Blade tip sealing structure of rotor blade

Abstract

The invention relates to a blade tip sealing structure of a rotor blade. The blade tip sealing structure of the rotor blade comprises an anti-leakage block which is arranged on the inner wall of a cartridge receiver of an aero-engine, and a labyrinth sealing structure in the circumferential direction of the engine is formed between the anti-leakage block and the cartridge receiver; the limiting ring is arranged on the outer side, in the radial direction of the axis of the engine, of the anti-leakage block, and the limiting ring is used for limiting deformation of the anti-leakage block when the aero-engine works, so that a gap is kept between the anti-leakage block and the cartridge receiver; the sealing strip is arranged on the inner side, in the radial direction of the axis of the engine, of the anti-leakage block, the blade tip of the rotor blade is inserted into the sealing strip, and when the aero-engine works, the sealing strip is used for fastening the blade tip so that the blade tip can be kept in the anti-leakage block. According to the blade tip sealing structure of the rotor blade, the blade tip gap can be controlled and reduced, the blade tip sealing effect is improved, and the rigidity of the rotor blade is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing of aero-engine blades, and particularly to a tip sealing structure for a rotor blade. Background Art

[0002] The cold-end rotor blades of an aero-engine mainly include fan blades, compressor rotor blades, etc., and are important components for generating thrust and compressing the gas in the flow passage for combustion work. There is a tip clearance between the tip of the rotor blade and the stator casing, and it is necessary to control and reduce the tip clearance as much as possible to reduce aerodynamic losses and improve efficiency. The rotor blade also needs to have sufficient stiffness and strength to maintain its shape and prevent fracture failures such as corner dropping under the action of loads such as aerodynamic forces.

[0003] In order to reduce and control the tip clearance, a certain structural form, i.e., sealing technology, can be adopted at the mating part of the tip and the stator casing, such as labyrinth seals, honeycomb / perforated damping seals, brush seals, etc., or a wearable structure of a hard material or coating at the tip - a soft material or coating on the outer ring of the stator casing can be used.

[0004] Chinese Patent Application CN104963886A discloses an axial compressor / fan rotor-stator radial clearance leak-free sealing structure and method. The tips of its rotor blades are connected by a hoop, and the rotor hoop is located in the annular groove of the outer casing. However, considering that the tip clearance is different under different engine operating conditions, there is still a leakage problem in this sealing structure.

[0005] The tip of the rotor blade can be divided into two forms: with a shroud and without a shroud. The blade body of the blade without a shroud is only constrained unilaterally by the tenon, which is a cantilever structure with poor stiffness and is prone to vibration; the blade body of the blade with a shroud is constrained bilaterally by the tenon and the shroud, with better stiffness, but the shroud is located on the outermost side of the entire blade, and a large centrifugal force is generated during rotation and acts on the blade root, which also becomes an adverse factor. Summary of the Invention

[0006] In view of the above problems of the prior art, the present invention provides a tip sealing structure for a rotor blade, which can control and reduce the tip clearance, improve the tip sealing effect, and increase the stiffness of the rotor blade.

[0007] Specifically, the present invention provides a tip sealing structure applicable to an aero-engine, which includes:

[0008] A leakage prevention block, which is arranged on the inner wall of the casing of the aero-engine, and a labyrinth sealing structure along the circumferential direction of the engine is formed between the leakage prevention block and the casing;

[0009] A limiting ring is arranged on the outer side of the leakage prevention block along the radial direction of the engine axis. The limiting ring is used to limit the deformation of the leakage prevention block during the operation of the aeroengine, so as to keep a gap between the leakage prevention block and the casing.

[0010] A sealing strip is arranged on the inner side of the leakage prevention block along the radial direction of the engine axis. The tip of the rotor blade is inserted into the sealing strip. During the operation of the aeroengine, the sealing strip is used to fasten the tip, so that the tip is kept within the leakage prevention block.

[0011] According to an embodiment of the present invention, a first installation groove is formed on the inner wall of the casing of the aeroengine. The leakage prevention block is structurally matched with the first installation groove to form the labyrinth seal structure between the leakage prevention block and the casing.

[0012] According to an embodiment of the present invention, a second installation groove is formed on the outer side of the leakage prevention block along the radial direction of the engine axis. The limiting ring is arranged in the second installation groove.

[0013] According to an embodiment of the present invention, a third installation groove is formed on the inner side of the leakage prevention block along the radial direction of the engine axis. The sealing strip is filled in the third installation groove.

[0014] According to an embodiment of the present invention, the sealing strip is made of an elastic material.

[0015] According to an embodiment of the present invention, the sealing strip is made of rubber.

[0016] According to an embodiment of the present invention, the limiting ring is made of a carbon fiber composite material.

[0017] According to an embodiment of the present invention, the length direction of the carbon fibers in the carbon fiber composite material is arranged along the circumferential direction of the engine.

[0018] A tip sealing structure for a rotor blade provided by the present invention generates a labyrinth seal structure between the leakage prevention block and the casing, and arranges a limiting ring and a sealing strip on the leakage prevention block to further prevent gas leakage. The tip sealing structure can effectively control and reduce the tip clearance, improve the tip sealing effect, and increase the stiffness of the rotor blade.

[0019] It should be understood that the above general description and the following detailed description of the present invention are both exemplary and explanatory, and are intended to provide further explanation for the present invention described. Description of the Drawings

[0020] The accompanying drawings are included to provide a further understanding of the present invention, and they are incorporated in and constitute a part of this application. The drawings illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0021] In the drawings:

[0022] Figure 1 A sectional view through the engine axis of the tip seal structure of a rotor blade showing an embodiment of the present invention.

[0023] Figure 2 A sectional view through a plane perpendicular to the engine axis of the tip seal structure of a rotor blade showing an embodiment of the present invention.

[0024] Among them, the above-mentioned drawings include the following reference numerals:

[0025] Tip seal structure 100

[0026] Leakage prevention block 101

[0027] Limit ring 102

[0028] Sealing strip 103

[0029] Casing 104

[0030] Rotor blade 105

[0031] Tip 106 Detailed implementation manners

[0032] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0033] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits this application and its application or use. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0034] It should be noted that the terms used here are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to this application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0036] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc., are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0037] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above", etc., can be used here to describe the spatial positional relationships of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientations described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned or rotated in other different ways by 90 degrees or in other orientations, and corresponding interpretations should be made for the spatial relative descriptions used here.

[0038] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is merely for the convenience of differentiating the corresponding components. Without additional statements, these terms have no special meanings, and thus should not be construed as limiting the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0039] The present invention provides a tip sealing structure for a rotor blade, which is applicable to a crowned rotor blade of an aeroengine. Here, the rotor blade refers to a cold-end rotor blade, which is an engine component operating under non-high-temperature conditions, that is, a component in the compression system of the engine that is pushed by a high-speed rotating airflow to do work and increase the gas pressure.

[0040] Figure 1 A cross-sectional view of the tip sealing structure of the rotor blade according to an embodiment of the present invention passing through the engine axis is shown. Figure 2 A cross-sectional view of the tip sealing structure of the rotor blade according to an embodiment of the present invention passing through a plane perpendicular to the engine axis is shown. As shown in the figure, the tip sealing structure 100 mainly includes a leakage prevention block 101, a limit ring 102, and a sealing strip 103.

[0041] Among them, the leakage prevention block 101 is arranged on the inner wall of the casing 104 of the aeroengine. A labyrinth sealing structure is formed between the leakage prevention block 101 and the casing 104 along the circumferential direction of the engine. This labyrinth sealing structure is used to reduce gas leakage generated by the gap between the leakage prevention block 101 and the casing 104.

[0042] The limit ring 102 is arranged on the outside of the leakage prevention block 101 along the radial direction of the engine axis. The limit ring 102 is used to limit the deformation of the leakage prevention block 101 during the operation of the aeroengine, so as to keep a gap between the leakage prevention block 101 and the casing 104. Specifically, the limit ring 102 is used to bear the centrifugal force generated by the rotation of the leakage prevention block 101 during engine operation.

[0043] The sealing strip 103 is arranged on the inside of the leakage prevention block 101 along the radial direction of the engine axis, and the tip 106 of the rotor blade 105 is inserted into the sealing strip 103 along the radial direction. During the operation of the aeroengine, the sealing strip 103 is used to fasten the tip 106, absorb vibration, so as to keep the tip 106 within the leakage prevention block 101. The sealing strip 103 allows the depth of insertion of the tip 106 of the rotor blade 105 into the leakage prevention block 101 to change, ensuring that there is almost no gas leakage between the rotor blade 105 and the leakage prevention block 101.

[0044] Preferably, a first installation groove is formed on the inner wall of the casing 104 of the aero-engine. The anti-leakage block 101 is structurally matched with the first installation groove, and a labyrinth seal structure is formed between the anti-leakage block 101 and the casing 104. Refer to Figure 1 , the gas flowing through the blade tip 106 needs to turn multiple times to bypass the anti-leakage block 101, that is, the labyrinth seal structure composed of the anti-leakage block 101 and the stator casing 104, reducing the leakage of the blade tip 106 and improving the sealing performance.

[0045] Preferably, a second installation groove is formed on the outer side of the anti-leakage block 101 along the radial direction of the engine axis. The limiting ring 102 is arranged in the second installation groove. The second installation grooves on the anti-leakage blocks 101 corresponding to each rotor blade 105 are connected front and back in the circumferential direction. The limiting ring 102 is annular and is arranged in the second installation groove connected front and back in the circumferential direction.

[0046] Preferably, a third installation groove is formed on the inner side of the anti-leakage block 101 along the radial direction of the engine axis, and a sealing strip 103 is filled in the third installation groove. More preferably, the sealing strip 103 is made of an elastic material, preferably made of rubber. Rubber is relatively soft and has a certain elasticity. When the engine is working, it can fasten the blade well and absorb vibration. When the relative position between the blade and the anti-leakage block 101 changes, the rubber elasticity allows the insertion depth of the blade into the anti-leakage block 101 to change.

[0047] Preferably, the limiting ring 102 is made of carbon fiber composite material. More preferably, the length direction of the carbon fiber in the carbon fiber composite material is arranged along the circumferential direction of the engine. This structure makes full use of the strength of the carbon fiber, greatly reducing the load on the blade while improving the stiffness and ensuring the stability of the overall structure.

[0048] The tip sealing structure of a rotor blade provided by the present invention has the following advantages:

[0049] 1. By using the anti-leakage block, the gas flowing through the blade tip needs to turn multiple times to bypass the anti-leakage block, that is, the labyrinth seal structure composed of the anti-leakage block and the stator casing, and it can be used in combination with other sealing technologies, which can further reduce the blade tip leakage.

[0050] 2. A flexible connection is formed between the blade and the anti-leakage block by using the sealing strip. Under different operating states of the engine, the insertion depth of the blade tip relative to the anti-leakage block groove (the third installation groove) is different, and a good sealing effect can always be achieved.

[0051] 3. The presence of the high-modulus and high-strength limiting ring can make the anti-leakage block have less deformation during rotation, and it is easy to ensure that the clearance value between the anti-leakage block and the stator casing does not change much. Combining with point 2, a good sealing effect can be achieved under different operating states of the engine.

[0052] 4. The anti-leakage block is fixed by a carbon fiber-based composite material annular limiting ring, which makes full use of the advantage that the carbon fiber has extremely high strength along the fiber length direction. The centrifugal force generated by the rotation of the anti-leakage block is mainly borne by the limiting ring. Compared with the crowned blade, while improving the stiffness, the load of the blade is greatly reduced.

[0053] It will be apparent to those skilled in the art that various modifications and variations can be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations of the present invention falling within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A blade tip sealing structure of a rotor blade, suitable for an aircraft engine, the blade tip sealing structure comprising: An anti-leakage block is arranged on the inner wall of the casing of the aircraft engine, and a labyrinth sealing structure is formed between the anti-leakage block and the casing along the circumference of the engine; A limiting ring is arranged on the radial outer side of the anti-leakage block along the axis of the engine, and the limiting ring is used to limit the deformation of the anti-leakage block when the aircraft engine is working, so as to maintain a gap between the anti-leakage block and the casing; A sealing strip is arranged on the radial inner side of the anti-leakage block along the axis of the engine, and the tip of the rotor blade is inserted into the sealing strip. When the aircraft engine is working, the sealing strip is used to tighten the tip of the blade to keep it in the anti-leakage block.

2. The tip sealing structure of the rotor blade according to claim 1, characterized in that: A first installation groove is provided on the inner wall of the casing of the aircraft engine, and the anti-leakage block cooperates with the first installation groove structure to form the labyrinth sealing structure between the anti-leakage block and the casing.

3. The tip sealing structure of the rotor blade according to claim 1, characterized in that: A second mounting groove is provided on the radial outer side of the anti-leakage block along the axis of the engine, and the limiting ring is arranged in the second mounting groove.

4. The tip sealing structure of a rotor blade according to claim 1, characterized in that: A third installation groove is provided on the inner side of the anti-leakage block along the radial direction of the engine axis, and the sealing strip is filled in the third installation groove.

5. The tip sealing structure of a rotor blade according to claim 1, characterized in that: The sealing strip is made of elastic material.

6. The tip sealing structure of a rotor blade according to claim 5, characterized in that: The sealing strip is made of rubber.

7. The tip sealing structure of a rotor blade according to claim 1, characterized in that: The limiting ring is made of carbon fiber composite material.

8. The tip sealing structure of a rotor blade according to claim 7, characterized in that: The length direction of the carbon fibers in the carbon fiber composite material is arranged along the circumferential direction of the engine.

Images