever to adjust the adjusting blades, e.g., an axial offset of the adjusting device / connecting rod relative to the longitudinal axis of the turbomachine is converted into a circumferential offset of the push rod / adjusting ring, the lever is rotated a certain distance around its axis of rotation. The arc-shaped strut provides stability in this process, and the force transmission occurs not only via the load and force arms but also via the arc-shaped strut.

[0007] Figuratively speaking, the arc-shaped strut pushes or pulls the adjustment connection point, with the strut being subjected primarily to normal forces. This means that predominantly or even exclusively normal forces occur in the strut, at least reducing torque and shear forces. If, for comparison, the lever were mounted without the arc-shaped strut and all forces were transmitted via the load and force arms, high forces and moments could occur in the arms, particularly at the respective transition to the pivot point. The arc-shaped strut prevents this, allowing the lever, despite the additional strut, to be manufactured with reduced material thickness in other areas and thus, for example, lighter. This can also be advantageous in terms of fuel consumption, such as in aircraft engines. By reducing the force application...If the transmission does not take the shortest path, the mechanical stress can be reduced. This can, for example, also increase the service life.

[0008] Preferred embodiments are found in the dependent claims and the entire disclosure, whereby the description of the features does not always differentiate in detail between apparatus and process or use aspects; in any case, the disclosure is to be read implicitly with regard to all claim categories. Furthermore, it is always to be read as referring to both the lever and an adjustment arrangement or a module for a turbomachine with such an adjustment arrangement.

[0009] In the description of the lever, terms such as "axial," "radial," and "circumferential" or "arc-shaped" refer to the lever's axis of rotation, around which it is rotatably mounted and rotated during operation to adjust the adjusting vanes. As will be explained in detail below, the lever can be constructed in several axially offset planes, with the different levels distinguished by "first" and "second," and the individual features within each plane referenced accordingly (first load arm, first force arm, first arc-shaped strut, etc.). This applies particularly to the claims; in the description, the features are also referenced generically (load arm, force arm, arc-shaped strut, etc.).

[0010] In general, "ein" and "eine" within the context of the present disclosure are to be read as indefinite articles and thus, unless expressly stated otherwise, always also as "at least one" and "at least one", so the lever as a whole can, for example, also have several arc-shaped struts (e.g. a first and a second, see also the embodiment for illustration).

[0011] As mentioned above, the braced design can enable an overall weight reduction. Generally, the lever is made of a metallic material, such as titanium or a titanium alloy. The lever can generally be manufactured using a casting process, meaning it can be a cast part. However, particularly in the case of a complex braced geometry, additive manufacturing is also possible. Additive Manufacturing In AM), for example in a powder bed process, the lever can therefore be an additively manufactured part.

[0012] The arc-shaped strut extends in the direction of rotation around the lever's axis of rotation, preferably in the form of a circular arc. The central angle of this arc or circular arc shape can be, for example, at least 15°, 25°, or 30° (possible upper limits could be, for example, a maximum of 165°, 155°, or 145°), whereby these details may also depend on the exact location of use (which stage, etc.).

[0013] According to a preferred embodiment, the arc-shaped strut, viewed axially, extends tangentially into the adjustment connection point. If, for example, a push rod is mounted there, this push rod is then preferably tangential to the arc-shaped strut when viewed axially, which allows for good force coupling. Alternatively, or preferably additionally, in a preferred embodiment, the arc-shaped strut extends tangentially into the adjustment connection point; in general, the tangential coupling can be advantageous, for example, with regard to the aforementioned normal force load.

[0014] According to a preferred embodiment, the lever additionally has a crossbar that connects the pivot point to the arc-shaped strut. The crossbar can generally also run obliquely into the arc-shaped strut, i.e., at an angle of less than 90° to a tangent applied to the arc-shaped strut. Preferably, however, it runs parallel to the radial direction into the arc-shaped strut, i.e., it is perpendicular to said tangent. The crossbar is also preferably subjected to normal forces during operation, meaning it does not have to absorb any significant moments.

[0015] In a preferred embodiment, the cross brace is arranged at a central pivot position between the connection points. Generally, there can also be several cross braces, even within the same plane; however, it is particularly preferred that there is exactly one cross brace per plane, which is further preferably arranged centrally.

[0016] According to a preferred embodiment, the load arm and the force arm span a plane; that is, the first load arm and the first force arm together form a first plane. Preferably, the first arc-shaped strut also lies in the first plane, i.e., it does not run at an angle or tilt relative to it.

[0017] According to a preferred embodiment, the lever has a second load arm that is axially offset from the first load arm, and it further has a second force arm that is axially offset from the first force arm. Preferably, the load arms and the force arms can each be arranged translationally symmetrically to each other along the axis of rotation. Preferably, the lever further has a second arcuate strut that connects a second adjustment connection point of the second load arm to a second adjustment connection point of the second force arm (and is preferably translationally symmetrical to the first arcuate strut).

[0018] In a preferred embodiment, the second load and force arm also spans a (second) plane, in which the second arc-shaped strut preferably also lies. The first and second planes are axially offset, preferably parallel to each other and further preferably each perpendicular to the axis of rotation.

[0019] In a preferred embodiment, a connecting strut is provided which links the arcuate struts of the first and second planes. The connecting strut can, for example, run obliquely into each arcuate strut, i.e., at an angle of less than 90° to the respective plane. Preferably, a first and a second connecting strut are provided that intersect, e.g., axially centrally between the arcuate struts and / or at a central pivot point.

[0020] The invention also relates to an adjusting arrangement which, in addition to the lever, has an adjusting device with a connecting rod mounted at the adjusting connection point(s). An axial offset, relative to the longitudinal axis of the turbomachine, is transmitted via the connecting rod, causing the lever to rotate about its axis of rotation. This rotational offset is transmitted to the adjusting blade via a push rod mounted at the adjusting connection point, for example, via an intermediate adjusting ring.

[0021] The connecting rod can be actuated, for example, by an actuator, in particular a linear actuator. It can extend over several stages, i.e., couple to the adjusting vanes of different stages. A lever as described herein can be provided for each stage, which converts the offset of the connecting rod into a rotational offset. Preferably, several or all of the levers can be designed according to the invention, i.e., with an arc-shaped strut, etc.

[0022] As discussed above, the arcuate strut(s) in the adjustment arrangement are preferably subjected to normal forces, which also preferably applies, for example, to the cross strut(s). As a result of the bracing, the load arm and the force arm, unlike in a reference case without an arcuate strut, can also be subjected primarily to normal forces, and thus not to significant moments. Due to this "normal force loading," predominantly or even exclusively normal forces occur; any damage mechanisms are then driven by normal forces, not by moments.

[0023] The invention also relates to a turbine or, in particular, a compressor module with such an adjustment arrangement and an adjustable blade, in particular several adjustable blades grouped in a ring. Generally, the adjustable blade is preferably a guide vane and is therefore arranged in a guide vane ring (stator).

[0024] Furthermore, the invention relates to the use of a lever disclosed herein for a turbomachine, in particular a jet engine. In this process, the lever is rotated about its axis of rotation during operation, and consequently, variable vanes are displaced. Brief description of the drawings

[0025] The invention will now be explained in more detail using an exemplary embodiment, whereby the individual features within the scope of the dependent claims may also be essential to the invention in other combinations, and no distinction will be made in detail between the different claim categories.

[0026] In detail, it shows Figure 1 shows a turbomachine in axial section; Figure 2 shows an adjustment arrangement for adjusting variable-pitch blades in an overview view; Figure 3 shows a lever according to the invention for the adjustment arrangement according to Figure 2 in a top view; Figure 4 shows the lever according to Figure 3 in an oblique view; Figure 5 the lever according to the Figures 3 and 4 in a side view. Preferred embodiment of the invention

[0027] Fig. 1Figure 1 shows a turbomachine 1, specifically a turbofan engine, in longitudinal section. Functionally, the turbomachine 1 is divided into compressor 1a, combustion chamber 1b, and turbine 1c. Both compressor 1a and turbine 1c are each composed of several stages. Each stage consists of a guide vane assembly 5 and a rotor blade assembly 6. The reference numeral 7 denotes the gas channel, i.e., the compressor gas channel in the case of compressor 1a or the hot gas channel in the case of turbine 1c. In the compressor gas channel, the intake air is compressed and then combusted in combustion chamber 1b with added kerosene. The resulting hot gas flows through the hot gas channel and drives the rotor blade assemblies 6 of turbine 1c.

[0028] In the present example, several guide vane rings 5 ​​of the compressor 1a are equipped with adjustable blades 10, which can be adjusted to adapt the angle of attack.

[0029] Fig. 2 Figure 1 shows an adjustment arrangement 20 provided for this purpose, which includes, among other things, a lever 21. A load arm 22 of the lever 21 is coupled to the adjustable blades of the respective stage at an adjustment connection point 32 via a push rod 25, which converts an offset of the lever 21 into a rotational offset of an adjusting ring 26. The adjusting ring 26 extends circumferentially around the longitudinal axis of the turbomachine 2 (not shown in detail here) and then transmits the offset to each individual adjustable blade of the respective ring.

[0030] The offset is transmitted to the lever 21 via a connecting rod 27, which is part of an actuating device 28 with an actuator 29. The connecting rod 27 couples to a force arm 23 of the lever 21, where it is mounted at an actuating connection point 33. The lever 21 is rotatably mounted about a pivot axis 35 at a pivot point 34.

[0031] Fig. 3Figure 1 shows a lever 21 according to the invention in a top view, specifically looking axially at it with respect to the axis of rotation 35. Also visible are a first force arm 23.1 with a first adjusting connection point 33.1 and a first load arm 22.1 with a first adjusting connection point 32.1. The push rod is mounted to the latter, but is not shown here for clarity. The connection points 32.1 and 33.1 are additionally connected to each other via a first strut 41, which extends in an arc around the axis of rotation 35 and runs tangentially into the connection points 32.1 and 33.1. The arc-shaped first strut 41 reduces the torques; essentially only normal forces are applied or transmitted. This is advantageous with regard to the overall mechanical stress level, which is why the lever 21 can be designed with reduced weight; see the introductory description for details.

[0032] In the top view, a first cross brace 51 can also be seen, which connects the pivot point 34 with the first arcuate brace 41 and is located radially. The first cross brace 51 supports the first arcuate brace 41, and is also essentially only subjected to normal forces.

[0033] Fig. 4 shows lever 21 in an oblique view, the following based on Figure 3 The described components lie in a first level 61 (level shown in Figure 5 ). Axially offset to this, there is a second level 62 (see also). Figure 5 ), in which a second load arm 22.2 with a second adjustment connection point 32.2 and a second force arm 23.2 with a second adjustment connection point 33.2 are arranged. Furthermore, there is a second arcuate strut 42 which connects the second connection points 32.2 and 33.2 to each other. The second arcuate strut 42 is connected to the pivot point 34 via a second cross strut 52.

[0034] Fig. 5 Figure 21 shows the lever 21 in a side view, looking radially at it with respect to the axis of rotation 35. The first and second arc-shaped struts 41, 42, as well as their respective planes 61, 62, are visible. Also visible are a first and a second connecting strut 71, 72 (not shown for clarity). Fig. 4 ), which connect the first and second arc-shaped struts 41, 42 to each other. The connecting struts 71, 72 cross each other, axially and also centrally with respect to a rotational position. REFERENCE MARK LIST Turbomachine (turbocharged engine) 1 compressor 1a combustion chamber 1b turbine 1c Longitudinal axis of the turbomachine 2 guide vane ring 5 Running shovel ring 6 Gas canal 7 Adjustable blades 10 Adjustment arrangement 20 lever 21 Load arm 22 First load arm 22.1 Second load arm 22.2 Power arm 23 First power arm 23.1 Second arm 23.2 Push rod 25 Adjustment ring 26 Stabilizer link 27 Actuator 28 actuator 29 Adjustment connection point 32 First adjustment connection point 32.1 Second adjustment connection point 32.2 Interchange point 33 First interchange 33.1 Second interchange point 33.2 pivot point 34 axis of rotation 35 First arched strut 41 Second arched strut 42 First cross brace 51 Second cross brace 52 First level 61 Second level 62 First connecting strut 71 Second connecting strut 72

Claims

1. Lever (21) for adjusting an adjustable blade (10) of a turbomachine (1), the lever (21) comprising a fulcrum (34) for rotatably mounting the lever (21) about an axis of rotation (35), a first load arm (22.1) having a first adjustment connection point (32.1) for at least indirectly connecting to the adjustable blade (10) and a first power arm (23.1) having a first control connection point (33.1) for connecting to a control device (28), characterized in that the lever (21) further has a first strut (41) which - connects together the first adjustment connection point and the first control connection point (32.1, 33.1), and - in so doing curves around the axis of rotation (35).

2. Lever (21) according to claim 1, wherein the first curved strut (41), viewed in an axial direction with respect to the axis of rotation (35), runs tangentially into the first adjustment connection point (32.1).

3. Lever (21) according to claim 1 or claim 2, wherein the first curved strut (41), viewed in the axial direction with respect to the axis of rotation (35), runs tangentially into the first control connection point (33.1).

4. Lever (21) according to any of the preceding claims, which additionally comprises a first cross strut (51) connecting together the fulcrum (34) and the first curved strut (41).

5. Lever (21) according to claim 4, wherein the first cross strut (51) runs radially into the first curved strut (41) with respect to the axis of rotation (35).

6. Lever (21) according to claim 4 or claim 5, wherein the first cross strut (51) is in a rotational position, centrally with respect to the axis of rotation (35), between the first adjustment connection point and the first control connection point (32.1, 33.1).

7. Lever (21) according to any of the preceding claims, wherein the first load arm (22.1) and the first power arm (23.1) are in a first plane (61).

8. Lever (21) according to any of the preceding claims, additionally comprising a second load arm (22.2) having a second adjustment connection point (32.2) for at least indirectly connecting to the adjustable blade (10), a second power arm (23.2) having a second control connection point (33.2) for connecting to the control device (28), as well as a second strut (42) curving around the axis of rotation (35), which strut connects together the second adjustment connection point and the second control connection point (32.2, 33.2).

9. Lever (21) according to claim 7 and claim 8, wherein the second load arm (22.2) and the second power arm (23.2) are in a second plane (62) which is axially offset with respect to the axis of rotation (35) and parallel to the first plane (61).

10. Lever (21) according to claim 8 or claim 9, additionally comprising a first connecting strut (71) which connects together the first and the second curved strut (41, 42).

11. Lever (21) according to claim 10, additionally comprising a second connecting strut (72) which connects together the first and the second curved strut (41, 42) and crosses the first connecting strut (71).

12. Adjustment arrangement (20) for adjusting an adjustable blade (10) of a turbomachine (1), comprising a lever (21) according to any of the preceding claims, a push rod (25) which is mounted at the first adjustment connection point (32.1), and a coupling rod (27) which is mounted at the first control connection point (33.1), a displacement of the coupling rod (27) via the lever being converted into a displacement of the push rod (25) and the displacement of the push rod (25) being converted into an adjustment of the adjustable blade (10).

13. Adjustment arrangement (20) according to claim 12, wherein the first curved strut (41) is subjected exclusively to normal force.

14. Compressor or turbine module comprising an adjustment arrangement (20) according to claim 12 or claim 13 and an adjustable adjustment blade (10).

15. Use of a lever (21) according to any of claims 1 to 11 for a turbomachine (1), in particular a jet engine.

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