Totally-synthetic high-bearing wind power gear oil composition and preparation method thereof

Abstract

The invention relates to a fully-synthetic high-bearing wind power gear oil composition and a preparation method thereof. The gear oil comprises a base oil combination of polyether, polyester, poly-alpha-olefin and alkyl naphthalene, an industrial gear oil complexing agent, an antioxidant, an anti-pitting complexing agent, an anti-wear agent, a pour point depressant and a defoaming agent, and all the components are reasonably proportioned. The preparation method comprises the steps of blending the base oil, adding the functional components in a staged temperature control manner, degassing in vacuum and filtering. Through the design, the wind power gear oil disclosed by the invention has excellent micro pitting corrosion resistance, wear resistance, high and low temperature adaptability, water-containing stability and long-term cleanliness, can effectively prolong the service life of a wind power gear box and reduce the failure rate of equipment, and is suitable for being applied under extreme weather conditions; meanwhile, the method has good industrial production feasibility and environment-friendly characteristics.

Description

Technical Field

[0001] The present invention relates to a fully synthetic high-load wind power gear oil composition and a preparation method thereof. Background Art

[0002] With the ongoing transformation of the global energy structure and the increasing proportion of renewable energy, wind power generation, as a key component of green and clean energy, has experienced rapid growth. As high-value, long-term equipment, the operational reliability of wind turbines is directly related to power generation efficiency and equipment lifespan. Gearboxes, as core components of wind turbines, are crucial for ensuring the long-term, efficient operation of wind turbines through the stability of their lubrication systems and the performance of their lubricants.

[0003] Existing wind turbine gear oils typically use polyalphaolefins (PAO), mineral oils, or esters as base oils, supplemented with a variety of extreme pressure and anti-wear additives to meet the lubrication requirements of gearboxes under diverse operating conditions. However, given the extreme operating environments in which wind turbines operate, such as large daytime temperature swings, extreme cold, high humidity and water-containing environments, and long-term heavy-load, low-speed operation, existing wind turbine gear oils still present the following major challenges.

[0004] First, in high-low temperature cycles and high-humidity environments, traditional gear oils lack lubrication stability, prone to oxidation degradation, viscosity loss, and reduced detergency. This results in a limited lubricant lifespan, shortened oil change intervals, and increased maintenance costs. Second, under heavy loads, low speeds, and high torque operating conditions, gearbox tooth surfaces are susceptible to micropitting due to the breakdown of the lubricating film. This can lead to crack propagation and gear spalling, seriously impacting the gearbox's service life and operational reliability.

[0005] Furthermore, existing gear oils exhibit poor low-temperature starting performance in extremely cold regions. The high pour point and viscosity of the base oils can lead to difficulties in unit startup, delayed oil supply, and increased risk of metal dry friction and wear. In high-speed meshing and vibration environments, lubricants are prone to foaming, resulting in poor lubricating film stability and exacerbated gear wear due to localized metal contact. Regarding the preparation process, the multi-component addition process for existing gear oils is complex and energy-intensive. Furthermore, the uneven dispersion of the components can easily lead to unstable reactions, large fluctuations in oil quality, and significant batch differences, hindering the realization of large-scale, stable production.

[0006] Existing wind turbine gear oils are also insufficiently adaptable in aqueous environments. Due to factors such as seal aging and humid climates, gear oils inevitably absorb trace amounts of water during use. Conventional oils are prone to emulsification and sludge deposition in aqueous environments, severely reducing lubrication performance and, in turn, impacting the reliability and service life of gearboxes. Summary of the Invention

[0007] The purpose of the present invention is to solve the above deficiencies in the prior art and to provide a fully synthetic high-load wind power gear oil composition and a preparation method thereof.

[0008] A fully synthetic high-load wind power gear oil composition comprises the following components in percentage by mass:

[0009] Base oil 85% to 92%;

[0010] Industrial gear oil compound 3% to 6%;

[0011] Antioxidant 0.2% to 0.5%;

[0012] Anti-micropitting compound 3% to 5%;

[0013] Antiwear agent 0.3% to 0.8%;

[0014] Pour point depressant 0.3% to 0.8%;

[0015] Defoaming agent 0.1% to 0.5%;

[0016] Wherein, the base oil includes polyether, polyester, polyalphaolefin and alkyl naphthalene;

[0017] The antioxidants include amine antioxidants and phenolic antioxidants;

[0018] The anti-micropitting composite agent includes a polar polymer compound;

[0019] The anti-wear agent is a molybdenum dialkyldithiocarbamate compound;

[0020] The pour point depressant is a combination of a pour point depressant polymer and a nitrogen-containing compound;

[0021] The defoaming agent is modified silicone oil.

[0022] Furthermore, the polyether base oil is oil-soluble polyalkylene glycol.

[0023] Furthermore, the polyester base oil is a high viscosity index polyester.

[0024] Furthermore, the industrial gear oil compound comprises boronated polyisobutylene succinimide, calcium alkylbenzene sulfonate, calcium sulfide alkylphenate and alkyl dibenzyltoluene.

[0025] Furthermore, the antioxidant consists of 4,4'-dioctyldiphenylamine, 2,4-dimethyl-6-tert-butylphenol and 2,5-di-tert-butylhydroquinone, and the mass ratio of each component is (1-3):(1-3):(1-3).

[0026] Furthermore, the anti-micropitting composite agent is composed of polyester polyol, polyricinoleate and alcoholamine borate, and the mass ratio of each component is (1-1.2):(0.5-1):(1-1.5).

[0027] A method for preparing wind power gear oil comprises the following steps:

[0028] Step 1: Mix the base oil evenly to prepare blended oil;

[0029] Step 2: After stirring evenly at 55-60°C, heat to 85±3°C, add antioxidant, and stir for 0.5-1 hour;

[0030] Step 3: Add industrial gear oil compound, anti-micropitting compound and anti-wear agent in sequence at 65-75°C, stirring for 20-40 minutes each step;

[0031] Step 4: Add pour point depressant and defoamer at about 65°C and continue stirring for 1 hour;

[0032] Step 5: Degas the mixture under vacuum at a negative pressure of 0.08-0.09 MPa for 20 minutes;

[0033] Step 6: Cool to room temperature and filter to obtain the finished product.

[0034] Furthermore, the blended oil is stirred for 0.5 to 1 hour, and the stirring is continued for 0.5 to 1 hour after the antioxidant is added.

[0035] Furthermore, in the process of adding the industrial gear oil compound, the anti-micropitting compound and the anti-wear agent, the stirring time of each step is 20 to 40 minutes.

[0036] Furthermore, the stirring temperature after adding the pour point depressant and the defoaming agent is maintained at 65°C ± 5°C.

[0037] Furthermore, the negative pressure range of the vacuum degassing treatment is 0.08-0.09 MPa, and the time is 20 minutes.

[0038] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0039] This wind turbine gear oil composition demonstrates excellent overall performance and long service life through the strategic combination of multiple base oils and functional additives. Its base oil system, composed of polyether (PAG), polyester, metallocene polyalphaolefin (PAO), and alkylated naphthalene, imparts a high viscosity index, strong lubricating film formation, excellent low-temperature fluidity, and outstanding high-temperature oxidative stability. The synergistic effect of these multiple base oils effectively extends the oil's service life and maintains stable operation in harsh climates, including extreme cold, high temperature, and high humidity.

[0040] This gear oil composition also demonstrates significant advantages in micropitting and wear resistance. Its anti-micropitting compound (polyester polyol, polyricinoleate, and alcoholamine borate) enhances polar adsorption and passivation protection on metal surfaces, significantly reducing the risk of microcracks and pitting propagation. Furthermore, the molybdenum dialkyldithiocarbamate antiwear agent forms a self-healing MoS2 lubricating film on the metal surface, effectively reducing friction and further enhancing gear durability.

[0041] Furthermore, this oil boasts excellent low-temperature starting performance and high-temperature oxidation resistance. The incorporation of metallocene polyalphaolefins and alkylated naphthalenes ensures smooth starting even at extremely low temperatures, while the antioxidants (a combination of amines and phenols) effectively inhibit oil oxidation at high temperatures, significantly extending oil change intervals.

[0042] In terms of detergency and water stability, the synergistic effect of boron-containing dispersants, detergents, and extreme pressure additives ensures uniform oil dispersion and prevents sludge deposition even in the presence of water. The excellent water solubility and detergency of the polyether base oil further ensure the clean operation of the lubrication system.

[0043] It is worth mentioning that the composition uses highly biodegradable ingredients (such as PAG and polyester), which not only has excellent performance, but also conforms to the development trend of green energy and shows good environmental sustainability.

[0044] This wind turbine gear oil preparation method ensures highly uniform dispersion of oil components and stable performance by scientifically optimizing process parameters, demonstrating the following key advantages:

[0045] First, a step-by-step temperature control process is used to stir the base oil within a temperature range of 55-60°C, allowing the oil components of different viscosities to fully blend and form a stable and uniform base system. Furthermore, antioxidants are introduced at a high temperature (85°C ± 3°C) to effectively promote their integration with the base oil and further enhance the oil's antioxidant capacity.

[0046] The preparation method adopts a phased, step-by-step strategy for the order in which the components are added: the industrial gear oil compound, the anti-micropitting compound, and the anti-wear agent are added sequentially, with each stage being thoroughly stirred for 20 to 40 minutes. This process effectively avoids potential mutual repulsion or degradation reactions between the different additives, significantly improving the overall performance of the final oil.

[0047] To ensure the purity of the oil, this method also introduces vacuum degassing treatment, setting the negative pressure to 0.08~0.09MPa, and promptly removing microbubbles and trace moisture during the mixing process, thereby significantly improving the oil's antioxidant, anti-foaming and lubrication stability, and extending its life in practical applications.

[0048] The overall preparation process is simple and efficient, with unified operating specifications, which facilitates large-scale and industrialized mass production. It has good economic efficiency and broad prospects for technology promotion, and can effectively meet the urgent demand of the wind power gear oil market for high-performance, long-life lubricants. DETAILED DESCRIPTION

[0049] A fully synthetic, high-load-bearing wind turbine gear oil composition comprises the following components by weight: 85% to 92% base oil; 3% to 6% industrial gear oil compound; 0.2% to 0.5% antioxidant; 3% to 5% anti-micropitting compound; 0.3% to 0.8% anti-wear agent; 0.3% to 0.8% pour point depressant; and 0.1% to 0.5% defoaming agent. The base oil comprises polyether, polyester, polyalphaolefin, and alkylnaphthalene; the antioxidant comprises an amine antioxidant and a phenolic antioxidant; the anti-micropitting compound comprises a polar polymer; the anti-wear agent is a molybdenum dialkyldithiocarbamate compound; the pour point depressant is a combination of a pour point depressing polymer and a nitrogen-containing compound; and the defoaming agent is a modified silicone oil.

[0050] This embodiment achieves the excellent performance of wind power gear oil under high load, high shear and high temperature conditions by rationally designing the composition ratio and the types of each component. The base oil part adopts polyether, polyester, polyalphaolefin and alkyl naphthalene, and comprehensively utilizes the high viscosity index, low temperature fluidity, oxidation stability and extreme pressure anti-wear properties of each base oil to form a synergistic effect. The antioxidant combination uses amine and phenol antioxidants, taking into account the requirements of high temperature anti-oxidation and long life, and preventing the oxidation and degradation of the oil. The anti-micropitting composite agent improves the ability of the gear surface to form a protective film by introducing polar polymer compounds, significantly inhibiting the occurrence of micropitting. Dialkyl dithiocarbamate molybdenum anti-wear agents form a protective film on the surface of the friction pair to reduce wear. The combination of depressing polymers and nitrogen-containing compounds effectively improves low temperature fluidity while maintaining good high temperature shear stability. The modified silicone oil defoamer can quickly break the foam generated during the stirring process of the oil, ensuring the overall lubrication performance and stability of the oil.

[0051] The fully synthetic, high-load-carrying wind turbine gear oil composition of this embodiment significantly improves the wear resistance, micropitting resistance, and service life of wind turbine gearboxes, while also exhibiting excellent high-temperature oxidation resistance and low-temperature fluidity. This composition maintains excellent oil film strength even in extreme environments, reducing gear wear and pitting rates, extending equipment operating cycles, and lowering maintenance costs. Furthermore, the oil's excellent foam control ensures the proper operation of the gearbox's internal lubrication system, contributing to improved overall wind turbine reliability and power generation efficiency.

[0052] In a possible embodiment, in the wind power gear oil, the polyether base oil is oil-soluble polyalkylene glycol.

[0053] Oil-soluble polyalkylene glycols possess excellent polarity and lubricity, forming a robust lubricating film on metal surfaces, effectively reducing the friction coefficient during gear meshing. They also exhibit excellent high- and low-temperature performance, meeting the requirements of wind turbine gearboxes operating in extreme climates. The oil-soluble structure avoids compatibility issues with other base oil components, ensuring overall oil stability and longevity.

[0054] By using oil-soluble polyalkylene glycol as the polyether base oil, the extreme pressure and anti-wear properties of wind power gear oil are significantly improved, the lubricating oil film on the friction pair surface is more durable, effectively reducing the wear rate and micropitting probability of the gear, extending the service life of the gearbox, and improving the reliability of equipment operation.

[0055] In a possible embodiment, in the wind power gear oil, the polyester base oil is a high viscosity index polyester.

[0056] High viscosity index polyester base oils offer excellent viscosity-temperature performance, maintaining stable viscosity over a wide range of temperatures. This effectively protects the oil film thickness of gear pairs and prevents lubrication failure due to viscosity drop. Furthermore, the ester bonds in the polyester molecular structure impart excellent oxidative and thermal stability.

[0057] By selecting high viscosity index polyester as the base oil component, wind power gear oil can adapt to different operating environments in cold and high temperature areas, provide continuous and stable lubrication protection, reduce gearbox failure rate and maintenance frequency, and improve the overall operation and maintenance efficiency of wind turbines.

[0058] In one possible embodiment, the industrial gear oil compound includes boronated polyisobutylene succinimide, calcium alkylbenzene sulfonate, calcium alkyl phenate sulfide, and alkyl dibenzyltoluene.

[0059] Boronated polyisobutylene succinimide provides excellent detergency and dispersancy, inhibiting deposit formation; calcium alkylbenzene sulfonate and calcium alkylphenol sulfide impart anti-wear and extreme pressure properties, respectively, to the oil, protecting gear surfaces; and alkyldibenzyltoluene acts as a stabilizer, improving the overall thermal and oxidative stability of the oil. These ingredients work synergistically to optimize the overall performance of wind turbine gear oil.

[0060] The use of the above-mentioned composite agent combination can effectively inhibit the formation of sludge and paint film inside the wind turbine gearbox, reduce tooth surface wear, increase the service life of the gear oil, reduce equipment failures, and extend the gearbox maintenance cycle.

[0061] In one possible embodiment, the antioxidant is composed of 4,4'-dioctyldiphenylamine, 2,4-dimethyl-6-tert-butylphenol and 2,5-di-tert-butylhydroquinone, and the mass ratio of each component is (1-3):(1-3):(1-3).

[0062] 4,4'-Dioctyldiphenylamine, an amine antioxidant, effectively captures free radicals and inhibits the oil's oxidation chain reaction. 2,4-Dimethyl-6-tert-butylphenol and 2,5-di-tert-butylhydroquinone, phenolic antioxidants, provide initial antioxidant protection against early oil aging. This multi-component system forms a multi-layered antioxidant protection system, slowing down oil performance degradation.

[0063] By combining the use of multiple types of antioxidants, the antioxidant properties of wind power gear oil have been greatly improved. The oil remains stable under long-term high temperature and high shear environments, significantly extending the oil change cycle and reducing operating and maintenance costs.

[0064] In a possible embodiment, the anti-micropitting composite agent is composed of polyester polyol, polyricinoleate and alcoholamine borate, and the mass ratio of each component is (1-1.2):(0.5-1):(1-1.5).

[0065] Polyester polyols provide excellent lubricating film formation; polyricinoleate enhances lubricating film flexibility and improves film stability under load; and alcoholamine borate provides micropitting inhibition, forming a boron oxide film on the metal surface, reducing metal contact and fatigue failure. This combination effectively inhibits micropitting on gear surfaces.

[0066] By rationally designing the composition of the anti-micropitting compound, wind power gear oil exhibits excellent anti-micropitting ability under long-term high-load operation conditions, extending the service life of the gear pair and reducing maintenance and replacement costs.

[0067] Example 2:

[0068] A method for preparing wind power gear oil comprises the following steps: Step 1: uniformly mixing base oil to prepare blended oil;

[0069] Step 2: After stirring evenly at 55-60°C, heat to 85±3°C, add antioxidant, and stir for 0.5-1 hour;

[0070] Step 3: Add industrial gear oil compound, anti-micropitting compound and anti-wear agent in sequence at 65-75°C, stirring for 20-40 minutes each step;

[0071] Step 4: Add pour point depressant and defoamer at about 65°C and continue stirring for 1 hour;

[0072] Step 5: Degas the mixture under vacuum at a negative pressure of 0.08-0.09 MPa for 20 minutes;

[0073] Step 6: Cool to room temperature and filter to obtain the finished product.

[0074] By controlling the temperature and stirring time in stages, we ensure that all additives are fully dissolved and dispersed, forming a stable lubricant system. Vacuum degassing removes bubbles introduced during the mixing process, ensuring a bubble-free oil product and improving oil film stability. A final cold filtration step ensures the cleanliness of the finished oil and prevents impurities from affecting performance.

[0075] This preparation method ensures the uniform dispersion and stable existence of various functional components of the gear oil. The finished oil produced has excellent anti-wear, anti-micropitting and anti-oxidation properties, and is suitable for the harsh operating environment of various wind power gearboxes.

[0076] In one possible embodiment, in the preparation method, the blended oil is stirred for 0.5 to 1 hour, and the stirring is continued for 0.5 to 1 hour after the antioxidant is added.

[0077] Prolonging the mixing and stirring time of the base oil and antioxidant is conducive to the full dissolution and uniform dispersion of the additives, improving the overall stability and functionality of the oil, and ensuring that the antioxidant is evenly distributed in the oil to maximize its effectiveness.

[0078] After optimizing the stirring time, the gear oil produced exhibits better antioxidant durability and lubrication stability during use, extending the service life of the oil and improving the reliability of equipment operation.

[0079] In one possible embodiment, in the preparation method, the stirring temperature after adding the pour point depressant and the defoaming agent is maintained at 65°C ± 5°C.

[0080] Controlling the stirring temperature within an appropriate range helps to fully mix and disperse the pour point depressant and defoamer, ensuring their maximum functional effect and preventing the pour point depressant from precipitating due to too low a temperature or the deterioration of the defoamer performance due to too high a temperature.

[0081] By optimizing the stirring temperature, the gear oil prepared has better low-temperature fluidity and foam control ability, and can still maintain excellent lubrication effect in cold and violent stirring environments.

[0082] In a possible embodiment, in the preparation method, the negative pressure range of the vacuum degassing treatment is 0.08 to 0.09 MPa, and the time is 20 minutes.

[0083] Vacuum degassing can effectively eliminate tiny bubbles generated during the mixing process, reduce the gas content in the oil, improve the density of the lubricating oil and the strength of the oil film, and prevent the lubricating oil film from breaking and gear damage caused by bubbles during operation.

[0084] Gear oil that has undergone vacuum degassing treatment has higher oil film integrity and load resistance, which improves the reliability of wind turbine gearboxes in long-term operation and reduces equipment failure rate.

[0085] To verify the comprehensive performance of the wind turbine gear oil of the present invention, a wind turbine gear oil sample prepared using the present invention's formulation (hereinafter referred to as the "Example") was compared with a conventional gear oil prepared using a conventional polyalphaolefin (PAO) and ester base oil supplemented with a traditional antiwear agent (hereinafter referred to as the "Comparative Example"). Test items included four-ball machine sintering load, wear spot diameter, micropitting grade, pour point, foam performance, and oxidation stability. The specific test methods and standards are as follows:

[0086] The sintering load (PB value) of the four-ball machine is carried out in accordance with GB / T 3142 standard;

[0087] Wear spot diameter test is based on SH / T 0189 standard;

[0088] Micropitting grade evaluation is based on DIN 51819FVA 54 test standard;

[0089] Pour point determination is carried out in accordance with GB / T 3535 standard;

[0090] Foam tendency and stability are in accordance with GB / T 12579 standard;

[0091] Oxidation stability was determined by ASTM D943 to determine the change in acid value after 1000 hours.

[0092] The test results show that the samples of the embodiments of the present invention are superior to the samples of the comparative examples in all performance indicators.

[0093] Specifically, in a four-ball sintering load test, the extreme pressure performance of the sample of the present invention reached 2800N, significantly higher than the 2300N of the comparative sample, an improvement of approximately 21.7%, demonstrating excellent anti-wear extreme pressure capabilities. In a wear spot diameter test, the wear spot diameter of the sample of the present invention was 0.28mm under the 60-minute / 196N working condition, approximately 20% lower than the 0.35mm of the comparative sample, further demonstrating the stability of the lubricating film and the improved protection of the friction pair.

[0094] In the micropitting performance test, the embodiment of the present invention obtained an excellent rating of Level 1, while the comparative example only reached Level 3, indicating that the gear oil of the present invention can significantly inhibit the generation of microcracks and micropitting pits on the gear surface under heavy-load and long-term operation conditions, effectively extending the service life of the gearbox.

[0095] The low-temperature pour point test shows that the pour point of the sample of the present invention is as low as -45°C, while that of the comparative example is -30°C, which fully proves that the gear oil of the present invention has better fluidity and startup lubrication guarantee capability in extremely cold environments.

[0096] In the foam performance test, the foam volume of the sample of the present invention was measured to be 30 / 20 / 20 ml in sequence I, II, and III tests, respectively. Compared with 80 / 50 / 50 ml of the comparative sample, the foam volume was reduced by about 60%, which significantly improved the stability of the lubricating oil film during operation and reduced the risk of poor lubrication caused by bubbles.

[0097] In the oxidation stability test, after 1000 hours of accelerated aging treatment, the acid value change of the sample of the present invention was only +0.5 mgKOH / g, while the acid value change of the comparative sample reached +1.2 mgKOH / g, indicating that the gear oil of the present invention has more excellent antioxidant stability, can effectively extend the oil change cycle and maintain long-term operating performance.

[0098] In summary, the experimental data fully verify that the wind power gear oil of the present invention has significant improvements in anti-micropitting performance, anti-wear extreme pressure performance, low-temperature fluidity, anti-foaming performance and oxidation stability compared with the existing technology. It can provide more lasting, stable and efficient lubrication protection for wind power gearboxes under extreme climatic conditions, and has broad application prospects and significant industrial promotion value.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fully synthetic high-load wind power gear oil composition, characterized in that: The composition includes the following components in mass percentage: Base oil 85% to 92%; Industrial gear oil compound 3% to 6%; Antioxidant 0.2% to 0.5%; Anti-micropitting compound 3% to 5%; Antiwear agent 0.3% to 0.8%; Pour point depressant 0.3% to 0.8%; Defoaming agent 0.1% to 0.5%; Wherein, the base oil includes polyether, polyester, polyalphaolefin and alkyl naphthalene; The antioxidants include amine antioxidants and phenolic antioxidants; The anti-micropitting composite agent includes a polar polymer compound; The anti-wear agent is a molybdenum dialkyldithiocarbamate compound; The pour point depressant is a combination of a pour point depressant polymer and a nitrogen-containing compound; The defoaming agent is modified silicone oil.

2. The wind power gear oil composition according to claim 1, characterized in that: The polyether base oil is oil-soluble polyalkylene glycol.

3. The wind power gear oil composition according to claim 1 or 2, characterized in that: The polyester base oil is a high viscosity index polyester.

4. The wind power gear oil composition according to any one of claims 1 to 4, characterized in that: The industrial gear oil compound comprises boronated polyisobutylene succinimide, calcium alkylbenzene sulfonate, calcium alkyl phenate sulfide and alkyl dibenzyl toluene.

5. The wind power gear oil according to any one of claims 1 to 5, characterized in that: The antioxidant consists of 4,4'-dioctyldiphenylamine, 2,4-dimethyl-6-tert-butylphenol and 2,5-di-tert-butylhydroquinone, and the mass ratio of the components is (1-3):(1-3):(1-3).

6. The wind power gear oil composition according to any one of claims 1 to 6, characterized in that: The anti-micropitting composite agent consists of polyester polyol, polyricinoleate and alcoholamine borate, and the mass ratio of each component is (1-1.2):(0.5-1):(1-1.5).

7. A method for preparing wind power gear oil, characterized in that: The steps include: Step 1: Mix the base oil evenly to prepare blended oil; Step 2: After stirring evenly at 55-60°C, heat to 85±3°C, add antioxidant, and stir for 0.5-1 hour; Step 3: Add industrial gear oil compound, anti-micropitting compound and anti-wear agent in sequence at 65-75°C, stirring for 20-40 minutes each step; Step 4: Add pour point depressant and defoamer at about 65°C and continue stirring for 1 hour; Step 5: Degas the mixture under vacuum at a negative pressure of 0.08-0.09 MPa for 20 minutes; Step 6: Cool to room temperature and filter to obtain the finished product.

8. The preparation method according to claim 8, characterized in that The stirring time of the blended oil is 0.5 to 1 hour, and the stirring is continued for 0.5 to 1 hour after the antioxidant is added. The preparation method according to any one of claims 8, characterized in that during the process of adding the industrial gear oil compound, the anti-micropitting compound and the anti-wear agent, the stirring time for each step is 20 to 40 minutes.

9. The preparation method according to any one of claim 8, characterized in that The stirring temperature after adding the pour point depressant and defoamer is maintained at 65℃±5℃.

10. The preparation method according to any one of claim 8, characterized in that The negative pressure range of the vacuum degassing treatment is 0.08-0.09 MPa, and the time is 20 minutes.