A vibration-resistant fixing device for high-voltage foil-wound dry-type transformers using a new process

Abstract

The present invention discloses an anti-vibration fixing device for a high-voltage foil-wound new process dry-type transformer, which relates to the technical field of transformers and includes a support base, an adjustable support screw assembly, and a multi-stage elastic damping assembly. The lower end of the adjustable support screw assembly is connected to the support base, and the multi-stage elastic damping assembly is arranged in series between the adjustable support screw assembly and the coil end cover to absorb the axial vibration generated by the coil during operation. The side wall of the coil is installed with an annular clamping seat to constrain the radial direction of the coil and absorb radial vibration. A guide positioning block is installed between the bottom of the coil and the support base. The present invention realizes the segmented absorption and attenuation function of the coil operation vibration by installing a multi-stage elastic damping assembly, solving the problem that a traditional single elastic element can only work in a limited frequency band and is difficult to simultaneously suppress the full-band vibration from tens of hertz to hundreds of hertz, effectively expanding the vibration isolation bandwidth, significantly reducing noise, and extending the service life of the coil and the box.

Description

Technical Field

[0001] The invention relates to the technical field of transformers, in particular to a vibration-resistant fixing device for a high-voltage foil-wound dry-type transformer using a new process. Background Art

[0002] Existing high-voltage foil-wound dry-type transformers typically use processes such as epoxy resin full impregnation or vacuum injection to secure the foil coil structure to the inner side of the iron core, with heat dissipation slots used to space the coils from the outer casing. However, with the development of foil-wound technology, the coil structure has become thinner and longer, resulting in reduced mechanical rigidity. When the transformer is powered on, electromagnetic excitation and the iron core's magnetic field cause the coil to vibrate relative to the core, resulting in high transformer noise, poor stability, and inconvenient maintenance.

[0003] Patent CN116092783B discloses a dry-type transformer for offshore ship power distribution with anti-vibration function, which achieves good stability when operating at sea.

[0004] The above patent provides an arc-shaped slide rail, a limit frame, a first support frame and a first fixed plate, which can enable the transformer device to remain stable at sea. When the ship is bumpy at sea, the limit frame will slide on the outer surface of the arc-shaped slide rail, thereby keeping the transformer device stable. However, it cannot effectively solve the vibration generated by the transformer itself during operation.

[0005] To this end, the present application proposes an anti-vibration fixing device for a high-voltage foil-wound dry-type transformer using a new process, which can effectively buffer the vibration generated by the operation of the transformer coil. Summary of the Invention

[0006] The purpose of the present invention is to provide a vibration-proof fixing device for a high-voltage foil-wound dry-type transformer with a new process, so as to solve the technical problem raised in the above background technology that the coil will generate relative vibration due to the action of electromagnetic excitation and the magnetic field of the iron core.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: an anti-vibration fixing device for a high-voltage foil-wound new process dry-type transformer, comprising a support base, an adjustable support screw assembly and a multi-stage elastic damping assembly, wherein the support base is used to be fixed to the bottom of the transformer box and carry the coil, the lower end of the adjustable support screw assembly is connected to the support base, the multi-stage elastic damping assembly is arranged in series between the adjustable support screw assembly and the coil end cover, and is used to absorb the axial vibration generated by the coil during operation, the side wall of the coil is installed with an annular clamping seat, and the annular clamping seat is connected to the multi-stage elastic damping assembly, and is used to constrain the radial direction of the coil and absorb radial vibration, a guide positioning block is installed between the bottom of the coil and the support base, and the guide positioning block is used to perform preliminary positioning and limiting of the coil in radial and horizontal directions.

[0008] Preferably, the support base is bent from a cold-rolled steel plate with a thickness of 4-8 mm. Transverse reinforcement ribs are provided inside the support base to increase the rigidity. The surface of the support base is sprayed with epoxy zinc-rich primer and polyurethane topcoat after phosphating treatment. Several screw holes are reserved on the support base to install an adjustable support screw assembly, and grooves for inserting guide positioning blocks are opened at corresponding positions.

[0009] Preferably, the adjustable support screw assembly comprises: a screw, a pre-tightening nut, a spring pre-compression assembly and an elastic sealing sleeve;

[0010] The screw is a 12mm diameter galvanized threaded steel rod, the preload nut is an M12×1.25 hexagonal nut, and the spring preload assembly is sleeved outside the screw to generate continuous preload force between the preload nut and the support base. The elastic sealing sleeve is sleeved outside the screw to prevent dust and limit the lateral swing of the spring preload assembly.

[0011] Preferably, the spring preload assembly comprises:

[0012] The helical compression spring is made of nickel-plated carbon steel wire with a wire diameter of 5mm, an outer diameter of 20mm, and a free length of 30mm. One end presses against the bottom surface of the pre-tightening nut, and the other end presses against the support base.

[0013] The anti-loosening washer is placed between the pre-tightening nut and the support base. The toothed structure of the anti-loosening washer generates friction under vibration conditions to prevent the pre-tightening nut from loosening;

[0014] When the pre-tightening nut is tightened to the designed position, the helical compression spring generates a pre-compression of 5-10mm, which maintains the clamping force between the pre-tightening nut and the screw and buffers the axial micro-vibration.

[0015] Preferably, the elastic sealing sleeve is made of neoprene, with the lower end clamped on the positioning step of the support base and the upper end fitted to the bottom circumference of the pre-tightening nut along the outer surface of the screw to form a closed dustproof structure, and laterally constrain the helical compression spring when the helical compression spring is subjected to lateral force.

[0016] Preferably, the multi-stage elastic damping assembly includes, from top to bottom:

[0017] The rubber cushion is made of hydrogenated nitrile rubber with a hardness of 60 Shore A and a thickness of 5-8 mm. The hollow inner hole matches the diameter of the screw and is fixed to the bottom boss of the coil end cover by screws.

[0018] The metal coil spring is made of carbon steel, with a wire diameter of 5mm, an outer diameter of 20mm, and a height of 25mm. It is nickel-plated. The upper end of the spring engages with the lower surface of the rubber pad through a plastic retaining ring, and the lower end is clamped in the bottom notch of the silicone grease damping block.

[0019] The silicone grease damping block includes a damping unit consisting of a 1.5mm thick sheet metal shell and internal silicone grease. Its appearance is like a piston-less oil pressure damping cylinder. The upper plane fits the lower end of the metal coil spring, and the lower part is connected to the screw through a fixed boss.

[0020] Preferably, the annular clamping seat is composed of six equally divided sector-shaped clamping blocks, each sector-shaped clamping block includes:

[0021] A U-shaped groove is opened on one side wall for the side wall of the environmentally friendly foil winding coil;

[0022] A 2mm thick PTFE pad is placed inside the U-shaped groove to reduce friction, and a 3mm thick elastic impact cotton block is embedded at the bottom of the U-shaped groove to absorb impact;

[0023] At least two bolt holes are provided on the outer side for fastening with the connecting plate by bolts to form a complete annular structure;

[0024] The fan-shaped clamps are fastened together by bolts, with an included angle of 60°.

[0025] Preferably, the connecting plate is a rectangular steel plate, one end of which is connected to the bolt hole on the outer side of the fan-shaped clamp block by an M8 bolt, and the lower end is connected to the upper fixed boss of the silicone grease damping block by a pull rod. The pull rod is an M8×160-200mm screw, equipped with a spring washer and a nylon locking nut to adjust the radial preload of the annular clamping seat on the side wall of the coil.

[0026] Preferably, the guide positioning block includes an upper block and a lower block:

[0027] The upper block is a ring-shaped positioning piece made of injection-molded PA66 material, which is installed on the bottom edge of the coil and fits with the bottom surface of the coil to achieve radial positioning;

[0028] The lower block is a concave positioning piece made of PA66 material, embedded in the reserved groove of the support base, and cooperates with the upper block to achieve horizontal limit;

[0029] The guide positioning blocks are matched with each other in shape, so that the coil can automatically obtain radial and horizontal dual positioning during installation.

[0030] Preferably, the pre-tightening nut on the adjustable support screw assembly and the locking nut on the pull rod of the annular clamping seat are both adjustable, so that the pre-compression deformation of the multi-stage elastic damping assembly and the annular clamping seat is maintained in the range of 5-10mm, so as to ensure that the transformer has sufficient vibration isolation margin and thermal expansion compensation capability during operation.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. This invention utilizes multi-stage elastic damping components to achieve segmented absorption and attenuation of coil vibration. This solves the problem that traditional single elastic elements can only operate in a limited frequency range and are unable to simultaneously suppress vibrations across the entire frequency range, from tens to hundreds of hertz. High-frequency vibrations are often directly transmitted to the housing, generating noise and resonance. This effectively expands the vibration isolation bandwidth. Low-frequency vibrations are absorbed by the rubber pad, mid-frequency vibrations are attenuated by the metal spring, and high-frequency vibrations are dissipated by silicone grease flow damping. This significantly reduces noise and extends the service life of the coil and housing.

[0033] 2. This invention incorporates a helical compression spring and a locking washer to buffer minute axial runout during vibration. This addresses the problem of common threaded connections loosening or even falling off under electromagnetic excitation and thermal expansion, leading to support failure and coil misalignment. This ensures that transformer connectors maintain stable clamping during vibration and temperature fluctuations, improving device reliability.

[0034] 3. This invention utilizes an annular clamping seat, PTFE gasket, and elastic impact pads to achieve elastic constraint on the coil, reducing friction and improving impact cushioning. This addresses the issues of traditional rigid clamping or non-cushioning designs that can easily cause foil surface damage and abrasions. It further attenuates radial vibration energy, improving coil structural integrity and operational safety.

[0035] 4. The present invention achieves an integrated assembly effect by installing a guide positioning block and an adjustable support screw assembly, solving the problem that large-sized foil-wound coils are prone to position deviation during assembly and operation, requiring multiple adjustments; traditional positioning mostly relies on external tools or bonding, lacks precision and is inconvenient for disassembly and maintenance. It ensures that the coil can still maintain a stable position under conditions of thermal expansion and vibration, reducing the failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a front view structural schematic diagram of the present invention;

[0037] Figure 2 It is a schematic diagram of the front structure of the present invention;

[0038] Figure 3 It is a schematic structural diagram of the multi-stage elastic damping assembly of the present invention;

[0039] Figure 4 This is a schematic diagram of the fan-shaped clamp structure of the present invention;

[0040] Figure 5 This is a schematic diagram of the bolt buckle structure of the present invention;

[0041] Figure 6 This is a schematic structural diagram of the guide positioning block of the present invention;

[0042] Figure 7 This is a schematic structural diagram of the adjustable support screw assembly of the present invention;

[0043] Figure 8 It is a schematic structural diagram of the multi-stage elastic damping component of the present invention.

[0044] In the figure: 1. Bottom of the transformer box; 2. Support base; 3. Screw; 4. Coil end cover; 5. Coil; 6. Multi-stage elastic damping assembly; 7. Bolt buckle; 8. Plastic retaining ring; 9. Fan-shaped clamping block; 10. U-shaped groove; 11. PTFE gasket; 12. Elastic impact cotton block; 13. Bolt hole; 15. Upper block; 16. Lower block; 17. Groove; 18. Pre-tightening nut; 19. Elastic sealing sleeve; 20. Helical compression spring; 21. Anti-loosening washer; 22. Pull rod; 23. Rubber pad; 24. Metal helical spring; 25. Silicone grease damping block; 26. Connecting plate. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] Example 1: Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A vibration-proof fixing device for a high-voltage foil-wound new process dry-type transformer is used. The support base 2 is fixed to the bottom 1 of the transformer box by M12 bolts. The horizontal error is adjusted within ±0.5mm. Eight screws 3 are inserted from the lower holes of the support base 2. The elastic sealing sleeve 19 is first installed, and the lower end is clamped on the support pad. Then, the anti-loosening washer 21 and the pre-tightening nut 18 are installed, but they are not locked yet. The high-voltage foil-wound coil 5 together with the coil end cover 4 are placed on the support base 2 as a whole. The bottom edge of the coil 5 is in contact with the upper block 15, and the upper block 15 is automatically inserted into the support. The groove 17 of the base 2 cooperates with the lower block 16 to achieve radial and horizontal positioning. Tighten the pre-tightening nut 18 one by one so that the bottom surface of the pre-tightening nut 18 compresses the coil compression spring 20 to a predetermined height (pre-load 6mm) until the pre-tightening nut 18 and the support base 2 have a slight friction but can be adjusted. At this time, the coil compression spring 20 maintains elastic pre-tightening between the pre-tightening nut 18 and the support base 2. Fix the rubber pad 23 on the reserved boss below the coil end cover 4 with an M5 screw, and then place the metal coil spring 24 on the rubber pad. 23 below, and make the lower end of the metal coil spring 24 stuck into the bottom notch of the silicone grease damping block 25, finally match the upper fixing boss of the silicone grease damping block 25 with the upper end of the screw 3, and then lock it with a φ12×20×2mm cylinder washer and a nylon locking nut to complete the installation of the multi-stage elastic damping component 6, and assemble the 6 sector-shaped clamping blocks 9 around the side wall of the coil 5, and connect them to the connecting plate 26 with M8 high-strength bolts to ensure that the inner diameter of the thick ring of the sector-shaped clamping blocks 9 is 500mm, and then pass the pull rod 22 through the lower end of the connecting plate 26 and assemble it with the silicone grease. The upper fixed boss of the damping block 25 is threaded and the locking nut is adjusted so that the fan-shaped clamping block 9 generates a radial preload of 100N on the side wall of the coil 5. Check the preload of each elastic component: the preload stress of the helical compression spring 20 is 6mm±0.5mm, the rubber cushion 23 and the metal helical spring 24 should be pre-shrinked by about 2mm, and after the pull rod 22 is adjusted, the gap between the fan-shaped clamping block 9 and the side wall of the coil 5 is 0, and the preload force is stabilized at 100±10N, ensuring the assembly level of the entire machine. The coil 5 can move axially up and down within the range of ±1mm;

[0049] When the dry-type transformer is powered on, the high-voltage foil coil 5 generates electromagnetic excitation and thermal expansion. Axial vibrations are preferentially absorbed by the rubber pad 23 in the 0-50 Hz range, while vibrations in the 50-200 Hz range are primarily attenuated by the metal coil spring 24. High-frequency vibrations above 200 Hz are dissipated by the flow of silicone grease within the silicone grease damping block 25. The three-layer damping in series reduces the amplitude of vibration transmitted to the enclosure by over 70%. Radial vibrations are buffered by the annular clamping seat via PTFE 11 and elastic impact cotton block 12, which is connected to the silicone grease damping block 25 via a pull rod 22. This directs radial impact energy into the metal coil spring 24 and rubber pad 23 for further attenuation. Due to the preload of the helical compression spring 20, the connection between the screw 3 and the preload nut 18 remains stable and prevents loosening due to vibration or thermal expansion. The elastic sealing sleeve 19 prevents the helical compression spring 20 from swinging laterally and is dust-proof. The guide positioning block ensures that the coil 5 can freely compensate for thermal expansion within a longitudinal range of ±1 mm without getting stuck or deflecting.

[0050] Example 2: Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A vibration-resistant fixing device for a high-voltage foil-wound dry-type transformer with a new process has been developed. The support base 2 has been increased to four transverse reinforcement ribs, and the anti-loosening washer 21 has been replaced with a micro-strip toothed disc spring washer to enhance the anti-loosening force. The material of the elastic sealing sleeve 1 fan-shaped clamping block 9 has been changed to thermoplastic polyurethane, and the material of the rubber pad 23 has been changed to silicone. It is fixed to the boss of the coil end cover 4 by three M5×1mm stainless steel screws to increase the contact area. The upper surface is provided with anti-slip fine grooves. The outer shell of the silicone grease damping block 25 has been changed to a rust-free damping cylinder bent from a 2mm stainless steel plate and filled with 60,000 cSt high-viscosity silicone grease. The number of fan-shaped clamping blocks 9 has been increased to eight, and the material has been changed to aluminum alloy plate, with a central angle of 45°. The size of the U-shaped groove 10 remains unchanged, with a 2mm thick nylon bushing attached to the inside, and a 4mm thick closed-cell sponge pad at the bottom to enhance the cushioning performance.

[0051] The support base 2 is fixed to the bottom 1 of the transformer box with M12 bolts. The eight screws 3 are passed through the screw holes of the support base 2 in sequence. The elastic sealing sleeve 19 is installed, and the disc-shaped anti-loosening washers and self-locking nuts are placed for preliminary locking. The coil 5 and the coil end cover 4 are placed on the support base 2. They are pre-positioned by the upper block 15 and the lower block 16, and the pre-tightening nut 18 is tightened. The helical compression spring 20 is compressed by about 7mm. The rubber pad 23, the metal helical spring 24 and the silicone grease damping block 25 are installed and locked. The eight fan-shaped clamping blocks 9 are assembled and locked with the connecting plate 26 and the pull rod 22. The radial force is adjusted to 120N±10N. Check that the three-layer damping preload is: the rubber pad 23 is compressed by 3mm, the metal helical spring 24 is compressed by 8mm, and the initial gap inside the silicone grease damping block 25 is 1mm.

[0052] Since the silicone cushion layer can still maintain its elasticity at low temperatures (-20°), this embodiment is suitable for cold climates. After the stiffness of the metal coil spring 24 is increased, it can more thoroughly absorb medium and high frequency vibrations of 50-250Hz. The combination of the aluminum alloy plate and the nylon bushing effectively reduces the weight of the annular clamping seat itself and reduces the additional force on the coil 5. The high-viscosity silicone grease damping block 25 further enhances the high-frequency suppression capability above 300Hz, reducing vibration transmission by more than 75%.

[0053] Example 3: Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A vibration-resistant fixture for a high-voltage foil-wound dry-type transformer using a new process is provided. This embodiment is designed for a small dry-type transformer (coil 5 with an outer diameter of 400 mm and a total height of 700 mm). The design is optimized primarily for compactness and lightweight construction.

[0054] The support base 2 has a size of 600mm×450mm and a plate thickness of 4mm; it is only equipped with two transverse reinforcement ribs; the coating method is the same as that of Example 1; 6 screw holes are reserved; grooves 17 are opened on both sides of the middle of the support base 2, and the adjustable support screw assembly has a total of 6 screws 3; the pre-tightening nut 18 is M10×1.25 with nylon locking; the anti-loosening washer 21 is a disc spring washer; the elastic sealing sleeve 1 fan-shaped clamp 9 is made of EPDM rubber; the coil end cover 4 is welded from carbon steel plate and has 6 M10 threaded holes on it; the bottom boss surface is sprayed with epoxy resin paint; the rubber pad 23 in the multi-stage elastic damping component 6 is nitrile rubber (NBR) with a hardness of 65Shore A, through two M4×12mm The end cover boss is fixed with screws, and the metal coil spring 24 is made of carbon steel; nickel-plated; the stiffness is about 30N / mm; the upper end is stuck in the plastic retaining ring under the rubber pad, and the lower end is stuck in the bottom groove of the silicone grease damping block 25; the shell material of the silicone grease damping block 25 is aluminum alloy (6063), 1.2mm thick, and anodized; the interior is filled with 40000cSt high-viscosity silicone grease; the upper part fits with the metal coil spring 24, and the lower fixed boss cooperates with the screw 3 and is locked with an aluminum washer and a nylon locking nut; the fan-shaped clamping block 9 is made of 3mm thick aluminum alloy plate (6061-T6); the U-shaped groove 10 dimensions are: width 10mm × depth 5mm, with a 1.5mm thick PTFE liner 11 on the inside, and a 2mm thick EVA foam is embedded in the bottom of the U-shaped groove 10; the outer side of the fan-shaped clamping block 9 is equipped with an M8×20mm Bolt hole 13 is fixed to one side of connecting plate 26, which is made of aluminum plate with a width of 25mm, a length of 100mm, and a thickness of 3mm. It is connected to the fan-shaped clamping block 9 via M8×20mm stainless steel bolts. The lower end is matched with the pull rod 22, which is equipped with a spring washer and a nylon lock nut, and the radial adjustment force is approximately 80N. The upper block 15 is PA6 injection molded, with an inner diameter of 400mm, an outer diameter of 410mm, and a thickness of 8mm. It is equipped with three positioning teeth with a width of 5mm and a length of 8mm. The lower block 16 is PA6 injection molded, with an outer diameter of 410mm, an inner diameter of 400mm, and a thickness of 6mm. The groove size is 5mm×8mm.

[0055] Fix the support base 2 to the inner bottom of the transformer box body 1 → penetrate the six screws 3 → install the EPDM elastic sealing sleeve 19 → disc lock washer 21 → preliminarily tighten the pre-tightening nut 18, place the coil 5 and coil end cover 4 on the support base 2 → put the guide block upper block 15 and lower block 16 in place, tighten the pre-tightening nut 18 one by one to preload the helical compression spring 20 by about 5mm, install the rubber pad 23, metal coil spring 24, and silicone grease damping block 25 and lock them, assemble the six fan-shaped clamping blocks 9, lock them with the connecting plate 26 and pull rod 22, adjust the radial force to 80N±8N, and check: adjust the foot pad so that the overall horizontal error is less than ±0.5mm, the metal coil spring 24 is preloaded by 5mm±0.5mm, the rubber pad 23 is compressed by 2mm, and the silicone grease damping block 25 has a gap of 1mm;

[0056] The compact structure, with a total height of 750 mm, only occupies limited space in the box. The low spring stiffness makes it suitable for low-power (less than 250kVA silicone grease damping block) dry-type transformers, effectively absorbing low-frequency vibrations of 0-150Hz. The aluminum alloy damping block and aluminum clamping block further reduce the weight, reducing the total weight of the component by approximately 20% of the spiral compression spring, reducing the load on the support base. The guide positioning block is simple and low-cost, with an initial coil positioning accuracy of ±0.5mm, improving installation efficiency by 30%.

[0057] Example 4: Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A vibration-proof fixing device for a high-voltage foil-wound dry-type transformer using a new process is provided. The elastic sealing sleeve 19 is replaced with a fluororubber material, the anti-loosening washer 21 is a toothed spring washer, and the rubber cushion layer 23 is made of silicone composite polyurethane. The fixing method is the same as in Example 1, but the silicone grease damping block 25 is replaced with a pneumatic damper. The specifications are a miniature pneumatic damping cylinder with an outer diameter of φ20mm, a length of 40mm, and an inner diameter of φ12mm, with no exposed piston rod. The damping oil chamber is filled with pressurized oil (the damping ratio is adjustable), and the upper end contacts the lower end of the metal coil spring 24. The lower end has a steel fixing boss connected to the upper part of the screw 3 through a φ12mm×φ20mm×2mm The steel washer and nylon locking nut are locked. The air pressure damper can adjust the internal damping coefficient through the top M4 inflation valve to achieve adjustable absorption of vibrations in different frequency bands. The elastic impact cotton block 12 is changed to EVA foam. The support base 2 is fixed on the bottom 1 of the transformer box. 8 screws 3 are installed. Fluorine rubber elastic sealing sleeve 19 is installed. Anti-loosening washer 21 is installed. Pre-locking is performed by pre-tightening nut 18. The coil 5 and coil end cover 4 are placed on the support base 2. The upper block 15 and the lower block 16 are positioned in place. The pre-tightening nut 18 is tightened to pre-load the spiral compression spring 20 by about 6mm. The rubber pad 23, metal spiral spring 24 and silicone grease damping block 25 are installed. The silicone grease damping block 25 is replaced with an air pressure damper. Insert the screw 3 into the lower boss of the air pressure damper and rotate and lock it with the pre-tightening nut 18 and the lock washer 21. Assemble the eight fan-shaped clamps 9 and connect them to the fixed boss below the air pressure damper through the connecting plate 26. Adjust the locking nut of the pull rod 22 so that the radial force reaches 110N±10N on the PTFE liner. Adjust the internal damping pressure through the M4 inflation valve on the top of the air pressure damper so that the damping force for 150-300Hz vibration is continuously adjustable within the range of 200-500N·s / m of the spiral compression spring. Check: the tightening torque of all nuts is 20N·m±2N·m, the preload of the three-layer damping is: 3mm for the silicone cushion layer, 6mm for the metal coil spring 24, and a 1mm buffer gap inside the air pressure damper.

[0058] The pneumatic damper can automatically adjust the damping ratio according to the on-site vibration spectrum. It is suitable for occasions where the vibration isolation performance needs to be frequently switched due to regional or load changes. After modification, it can accurately adjust the high-frequency vibration of 100-400Hz, and the vibration transmission is reduced by 80%. The fluororubber elastic sealing sleeve 19 is resistant to high temperatures above 150°C and is suitable for environments with large temperature fluctuations. The POM guide block has a low friction coefficient and good wear resistance, and can maintain a positioning accuracy of ±0.5mm for a long time.

[0059] Example 5: Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A vibration-resistant fixture for high-voltage foil-wound dry-type transformers using a novel process. Based on a small transformer, this embodiment integrates the support base and guide positioning blocks into an integrated design. Shape memory alloy elastic elements are added to the multi-stage damping assembly to improve thermal expansion compensation and overall reliability.

[0060] Integrated support base 2 and guide positioning block: 6mm thick aluminum alloy plate (6061-T6) is bent into an integral support base with an overall dimension of 650mm × 500mm. A pair of concave positioning grooves (90mm each × 15mm for the upper block) are provided on either side of the center of the bottom surface, with the bottom surface of the groove coplanar with the external base plate. The guide positioning block is cast integrally with the base, and a partially boss-like structure is formed: the boss is 8mm high × 12mm wide × 80mm long, corresponding to the positioning groove at the bottom of the coil, with a positioning accuracy of ±0.3mm. The entire base is anodized for corrosion resistance. Two 30mm × 6mm aluminum profile reinforcement ribs are welded to the inner wall of the base to enhance rigidity. Six 11mm screw holes with φPTFE pads are reserved for installing the adjustable support screw assembly.

[0061] The multi-stage elastic damping assembly 6 includes: a rubber pad 23: the material is a composite layer of NBR and shape memory alloy (SMA) sheets, the rubber thickness is 5mm, the SMA sheet thickness is 1mm, the outer diameter is φ28mm, and the inner hole is φ10.2mm; it is embedded in the end cover boss through a matching positioning ring and does not require screw fixation; a shape memory alloy elastic element: located below the rubber pad 23, and is composed of two Φ3 mm × 50mm long 0Cr18Ni9TiSMA wire and welded in parallel to the base boss. The length is designed to maintain a superelastic state at 20°C and can automatically adjust the preload force within the range of 20-80°C to provide thermal compensation. Metal coil spring 24: TN101 titanium alloy, wire diameter 4mm, outer diameter 16mm, height 22mm, stiffness 30N / mm; the upper end clamps the lower end of the shape memory alloy elastic element, and the lower end is clamped into the bottom groove of the silicone grease damping block 25; Silicone grease damping block 25: shell material 1.2mmSUS304, stainless steel bending; inner diameter φ16mm, height 18mm; filled with 45000cSt medical grade silicone grease; the upper end fits with the metal coil spring 24, the lower end boss φ10mm×height 5mm, docks with the screw 3, and is locked with a φ10mm×φ16mm×2mm stainless steel washer and a nylon locking nut;

[0062] The shape memory alloy elastic element has the superelastic performance of a coil compression spring at 20-80℃. It not only provides an elastic stiffness of 35N / mm at room temperature, but also automatically restores its shape and maintains a certain preload as the temperature rises, offsetting the deflection caused by thermal expansion of the coil; the titanium alloy spring can still maintain stable stiffness in a high temperature environment (80℃), while taking into account light weight and corrosion resistance; the integrated aluminum alloy base is combined with the guide positioning block to simplify the installation process, eliminating the need for additional alignment operations during installation, and saving 20% ​​of the working hours of the coil compression spring; since the materials are all made of corrosion-resistant aluminum alloy, 316L stainless steel, and SUS304 stainless steel, the entire device can adapt to operating conditions of -40℃ to 120℃, and is suitable for use in corrosive environments such as coastal areas and chemical plants; the three-stage damping coupling design has an 85% vibration absorption efficiency in the full frequency band of 0-300Hz, effectively reducing noise and extending the service life of the transformer.

[0063] Working Principle: When the high-voltage foil coil 5 is powered on, it will generate electromagnetic excitation and thermal expansion, which concentrates stress in the axial direction. The helical compression spring 20 provides primary buffering for the axial micro-vibration. The rubber pad 23, metal helical spring 24, and silicone grease damping block 25 in the multi-stage elastic damping assembly 6 are connected in series to achieve step-by-step energy absorption and attenuation from low to high frequencies, preventing vibration from being directly transmitted to the transformer box.

[0064] The sidewalls of the coil 5 are susceptible to radial impact and displacement. The segmented annular clamping seat surrounds the sidewalls of the coil 5 with multiple sector-shaped clamping blocks 9. Adjustable pull rods 22 link the sector-shaped clamping blocks 9 with silicone grease damping blocks 25, providing uniform elastic restraint against radial vibration. An internal PTFE liner 11 reduces friction, and elastic impact pads 12 absorb transient impact energy, attenuating radial vibration in steps and feeding it back to the multi-stage damping system for further attenuation.

[0065] The guide positioning block performs preliminary radial and horizontal bidirectional positioning of the coil 5 during the assembly stage to ensure the positioning accuracy of the coil 5; at the same time, the spiral compression spring 20 and the multi-stage elastic damping component 6 have a movable buffer stroke when the temperature changes, which can automatically compensate for the slight displacement of the coil 5 caused by thermal expansion and contraction, ensuring a stable connection without sticking.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A vibration-proof fixing device for a high-voltage foil-wound new process dry-type transformer, comprising a support base (2), an adjustable support screw assembly and a multi-stage elastic damping assembly (6), characterized in that: The support base (2) is used to be fixed to the bottom (1) of the transformer box and to carry the coil (5); the lower end of the adjustable support screw assembly is connected to the support base (2); the multi-stage elastic damping assembly (6) is arranged in series between the adjustable support screw assembly and the coil end cover (4) and is used to absorb the axial vibration generated by the coil (5) during operation; the side wall of the coil (5) is installed with an annular clamping seat, and the annular clamping seat is connected to the multi-stage elastic damping assembly (6) and is used to radially constrain the coil (5) and absorb radial vibration; a guide positioning block is installed between the bottom of the coil (5) and the support base (2); the guide positioning block is used to perform preliminary positioning and limiting of the coil (5) in radial and horizontal directions; The adjustable support screw assembly comprises: a screw (3), a pre-tightening nut (18), a spring pre-load assembly and an elastic sealing sleeve (19); The screw (3) is a galvanized threaded steel rod with a diameter of 12 mm, the preload nut (18) is an M12×1.25 hexagonal nut, the spring preload assembly is sleeved outside the screw (3) and is used to generate a continuous preload force between the preload nut (18) and the support base (2), and the elastic sealing sleeve (19) is sleeved outside the screw to prevent dust and limit the lateral swing of the spring preload assembly; The multi-stage elastic damping component (6) comprises, from top to bottom: The rubber cushion layer (23) is made of hydrogenated nitrile rubber, has a hardness of 60 Shore A, a thickness of 5-8 mm, a hollow inner hole that matches the diameter of the screw (3), and is fixed to the bottom boss of the coil end cover (4) by screws; The metal coil spring (24) is made of carbon steel, has a wire diameter of 5 mm, an outer diameter of 20 mm, a height of 25 mm, and is nickel-plated. The upper end of the spring is engaged with the lower surface of the rubber pad (23) through a plastic retaining ring (8), and the lower end is clamped in the bottom notch of the silicone grease damping block (25); The silicone grease damping block (25) comprises a damping unit consisting of a 1.5 mm thick sheet metal shell and internal silicone grease, and has an appearance similar to an oil pressure damping cylinder without a piston, wherein the upper plane is fitted on the lower end of the metal coil spring (24), and the lower part is connected to the screw (3) via a fixed boss.

2. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 1 is characterized in that: The support base (2) is formed by bending a cold-rolled steel plate with a thickness of 4-8 mm. The support base (2) is provided with transverse reinforcing ribs inside to improve the rigidity. The surface of the support base (2) is sprayed with epoxy zinc-rich primer and polyurethane topcoat after phosphating. A plurality of screw holes are reserved on the support base (2) for installing an adjustable support screw assembly, and grooves (17) for inserting guide positioning blocks are opened at corresponding positions.

3. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 1 is characterized in that: The spring preload assembly comprises: The helical compression spring (20) is made of nickel-plated carbon steel wire with a wire diameter of 5 mm, an outer diameter of 20 mm, and a free length of 30 mm. One end of the helical compression spring is pressed against the bottom surface of the pre-tightening nut (18), and the other end is pressed against the support base (2). An anti-loosening washer (21) is placed between the pre-tightening nut (18) and the support base (2), and the toothed structure of the anti-loosening washer (21) generates friction under vibration conditions to prevent the pre-tightening nut (18) from loosening; When the pre-tightening nut (18) is tightened to the designed position, the helical compression spring (20) generates a pre-compression of 5-10 mm, so that the clamping force between the pre-tightening nut (18) and the screw (3) is maintained, and the axial micro-vibration is buffered at the same time.

4. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 1 is characterized in that: The elastic sealing sleeve (19) is made of chloroprene rubber, with its lower end clamped on the positioning step of the support base (2), and its upper end affixed to the bottom circumference of the pre-tightening nut (18) along the outer surface of the screw (3), forming a closed dustproof structure and laterally constraining the helical compression spring (20) when the helical compression spring (20) is subjected to a lateral force.

5. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 1 is characterized in that: The annular clamping seat is composed of six equally divided sector-shaped clamping blocks (9), each sector-shaped clamping block (9) comprising: A U-shaped groove (10) is provided on one side wall for the side wall of the environmentally friendly foil winding coil (5); A 2mm thick PTFE pad (11) is attached to the inner side of the U-shaped groove (10) to reduce friction, and a 3mm thick elastic impact cotton block (12) is embedded at the bottom of the U-shaped groove (10) to absorb impact; At least two bolt holes (13) are provided on the outer side for being fixed with bolts to the connecting plate (26) to form a complete annular structure; The fan-shaped clamping blocks (9) are joined together by bolt buckles (7) with an included angle of 60°.

6. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 5, characterized in that: The connecting plate (26) is a rectangular steel plate, one end of which is connected to the outer bolt hole (13) of the fan-shaped clamping block (9) through an M8 bolt, and the lower end is connected to the upper fixed boss of the silicone grease damping block (25) through a pull rod (22). The pull rod (22) is an M8×160-200mm screw, equipped with a spring washer and a nylon locking nut to adjust the radial preload of the annular clamping seat on the side wall of the coil (5).

7. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 1 is characterized in that: The guide positioning block includes an upper block (15) and a lower block (16): The upper block (15) is an annular positioning piece made of injection-molded PA66 material, which is installed on the bottom edge of the coil (5) and fits with the bottom surface of the coil (5) to achieve radial positioning; The lower block (16) is a concave positioning piece made of corresponding PA66 material, embedded in the reserved groove (17) of the support base (2), and cooperates with the upper block (15) to achieve horizontal limit; The guide positioning blocks are matched with each other in shape so that the coil (5) automatically obtains radial and horizontal dual positioning during installation.

8. The vibration-proof fixing device for a high-voltage foil-wound dry-type transformer according to claim 6, characterized in that: The pre-tightening nut on the adjustable support screw assembly and the locking nut on the pull rod (22) of the annular clamping seat are both adjustable so that the pre-compression deformation of the multi-stage elastic damping assembly (6) and the annular clamping seat is maintained in the range of 5-10 mm, thereby ensuring that the transformer has sufficient vibration isolation margin and thermal expansion compensation capability during operation.

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