A shape memory alloy anti-loosening washer made of iron-chromium-nickel-titanium alloy and the equipment using the anti-loosening washer.

Abstract

This utility model belongs to the technical field, specifically relating to an anti-loosening washer and a device using it. The problem this utility model aims to solve is: how to effectively prevent loosening caused by dynamic load bolts. To solve the above technical problem, this utility model provides the following technical solution: an iron-chromium-nickel-titanium shape memory alloy anti-loosening washer, composed of at least one pair of single iron-chromium-nickel-titanium shape memory alloy washers with shared teeth. The front of each washer has 31-180 radially evenly distributed outward serrations, and the back of each washer has 12-60 internal cams evenly distributed. The backs of two single washers are connected by shared teeth. A through hole for the bolt to pass through is opened at the center of each washer. The distance between each outward serration at the inner diameter is 1mm. The inclination angle α of the internal cams is greater than the thread helix angle, with α ranging from 28° to 30°, and the thread helix angle ≤ 10°.

Description

Technical Field

[0001] This utility model belongs to the technical field, specifically relating to an anti-loosening washer and a device for using the anti-loosening washer. Background Technology

[0002] Bolts are a common structural component used to fasten and connect metal parts. In use, a bolt is passed through a hole in one metal part and then inserted into a threaded hole in another metal part. Tightening the bolts engages the threads, thus achieving a connection and fixation. However, bolts can loosen under dynamic loads. For such structures, it is necessary to enhance the reliability of bolt fastening to prevent loosening or even detachment due to vibration and dynamic loads, which could lead to the separation of metal parts and cause various malfunctions and safety hazards. Existing technologies primarily employ the following two categories to address bolt loosening issues: Currently, there are two main types of anti-loosening methods on the market: The first type is detachable anti-loosening, which includes friction anti-loosening and mechanical anti-loosening.

[0003] Friction locking mechanisms include the use of washers, self-locking nuts, and double nuts. They primarily utilize the friction generated by rotation between the threaded parts to prevent bolt loosening. While easy to install, with increasing vibration, the bolt preload decreases, eventually leading to bolt loosening and potential accidents or hazards.

[0004] Mechanical anti-loosening methods include the use of cotter pins, locking washers, slotted nuts, and wire ropes. They primarily utilize mechanical principles to prevent bolt loosening. However, they are characterized by complex installation, high cost, cumbersome disassembly, and high reinstallation costs after disassembly.

[0005] The second type is non-removable anti-loosening. This includes spot welding, riveting, punching, and bonding. This method involves using spot welding, riveting, punching, or bonding after tightening the nut to render the threaded pair non-removable, eliminating its movement characteristics. The disadvantage of this method is that the threaded pair can only be used once, and disassembly is extremely difficult, requiring damage to the threaded pair for removal. Utility Model Content

[0006] The problem this invention aims to solve is: how to effectively prevent loosening caused by dynamic load bolts.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution: In one aspect, this utility model provides an iron-chromium-nickel-titanium shape memory alloy anti-loosening washer, which is composed of at least one pair of iron-chromium-nickel-titanium shape memory alloy single-piece washers with common teeth. The front of the single-piece washer is provided with 31-180 radially outward serrations evenly distributed in a radial pattern, and the back of the single-piece washer is provided with 12-60 internal cams evenly distributed. The backs of the two single-piece washers are connected by common teeth. A through hole for bolts to pass through is opened at the center of the single-piece washer. The distance between each outward saw tooth at the inner diameter of the outward saw teeth is 1mm; The tilt angle α of the internal cam is greater than the thread helix angle, with α ranging from 28° to 30° and the thread helix angle ≤ 10°; the hardness of a single washer is greater than the hardness of its contact surface.

[0008] In some embodiments, the material thickness of a single washer is 1.0mm-4.5mm.

[0009] In some embodiments, the single washer is bent at more than 35° and does not completely break on both sides.

[0010] In some embodiments, the width of a single washer includes the width of a standard washer and the width of a large outer diameter washer, wherein the width of the large outer diameter washer is one-half larger than the width of the standard washer.

[0011] In some embodiments, the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer has a tensile strength of 1000MPa-1200MPa, including the endpoint values.

[0012] In some embodiments, the working temperature range of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is -196℃ to 1000°.

[0013] In some embodiments, the hardness of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is 52 Vickers hardness.

[0014] Secondly, this utility model provides a device using an iron-chromium-nickel-titanium shape memory alloy anti-loosening washer, comprising the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer as described above, as well as a bolt and a nut. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer and the nut are connected together on the bolt, and the hardness of the contact surface between the nut and the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is less than the hardness of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer; the thread helix angle of bolt loosening is less than the tilt angle α of the internal cam.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy. Utilizing its material memory, high strength, high corrosion resistance, and biocompatibility, and provided the contact surface strength does not exceed the hardness of the iron-chromium-nickel-titanium alloy, it effectively prevents dynamic load bolts from loosening by employing the interlocking of internal cams with shared teeth on the reverse side and the increased friction from the external radial serrations. This achieves an anti-loosening and locking effect, applicable to all bolt grades and with a wide range of applications, especially in aerospace, defense equipment, marine engineering, shipbuilding, and railway industries. Furthermore, it requires no maintenance, saving significant labor and material costs, as well as potential future risks, and preventing property damage or even personal injury.

[0016] Currently, the thread helix angle required for high-precision bolts is within 10°. The internal cam tilt angle α of this invention is in the range of 28°-30°, which is greater than the thread helix angle. It has an angle that meets the high precision requirements of bolts and can effectively prevent bolt loosening caused by the increase of thread slope.

[0017] Large-diameter iron-chromium-nickel-titanium alloy sawtooth anti-loosening washers with 31-180 radial sawtooths can effectively engage with the contact surface to increase the friction of the end face. Any loosening of the bolt must overcome the friction between its large-diameter radial sawtooths and the contact surface. If the loosening of the bolt overcomes the friction between the large-diameter bolt sawtooths and the contact surface, its internal 12-60 cams form a second anti-loosening defense line. The bolt loosening must also overcome the second anti-loosening defense line. The internal cams undergo planar displacement, causing the cams to lift. Since the thread helix angle of the loosened bolt is less than the internal cam angle α, the nut will not loosen, thus achieving the anti-loosening locking effect.

[0018] This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy, with controllable pre-tightening force that is not affected by the friction of the contact surface.

[0019] This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy, whose locking effect is not affected by the lubricant on the contact surface.

[0020] This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy, which is easy to install and disassemble, can be reused, and maintains its quality.

[0021] This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy, which has better temperature adaptability.

[0022] This utility model provides a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy. When connected with bolts and / or nuts, the outer radial serrations tightly bite the contact surface when the bolts and / or nuts are tightened, increasing the friction between the washer and the contact surface and the nut. The inner cams interlock, fixing the anti-loosening washer in place. Any tendency to loosen is prevented by the interlocking effect of the outer radial serrations and the inner cams. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer of this utility model; Figure 2 This is a schematic diagram of the front structure of the monolithic washer of this utility model; Figure 3 This is a schematic diagram of the reverse side of the monolithic washer of this utility model; Figure 4 This is a schematic diagram of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer of this utility model from the front view direction; Figure 5 The vibration test comparison diagram shows the connection when using the iron-chromium-nickel-titanium shape memory alloy sawtooth anti-loosening washer of Example 1, and the safety performance test when not using this component or using other loosening components.

[0024] Figure label: 1. Single-piece washer; 11. Outward serrations; 12. Internal cam; 13. Through hole. Detailed Implementation

[0025] The technical solution of this utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of this utility model. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] It should be noted that the terms "center", "upper", "lower", "horizontal", "left", "right", "front", "back", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Example 1 Combination Figures 1-4As shown, this embodiment provides a shape memory alloy anti-loosening washer, which is composed of at least one pair of single iron-chromium-nickel-titanium shape memory alloy washers 1 with common teeth. The front of the single washer 1 is provided with 31-180 radially outward serrations 11 evenly distributed in a radial pattern, and the back of the single washer 1 is provided with 12-60 internal cams 12 evenly distributed. The backs of the two single washers 1 are connected by common teeth; a through hole 13 for bolts to pass through is opened at the center of the single washer 1. The distance between each outward sawtooth 11 at the inner diameter is 1mm; The tilt angle α of the internal cam 12 is greater than the thread helix angle, and the range of α is 28°-30°, while the thread helix angle is ≤10°.

[0028] This invention relates to a serrated anti-loosening washer made of iron-chromium-nickel-titanium shape memory alloy. Iron-chromium-nickel-titanium shape memory alloy is a type of shape memory alloy. Based on an iron (Fe) metal, different metal formulations are added in stages at different melting temperatures and times. This alloy material possesses material memory function, high strength (tensile strength up to 1200 MPa), and exhibits high strength, excellent corrosion resistance and fatigue resistance, good compatibility with other materials, no diffusion-shear phase transformation, good thermal stability, and good machinability. Its high strength ensures the reliability of the washer. However, it is important to note that this washer should not be used if the strength of the contact surface material is less than the strength of the iron-chromium-nickel-titanium alloy anti-loosening washer.

[0029] Provided that the contact surface strength does not exceed the hardness of the iron-chromium-nickel-titanium alloy material, the product effectively prevents the dynamic load bolt from loosening by utilizing the principle of the interlocking of the internal cams 12 and the interlocking of the external radial outward sawtooth 11 with the contact surface to increase the friction. This achieves the effect of anti-loosening and locking, and is applicable to all bolt grades. It has a wide range of applications, especially in special fields such as aerospace, defense equipment, marine engineering, shipbuilding, and railways.

[0030] Iron-chromium-nickel-titanium shape memory alloy is an iron-based material with shape memory properties. While retaining the shape memory characteristics of iron-chromium-nickel-titanium alloys, it incorporates other metals to enhance its hardness, toughness, corrosion resistance, ductility, and machinability. This alloy possesses shape memory, high strength (tensile strength up to 1200 MPa), excellent corrosion resistance and fatigue resistance, good thermal stability, and good machinability. The M24 monolithic washer 1 sample remained intact after a 1000-hour salt spray test, demonstrating its corrosion resistance.

[0031] The working temperature range of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is -196℃ to 1000℃. This working temperature range can meet the temperature range of any region in China. The main reason is that during the slow heating process of its crystallization, each metal atom has enough time to fill every gap. At this time, its arrangement is the tightest. Therefore, it has an unparalleled advantage over other anti-loosening methods. Its superior performance is satisfactory in anti-loosening effect.

[0032] To ensure the biting force and friction of the outward-facing saw teeth 11, the distance between each outward-facing saw tooth 11 at the inner diameter is 1mm, arranged radially, and the number of outward-facing saw teeth 11 ranges from 31 to 180; serving as the first line of defense against loosening. The number of internal cams 12 ranges from 12 to 60, used to construct the second line of defense against loosening.

[0033] The iron-chromium-nickel-titanium shape memory alloy sawtooth anti-loosening washer of this utility model has an angle that meets the high precision requirements of bolts, wherein the tilt angle α of the internal cam 12 is in the range of 28°-30°. Currently, the thread helix angle required for high precision bolts is within 10°. The iron-chromium-nickel-titanium shape memory alloy sawtooth anti-loosening washer of this utility model can effectively prevent bolt loosening caused by the increase of thread slope.

[0034] The material thickness of single-piece washer 1 is 1.0mm-4.5mm. Single-piece washer 1 is bent at more than 35° and does not completely break on both sides.

[0035] The width of a single washer 1 includes the width of a standard washer and the width of a large outer diameter washer, with the large outer diameter washer being half the width of the standard washer. For applications with high vibration, large outer diameter washers are used, and all large outer diameter washers are half the width of the standard washer to completely cover the nut installation dimensions, ensuring the engagement force and friction between the outward serrations 11 and the nut.

[0036] The number of cams inside the iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers ranges from 12 to 60, suitable for left-hand or right-hand bolt applications, and applicable to all bolt sizes and grades.

[0037] This utility model uses iron-chromium-nickel-titanium shape memory alloy anti-loosening washers. The front of the outward serrations 11 are used to contact the end face of the nut. A pair of single washers 1 are installed with common teeth. Iron-chromium-nickel-titanium alloy serrated anti-loosening washers can be installed at both ends of nuts with through holes. For working conditions with strong vibration, two pairs of single washers 1 can be used to deepen the engagement of the radial outward serrations 11 on the end face, thereby increasing the friction and achieving a better anti-loosening effect, reducing loosening caused by vibration.

[0038] The large-diameter iron-chromium-nickel-titanium alloy sawtooth anti-loosening washer with 31-180 radial outward sawtooths 11 can effectively engage with the contact surface to increase the friction of the end face. Any loosening of the bolt must overcome the friction between its large-diameter radial sawtooths and the contact surface. If the loosening of the bolt overcomes the friction between the large-diameter outward sawtooths 11 and the contact surface, its internal 12-60 cams form a second anti-loosening defense line. The bolt loosening must also overcome the second anti-loosening defense line. The internal cam 12 undergoes planar displacement, causing the cam to lift. Since the thread helix angle of the loosened bolt is less than the α angle of the internal cam 12, the nut will not loosen, thus achieving the anti-loosening locking effect.

[0039] The large-diameter iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer can increase the engagement with the nut and the contact surface, and increase the friction. Compared with the previous Chinese patent CN205823882U, entitled "A Shape Memory Alloy Anti-Loosening Washer", the large-diameter iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer of this utility model has a large outer diameter area increased by half. At the same time, due to the material upgrade, the material hardness is higher, so the friction with the nut and the contact surface is greater. The friction can be calculated by the formula F = µ*N (µ is the coefficient of friction, N is the normal force).

[0040] When disassembling the iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer, it is necessary to overcome the lifting distance of the internal cam 12. Therefore, the disassembly torque is often greater than the locking force. Generally, when disassembling the iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer, a "click" sound can be heard, indicating that the lifting distance of the internal cam 12 has been overcome. This can be verified by the radial serrated indentation between the washer and the nut.

[0041] When using a standard nut with a large-diameter iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer: the indentation is widely distributed, and the contact surface is slightly deformed; when using a flange nut with a large-diameter iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer: the indentation is widely distributed, and the deformation of the contact surface is minimized, making it the best solution.

[0042] Based on the Junker vibration testing principle, a vibration testing device was used to conduct safety performance tests on the connection points when using the iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer, as well as when not using this component or using other loosening components. The experimental results are as follows: Figure 5 As shown. The Junker vibration test, conforming to DIN 65151, is an excellent method for testing and comparing the safety of bolted connections. In the Junker vibration test, the bolt is forced to move laterally, and the clamping force is continuously measured by a load sensor.

[0043] Vibration test Figure 5 This shows the clamping force of bolts during vibration testing of common fasteners. Most commonly used locking devices today have very limited performance under vibration.

[0044] Vibration tests on the iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers showed good results, although the clamping force initially decreased due to the normal sinking of the contact surface. When the nut was removed with a wrench, the clamping force increased significantly, demonstrating the washer's superior locking function.

[0045] Example 2 A device using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a rigid contact rail, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts pass through the rigid contact rail, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the rigid contact rail, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the rigid contact rail.

[0046] An M12-sized iron-chromium-nickel-titanium shape memory alloy anti-loosening washer was used. When tested and compared with an ordinary washer, the ordinary washer loosened, while the iron-chromium-nickel-titanium alloy serrated anti-loosening washer of this invention did not move, and the locking force was equal to the pre-tightening force.

[0047] Example 3 An apparatus using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a flexible contact wire, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts are inserted through the flexible contact wire, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the flexible contact wire, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the flexible contact wire.

[0048] A trial of M12-sized iron-chromium-nickel-titanium shape memory alloy anti-loosening washers at the flexible contact network connection points of a certain subway line lasted for 6 months, and not a single case of loosening was observed. Compared with the original ordinary washers for anti-loosening, this significantly saved a lot of labor costs and potential risks, demonstrating remarkable effectiveness.

[0049] Example 4 A device using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a rail transit cantilever arm, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts are inserted through the rail transit cantilever arm, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the rail transit cantilever arm, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the rail transit cantilever arm.

[0050] A rail transit cantilever arm was tested for 6 months with an M10 iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer. No loosening was observed, the locking force and preload were maintained, and there was no displacement of the red line.

[0051] Example 5 A device using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a turnout, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, nuts, and spring washers. The bolts are inserted into the turnout, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the turnout, and / or at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the turnout. A spring washer is also provided, which contacts the turnout, and the nut contacts the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer.

[0052] After the improvement of a certain turnout, M24 size iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers were used; before the improvement, spring washers and double nuts were used for anti-loosening, and the bolts needed to be checked frequently for loosening due to vehicle vibration; after the improvement, the bolts did not loosen, and the problem was solved.

[0053] Example 6 A device using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes heavy equipment and iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, nuts, cotter pins, and spring washers. The bolts are inserted into the heavy equipment, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the heavy equipment, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer and spring washer are provided between the nut and the heavy equipment, the spring washer is in contact with the nut, and the heavy equipment is in contact with the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer. The cotter pin is inserted at the end of the bolt closest to the nut.

[0054] Before the improvement, the anti-loosening product used on a certain heavy equipment was cotter pin + flat washer + spring washer, which often came loose and caused equipment failure. After the improvement, M16 size iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers were used. It has been installed for more than a year and has not come loose.

[0055] Example 7 An apparatus using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a heavy-duty truck frame, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts are inserted through the connection points of the heavy-duty truck frame, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the connection point of the heavy-duty truck frame, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the connection point of the heavy-duty truck frame.

[0056] After installing M24 size iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers at the frame connection of a heavy truck, the heavy truck underwent a three-month road test without any loosening.

[0057] Example 8 An apparatus using a shape memory alloy anti-loosening washer made of iron-chromium-nickel-titanium alloy includes a heavy-duty truck axle, a shape memory alloy anti-loosening washer made of iron-chromium-nickel-titanium alloy, a bolt, and a nut. The bolt is inserted through the connection of the heavy-duty truck axle, and the nut is fitted onto the bolt and connected to the bolt. At least one shape memory alloy anti-loosening washer is provided between the bolt head and the connection of the heavy-duty truck axle, and / or at least one shape memory alloy anti-loosening washer is provided between the nut and the connection of the heavy-duty truck axle.

[0058] The axle connection of a heavy truck originally used double nuts and flat washers to prevent loosening, but they were prone to coming loose. After using M16 size iron-chromium-nickel-titanium alloy serrated anti-loosening washers, they did not come loose, and the problem was solved.

[0059] Example 9 An apparatus using a shape memory alloy anti-loosening washer of iron-chromium-nickel-titanium alloy includes an air compressor, an iron-chromium-nickel-titanium shape memory alloy anti-loosening washer, a bolt, and a nut. The bolt passes through the air compressor, and the nut is fitted onto the bolt and connected to it. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the air compressor, and / or at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the air compressor.

[0060] An air compressor bolt was fitted with an M10 size iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer, and after 6 months of testing, it remained secure.

[0061] Example 10 An apparatus using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a power plant chiller unit, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts are inserted into the base of the power plant chiller unit, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the base of the power plant chiller unit, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the base of the power plant chiller unit.

[0062] The base of a power plant chiller unit was previously equipped with ordinary washers for anti-loosening, which caused bolts to loosen due to vibration. After the improvement, M16 iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washers were used, and the bolts did not loosen, thus solving the problem.

[0063] Example 11 A device using iron-chromium-nickel-titanium shape memory alloy anti-loosening washers includes a vertical suspension motor, iron-chromium-nickel-titanium shape memory alloy anti-loosening washers, bolts, and nuts. The bolts pass through the vertical suspension motor, and the nuts are fitted onto the bolts and connected to them. At least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the bolt head and the vertical suspension motor, and / or, at least one iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is provided between the nut and the vertical suspension motor.

[0064] A vertically suspended motor for a certain piece of equipment previously used an M36 double nut and cotter pin anti-loosening mechanism, which exhibited loosening issues. After the improvement, a single nut and an M16 iron-chromium-nickel-titanium shape memory alloy serrated anti-loosening washer were used. After six months of testing, no loosening was observed. The improved anti-loosening structure shortened the stud, saving significant costs and labor. The above technical features constitute the preferred embodiment of this utility model, which has strong adaptability and optimal implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0065] Finally, it should be noted that the above content is only used to illustrate the technical solution of this utility model, and is not intended to limit the scope of protection of this utility model. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model do not depart from the essence and scope of the technical solution of this utility model.

Claims

1. A shape memory alloy anti-loosening washer, characterized in that, It consists of at least one pair of iron-chromium-nickel-titanium shape memory alloy single-piece washers with common teeth. The front of the single-piece washer is provided with 31-180 radially outward serrations evenly distributed in a radial pattern, and the back of the single-piece washer is provided with 12-60 internal cams evenly distributed. The back of the two single-piece washers are connected by common teeth. A through hole for bolts to pass through is opened at the center of the single-piece washer. The distance between each outward saw tooth at the inner diameter of the outward saw teeth is 1mm; The tilt angle α of the internal cam is greater than the thread helix angle, with α ranging from 28° to 30° and the thread helix angle ≤ 10°; the hardness of a single washer is greater than the hardness of its contact surface.

2. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, The material thickness of a single washer is 1.0mm-4.5mm.

3. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, A single washer is bent at more than 35° and partially breaks on both sides.

4. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, The width of a single washer includes the standard washer width and the width of the large outer diameter washer, which is half the width of the standard washer.

5. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, The tensile strength range of iron-chromium-nickel-titanium shape memory alloy anti-loosening washers is 1000MPa-1200MPa.

6. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, The working temperature range of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is -196℃ to 1000℃.

7. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer according to claim 1, characterized in that, The hardness of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is 52 on the Vickers scale.

8. A device using an iron-chromium-nickel-titanium shape memory alloy anti-loosening washer, characterized in that, The invention includes the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer as described in any one of claims 1-7, as well as a bolt and a nut. The iron-chromium-nickel-titanium shape memory alloy anti-loosening washer and the nut are connected together on the bolt, and the hardness of the contact surface between the nut and the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer is less than the hardness of the iron-chromium-nickel-titanium shape memory alloy anti-loosening washer; the thread helix angle of bolt loosening is less than the tilt angle α of the internal cam.

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