Multi-fiber composite friction plate material for wind power brake

Abstract

The invention discloses a multi-fiber composite friction plate material for a wind power brake, which comprises a composite friction plate used for friction braking in the wind power brake; the composite friction plate is provided with a three-dimensional network reinforcing structure, the three-dimensional network reinforcing structure is formed by a first fiber layer and a second fiber layer through gradient distribution, a fiber weaving and particle interlocking structure is formed between the first fiber layer and the second fiber layer, and the fiber weaving density is gradually increased layer by layer. And the material performance of the brake friction plate is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of friction materials, and particularly to a multi-fiber composite friction plate material for a wind power brake. Background Art

[0002] In the context of the continuous rise in the global demand for clean energy, wind power generation, as an important way of renewable energy utilization, has achieved large-scale application. As the core mechanism to ensure the stable operation of wind turbine units, the performance of the brakes in the pitch and yaw systems of wind turbines directly determines the system safety and operation reliability. It is worth noting that the existing friction plate material systems applied to the brakes in the pitch and yaw systems of wind turbines have significant technical bottlenecks in key indicators such as extreme temperature tolerance, wear resistance, and braking stability, and it has been difficult to meet the high-speed development needs of the wind power industry.

[0003] In the wind power generation technology system, the precise control of the pitch and yaw systems is an important prerequisite for ensuring the efficient operation of the units. As the core actuating element of this system, the performance parameters of the brakes are directly related to the operation safety and power generation efficiency of the units. The friction plate materials of the brakes commonly used in the current industry have exposed several technical defects that need to be solved urgently in actual working conditions.

[0004] The primary problem is reflected in the environmental sensitivity of the friction coefficient. Given the extreme characteristics of the operating environment of wind turbine units, the dynamic friction coefficient of traditional friction materials shows significant non-linear changes under conditions of sudden temperature changes (-30°C to 50°C) and relative humidity fluctuations (60%-95%RH). Specifically, in the low-temperature and high-humidity working conditions, the friction coefficient can drop by 30%-40%, resulting in unstable output of braking torque and seriously affecting the accuracy of blade angle adjustment and the accuracy of yaw positioning.

[0005] Secondly, there are obvious shortcomings in the wear resistance and service life of the materials. According to the wind farm operation and maintenance data, under the working conditions of typical annual 2000 pitch operations and 150 yaw adjustments, a wear layer of ≥0.5mm appears on the surface of the traditional friction plate after 500 hours of operation, and scaly peeling and groove wear occur in local areas, resulting in the average effective braking times of the friction plate only maintaining 80 to 100 cycles, significantly increasing the annual maintenance frequency by 4-6 times, and reducing the unit availability by about 15%.

[0006] In addition, the thermal fade characteristics of the materials pose a major safety hazard. Laboratory bench tests show that under continuous braking conditions, the temperature gradient at the friction interface can reach 120-150°C / min. When the friction surface temperature exceeds the threshold of 80°C, the braking efficiency of traditional materials shows an exponential decay, and the friction coefficient decay rate exceeds 45%, posing a risk of braking failure. Therefore, a new multi-fiber composite friction plate for wind power brakes has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0007] This application provides a multi-fiber composite friction plate material for a wind power brake, including:

[0008] A composite friction plate for friction braking in a wind power brake;

[0009] The composite friction plate is provided with a three-dimensional network reinforcement structure, which is formed by the gradient distribution of a first fiber layer and a second fiber layer. A fiber braiding and particle interlocking structure is formed between the first fiber layer and the second fiber layer, and the fiber braiding density increases layer by layer.

[0010] Optionally, the composite friction plate contains the following components by mass percentage:

[0011] Phenolic resin 20-30%, elastic rubber 10-15%, first fiber layer 7-12%, second fiber layer 8-15%, steel fiber 5-10%, copper fiber 5-10%, graphite 3-7%, calcium carbonate 10-20%, and the balance is impurities.

[0012] Optionally, the first fiber layer is basalt fiber.

[0013] Optionally, the second fiber layer is carbon fiber.

[0014] Optionally, the nitrile rubber and the phenolic resin form a rigid-elastic interpenetrating network, improving the wear resistance and heat fade resistance of the friction plate and ensuring the stable performance of the wind power brake under extreme working conditions.

[0015] Optionally, the ratio range of the graphite to the calcium carbonate is 1:3 to 1:3.3.

[0016] Optionally, the elastic material is nitrile rubber.

[0017] This application also provides a multi-fiber composite friction plate material for a wind power brake. In a storage device, phenolic resin 30%, nitrile rubber 10%, basalt fiber 7%, carbon fiber 15%, steel fiber 5%, copper fiber 10%, graphite 3%, and calcium carbonate 20% are prefabricated as preparation materials. 7% of basalt fiber and 15% of carbon fiber are added to a preparation device for stirring to form a fiber braiding and particle interlocking structure and a three-dimensional network reinforcement architecture. Then, 20%-30% of phenolic resin, 5-10% of steel fiber, 5-10% of copper fiber, 3-7% of graphite, and 10-20% of calcium carbonate are added to the mixture of 7% of basalt fiber and 15% of carbon fiber and stirred until the mixture is completely fused. Finally, 10-15% of elastic rubber is added to form a rigid-elastic interpenetrating structure between the mixture and the elastic rubber. The prepared solution is used as a material for pressing the friction plate.

[0018] The beneficial effects of the present application are as follows:

[0019] 1. Multi-fiber synergistic reinforcement: Through the gradient distribution of basalt fibers (with high temperature resistance characteristics) and carbon fibers (with high thermal conductivity), a three-dimensional network structure is formed, effectively improving the strength and thermal conductivity of the material in high-temperature environments; at the same time, the combined use of steel fibers (providing high hardness) and copper fibers (with good ductility) optimizes the dynamic response ability of the material and helps to inhibit the phenomenon of heat accumulation;

[0020] 2. Matrix modification: Using the rigid-elastic interpenetrating network structure formed by phenolic resin and nitrile rubber significantly enhances the mechanical stability of the material in a wide temperature range;

[0021] 3. Functional filler regulation: Adding a small amount of graphite to reduce friction noise and using calcium carbonate with a microporous structure to adsorb thermal stress, thereby reducing the thermal expansion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a scanning electron microscope photograph of the friction plate at 100 times magnification for the surface morphology analysis of Example 1 of the present invention;

[0023] Figure 2 It is a scanning electron microscope photograph of the friction plate at 500 times magnification for the surface morphology analysis of Example 1 of the present invention

[0024] Figure 3 It is the observation of the scanning electron microscope photograph of the friction plate at 1000 times magnification for the surface morphology analysis of Example 1 of the present invention Figure 1

[0025] Figure 4 It is the observation of the scanning electron microscope photograph of the friction plate at 1000 times magnification for the surface morphology analysis of Example 1 of the present invention Figure 2 . DETAILED DESCRIPTION OF THE INVENTION

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0027] The present invention provides a multi-fiber composite friction plate for a wind power brake, which significantly improves the wear resistance, thermal stability and braking reliability of the friction plate of the wind power brake in a wide temperature range. The present invention forms a three-dimensional network reinforcement structure through the gradient distribution of basalt fibers and carbon fibers, so that the friction layer can still maintain its original strength above 200 °C. At the same time, the interfacial bonding force between the fibers and the matrix is improved, and the wear resistance is increased. In addition, the composite addition of steel fibers and copper fibers further optimizes the dynamic response of the friction interface. The high hardness and anti-shear ability of the steel fibers enhance the instantaneous braking efficiency of the friction plate, while the high thermal conductivity of the copper fibers enables the friction heat to be quickly dissipated, avoiding performance degradation caused by local overheating. The two work together to increase the thermal conductivity, and at the same time, the shedding of hard particles is reduced by the compensation of ductility, effectively prolonging the service life of the friction plate, ensuring stable braking performance under extreme working conditions, and significantly reducing the maintenance frequency.

[0028] At the same time, phenolic resin, as the core component of the matrix, its high proportion ensures the rigid support and dimensional stability of the friction plate under high-temperature working conditions. If the content of phenolic resin is less than 20%, the heat resistance of the matrix is insufficient, which is likely to cause softening at high temperatures. If the content of phenolic resin is higher than 30%, it may lead to an increase in the brittleness of phenolic resin and cause microcracks in a low-temperature environment.

[0029] Therefore, nitrile rubber is added thereto, and the proportion of the added nitrile rubber is 10%-15%. The nitrile rubber has elastic characteristics, neutralizes the brittleness of phenolic resin, and endows the matrix with impact resistance at a low temperature of -40 °C. The synergistic ratio of the phenolic resin and the nitrile rubber forms a rigid-elastic interpenetrating network. Phenolic resin, as a thermosetting material, generates a highly cross-linked rigid three-dimensional network through a polycondensation reaction during the curing process. This network has high modulus and high temperature resistance, but is relatively brittle. The nitrile rubber, as an elastic phase, the polar cyano groups of its molecular chains can form hydrogen bond interactions with the hydroxyl groups of phenolic resin. This intermolecular interaction effectively improves the compatibility of the two phases and inhibits macroscopic phase separation. From the microscopic morphology, this interpenetrating network presents a unique structure of "sea-island" and continuous intersection. The rigid phenolic resin forms a continuous phase, while the nitrile rubber is dispersed therein in the form of elastic domains with a scale from nanometers to micrometers, and even forms a double continuous phase in some areas. A transition layer is formed at the interface of the two phases due to hydrogen bond and physical entanglement effects. This strong interfacial binding energy can effectively transfer stress. When the material is subjected to external impact, the rigid phenolic network bears the main load, while the nitrile rubber absorbs energy through the stretching, slipping and cavitation of molecular chains. At the same time, the crack propagation path is repeatedly deflected and passivated by the elastic phase, thus significantly improving the fracture toughness of the material.

[0030] In the reinforcing fiber system, the mass percentages of the basalt fiber and the carbon fiber are 7-12% for the basalt fiber and 8-15% for the carbon fiber respectively, ensuring the structural stability of the fiber network at high temperatures and the flexibility at low temperatures. Moreover, the basalt fiber and the carbon fiber form a three-dimensional network structure with a gradient distribution, effectively improving the comprehensive performance of the friction plate within the wide temperature range from -40°C to 200°C and ensuring the braking reliability in extreme environments.

[0031] The formation method of the three-dimensional network structure is as follows: By laying different proportions of basalt fiber and carbon fiber layer by layer and curing under high temperature and high pressure conditions, the fiber layers are tightly combined to form a dense three-dimensional network structure, further enhancing the overall mechanical properties and thermal stability of the friction plate. This structure not only improves the high-temperature resistance of the friction plate but also ensures its flexibility and impact resistance in low-temperature environments. Thus, within the wide temperature range from -40°C to 200°C, the friction plate can exhibit excellent braking performance and long durability, significantly improving the operation safety and stability of wind power equipment.

[0032] The basalt fiber has the characteristics of high temperature resistance and corrosion resistance and mainly undertakes the structural support function in high-temperature environments. While the carbon fiber enhances the instantaneous braking efficiency and accelerates heat dissipation through a modulus of 200-300 GPa and thermal conductivity. The three-dimensional network structure formed between the two not only avoids the decrease in processing fluidity caused by excessive single fiber but also ensures the stability of the bonding force between the fiber layers and the collective interface, enabling the friction layer to maintain its strength without attenuation at high temperatures and still possess good toughness at low temperatures, effectively dispersing stress and preventing crack propagation.

[0033] In addition, the composite addition of steel fiber (5% - 10%) and copper fiber (5% - 10%) further optimizes the dynamic response of the material. The steel fiber has high strength to enhance the anti-shear ability, while the ductility and thermal conductivity of the copper fiber synergistically inhibit the accumulation of braking heat, increase the overall thermal coefficient, and at the same time reduce the aggravation of wear caused by the shedding of hard particles. The mass ratio between the first functional filler and the second functional filler balances the friction performance and thermal stress.

[0034] The lubricating material is graphite with a mass ratio of 3-7%. Its low proportion setting can not only reduce the fluctuation of the friction coefficient but also avoid the problem of matrix strength attenuation caused by excessive addition. Calcium carbonate with a proportion of 10-20% adsorbs the thermal expansion stress through its microporous structure and reduces the thermal expansion coefficient of the matrix.

[0035] Meanwhile, the graphite and the calcium carbonate can cooperate to remain stable under high-temperature and high-load conditions and reduce braking noise.

[0036] Example 1:

[0037] This application provides a method for preparing a friction plate, which includes mixing basalt fiber, carbon fiber, steel fiber, copper fiber and lubricating material. The mass ratio is 30% phenolic resin, 10% nitrile rubber, 7% basalt fiber, 15% carbon fiber, 5% steel fiber, 10% copper fiber, 3% graphite, and 20% calcium carbonate. After mixing evenly, it is placed in a mold and cured under high temperature and high pressure to ensure that each component is closely integrated, forming a stable three-dimensional network structure, effectively improving the comprehensive performance of the friction plate.

[0038] The following is a comparative test on the friction performance of the friction plate prepared in Example 1:

[0039] 1. Friction and wear test:

[0040] Using a constant-speed friction testing machine, the friction and wear test of the friction plate in Example 1 was carried out according to GB / T 5764-2021.

[0041] The results of the friction and wear test are shown in Table 1. The results show that the friction coefficient of the friction plate in Example 1 meets the national standard requirements. A higher friction coefficient can significantly enhance the braking torque of the brake, reduce the braking time, and improve the braking effect; a stable friction coefficient can provide a stable torque for the brake, improving braking safety. The wear rate of the friction plate in Example 1 is relatively low. A lower wear rate can increase the wear resistance times of the brake, extend the service life of the brake, reduce the risk of dragging brake operation, reduce the maintenance cost of the brake, and thus improve economic benefits.

[0042]

[0043] 2. High and low temperature tolerance test:

[0044] The friction plate prepared in Example 1 was installed on a wind power brake and placed in a thermo-hygrostat chamber. The torque of the brake was tested at room temperature, -20°C, and 120°C respectively, and its attenuation rate was calculated. The test results are shown in Table 2.

[0045]

[0046] The results show that the torque attenuation rate of the brake equipped with the friction plate in Example 1 is 7.37% at -20°C low temperature and 13.36% at 120°C high temperature. Good high and low temperature tolerance can reduce the risk of brake failure in extreme environments, improve braking safety, and extend the service life of the brake.

[0047] Example Two:

[0048] The formula of a wide-temperature-range, high-wear-resistant, multi-fiber composite friction plate for a wind power brake provided in this example is as follows:

[0049] 30% phenolic resin, 10% nitrile rubber, 7% basalt fiber, 15% carbon fiber, 5% steel fiber, 10% copper fiber, 3% graphite, 20% calcium carbonate

[0050] The specific manufacturing process is as follows:

[0051] First, weigh and mix phenolic resin, nitrile rubber, basalt fiber, carbon fiber, steel fiber, copper fiber, graphite, and calcium carbonate in proportion. Subsequently, preheat the mold and press it into shape through a flat vulcanizing machine. Ensure the material density by manual exhaust, and demold after pressure holding. Finally, eliminate internal stress through gradient heat treatment and obtain the finished product by fine grinding.

[0052] Next, conduct a friction performance comparison test on the friction plate prepared in Example 2:

[0053] 1. Friction and wear test:

[0054] Use a constant-speed friction testing machine to conduct a friction and wear test on the friction plate of Example 2 according to GB / T 5764-2021.

[0055] The friction and wear test results are shown in Table 3.

[0056]

[0057] 2. High and low temperature tolerance test:

[0058] Install the friction plate prepared in Example 2 on a wind power brake and place it in a constant temperature and humidity test chamber. Test the torque of the brake and calculate its attenuation rate at room temperature, -20°C, and 120°C respectively. The test results are shown in Table 4.

[0059]

[0060] The results show that the torque attenuation rate of the brake equipped with the friction plate of Example 2 is 4.24% at -20°C low temperature and 13.18% at 120°C high temperature.

[0061] Example Three:

[0062] The formula of a wide-temperature-range, high-wear-resistant, multi-fiber composite friction plate for a wind power brake provided in this example is as follows:

[0063] 25% phenolic resin, 13% nitrile rubber, 10% basalt fiber, 12% carbon fiber, 8% steel fiber, 5% copper fiber, 7% graphite, 20% calcium carbonate

[0064] The specific manufacturing process is as follows:

[0065] First, weigh phenolic resin, nitrile rubber, basalt fiber, carbon fiber, steel fiber, copper fiber, graphite, and calcium carbonate in proportion and mix them evenly. Subsequently, preheat the mold and press it into shape using a flat vulcanizing machine. Ensure the material density by manual exhaust, and demold after pressure holding. Finally, eliminate internal stress through gradient heat treatment and obtain the finished product by fine grinding.

[0066] The following is a friction performance comparison test on the friction plate prepared in Example 3:

[0067] 1. Friction and wear test:

[0068] Use a constant-speed friction testing machine to conduct a friction and wear test on the friction plate of Example 3 according to GB / T 5764-2021.

[0069] The friction and wear test results are shown in Table 5.

[0070]

[0071]

[0072] 2. High and low temperature tolerance test:

[0073] Install the friction plate prepared in Example 3 on a wind power brake and place it in a thermostatic and humidity-controlled test chamber. Test the torque of the brake at room temperature, -20°C, and 120°C respectively and calculate its attenuation rate. The test results are shown in Table 6.

[0074]

[0075] The results show that the torque attenuation rate of the brake equipped with the friction plate of Example 3 is 3.63% at -20°C low temperature and 14.77% at 120°C high temperature.

[0076] Example Four:

[0077] The formula of a wide-temperature-range, high-wear-resistant, multi-fiber composite friction plate for a wind power brake provided in this example is as follows:

[0078] Phenolic resin 29%, nitrile rubber 13%, basalt fiber 12%, carbon fiber 15%, steel fiber 8%, copper fiber 8%, graphite 5%, calcium carbonate 10%

[0079] The specific production process is as follows:

[0080] First, weigh phenolic resin, nitrile rubber, basalt fiber, carbon fiber, steel fiber, copper fiber, graphite, and calcium carbonate according to the proportion and mix them evenly. Subsequently, preheat the mold and press it into shape through a flat vulcanizing machine. Ensure the material density by manual exhaust, and demold after pressure holding. Finally, eliminate internal stress through gradient heat treatment and obtain the finished product by fine grinding.

[0081] The following is a comparative test on the friction performance of the friction plate prepared in Example 4:

[0082] 1. Friction and wear test:

[0083] Use a constant-speed friction testing machine to conduct friction and wear tests on the friction plate of Example 4 according to GB / T 5764-2021.

[0084] The friction and wear test results are shown in Table 7.

[0085]

[0086] 2. High and low temperature tolerance test:

[0087] Install the friction plate prepared in Example 4 on a wind power brake and place it in a thermo-hygrostat chamber. Test the torque of the brake and calculate its attenuation rate at room temperature, -20°C, and 120°C respectively. The test results are shown in Table 8.

[0088]

[0089]

[0090] The results show that the torque attenuation rate of the brake equipped with the friction plate of Example 4 is 3.81% at -20°C low temperature and 11.67% at 120°C high temperature.

[0091] The above are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the disclosed technical content is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A multi-fiber composite friction plate material for wind power brake, characterized in that: include: Composite friction plates, used for friction braking in wind turbine brakes; The composite friction plate includes a three-dimensional network reinforcement structure, which is formed by a first fiber layer and a second fiber layer through gradient distribution. A fiber weaving and particle interlocking structure is formed between the first fiber layer and the second fiber layer, and the fiber weaving density increases layer by layer.

2. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The composite friction plate comprises the following components in percentage by mass: Phenolic resin 20-30%, elastic rubber 10-15%, first fiber layer 7-12%, second fiber layer 8-15%, steel fiber 5-10%, copper fiber 5-10%, graphite 3-7%, calcium carbonate 10-20%, and the remainder is impurities.

3. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The first fiber layer is basalt fiber.

4. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The second fiber layer is carbon fiber.

5. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The nitrile rubber and the phenolic resin form a rigid-elastic interpenetrating network, which improves the wear resistance and thermal decay resistance of the friction plate and ensures the stable performance of the wind power brake under extreme working conditions.

6. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The ratio of the graphite to the calcium hydrochloride is in the range of 1:3 to 1:3.

3.

7. The multi-fiber composite friction plate material for wind power brake according to claim 1, characterized in that: The elastic material is nitrile rubber.

8. A method for preparing a multi-component composite friction plate material for a wind turbine brake, characterized in that: In a material storage device, 30% of phenolic resin, 10% of nitrile rubber, 7% of basalt fiber, 15% of carbon fiber, 5% of steel fiber, 10% of copper fiber, 3% of graphite and 20% of calcium carbonate are prefabricated as preparation materials in a mass ratio. 7% of basalt fiber and 15% of carbon fiber are added into the preparation device for stirring to form a fiber weaving and particle interlocking structure and a three-dimensional network reinforcement framework. 20%-30% of phenolic resin, 5-10% of steel fiber, 5-10% of copper fiber, 3-7% of graphite and 10-20% of calcium carbonate are added into the mixed solution of 7% of basalt fiber and 15% of carbon fiber and stirred until the mixed solution is completely fused. Finally, 10-15% of elastic rubber is added to form a rigid-elastic interpenetrating structure between the mixed solution and the elastic rubber. The prepared solution is used as a material for pressing a friction plate.

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