An outer embracing clamping type multi-frequency vibration ring and a use method thereof

Abstract

The present application relates to the technical field of water turbine vibration control, and discloses a multi-frequency damping ring of an outer clamping type and a use method; the multi-frequency damping ring comprises a hoop body, a fastening assembly and a damping unit; the hoop body comprises at least two connecting pieces; the damping unit is detachably arranged in an assembly cavity of the connecting pieces, and the damping unit comprises an elastic piece and a mass block; and a damping gap is arranged between the mass block and the assembly cavity. By replacing the elastic pieces with different stiffness and the mass blocks with different weight, the natural frequency of the damping unit is changed to match the target vibration frequency of the main shaft, and vibration energy is converted into the motion of the mass block; the damping gap is filled with a composite damping medium, and shear damping dissipation energy is generated when the mass block moves. The present application realizes non-invasive and lossless installation and efficient elimination of broadband vibration, solves the problems of strong invasiveness, poor broadband adaptability and low dissipation efficiency of traditional installation, prolongs the service life of equipment, and guarantees operation accuracy.

Description

Technical Field

[0001] This invention relates to the field of turbine vibration control technology, specifically to an external clamping multi-frequency vibration damping ring and its usage method. Background Technology

[0002] The turbine is a crucial power source in a hydropower station, with the main shaft system responsible for transmitting torque and supporting the runner. During operation under non-design conditions such as low or high flow rates, hydraulic vibration sources like cavitation vortices in the tailrace can generate vibrations in a wide frequency range of 20-2000Hz. These vibrations are transmitted to the main shaft via the runner, causing combined radial and torsional vibrations. This can lead to seal wear, bearing overheating, and fatigue cracking of the runner blades, seriously threatening the safe operation of the unit.

[0003] To address these issues, related technologies include optimizing the spindle structure, such as improving the spindle material or increasing rigidity, to suppress vibration. However, these methods are costly, time-consuming, and cannot flexibly adapt to changes in operating conditions. Bearing vibration reduction technology uses elastic or damping bearings to absorb vibrations in specific frequency bands, but it suffers from poor adjustability, a narrow frequency range, and difficulty in covering wide-frequency hydraulic excitation. Furthermore, the vibration reduction effect is prone to continuous attenuation due to wear. While external vibration damping devices can be directly installed outside the spindle, they are mostly invasive installations that require drilling and tapping the spindle or flange, compromising the strength and balance accuracy of the original structure. Non-invasive devices generally suffer from insufficient connection reliability and are prone to loosening during high-speed operation. Moreover, vibration damping structures with fixed parameters cannot match multimodal vibrations over a wide frequency range.

[0004] Therefore, the relevant technologies have not solved the problem of achieving stable clamping and precise and efficient elimination of wide-band vibration of the spindle without damaging the spindle structure. Summary of the Invention

[0005] In view of this, the present invention provides an externally clamping multi-frequency vibration damping ring and a method of using it to solve the problems mentioned in the background art.

[0006] In a first aspect, the present invention provides an externally clamping multi-frequency vibration damping ring, comprising: The clamp body includes at least two interlocking connectors, and each connector has at least one assembly cavity. Multiple fastening components are provided for securing adjacent connectors, such that all connectors form annular cavities suitable for radially fixing the spindle. The vibration damping unit is detachably disposed in the assembly cavity. The vibration damping unit includes an elastic element and a mass block. The mass block and the inner wall of the assembly cavity are provided with a damping gap. The elastic element is axially connected between the assembly cavity and the mass block, so that the mass block is elastically supported in the assembly cavity. Specifically, by replacing elastic elements with different stiffnesses and mass blocks with different weights, the natural frequency of the vibration damping unit is changed, so that the natural frequency of the vibration damping unit matches the target vibration frequency of the main shaft, and the vibration energy transmitted by the main shaft is converted into the motion of the mass block; the damping gap is filled with a composite damping medium, which is used to generate damping when the mass block moves, so as to dissipate vibration energy.

[0007] Beneficial effects: This application achieves non-invasive, non-destructive installation of the spindle by using a clamp body composed of at least two connectors spliced ​​together and fixed to the spindle by fastening components, forming a radially clamping annular cavity. This avoids destructive operations such as drilling, ensures connection reliability, and protects the original structural strength and balance accuracy of the spindle. A vibration damping unit is detachably installed within the assembly cavity of the connectors. When the spindle generates broadband vibration, by replacing elastic elements with different stiffness and mass blocks of different weights, the natural frequency of the vibration damping unit is actively changed to match the target vibration frequency of the spindle. This efficiently converts the spindle vibration energy into the reverse motion of the mass block, achieving the capture and conversion of multi-frequency vibrations. A composite damping medium is filled in the damping gap between the mass block and the assembly cavity. When the mass block is excited, the composite damping medium generates a strong shear damping effect in the tiny gap, rapidly converting vibration kinetic energy into heat dissipation, improving vibration attenuation efficiency, ensuring sufficient dissipation of vibration energy, and preventing back transmission to the spindle. This application solves the problems of strong installation intrusion, poor broadband adaptability, and low vibration energy dissipation efficiency in related technologies, and achieves non-intrusive and stable installation and precise and efficient dissipation of broadband vibration, which can effectively extend the service life and operating accuracy of water turbine equipment.

[0008] In some embodiments, the assembly cavity is configured as a cylindrical cavity, and all the assembly cavities on the clamp body are centrally symmetrically distributed about the central axis of the annular inner cavity.

[0009] Beneficial effects: The assembly cavity adopts a cylindrical cavity, providing space for the installation and movement of the mass block and elastic element, enabling the elastic element and mass block to move stably in the desired direction and reducing motion interference; all assembly cavities are centrally symmetrically distributed about the central axis of the annular inner cavity, making the center of mass of each vibration damping unit uniformly distributed. When the main shaft rotates at high speed, it can effectively avoid additional unbalanced vibration caused by mass eccentricity, improve the dynamic balance characteristics of the vibration damping ring itself, ensure consistent vibration suppression effect in all radial directions of the main shaft, and guarantee the operational stability of the overall structure under high-speed rotation conditions.

[0010] In some embodiments, a closure component is further included, the closure component including a detachably disposed cover and a fixing member, the assembly cavity being recessed on the connector; the cover is fixedly connected to the opening side of the assembly cavity by the fixing member.

[0011] Beneficial effects: The enclosed assembly adopts a detachable cover and fixing parts, with the assembly cavity recessed on the connector. The cover is fixed to the opening side of the assembly cavity by the fixing parts, which can effectively encapsulate the vibration damping unit inside the assembly cavity, reasonably accommodate the composite damping medium, and prevent external moisture, dust and other impurities from entering the assembly cavity, ensuring the long-term reliability of the vibration damping unit. This detachable design allows operators to easily open the assembly cavity to replace components when it is necessary to replace elastic parts or mass blocks to adapt to different vibration frequencies. After adjustment, it can be resealed, improving the parameter tuning efficiency of the vibration damping ring and the flexibility of adapting to multiple working conditions.

[0012] In some embodiments, each connector has a step corresponding to the assembly cavity, the step is disposed on the outer periphery of the opening side of the assembly cavity, and the cover is disposed on the step; the step has a ring of fixed holes, and the fixed end of the fixing member passes through the cover and is connected to the fixed hole.

[0013] Beneficial effects: A stepped platform is set on the outer periphery of the assembly cavity opening side to provide the mounting bearing surface and axial limit for the cover, ensuring accurate positioning after the cover is closed; a ring of fixing holes is set on the stepped platform, and the fixing end of the fixing part is inserted through the cover and connected to the fixing hole, so that the clamping force of the cover is evenly distributed along the circumference, improving the connection rigidity and anti-vibration loosening ability of the cover, avoiding loosening or sealing failure of the sealing component under high-speed rotation and vibration environment of the spindle, and ensuring that the composite damping medium is stably sealed in the closed cavity.

[0014] In some embodiments, the vibration damping unit further includes a damping cylinder, which is installed inside the assembly cavity. The elastic element and the mass block are disposed within the inner cavity of the damping cylinder. The mass block is configured as a rotating body structure. The elastic element is installed between the mass block and the inner bottom wall of the assembly cavity. The mass block and the elastic element are coaxially disposed within the inner cavity of the damping cylinder. One end of the damping cylinder abuts against and seals the inner bottom wall of the assembly cavity, and the other end abuts against and seals the capping member of the sealing assembly, thereby sealing the composite damping medium within the cavity formed by the damping cylinder, the assembly cavity, and the capping member.

[0015] Beneficial effects: The elastic element and the mass block are coaxially installed in the inner cavity of the damping cylinder. The mass block is set as a rotating body structure. When it moves axially under the support of the elastic element, a controllable damping gap is formed between its outer circumference and the inner wall of the damping cylinder, which is conducive to the stable generation of shear damping effect. At the same time, one end of the damping cylinder is sealed against the bottom wall of the assembly cavity, and the other end is sealed against the cover of the sealing component. The composite damping medium is sealed in the closed cavity formed by the damping cylinder, the assembly cavity and the cover, which realizes double sealing protection for the composite damping medium. This prevents the high viscosity damping grease from being thrown out from the assembly gap under centrifugal force or vibration, and also prevents external contaminants from entering the cavity, ensuring reliable damping performance.

[0016] In some embodiments, each connector is provided with a connecting portion at its beginning and end, the connecting portion extending radially along the annular inner cavity, and the connecting portion being provided with a plurality of positioning holes, and two adjacent connectors being fixed by the fastening assembly passing through the positioning holes; The fastening assembly includes a first fastener and a second fastener. One end of the first fastener passes through a positioning hole and is threaded onto the connecting portion of two adjacent connectors, and is threadedly connected to the second fastener.

[0017] Beneficial effects: Each connector has a connecting part extending radially along the annular inner cavity at both ends. The fastening components pass through the positioning holes on the connecting parts to fix adjacent connectors, so that the clamping force is concentrated radially. This can efficiently convert the pre-tightening force of the fastening components into the radial clamping force of the connectors on the outer circumference of the spindle, ensuring a stable fit between the clamp body and the spindle. The fastening components adopt a threaded engagement of the first fastener and the second fastener. By fastening adjacent connectors with multiple sets of fastening components, the vibration loosening effect under high-speed rotation can be effectively resisted, ensuring that the installation position of the damping ring does not shift during operation, thereby ensuring a stable vibration damping effect.

[0018] In some embodiments, the elastic element is configured as a disc spring assembly, which is configured as a mating combination or a stacked combination; or, the elastic element is configured as a metal rubber pad.

[0019] Beneficial effects: Disc spring assemblies can be used as the elastic element. These assemblies can be configured as paired or stacked combinations. By adjusting the combination method, the overall stiffness of the elastic element can be changed within a wide range, meeting the requirements of low stiffness and high load-bearing capacity in low-frequency vibration absorption scenarios. Alternatively, metal rubber pads can be used as the elastic element. Utilizing the dry friction damping characteristics between the metal wires in the metal rubber pad and its designable elastic modulus, it is suitable for precise tuning and wide-band damping dissipation of mid-to-high frequency vibrations. These two optional solutions enable the vibration damping unit to achieve natural frequency matching within a wide frequency range of 20-2000Hz, improving the adaptability and vibration damping performance of the multi-frequency vibration damping ring.

[0020] In some embodiments, the damping gap is set to 0.1-0.5 mm; the composite damping medium is formed by mixing metal rubber fragments and damping grease in a mass ratio of 3:7.

[0021] Beneficial effects: With a damping gap width set to 0.1-0.5mm, the high shear rate of the fluid within the tiny gap allows the composite damping medium to generate significant damping force even with minor displacement of the mass block, thus rapidly dissipating vibrational energy. The composite damping medium is formulated as a mixture of metal rubber fragments and damping grease in a 3:7 mass ratio. This ratio balances the frictional damping provided by the metal rubber fragments with the viscous shear damping provided by the high-viscosity damping grease, resulting in a damping medium with both high energy dissipation density and good filling properties and energy dissipation stability. It efficiently converts vibrational kinetic energy into heat dissipation over a wide frequency range, thus improving vibration attenuation efficiency.

[0022] Secondly, the present invention also provides a method for using an externally clamping multi-frequency vibration damping ring, including: Monitor the vibration parameters of the spindle. When the vibration parameters meet the preset vibration reduction conditions, it is determined to be a vibration reduction condition. When vibration reduction is required, the clamp body is fastened to the outer circumference of the spindle, and a preload is applied through the fastening assembly to clamp the spindle. Based on the vibration frequency of the spindle, the elastic element with the required stiffness and the mass block with the required weight are determined so that the natural frequency of the vibration reduction unit matches the vibration frequency of the spindle. Once the spindle vibration parameters return to within the allowable range, disassemble the multi-frequency damping ring.

[0023] Beneficial effects: By monitoring the vibration parameters of the main shaft and determining whether the preset vibration reduction conditions are met, the vibration damping ring is activated promptly when the main shaft vibrates abnormally due to non-design conditions. This avoids unnecessary operation of the vibration damping ring under normal conditions, which would cause additional energy consumption and resistance loss. When vibration reduction is required, the clamp body is tightened using fastening components. Matching elastic elements and mass blocks are selected based on the vibration frequency for frequency tuning, ensuring that the natural frequency of the vibration damping unit matches the vibration frequency of the main shaft. This achieves accurate vibration absorption and improves vibration energy conversion efficiency. The vibration damping ring is removed only after the main shaft vibration parameters return to the allowable range, avoiding additional rotational resistance and component wear caused by long-term installation. This ensures that the unit maintains its original efficiency under design conditions. The usage method provided in this application makes the vibration damping ring adaptable to different operating conditions, easy to operate, effectively improving the operational stability of the turbine under non-design conditions without affecting normal output.

[0024] In some embodiments, the preset vibration reduction condition includes a spindle vibration acceleration ≥ 5 m / s². 2The vibration displacement amplitude is ≥0.08mm, and at least one of the resonant frequency components in the range of 20-2000Hz is present; the allowable range is a principal shaft vibration acceleration <3m / s². 2 And the vibration displacement amplitude is <0.05mm; And / or, The steps for determining the required stiffness of the elastic element and the required weight of the mass block based on the vibration frequency of the spindle include: for low-frequency vibration of 20-100Hz, select a disc spring assembly with a stiffness of 500-1000N / mm and a mass block with a weight of 10-20kg; for high-frequency vibration of 100-2000Hz, select a metal rubber pad with a stiffness of 1000-2000N / mm and a mass block with a weight of 5-10kg. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 2 This is a schematic diagram showing the connection between the clamp body and the fastening assembly in the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 3 This is a three-dimensional schematic diagram of the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 5 This is a partial schematic diagram of the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the enclosed assembly and damping cylinder in the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the sealing component and damping cylinder in the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the elastic element and mass block in the external clamping multi-frequency vibration damping ring according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures: 1. Clamp body; 101. First connecting piece; 102. Second connecting piece; 103. Assembly cavity; 104. Annular inner cavity; 105. Step; 106. Connecting part; 107. Positioning hole; 2. Sealing assembly; 201. Cover piece; 202. Fixing piece; 3. Fastening assembly; 301. First fastener; 302. Second fastener; 4. Vibration damping unit; 401. Elastic element; 402. Mass block; 403. Damping cylinder. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The following is combined with Figures 1 to 8 The following describes embodiments of the present invention.

[0030] According to an embodiment of the present invention, in one aspect, an externally clamping multi-frequency vibration damping ring is provided, comprising a clamping body 1, a fastening assembly 3, and a vibration damping unit 4; as shown below. Figure 1 and Figure 2 As shown, the clamp body 1 includes at least two interconnected connectors, each connector having at least one assembly cavity 103; multiple fastening components 3 are provided, which are used to fix adjacent connectors, so that all connectors form an annular inner cavity 104 suitable for radially fixing the main shaft; the vibration damping unit 4 is detachably disposed in the assembly cavity 103.

[0031] In a basic embodiment, such as Figure 1 As shown in Figure 4, the clamp body 1 is composed of two interconnected connecting parts, specifically including a first connecting part 101 and a second connecting part 102; both the first connecting part 101 and the second connecting part 102 are semi-circular rings, which are interlocked and sleeved on the main shaft to form an annular inner cavity 104.

[0032] In another alternative embodiment, the clamp body 1 may include three or more connectors, which are sequentially spliced ​​along the circumferential direction to accommodate spindles with different outer diameters and achieve more uniform circumferential clamping.

[0033] In specific embodiments, such as Figure 5 and Figure 8As shown, the vibration damping unit 4 includes an elastic element 401 and a mass block 402. The elastic element 401 is axially connected between the assembly cavity 103 and the mass block 402, so that the mass block 402 is elastically supported in the assembly cavity 103. The mass block 402 and the inner wall of the assembly cavity 103 are provided with damping gaps. The mass block 402 is a rotating body structure. The outer circular side wall of the mass block 402 and the inner ring wall of the assembly cavity 103 are provided with damping gaps. The side end wall of the mass block 402 and the bottom end wall of the assembly cavity 103 are also provided with damping gaps. The damping gaps are filled with a composite damping medium. The composite damping medium is used to generate damping when the mass block 402 moves, so as to dissipate vibration energy.

[0034] In this embodiment, by replacing the elastic element 401 with different stiffness and the mass block 402 with different weight, the natural frequency of the vibration damping unit 4 is changed, so that the natural frequency of the vibration damping unit 4 matches the target vibration frequency of the spindle, and the vibration energy transmitted by the spindle is converted into the motion of the mass block 402.

[0035] In specific embodiments, such as Figures 1 to 4 As shown, each connector has a connecting part 106 at its beginning and end. The connecting part 106 extends radially along the annular inner cavity 104. The connecting part 106 has multiple positioning holes 107. Two adjacent connectors are fixed by fastening components 3 passing through the positioning holes 107.

[0036] The fastening assembly 3 includes a first fastener 301 and a second fastener 302. One end of the first fastener 301 passes through the positioning hole 107 and is threaded onto the connecting portion 106 of two adjacent connectors, and is threaded into the second fastener 302. The first fastener 301 can be configured as a positioning pin, and the second fastener 302 as a positioning nut. After the adjacent connectors are fastened, the fastening assembly 3 ensures that the coaxiality of the two is ≤0.05mm; the preload torque is set to 80-200 N·m.

[0037] In this embodiment, a connecting portion 106 extending radially along the annular inner cavity 104 is provided at the beginning and end of each connector. The fastening assembly 3 passes through the positioning hole 107 on the connecting portion 106 to fix adjacent connectors, so that the clamping force is applied radially in a concentrated manner. This can efficiently convert the pre-tightening force of the fastening assembly 3 into a radial clamping force of the connector on the outer circumference of the spindle, ensuring a stable fit between the clamp body 1 and the spindle. The fastening assembly 3 adopts a threaded engagement form of the first fastener 301 and the second fastener 302. By fastening adjacent connectors with multiple sets of fastening assemblies 3, the vibration loosening effect under high-speed rotation can be effectively resisted, ensuring that the installation position of the vibration damping ring does not shift during operation, thereby ensuring a stable vibration damping effect.

[0038] In an optional embodiment, the inner circumferential surface of the annular cavity 104 of the clamp body 1 is provided with an anti-slip treatment layer. For example, a metal-based composite coating reinforced with tungsten carbide or ceramic particles is deposited on the inner circumferential surface by thermal spraying, and the surface roughness Ra is 1.6-3.2 μm.

[0039] In a specific embodiment, the clamp body 1 is made of a high-rigidity metal material, such as high-strength alloy steel or titanium alloy, to ensure that no plastic deformation occurs under a large preload and to meet the fatigue strength requirements under long-term operation.

[0040] In specific embodiments, such as Figure 1 and Figure 2 As shown, the assembly cavity 103 is configured as a cylindrical cavity, and all assembly cavities 103 on the clamp body 1 are centrally symmetrically distributed about the central axis of the annular inner cavity 104. In this embodiment, the assembly cavity 103 adopts a cylindrical cavity to provide accommodating space for the installation and movement of the mass block 402 and the elastic element 401, so that the elastic element 401 and the mass block 402 move stably in the desired direction, reducing motion interference; the central symmetrical distribution of all assembly cavities 103 about the central axis of the annular inner cavity 104 makes the center of mass of each damping unit 4 uniformly distributed, which can effectively avoid additional unbalanced vibration caused by mass eccentricity when the main shaft rotates at high speed, improve the dynamic balance characteristics of the damping ring itself, ensure consistent vibration suppression effect in all radial directions of the main shaft, and ensure the operational stability of the overall structure under high-speed rotation conditions.

[0041] In specific embodiments, such as Figure 3 and Figure 6 As shown, the multi-frequency vibration damping ring also includes a sealing component 2, which includes a detachable cover 201 and a fixing component 202. The assembly cavity 103 is recessed on the connector. The cover 201 is fixedly connected to the opening side of the assembly cavity 103 through the fixing component 202. The sealing component 2 adopts a detachable cover 201 and a fixing component 202, and the assembly cavity 103 is recessed on the connector, so that the cover 201 is fixed to the opening side of the assembly cavity 103 through the fixing component 202. This can effectively encapsulate the vibration damping unit 4 inside the assembly cavity 103, reasonably accommodate the composite damping medium, and prevent external moisture, dust and other impurities from entering the assembly cavity 103, ensuring the long-term reliability of the vibration damping unit 4. This detachable design allows the operator to easily open the assembly cavity 103 to replace the components when it is necessary to replace the elastic component 401 and the mass block 402 to adapt to different vibration frequencies. After adjustment, it can be resealed, which improves the parameter tuning efficiency and multi-condition adaptability of the vibration damping ring.

[0042] In specific embodiments, such as Figure 2As shown, each connector has a step 105 corresponding to the assembly cavity 103. The step 105 is located on the outer periphery of the opening side of the assembly cavity 103, and the cover 201 is fitted onto the step 105. The step 105 has annularly distributed fixing holes, and the fixing end of the fixing member 202 passes through the cover 201 and connects with the fixing holes. The step 105 on the outer periphery of the opening side of the assembly cavity 103 provides an installation bearing surface and axial limit for the cover 201, ensuring accurate positioning after the cover 201 is closed. The annularly distributed fixing holes on the step 105, and the fixing end of the fixing member 202 passing through the cover 201 and connecting with the fixing holes, make the clamping force of the cover 201 evenly distributed along the circumference, improving the connection stiffness and anti-vibration loosening ability of the cover 201, avoiding loosening or sealing failure of the sealing component 2 under high-speed rotation and vibration environment of the spindle, and ensuring that the composite damping medium is stably sealed in the closed cavity.

[0043] In a further embodiment, an annular sealing ring is provided on the side of the cover 201 facing the assembly cavity 103. The sealing ring is pressed and engaged with the end face of the step 105 to form an additional sealing barrier after the cover 201 is fixed, further preventing leakage of the composite damping medium and intrusion of external pollutants.

[0044] In specific embodiments, such as Figure 6 and Figure 7 As shown, the damping unit 4 also includes a damping cylinder 403, which is installed inside the assembly cavity 103. An elastic element 401 and a mass block 402 are disposed inside the damping cylinder 403. The mass block 402 is configured as a rotating body structure. The elastic element 401 is installed between the mass block 402 and the inner bottom wall of the assembly cavity 103. The mass block 402 and the elastic element 401 are coaxially disposed inside the damping cylinder 403. The damping gap is the gap between the outer wall surface of the mass block 402 and the inner wall surface of the damping cylinder 403. One end of the damping cylinder 403 abuts against and seals the inner bottom wall of the assembly cavity 103, and the other end abuts against and seals the sealing member 201 of the sealing component 2, so as to seal the composite damping medium in the cavity formed by the damping cylinder 403, the assembly cavity 103 and the sealing member 201.

[0045] The elastic element 401 and the mass block 402 are coaxially installed in the inner cavity of the damping cylinder 403. The mass block 402 is set as a rotating body structure. When it moves axially under the support of the elastic element 401, a controllable damping gap is formed between its outer peripheral surface and the inner wall of the damping cylinder 403, which is conducive to the stable generation of shear damping effect. At the same time, one end of the damping cylinder 403 is sealed against the bottom wall of the assembly cavity 103, and the other end is sealed against the cover 201 of the sealing component 2. The composite damping medium is sealed in the closed cavity formed by the damping cylinder 403, the assembly cavity 103 and the cover 201, which realizes double sealing protection for the composite damping medium, prevents the high viscosity damping grease from being thrown out from the assembly gap under centrifugal force or vibration, and also blocks external contaminants from entering the cavity, ensuring reliable damping performance.

[0046] When the clamp body 1 rotates at high speed with the main shaft, the mass block 402 is subjected to centrifugal force in the radial direction. This centrifugal force may cause the mass block 402 to press against the radial inner wall of the damping cylinder 403 or the assembly cavity 103, resulting in uneven distribution of the damping gap and even contact friction, affecting the damping dissipation efficiency and motion stability of the vibration damping unit 4. Therefore, in this embodiment, all assembly cavities 103 are centrally symmetrically distributed about the central axis of the annular inner cavity 104. This design ensures that the centrifugal forces generated by each mass block 402 are balanced, avoiding overall unbalanced vibration. Simultaneously, a small damping gap of 0.1-0.5 mm is maintained between the inner wall of the damping cylinder 403 and the outer wall of the mass block 402. Under the action of centrifugal force, the damping grease in the composite damping medium can form an extremely thin hydrodynamic oil film, generating a certain radial support force, thereby preventing rigid contact between the mass block 402 and the damping cylinder 403.

[0047] In a preferred embodiment, the damping cylinder 403 is made of metal rubber. The metal rubber is formed by winding and pressing stainless steel wire and has an elastic porous structure. When the mass block 402 moves, the dry friction effect of the damping cylinder 403 itself can further dissipate vibration energy. When combined with the composite damping medium, it can broaden the vibration reduction frequency band and improve the energy dissipation efficiency.

[0048] In one specific embodiment, the elastic element 401 is configured as a disc spring assembly, which is configured as a mating combination or a stacked combination. By adjusting the combination method, the overall stiffness of the elastic element 401 can be changed within a large range to meet the requirements of low stiffness and high load-bearing capacity in low-frequency vibration absorption scenarios. In terms of specific installation, the upper end of the disc spring assembly can be sleeved on the protrusion on the bottom wall of the assembly cavity 103, and the lower end can be sleeved into the inner groove of the mass block 402 facing the end face of the disc spring assembly. It can be connected by interference fit or fixed by adhesive.

[0049] In another alternative embodiment, the elastic element 401 is configured as a metal rubber pad. The elastic element 401 can be a metal rubber pad, which, by utilizing the dry friction damping characteristics between the metal wires in the metal rubber pad and the designable elastic modulus, is suitable for precise tuning and broadband damping dissipation of mid-to-high frequency vibrations.

[0050] Through the above two implementation schemes, the vibration damping unit 4 can achieve natural frequency matching in a wide frequency range of 20-2000Hz, thereby improving the working condition adaptability and vibration damping performance of the multi-frequency vibration damping ring.

[0051] In a specific embodiment, the damping gap is set to 0.1-0.5 mm; by utilizing the high shear rate of the fluid within the small gap, the composite damping medium can generate significant damping force even with a small displacement of the mass block 402, thereby rapidly dissipating vibration energy.

[0052] In a specific embodiment, the composite damping medium is formed by mixing metal rubber fragments and damping grease in a mass ratio of 3:7. This ratio balances the frictional damping provided by the metal rubber fragments and the viscous shear damping provided by the high-viscosity damping grease, giving the damping medium both high energy dissipation density and good filling properties and energy dissipation stability. It can efficiently convert vibration kinetic energy into heat dissipation over a wide frequency range, which is beneficial to improving vibration attenuation efficiency.

[0053] The external clamping multi-frequency vibration damping ring provided in this embodiment, through a clamping body 1 composed of at least two connecting parts, is fixed to the spindle by a fastening assembly 3, forming a radially clamping annular inner cavity 104. This achieves non-invasive and non-destructive installation of the spindle, avoiding destructive operations such as drilling, ensuring connection reliability, and protecting the original structural strength and balance accuracy of the spindle. A vibration damping unit 4 is detachably installed within the assembly cavity 103 of the connecting parts. When the spindle generates wide-frequency vibration, the damping unit 4 can be adjusted by replacing elastic elements 401 with different stiffnesses and mass blocks of different weights. 402 actively changes the natural frequency of the vibration damping unit 4 to match the target vibration frequency of the main shaft, thereby efficiently converting the vibration energy of the main shaft into the reverse motion of the mass block 402, realizing the capture and conversion of multi-frequency vibration; the damping gap between the mass block 402 and the assembly cavity 103 is filled with a composite damping medium. When the mass block 402 is excited, the composite damping medium generates a strong shear damping effect in the tiny gap, which quickly converts the vibration kinetic energy into heat energy dissipation, improves the vibration attenuation efficiency, ensures that the vibration energy is fully dissipated, and avoids back transmission to the main shaft.

[0054] This invention solves the problems of strong invasiveness, poor broadband compatibility, and low vibration energy dissipation efficiency in related technologies. It achieves non-invasive and stable installation and precise and efficient dissipation of broadband vibration, which can effectively extend the service life and operating accuracy of water turbine equipment.

[0055] According to an embodiment of the present invention, another aspect provides a method for using an externally clamping multi-frequency vibration damping ring, comprising: Monitor the vibration parameters of the spindle. When the vibration parameters meet the preset vibration reduction conditions, it is determined to be a vibration reduction condition. When vibration reduction is required, the clamp body 1 is fastened to the outer circumference of the spindle, and a pre-tightening force is applied by the fastening component 3 to clamp the clamp body 1 to the spindle; according to the vibration frequency of the spindle, the elastic element 401 with the required stiffness and the mass block 402 with the required weight are determined so that the natural frequency of the vibration reduction unit 4 matches the vibration frequency of the spindle. Once the spindle vibration parameters return to within the allowable range, disassemble the multi-frequency damping ring.

[0056] By monitoring the spindle vibration parameters and determining whether the preset vibration reduction conditions are met, the vibration damping ring is activated in a timely manner when the spindle vibrates abnormally due to non-design conditions. This avoids unnecessary operation of the vibration damping ring under normal conditions, which would cause additional energy consumption and resistance loss. When vibration reduction is required, the clamp body 1 is clamped by the fastening component 3. The matching elastic element 401 and mass block 402 are selected according to the vibration frequency for frequency tuning, so that the natural frequency of the vibration damping unit 4 matches the vibration frequency of the spindle, thereby achieving accurate vibration absorption and improving the vibration energy conversion efficiency. The vibration damping ring is removed only after the spindle vibration parameters return to the allowable range, avoiding additional rotational resistance and component wear caused by long-term installation, and ensuring that the unit maintains its original efficiency under design conditions.

[0057] In a specific embodiment, the preset vibration reduction conditions include: spindle vibration acceleration ≥ 5 m / s². 2 The vibration displacement amplitude is ≥0.08mm, and at least one of the following is present: a resonant frequency component in the range of 20-2000Hz.

[0058] In a specific embodiment, the permissible range is vibration acceleration < 3 m / s². 2 And the displacement amplitude is <0.05mm.

[0059] In a specific embodiment, the steps of determining the required stiffness of the elastic element 401 and the required weight of the mass block 402 according to the vibration frequency of the spindle include: for low-frequency vibration of 20-100Hz, a disc spring assembly with a stiffness of 500-1000N / mm is selected, and a mass block 402 with a weight of 10-20kg is selected; for high-frequency vibration of 100-2000Hz, a metal rubber pad with a stiffness of 1000-2000N / mm is selected, and a mass block 402 with a weight of 5-10kg is selected.

[0060] The usage method provided in this embodiment enables the vibration damping ring to be adaptable to different working conditions, is easy to operate, effectively improves the operating stability of the turbine under non-design conditions, and does not affect the normal output.

[0061] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An externally clamping multi-frequency vibration damping ring, characterized in that, include: The clamp body (1) includes at least two connectors that are spliced ​​together, and each connector is provided with at least one assembly cavity (103); Multiple fastening components (3) are used to secure adjacent connectors, such that all connectors form annular cavities (104) suitable for radially fixing the spindle. The vibration damping unit (4) is detachably disposed in the assembly cavity (103). The vibration damping unit (4) includes an elastic element (401) and a mass block (402). The mass block (402) and the inner wall of the assembly cavity (103) are provided with a damping gap. The elastic element (401) is axially connected between the assembly cavity (103) and the mass block (402), so that the mass block (402) is elastically supported in the assembly cavity (103). The natural frequency of the damping unit (4) is changed by replacing the elastic element (401) with one of different stiffness and the mass block (402) with one of different weight, so that the natural frequency of the damping unit (4) matches the target vibration frequency of the main shaft, and the vibration energy transmitted by the main shaft is converted into the motion of the mass block (402). The damping gap is filled with a composite damping medium, which is used to generate damping when the mass block (402) moves, so as to dissipate vibration energy.

2. The externally clamping multi-frequency vibration damping ring according to claim 1, characterized in that, The assembly cavity (103) is configured as a cylindrical cavity, and all the assembly cavities (103) on the clamp body (1) are centrally symmetrically distributed about the central axis of the annular inner cavity (104).

3. The externally clamping multi-frequency vibration damping ring according to claim 2, characterized in that, It also includes a sealing component (2), which includes a detachably disposed cover (201) and a fixing component (202), and the assembly cavity (103) is recessed on the connector; the cover (201) is fixedly connected to the opening side of the assembly cavity (103) through the fixing component (202).

4. The external clamping multi-frequency vibration damping ring according to claim 3, characterized in that, Each connector has a step (105) corresponding to the assembly cavity (103). The step (105) is located on the outer periphery of the opening side of the assembly cavity (103). The cover (201) is fitted onto the step (105). The step (105) has a ring of fixing holes. The fixing end of the fixing member (202) passes through the cover (201) and connects with the fixing holes.

5. The externally clamping multi-frequency vibration damping ring according to claim 3, characterized in that, The vibration damping unit (4) further includes a damping cylinder (403), which is installed in the assembly cavity (103). The elastic element (401) and the mass block (402) are disposed in the inner cavity of the damping cylinder (403). The mass block (402) is configured as a rotating body structure. The elastic element (401) is installed between the mass block (402) and the inner bottom wall of the assembly cavity (103). The mass block (402) and the elastic element (401) are coaxially disposed in the inner cavity of the damping cylinder (403). One end of the damping cylinder (403) abuts against and seals the inner bottom wall of the assembly cavity (103), and the other end abuts against and seals the cover (201) of the sealing component (2) to seal the composite damping medium in the cavity formed by the damping cylinder (403), the assembly cavity (103) and the cover (201).

6. The externally clamping multi-frequency vibration damping ring according to any one of claims 1-5, characterized in that, Each connector is provided with a connecting part (106) at its head and tail ends. The connecting part (106) extends radially along the annular inner cavity (104). The connecting part (106) is provided with a plurality of positioning holes (107). Two adjacent connectors are fixed by the fastening assembly (3) passing through the positioning holes (107). The fastening assembly (3) includes a first fastener (301) and a second fastener (302). One end of the first fastener (301) passes through a positioning hole (107) through a connecting portion (106) on two adjacent connectors and is threadedly connected to the second fastener (302).

7. The external clamping multi-frequency vibration damping ring according to any one of claims 1-5, characterized in that, The elastic element (401) is configured as a disc spring assembly, which is configured as a mating combination or a stacked combination; or, the elastic element (401) is configured as a metal rubber pad.

8. The external clamping multi-frequency vibration damping ring according to any one of claims 1-5, characterized in that, The damping gap is set to 0.1-0.5 mm; the composite damping medium is formed by mixing metal rubber fragments and damping grease in a mass ratio of 3:

7.

9. A method of using the external clamping multi-frequency vibration damping ring according to any one of claims 1-8, characterized in that, include: Monitor the vibration parameters of the spindle. When the vibration parameters meet the preset vibration reduction conditions, it is determined to be a vibration reduction condition. When vibration reduction is required, the clamp body (1) is fastened to the outer circumference of the spindle, and a pre-tightening force is applied by the fastening assembly (3) to clamp the spindle. Based on the vibration frequency of the spindle, the elastic element (401) with the required stiffness and the mass block (402) with the required weight are determined so that the natural frequency of the vibration reduction unit (4) matches the vibration frequency of the spindle. Once the spindle vibration parameters return to within the allowable range, disassemble the multi-frequency damping ring.

10. The method of use according to claim 9, characterized in that, The preset vibration reduction conditions include a spindle vibration acceleration ≥ 5 m / s². 2 The vibration displacement amplitude is ≥0.08mm, and at least one of the resonant frequency components in the range of 20-2000Hz is present; the allowable range is set to a spindle vibration acceleration <3m / s². 2 And the vibration displacement amplitude is <0.05mm; And / or, The steps for determining the required stiffness of the elastic element (401) and the required weight of the mass block (402) based on the vibration frequency of the spindle include: for low-frequency vibration of 20-100Hz, a disc spring assembly with a stiffness of 500-1000N / mm is selected, and a mass block (402) with a weight of 10-20kg is selected; for high-frequency vibration of 100-2000Hz, a metal rubber pad with a stiffness of 1000-2000N / mm is selected, and a mass block (402) with a weight of 5-10kg is selected.

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