A fir-type blade root gradient wave frictional damping structure
Patent Information
- Application Number
- CN202611260915.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-19
- Publication Date
- 2026-10-13
AI Technical Summary
即使在接触良好的情况下，高温下摩擦系数的剧烈变化也会导致阻尼力波动很大，难以保持稳定的减振效果
本发明采用功能梯度材料制备波纹摩擦阻尼片，使其沿厚度方向的热膨胀系数从叶片侧向轮盘侧逐渐过渡，自动补偿了高温下叶片和轮盘之间巨大的热变形差。避免了在极端高温下因材料膨胀不均导致接触面出现间隙和接触压力丧失的问题，使热变形量自动匹配并保持接触面正压力稳定，从而实现了高温下阻尼性能的长期稳定。
Smart Images
Figure CN122899540A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of blade vibration suppression and relates to a fir-shaped leaf root gradient corrugated friction damping structure. Background Technology
[0002] Fir-shaped blade roots are a practical connection method for turbine high-pressure cylinder blades, offering advantages such as extremely high load-bearing capacity, uniform load distribution, and adaptability to extreme high-temperature environments. Turbine high-pressure cylinder blades operate at high temperatures, and the blades and rotor are subjected to enormous thermal and centrifugal stresses.
[0003] Under such extreme operating conditions, blade vibration becomes particularly prominent, and traditional friction damping devices face insurmountable technical bottlenecks due to the difference in thermal expansion coefficients between the blades and the impeller. At high temperatures, the blades and impeller experience significant thermal deformation differences, leading to gaps between the damping pads and the contact surface, complete loss of contact pressure, and utter failure of damping performance. Furthermore, traditional damping pad materials undergo severe oxidation and wear at high temperatures, resulting in a service life of only a few hundred hours. Even with good contact, the drastic changes in the coefficient of friction at high temperatures cause large fluctuations in damping force, making it difficult to maintain a stable vibration reduction effect.
[0004] To address these issues, international turbine manufacturers currently primarily use the addition of shrouds and bracing to improve the vibration resistance of blades. However, this leads to an increase in blade weight, significantly impacting turbine efficiency. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fir-shaped leaf root gradient corrugated friction damping structure that can automatically compensate for the thermal deformation difference between the blade and the wheel, and achieve long-term stability of damping performance at high temperatures.
[0006] To achieve the above objectives, the present invention employs the following technical solution: A fir-shaped leaf root gradient corrugated friction damping structure includes a blade damping groove, a wheel damping groove, and a corrugated friction damping plate. The blade damping groove is located at the bottom of the blade root platform; the wheel damping groove is located on the contact surface of the wheel root platform, and the position of the wheel damping groove corresponds to that of the blade damping groove. The corrugated friction damping plate is disposed between the blade damping groove and the wheel disk damping groove. The corrugated friction damping plate is made of functionally graded material and is divided into multiple layers along the thickness direction. The coefficient of thermal expansion of each layer changes in a gradient from the side closer to the blade to the side closer to the wheel disk.
[0007] Optionally, the blade damping groove, the wheel disc damping groove, and the corrugated friction damping plate are all in the form of continuous triangular tooth structure.
[0008] Optionally, the tooth height of the blade damping groove gradually changes along the circumference; the shape parameters of the wheel damping groove are the same as those of the blade damping groove.
[0009] Optionally, the tip angle of the blade damping groove is 70°; the tooth pitch of the blade damping groove is 3mm; and the tooth height of the blade damping groove gradually changes from 1.4mm to 1.6mm along the circumferential direction.
[0010] Optionally, the tooth tip angle of the corrugated friction damper is 65°-75°; the tooth pitch of the corrugated friction damper is 2.5mm-3.5mm; and the tooth height of the corrugated friction damper is 1.2mm-1.8mm.
[0011] Optionally, the corrugated friction damping sheet is divided into five layers along the thickness direction, with the first, second, third, fourth, and fifth layers arranged sequentially from the side closest to the blade to the side closest to the wheel disk.
[0012] Optionally, the first layer is made of NiCoCrAlY, and the coefficient of thermal expansion of the first layer is 14.5×10-6 / ℃; The second layer is made of NiCoCrAlY containing 20% Al2O3, and its coefficient of thermal expansion is 14.45×10-6 / ℃. The third layer is made of NiCoCrAlY containing 40% Al2O3, and its coefficient of thermal expansion is 14.4×10-6 / ℃. The fourth layer is made of NiCoCrAlY containing 60% Al2O3, and its coefficient of thermal expansion is 14.35×10-6 / ℃. The fifth layer is made of NiCoCrAlY containing 80% Al2O3, and its coefficient of thermal expansion is 14.3×10-6 / ℃.
[0013] Optionally, each layer can be 0.5 mm thick.
[0014] Optionally, the surface of the corrugated friction damper is coated with a YSZ-Al2O3 composite ceramic coating; the thickness of the YSZ-Al2O3 composite ceramic coating is 80μm-120μm.
[0015] Optionally, the surface roughness of the blade damping groove and the wheel disk damping groove is less than or equal to 0.8 μm.
[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention employs functionally graded materials to fabricate corrugated friction damping sheets, ensuring that the coefficient of thermal expansion along the thickness direction gradually transitions from the blade side to the disk side. This automatically compensates for the significant thermal deformation difference between the blade and the disk at high temperatures. It avoids the problem of gaps and loss of contact pressure at the contact surface caused by uneven material expansion under extreme temperatures, automatically matching the amount of thermal deformation and maintaining stable positive pressure at the contact surface, thereby achieving long-term stability of damping performance at high temperatures.
[0017] Furthermore, the blade damping groove, the wheel disk damping groove, and the corrugated friction damping plate all adopt a continuous triangular tooth structure, which significantly increases the effective contact area between components. Under the action of huge centrifugal stress, this tooth shape can provide multi-point and uniformly distributed contact normal pressure, enhance the efficiency of frictional energy dissipation during micro-amplitude relative slippage, and thus enhance the ability to suppress blade vibration.
[0018] Furthermore, the design of the blade damping groove with gradually varying tooth height along the circumference can adapt to the non-uniform strain distribution of the blade under complex high-frequency vibration modes. This gradual geometry can make the contact normal load at each point on the working surface more reasonable, prevent contact failure caused by sudden changes in local edge stress, and ensure that the damping plates can work together to output a stable vibration reduction effect under different vibration modes.
[0019] Furthermore, the tolerance range defined by the tooth profile parameters of the corrugated friction damper gives it dimensional compliance during assembly and initial operation. Under initial centrifugal load, this range allows the corrugated friction damper to quickly fill machining deviations through its own local deformation, prompting the contact surfaces to accelerate into and maintain a tight-fitting frictional damping state for a long time.
[0020] Furthermore, the corrugated friction damping sheet is divided into five layers along the thickness direction for gradient transition design. The multi-layer composite structure disperses the macroscopic thermal expansion differences, so that there are no obvious interfaces between the layers. This weakens the thermal deformation gradient misalignment on a single interface, avoids thermal stress concentration damage to the material under severe temperature fluctuations, and improves the integrity of the overall structure under harsh working conditions.
[0021] Furthermore, by progressively increasing the Al2O3 ceramic content layer by layer in the NiCoCrAlY alloy matrix, the thermal expansion coefficient of the five layers achieves a smooth transition from 14.5×10⁻⁶ / ℃ to 14.3×10⁻⁶ / ℃. This combination of the toughness of metal and the high-temperature properties of ceramic eliminates the potential for expansion mismatch between the damping structure and the components on both sides (blades and wheel disc), ensuring precise self-adaptation of thermal deformation.
[0022] Furthermore, an 80μm-120μm YSZ-Al2O3 composite ceramic coating is applied to the surface of the corrugated friction damping sheet, constructing a dense high-temperature protective barrier. This directly overcomes the technical bottleneck of traditional damping materials experiencing severe oxidation and wear at high temperatures. The moderately thick coating ensures excellent wear resistance and oxidation resistance while avoiding stress peeling caused by excessive coating thickness. This prevents drastic fluctuations in the coefficient of friction at high temperatures, ensuring smooth damping force output.
[0023] Furthermore, by limiting the surface roughness Ra to ≤ 0.8 μm, the mechanical jamming phenomenon caused by micro-protrusions on frictional behavior is eliminated, ensuring extremely high contact accuracy. This high-precision fit ensures that within the operating temperature range, the rate of change of normal pressure on the contact surface is less than 10%, and the damping performance retention rate is greater than 90%. Attached Figure Description
[0024] Figure 1 This is an assembly diagram of the present invention; Figure 2 This is a schematic diagram of the fir tree-shaped leaf root gradient corrugated friction damping structure of the present invention; Figure 3 This is a schematic diagram of the blade of the present invention; Figure 4 This is a schematic diagram of the roulette wheel of the present invention.
[0025] Wherein: 1-blade; 2-corrugated friction damping plate; 3-disc; 4-blade damping groove; 5-disc damping groove; 6-first layer; 7-second layer; 8-third layer; 9-fourth layer; 10-fifth layer. Detailed Implementation
[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terms “installation,” “connection,” and “linkage” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection, an electrical connection, or a connection that allows communication; a direct connection or an indirect connection via an intermediate medium; or a connection within two elements or an interaction between two elements. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.
[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0030] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.
[0031] This embodiment provides a fir-shaped leaf root gradient corrugated friction damping structure, such as... Figure 1 As shown, the leaf roots of the fir-shaped leaf 1 and the contact surfaces of the disc 3 near both sides are arranged, with the leaf roots mounted on the disc 3.
[0032] like Figure 3 As shown, a blade damping groove 4 is provided at the bottom of the blade root platform, and the tooth height of the groove gradually changes along the circumference; as Figure 4 As shown, a disc damping groove 5 corresponding to the blade damping groove 4 is provided on the contact surface of the blade root platform; both the blade damping groove 4 and the disc damping groove 5 are toothed grooves with a continuous triangular tooth structure.
[0033] A corrugated friction damping plate 2 is provided between the blade damping groove 4 and the wheel disc damping groove 5, such as Figure 2 As shown, the corrugated friction damper 2 has a continuous triangular tooth structure. The corrugated friction damper 2 is made of functionally graded material. Along the thickness direction from the blade side to the disk side, the coefficient of thermal expansion gradually transitions from the coefficient of thermal expansion of the blade material to the coefficient of thermal expansion of the disk material.
[0034] When the operating temperature rises, the thermal deformation of the corrugated friction damper 2 automatically matches the thermal deformation of the blade and the wheel, maintaining a stable positive pressure on the contact surface.
[0035] Blade 1 is made of directionally solidified nickel-based superalloy DZ411 material, with a coefficient of thermal expansion of 14.5 × 10⁻⁶. -6 / ℃, the blade root platform has a blade damping groove 4 at the bottom, the tooth tip angle is 70°, the tooth pitch is 3mm, the tooth height gradually changes from 1.4mm to 1.6mm along the circumference, and the surface roughness is Ra0.8μm.
[0036] The roulette wheel 3 is made of powder metallurgy high-temperature alloy FGH96, with a coefficient of thermal expansion of 14.4 × 10⁻⁶. -6 / ℃, the blade root platform contact surface is provided with a disc damping groove 5, the parameters of which are exactly the same as those of the blade damping groove 4.
[0037] The corrugated friction damping sheet 2 is prepared using powder metallurgy and consists of 5 layers along the thickness direction. The coefficient of thermal expansion of each layer gradually changes, and there is a gradient transition between the layers. The composition and coefficient of thermal expansion of each layer are as follows: First layer 6 (blade side): NiCoCrAlY, coefficient of thermal expansion 14.5×10 -6 / ℃, thickness 0.5mm.
[0038] Second layer 7: NiCoCrAlY + 20% Al2O3, thermal expansion coefficient 14.45 × 10⁻⁶ -6 / ℃, thickness 0.5mm.
[0039] Third layer 8: NiCoCrAlY + 40% Al2O3, coefficient of thermal expansion 14.4 × 10⁻⁶ -6 / ℃, thickness 0.5mm.
[0040] Fourth layer 9: NiCoCrAlY + 60% Al2O3, coefficient of thermal expansion 14.35 × 10 -6 / ℃, thickness 0.5mm.
[0041] Fifth layer 10 (wheel side): NiCoCrAlY + 80%Al2O3, coefficient of thermal expansion 14.3×10 -6 / ℃, thickness 0.5mm.
[0042] The layers are gradient transitioned without obvious interfaces, thus avoiding thermal stress concentration.
[0043] The corrugated friction damping plate 2 has a tooth tip angle of 65°~75°, a tooth pitch of 2.5~3.5mm, and a tooth height of 1.2~1.8mm.
[0044] The corrugated friction damping sheet 2 has a total thickness of 2.5 mm and is coated with a YSZ-Al2O3 composite ceramic coating using a plasma spraying process. The coating thickness is 80~120 μm, which can maintain good oxidation resistance and wear resistance at high temperatures.
[0045] The surface roughness Ra of the blade damping groove 4 and the wheel disk damping groove 5 is ≤0.8μm, ensuring good contact accuracy.
[0046] Within the operating temperature range, the rate of change of the normal pressure on the contact surface is less than 10%, and the damping performance retention rate is greater than 90%.
[0047] The blade 1 is made of directionally solidified nickel-based high-temperature alloy material, and the wheel 3 is made of powder metallurgy high-temperature alloy material.
[0048] In this embodiment, the coefficient of thermal expansion of the corrugated friction damper 2 with functional gradient gradually transitions from the coefficient of thermal expansion of the blade 1 material to the coefficient of thermal expansion of the disk material along the thickness direction. Therefore, when the temperature changes, the amount of thermal deformation of the corrugated friction damper 2 can automatically match the amount of thermal deformation of the blade 1 and the disk 3, avoiding contact gaps caused by thermal deformation differences.
[0049] Meanwhile, the gradient tooth height structure can further compensate for the local thermal deformation caused by uneven temperature distribution, ensuring uniform contact across the entire tooth surface. Stable contact pressure ensures long-term stability of damping performance under extreme high-temperature environments.
[0050] Employing functionally graded materials and a gradient tooth height structure, the contact surface normal pressure change rate is less than 10% within the operating temperature range, completely resolving the contact failure problem caused by thermal deformation mismatch. The synergistic effect of the functionally graded materials and composite ceramic coating ensures that the corrugated friction damper 2 maintains low wear even after prolonged continuous operation at high temperatures, exhibiting excellent oxidation resistance. Over the entire temperature range, the damping performance retention rate is greater than 90%, and the first-order bending vibration amplitude of blade 1 can be reduced by more than 65%. With no moving parts, the structure is simple and reliable, and its service life is synchronized with blade 1, eliminating the need for periodic replacement. The damping structure is located at the bottom of the blade root platform, not affecting the aerodynamic characteristics and cooling system of blade 1, and its impact on turbine efficiency is less than 0.1%.
[0051] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0052] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0053] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.
[0054] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0055] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
[0056] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this application should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.
Claims
1. A fir-shaped leaf root gradient corrugated friction damping structure, characterized in that, It includes blade damping groove (4), wheel disk damping groove (5) and corrugated friction damping plate (2); The blade damping groove (4) is set at the bottom of the blade root platform of the blade (1); the wheel damping groove (5) is set on the contact surface of the blade root platform of the wheel (3), and the position of the wheel damping groove (5) corresponds to the blade damping groove (4). The corrugated friction damping plate (2) is set between the blade damping groove (4) and the wheel disk damping groove (5); the corrugated friction damping plate (2) is made of functionally graded material, and the corrugated friction damping plate (2) is divided into multiple layers along the thickness direction, and the coefficient of thermal expansion of each layer changes in a gradient from the side closer to the blade (1) to the side closer to the wheel disk (3).
2. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 1, characterized in that, The blade damping groove (4), the wheel disk damping groove (5), and the corrugated friction damping plate (2) all have a continuous triangular tooth structure.
3. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 2, characterized in that, The tooth height of the blade damping groove (4) gradually changes along the circumference; the shape parameters of the wheel damping groove (5) are the same as those of the blade damping groove (4).
4. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 3, characterized in that, The tooth tip angle of the blade damping groove (4) is 70°; the tooth pitch of the blade damping groove (4) is 3mm; the tooth height of the blade damping groove (4) gradually changes from 1.4mm to 1.6mm along the circumferential direction.
5. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 2, characterized in that, The tooth tip angle of the corrugated friction damper (2) is 65°-75°; the tooth pitch of the corrugated friction damper (2) is 2.5mm-3.5mm; and the tooth height of the corrugated friction damper (2) is 1.2mm-1.8mm.
6. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 1, characterized in that, The corrugated friction damping plate (2) is divided into five layers along the thickness direction. The corrugated friction damping plate (2) is divided into the first layer (6), the second layer (7), the third layer (8), the fourth layer (9) and the fifth layer (10) from the side closest to the blade (1) to the side closest to the wheel disk (3).
7. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 6, characterized in that, The first layer (6) is made of NiCoCrAlY, and the coefficient of thermal expansion of the first layer (6) is 14.5×10-6 / ℃; The second layer (7) is made of NiCoCrAlY containing 20% Al2O3, and the coefficient of thermal expansion of the second layer (7) is 14.45×10-6 / ℃; The third layer (8) is made of NiCoCrAlY containing 40% Al2O3, and the coefficient of thermal expansion of the third layer (8) is 14.4×10-6 / ℃; The fourth layer (9) is made of NiCoCrAlY containing 60% Al2O3, and the coefficient of thermal expansion of the fourth layer (9) is 14.35×10-6 / ℃; The fifth layer (10) is made of NiCoCrAlY containing 80% Al2O3, and the coefficient of thermal expansion of the fifth layer (10) is 14.3×10-6 / ℃.
8. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 7, characterized in that, Each layer is 0.5mm thick.
9. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 1, characterized in that, The surface of the corrugated friction damper (2) is coated with a YSZ-Al2O3 composite ceramic coating; the thickness of the YSZ-Al2O3 composite ceramic coating is 80μm-120μm.
10. The fir-shaped leaf root gradient corrugated friction damping structure according to claim 1, characterized in that, The surface roughness of the blade damping groove (4) and the wheel disk damping groove (5) is less than or equal to 0.8 μm.