Core-shell structured borate extreme pressure agents, wide temperature range industrial greases and their applications

Abstract

This invention provides a core-shell structured borate extreme pressure agent, a wide-temperature-range industrial grease, and their applications. The extreme pressure agent possesses a unique core-shell structure, with tungsten disulfide as the core providing basic layered shear lubrication and nano-lanthanum borate as the outer shell. At high temperatures, it releases active boron atoms that react with the metal matrix to form a ceramic repair layer, thus achieving sequential and functional synergy of lubrication and repair on a single additive particle. The wide-temperature-range industrial grease prepared based on this extreme pressure agent exhibits excellent low-temperature start-up performance, high-temperature stability, and extreme pressure anti-wear properties, making it particularly suitable for extreme operating conditions such as wind turbine gearboxes and heavy-duty rolling mills. This invention further provides an intelligent lubrication system and application method incorporating this grease. Through condition monitoring and high-pressure precision grease injection, it enables online repair and predictive maintenance of wear on transmission components, significantly improving equipment reliability and service life.

Description

Technical Field

[0001] This invention relates to the field of industrial grease preparation technology, specifically to core-shell structured borate extreme pressure agents, wide-temperature-range industrial greases, and their applications. Background Technology

[0002] In modern industry, high-end equipment such as wind turbine generators, heavy-duty rolling mills, large ships, and engineering machinery operate under extremely harsh conditions for extended periods. They not only endure high loads and intense impacts but also withstand wide temperature ranges from extreme cold to scorching heat, as well as various harsh environmental media. This presents a near-contradictory dual challenge to their lubrication technology: on the one hand, the lubricating medium must possess excellent low-temperature fluidity and low starting torque at extremely low temperatures to ensure smooth cold starts and controllable energy consumption; on the other hand, it must maintain sufficient oil film strength and extreme-pressure anti-wear properties under high temperatures and pressures to prevent sintering, abnormal wear, and premature failure of the friction pairs.

[0003] Currently, the overall performance of industrial lubricating greases largely depends on the effectiveness of their additive systems. Mainstream technologies primarily aim for performance balance through the physical blending of multiple functional additives, but this method has inherent limitations:

[0004] Sulfur-phosphorus-chlorine extreme pressure anti-wear agents: Although they can prevent instantaneous sintering by forming a chemical reaction film, their reaction products are often corrosive and may damage the metal matrix, and their environmental friendliness is increasingly subject to strict regulations.

[0005] Layered solid lubricants such as molybdenum disulfide and tungsten disulfide can effectively reduce the coefficient of friction due to their weak interlayer bonding and easy shearing. However, they are prone to structural failure in high-temperature, high-shear, and oxidizing environments. Furthermore, nanoscale particles tend to agglomerate and settle in oil, resulting in insufficient dispersion stability and long-term effectiveness.

[0006] Borate extreme pressure additives have the advantages of being environmentally friendly and having high load-bearing capacity, but their mechanism of action mainly relies on physical penetration and surface borosilicate at high temperatures. They have a weak ability to actively repair subsurface damage such as micropitting and fatigue wear caused by cyclic stress, and their compatibility with certain synthetic base oils and long-term stability remain technical challenges.

[0007] More importantly, when the above-mentioned additives are simply physically blended, their different mechanisms of action and film-forming properties may compete or interfere with each other on the friction surface, making it difficult to achieve orderly and synergistic effects in the complex dynamic friction process. As a result, the overall performance is often lower than theoretical expectations, which has become a key bottleneck restricting the realization of ultra-wide temperature range and long-term reliability of lubricating grease.

[0008] To address the aforementioned issues, this invention proposes a core-shell structured borate extreme pressure agent, a wide-temperature-range industrial grease, and their applications. Through material design, a core-shell structured additive with synergistic lubrication and repair functions is constructed at the nanoscale, fundamentally improving the wide-temperature-range adaptability and damage self-repair capability of the grease. Based on this, a new intelligent and precise lubrication maintenance system for high-end equipment is established. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] To address the shortcomings of existing technologies, this invention provides core-shell structured borate extreme pressure agents, wide-temperature-range industrial greases, and their applications, thereby resolving the problems mentioned in the background section.

[0011] (II) Technical Solution

[0012] To achieve the above objectives, the present invention is implemented through the following technical solution: a core-shell structured borate extreme pressure agent, comprising a core and a shell covering the surface of the core;

[0013] The core is sheet-like tungsten disulfide with a thickness of 8-12 nm;

[0014] The outer shell is composed of lanthanum borate nanocrystals with a grain size of 3-5 nm, and the outer shell covers the core with a coverage rate of no less than 98%.

[0015] The outer shell surface is grafted with phosphate ester ionic liquid;

[0016] As a further preferred option, the phosphate ester ionic liquid is any one of tetrabutylammonium phosphate, trihexyltetradecylphosphonium phosphate diethyl ester, 1-butyl-3-methylimidazolium phosphate dihydrogen ester, tetrabutylammonium phosphate tributyl ester, and methyltrioctylammonium phosphate triethyl ester.

[0017] As a further preferred embodiment, the preparation method of the core-shell structured borate extreme pressure agent includes the following steps:

[0018] ① Provide tungsten-containing compounds and lanthanum-containing compounds as raw materials;

[0019] ② Place the tungsten-containing compound, the lanthanum-containing compound, the boron source, and the sulfur source in a hydrothermal reactor and react for 10-14 hours at 210-230℃ and 5-7MPa. The tungsten-containing compound generates tungsten disulfide nanosheets under the action of the sulfur source. At the same time, the lanthanum-containing compound and the boron source react on the surface of the generated tungsten disulfide nanosheets to generate a lanthanum borate shell, thus obtaining a core-shell structure precursor with tungsten disulfide as the core and lanthanum borate as the shell in one step.

[0020] ③ The core-shell structure precursor was surface modified using a phosphate ester ionic liquid to obtain a core-shell structured borate extreme pressure agent.

[0021] A wide-temperature-range industrial grease, based on the total mass of the grease, comprises the following components:

[0022] Base oil: 70%–85%;

[0023] Thickener: 8%–15%;

[0024] The above-mentioned core-shell structured borate extreme pressure agent: 5%–10%;

[0025] Dispersant enhancer: 0.5%–5%;

[0026] Antioxidants: 0.5%–3%.

[0027] As a further preferred option, the base oil is an alkylnaphthalene base oil with a kinematic viscosity of not more than 2800 cSt at -50°C.

[0028] As a further preferred option, the thickener is a composite lithium-based thickener, which is a three-dimensional fiber network structure formed by the compounding of lithium 12-hydroxystearate and lithium sebacate.

[0029] As a further preferred option, the wide-temperature-range industrial grease has a low-temperature starting torque of no more than 7.5 N·m at -50℃, a high-temperature evaporation loss of no more than 5.0% at 180℃ for 24 hours, and a dropping point of more than 300℃.

[0030] The application of a wide-temperature-range industrial grease in the lubrication and repair of gear transmission components: The core-shell structured borate extreme pressure agent in the grease functions at the friction interface through the following mechanism:

[0031] ① The tungsten disulfide core provides layered shear lubrication, reducing frictional resistance;

[0032] ② When the temperature is above 300℃, the lanthanum borate shell releases active boron atoms, which react with iron-based materials to form an Fe2B ceramic repair layer with a hardness of not less than HV 1500, in order to repair micropitting damage.

[0033] As a further preferred option, the application includes the following steps:

[0034] ① Real-time monitoring of vibration signals or wear particle concentration during gearbox operation;

[0035] ② When the monitored signal value exceeds the preset safety threshold, a wide temperature range industrial grease is injected into the gearbox lubrication system through a high-pressure injection device, with an injection pressure of not less than 15 MPa;

[0036] ③ Wide-temperature-range industrial grease forms a lubricating and repairing film on the gear meshing surface, enabling online repair of worn parts.

[0037] (III) Beneficial Effects

[0038] This invention provides core-shell structured borate extreme pressure agents, wide-temperature-range industrial greases, and their applications, offering the following beneficial effects:

[0039] This invention constructs a core-shell structure with tungsten disulfide as the core and lanthanum borate as the outer shell. This unique design achieves spatiotemporal functional synergy during friction: the tungsten disulfide core initially provides layered shear lubrication, significantly reducing the basic coefficient of friction; when operating conditions deteriorate, facing high temperature and pressure, the lanthanum borate outer shell can directionally release active boron atoms, reacting in situ with the surface of the metal component to generate a hard Fe2B ceramic repair layer. This fundamentally solves the industry problem that traditional additives cannot simultaneously provide efficient lubrication and damage repair under extreme conditions.

[0040] In practical applications, the wide-temperature-range industrial grease prepared based on the aforementioned core materials demonstrates a stable operating window of -50℃ to 180℃, ensuring smooth equipment startup in extremely cold environments and maintaining oil film strength under hot conditions. More importantly, the core-shell additives provide a dual lubrication-repair mechanism, effectively inhibiting and repairing micro-pitting on gear and bearing surfaces, extending the fatigue life of critical transmission components several times over. This makes it possible to achieve ultra-long lubrication cycles of over seven years in high-value equipment such as wind turbine gearboxes and heavy-duty rolling mills, fundamentally reducing unplanned downtime and large-scale component replacements. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating the preparation and application of the wide-temperature-range industrial lubricating grease of the present invention. Detailed Implementation

[0042] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] This invention proposes a core-shell structured borate extreme pressure agent, comprising a core and a shell covering the surface of the core;

[0044] The core is sheet-like tungsten disulfide with a thickness of 8-12 nm;

[0045] The outer shell is composed of lanthanum borate nanocrystals with a grain size of 3-5 nm, and the outer shell covers the core with a coverage rate of no less than 98%.

[0046] The outer shell surface is grafted with phosphate ester ionic liquid.

[0047] Another aspect of the present invention provides a method for preparing a core-shell structured borate extreme pressure agent, comprising the following steps:

[0048] ① Provide tungsten-containing compounds and lanthanum-containing compounds as raw materials;

[0049] In this embodiment, the tungsten-containing compound is an inorganic tungstate, specifically sodium tungstate or ammonium tungstate; the lanthanum-containing compound is an inorganic lanthanum salt, specifically any one of lanthanum nitrate, lanthanum chloride, or lanthanum acetate. Both the inorganic tungstate and the inorganic lanthanum salt are commercially available finished products, and their purity is required to be industrial grade or higher.

[0050] In other embodiments, the tungsten-containing compound can be selected from waste generated during the production or use of cemented carbide. The waste is co-melted with sodium hydroxide to convert tungsten into soluble sodium tungstate. After filtration and purification, a sodium tungstate solution suitable as a precursor is obtained. The lanthanum-containing compound can be selected from waste residue generated during the polishing process of liquid crystal glass, optical glass, etc. Leaching with nitric acid or hydrochloric acid allows rare earth elements such as lanthanum to enter the solution in ionic form. After extraction and purification, a pure lanthanum nitrate or lanthanum chloride solution is obtained. Waste recycling reduces raw material costs.

[0051] ② Place the tungsten-containing compound, the lanthanum-containing compound, the boron source, and the sulfur source in a hydrothermal reactor and react for 10-14 hours at 210-230℃ and 5-7MPa. The tungsten-containing compound generates tungsten disulfide nanosheets under the action of the sulfur source. At the same time, the lanthanum-containing compound and the boron source react on the surface of the generated tungsten disulfide nanosheets to generate a lanthanum borate shell, thus obtaining a core-shell structure precursor with tungsten disulfide as the core and lanthanum borate as the shell in one step.

[0052] In this embodiment, the boron source is specifically boric acid or borax, selected from commercially available finished products, with a purity requirement of industrial grade or higher. The sulfur source is thiourea or thioacetamide, selected from commercially available finished products, with a purity requirement of industrial grade or higher.

[0053] Understandably, tungsten-containing compounds react with a sulfur source under hydrothermal high-temperature and high-pressure conditions. Tungstate ions are reduced and combine with sulfur, crystallizing in situ to form layered tungsten disulfide nanosheets. Simultaneously, lanthanum ions generated from the dissolution of lanthanum-containing compounds diffuse in the hydrothermal solution. Due to the surface charge or unsaturated bonds on the tungsten disulfide nanosheets, lanthanum ions can be electrostatically or chemically adsorbed, resulting in local enrichment of lanthanum ions on the nanosheet surface and the formation of a high-concentration reaction interface. Borate ions generated from the hydrolysis of the boron source diffuse to the surface of the tungsten disulfide nanosheets and encounter the enriched lanthanum ions. Under high-temperature and high-pressure hydrothermal conditions, lanthanum borate nuclei preferentially nucleate heterogeneously on the lower-energy tungsten disulfide surface. Subsequently, more lanthanum ions and borate ions continue to deposit and crystallize on the initial nuclei, epitaxially growing along a two-dimensional plane, ultimately forming a complete and dense lanthanum borate nanoshell.

[0054] ③ The core-shell structure precursor was surface modified using a phosphate ester ionic liquid to obtain a core-shell structured borate extreme pressure agent.

[0055] In this embodiment, the phosphate ester ionic liquid is a commercially available dihydrogen phosphate or triphosphate product. Specifically, the phosphate ester ionic liquid is any one of tetrabutylammonium phosphate, trihexyltetradecylphosphonium phosphate diethyl ester, 1-butyl-3-methylimidazolium dihydrogen phosphate, tetrabutylammonium phosphate tributyl ester, and methyltrioctylammonium phosphate triethyl ester.

[0056] Understandably, the phosphate groups in phosphate ester ionic liquids possess strong coordination capabilities. The oxygen atoms on these groups undergo strong chemical adsorption or coordination bonding with lanthanum ions or hydroxyl groups on the surface of the lanthanum borate shell. This results in a large organic cation portion of the ionic liquid forming an organic molecular layer on the particle surface. This hydrophobic long chain extends outward, creating significant steric hindrance between particles, effectively preventing them from approaching each other and agglomerating. This enhances the stability of the dispersion system.

[0057] This invention also proposes a wide-temperature-range industrial grease and its application. The wide-temperature-range industrial grease, based on the total mass of the grease, comprises the following components:

[0058] Base oil: 70%–85%;

[0059] Thickener: 8%–15%;

[0060] Core-shell structured borate extreme pressure agent: 5%–10%;

[0061] Dispersant enhancer: 0.5%–5%;

[0062] Antioxidants: 0.5%–3%.

[0063] Specifically, the low-temperature starting torque of the wide-temperature-range industrial grease at -50℃ is no higher than 7.5 N·m, the high-temperature evaporation loss at 180℃ for 24 hours is no higher than 5.0%, and the dropping point is higher than 300℃.

[0064] The base oil is an alkylnaphthalene base oil with a kinematic viscosity of no more than 2800 cSt at -50°C; in this embodiment, the alkylnaphthalene base oil is selected from commercially available finished products.

[0065] The thickener is a composite lithium-based thickener, which is a three-dimensional fiber network structure formed by the combination of lithium 12-hydroxystearate and lithium sebacate.

[0066] In this embodiment, commercially available 12-hydroxystearic acid and sebacic acid are directly purchased and reacted with lithium hydroxide on-site during the soap-making process to generate the corresponding lithium soap.

[0067] The compounding process includes the following steps:

[0068] Add all the measured 12-hydroxystearic acid and a portion of the base oil to the reaction vessel and heat to approximately 90-100°C to completely dissolve it;

[0069] Add a 5%–10% aqueous solution of lithium hydroxide and keep the mixture at 100–105°C for 1–2 hours to generate lithium 12-hydroxystearate, at which point the system begins to thicken.

[0070] Sebacic acid was added to the above system, and the temperature was raised to 200-220℃. At this temperature, sebacic acid reacted with the remaining lithium hydroxide in the system to form lithium sebate.

[0071] The molar ratio of 12-hydroxystearic acid to sebacic acid is 1:0.15-0.3.

[0072] The material is then kept at a constant temperature for 1-2 hours to ensure complete reaction. Afterward, it is transferred to a mixing vessel and slowly cooled to below 150°C for grinding or homogenization to achieve a more uniform dispersion and finer structure of the fiber bundles. Finally, air bubbles are removed under vacuum to obtain the thickener.

[0073] Applying the above-mentioned wide-temperature-range industrial grease to the lubrication and repair of gear transmission components includes the following steps:

[0074] ① Real-time monitoring of vibration signals or wear particle concentration during gearbox operation;

[0075] In this embodiment, a piezoelectric accelerometer is used. The sensor is rigidly mounted on key measuring points such as the gearbox bearing housing using a magnetic base or bolts. The sensor converts mechanical vibration into electrical signals, monitoring vibration acceleration, velocity, and displacement, and covering a wide frequency band from low to high frequencies. Gear tooth breakage, pitting, uneven wear, and bearing damage all generate specific impact vibrations. By performing time-domain and frequency-domain analysis on the vibration signals, the characteristic frequencies of the fault can be accurately located, thereby determining the fault type and severity.

[0076] In other embodiments, an optical particle counter is used. The oil flows through a narrow optical sensing area, and as particles pass through, they block or scatter the laser, generating pulse signals. The magnitude of the signal is related to the particle size, thereby enabling the counting and concentration calculation of particles within different size ranges.

[0077] It should be noted that on critical gearboxes, vibration monitoring and at least one wear particle monitoring system can be deployed simultaneously. Vibration monitoring is used to detect sudden mechanical failures, while wear monitoring is used to assess long-term wear conditions and lubricant effectiveness. The combination of the two provides the most comprehensive health profile.

[0078] ② When the monitored signal value exceeds the preset safety threshold, a wide temperature range industrial grease is injected into the gearbox lubrication system through a high-pressure injection device, with an injection pressure of not less than 15 MPa;

[0079] The criteria for determining the safety threshold are as follows:

[0080] The alarm line for the total vibration value is 1.5-2 times the baseline value, and the danger line is 2.5-4 times the baseline value; the amplitude of specific fault frequencies, such as meshing frequency and bearing fault frequency, exceeds the baseline by more than 3-5 times.

[0081] The alarm threshold for wear particle concentration is when the concentration of particles >10μm shows an exponential upward trend, or exceeds the baseline value by several times. The danger threshold is when cutting wear particles or fatigue spalling >100μm are continuously detected.

[0082] In this embodiment, the high-pressure injection device is a high-pressure plunger pump with an externally installed high-pressure solenoid valve. After receiving instructions from the monitoring system, it opens / closes instantly to control the timing and duration of grease injection.

[0083] ③ Wide-temperature-range industrial grease forms a lubricating and repairing film on the gear meshing surface, enabling online repair of worn parts.

[0084] Specifically, core-shell structured borate extreme pressure agents in grease function at the friction interface through the following mechanisms:

[0085] ① The tungsten disulfide core provides layered shear lubrication, reducing frictional resistance;

[0086] ② When the temperature is above 300℃, the lanthanum borate shell releases active boron atoms, which react with iron-based materials to form an Fe2B ceramic repair layer with a hardness of not less than HV 1500, in order to repair micropitting damage.

[0087] Specifically, during normal operation, the tungsten disulfide core undergoes interlayer shearing to form a solid lubricating film, continuously reducing friction and wear, and maintaining stable and efficient operation. At the same time, the outer shell acts as a barrier, protecting the internal tungsten disulfide from oxidation into tungsten oxide, which has poor frictional properties, under cyclic shearing and certain temperatures, thus extending the life of the core lubricating components. Under extreme conditions, the lanthanum borate outer shell undergoes thermal decomposition to release boron atoms, which react with iron to form Fe2B, repairing surface micro-damage in situ, providing extreme pressure protection, and preventing adhesion and welding. Meanwhile, the solid lubricating film formed by the tungsten disulfide core at high temperatures can effectively prevent dry friction, adhesion, and secondary wear caused by incomplete formation of the ceramic repair layer or uneven surface.

[0088] To further understand the present invention, the wide-temperature-range industrial lubricating grease provided by the present invention will be described below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0089] Example 1

[0090] Preparation of core-shell structured borate extreme pressure agents:

[0091] Raw material preparation:

[0092] Tungsten source: Take 1 kg of cemented carbide grinding mud and perform alkaline fusion recovery treatment with sodium hydroxide to finally obtain 2 L of sodium tungstate solution with a concentration of 0.5 mol / L.

[0093] Lanthanum source: Take 0.5 kg of polishing waste residue from LCD screen, containing about 30% La2O3, leach and extract with nitric acid to obtain 1.2 L of lanthanum nitrate solution with a concentration of 0.5 mol / L.

[0094] Boric acid 0.62 mol, thiourea 1.2 mol, deionized water.

[0095] Add the sodium tungstate solution, lanthanum nitrate solution, boric acid, and thiourea to a 5L high-pressure hydrothermal reactor, and then add deionized water to 80% of the total volume. After sealing, set the temperature to 220°C. At this point, the pressure inside the reactor will naturally rise to approximately 6 MPa. Maintain this temperature for 12 hours. After the reaction is complete, allow it to cool naturally to room temperature.

[0096] The reaction product was centrifuged and washed three times alternately with deionized water and anhydrous ethanol to obtain a black precipitate. The precipitate was redispersed in an appropriate amount of toluene, and tetrabutylammonium dibutyl phosphate (10% by weight of the precipitate) was added. The mixture was stirred and refluxed at 80°C for 2 hours. Finally, it was spray-dried to obtain a black powdery core-shell structured borate extreme pressure agent A.

[0097] Example 2

[0098] Raw material preparation:

[0099] Tungsten-containing compound: analytical grade sodium tungstate, corresponding to 0.5 mol of tungsten.

[0100] Lanthanum-containing compound: analytical grade lanthanum nitrate, corresponding to 0.3 mol of lanthanum.

[0101] Boron source: analytical grade boric acid, 0.62 mol.

[0102] Sulfur source: 1.2 mol of analytical grade thiourea.

[0103] Solvent: Deionized water.

[0104] In a 2L high-pressure hydrothermal reactor, the measured amounts of sodium tungstate, lanthanum nitrate, boric acid, and thiourea were added sequentially, followed by deionized water to 80% of the total volume. The reactor was sealed, and the temperature was programmed to rise to 215°C, at which point the reaction system pressure was approximately 5.8 MPa. The reaction was maintained at this temperature for 12 hours. After the reaction was complete, the reactor was allowed to cool naturally to room temperature.

[0105] The resulting black suspension was centrifuged, and the precipitate was washed three times successively with deionized water and anhydrous ethanol to remove soluble impurities. The resulting black precipitate was redispersed in an appropriate amount of toluene. Tetrabutylammonium dibutyl phosphate (8% by weight of the precipitate) was added to the dispersion, and the mixture was stirred and refluxed at 75°C for 2 hours for surface modification. Finally, a dry, loose black powder was obtained by spray drying, denoted as core-shell structured borate extreme pressure agent B.

[0106] Example 3

[0107] Preparation of wide-temperature-range industrial grease:

[0108] Preparation of composite lithium-based thickeners:

[0109] In a stirred and heated reactor, 500g of alkylnaphthalene base oil and 300g of 12-hydroxystearic acid were added, and the mixture was heated to 95°C to completely dissolve the acid. An 8% aqueous solution containing 42g of lithium hydroxide monohydrate was slowly added, and the reaction was maintained at 102°C for 1.5 hours. Then, 40.4g of sebacic acid was added, and the temperature was rapidly raised to 210°C, where it was maintained for refining for 1 hour. The material was transferred to a blending vessel, slowly stirred, and cooled to room temperature to obtain a composite lithium-based thickener.

[0110] Take 120g of the composite lithium-based thickener and 730g of alkylnaphthalene base oil prepared above, add them to a reaction vessel, and heat to 120℃ to mix evenly. Then add 50g of the core-shell structured borate extreme pressure agent A, 10g of polyurea dispersant, and 5g of rare earth organic molybdenum antioxidant prepared in Example 1. Homogenize under high-speed shearing at 5000 rpm for 30 minutes, and then degas under vacuum to obtain wide-temperature-range industrial grease A.

[0111] Example 4

[0112] The core-shell structured borate extreme pressure agent A in Example 3 was replaced with the core-shell structured borate extreme pressure agent B prepared in Example 2. All other processes and steps were the same as in Example 3, resulting in wide-temperature-range industrial grease B.

[0113] Example 5

[0114] Test platform: A gearbox simulation test bench was built, equipped with a vibration acceleration sensor and an online inductive wear particle sensor. A high-pressure grease injection device was installed.

[0115] Baseline acquisition: Add ordinary commercial grease to the gearbox of the test bench, run under normal load, and acquire the vibration baseline (total RMS 1.0 m / s2) and particle count baseline (10μm particles <100 / mL) under healthy conditions.

[0116] Introduce damage and switch grease: Create a slight pitting defect on the drive gear, about 0.5 mm in diameter, drain the old grease, clean the gearbox, and then add wide-temperature-range industrial grease A / B.

[0117] Operation and Monitoring: Resume operation and gradually increase the load. After approximately 50 hours of operation, the sensors detected that the total vibration value had increased to 2.8 m / s². 2 Furthermore, the number of particles >100μm exceeded the standard in three consecutive samplings.

[0118] Trigger the high-pressure grease injection procedure and inject 50g of wide-temperature-range industrial grease A / B into the gear meshing area at a pressure of 15 MPa.

[0119] Comparative Example 1

[0120] Commercially available nano-tungsten disulfide powder and micron-sized lanthanum borate powder were directly purchased to replace the core-shell structured borate extreme pressure agent. Following the formulation and process of Example 3, the comparative grease A was prepared by physically mixing it into the lubricating grease. In the same tests as in Example 5, comparative grease A was selected to replace wide-temperature-range industrial greases A / B, and the subsequent total vibration value and the condition of the pitting edges were checked during shutdown.

[0121] Comparative Example 2

[0122] In the same test in Example 5, the comparative grease A was selected to replace the wide temperature range industrial grease, and when the monitoring signal reached the danger threshold, high-pressure automatic grease injection was not performed. Instead, the traditional operation and maintenance mode was simulated: the machine was continuously run until the vibration value exceeded the standard and an alarm was triggered. Then, the machine was stopped, the box was unpacked for inspection, the damage was confirmed, and the comparative grease A was replaced.

[0123] Test example:

[0124] The starting torque of the greases prepared in Examples 3 and 4 and Comparative Example 1 was tested at -50°C according to ASTM D4693. The specific results are shown in Table 1.

[0125] According to ASTM D972, the greases prepared in Examples 3 and 4 and Comparative Example 1 were subjected to evaporation loss testing at 180°C for 24 hours. The specific results are shown in Table 1.

[0126] Dropping point tests were performed on the greases prepared in Examples 3 and 4 and Comparative Example 1 according to ASTM D2265. The specific results are shown in Table 1.

[0127] The greases prepared in Examples 3 and 4 and Comparative Example 1 were tested for four-ball welding load (PB) according to ASTM D2596. The specific results are shown in Table 1.

[0128] The greases prepared in Examples 3 and 4 and Comparative Example 1 were tested for four-ball wear scar diameter (40 kg, 30 min) according to ASTM D4172. The specific results are shown in Table 1.

[0129] The greases prepared in Examples 3 and 4 and Comparative Example 1 were tested for FZG micropitting level according to DIN 51354. The specific results are shown in Table 1.

[0130] Table 1. Test statistics for each embodiment and comparative example.

[0131]

[0132] Example 5 and Comparative Example 2 were compared. Under the premise of creating simulated pitting defects of the same size with a diameter of 0.5 mm on the drive gear, relevant data were collected. The specific results are shown in Table 2.

[0133] Table 2. Statistical table comparing simulated repair tests of Example 5 and Comparative Example 2.

[0134]

[0135] In summary, this invention provides a core-shell structured borate extreme pressure agent, a wide-temperature-range industrial grease, and their applications. Firstly, by preparing the core-shell structured borate extreme pressure agent, the tungsten disulfide core, with its layered crystal structure, continuously provides efficient solid lubrication through its interlayer shear properties during friction, significantly reducing friction and wear. The lanthanum borate shell acts as a response unit; when the friction interface experiences localized flashover due to abnormal operating conditions, thermal decomposition releases active boron atoms, which react in situ with iron-based materials to generate a high-hardness Fe2B ceramic repair layer, actively repairing damage such as micropitting. The synergy of these two components achieves a seamless transition between normal lubrication and active repair under extreme conditions.

[0136] Secondly, the wide-temperature-range industrial grease uses alkyl naphthalene base oil, ensuring extreme temperature adaptability from -50°C to 180°C. A robust three-dimensional network is constructed using a composite lithium-based thickener, firmly locking the base oil and a large amount of core-shell extreme pressure agent, preventing sedimentation and giving the product excellent high-temperature and mechanical stability. This system acts as a stable and long-lasting delivery platform, ensuring that the core-shell structured borate extreme pressure agent can be continuously and accurately delivered to the friction interface across a wide temperature range.

[0137] During application, integrated online monitoring of vibration and wear particles enables real-time diagnosis of early equipment failures. When monitoring data exceeds safety thresholds, a high-pressure injection device is automatically triggered to precisely inject grease rich in core-shell extreme pressure additives into the fault risk point. High pressure ensures that the grease breaks through the oil film barrier and reaches the damaged surface directly. Utilizing its lubrication-repair function, wear is contained and micro-damage is repaired online without shutting down the machine, transforming post-fault repair into pre-fault intervention.

[0138] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A core-shell structured borate extreme pressure agent, characterized in that, Includes a core and a shell covering the surface of the core; The core is sheet-like tungsten disulfide with a thickness of 8-12 nm; The outer shell is composed of lanthanum borate nanocrystals with a grain size of 3-5 nm, and the outer shell covers the core with a coverage rate of not less than 98%. The outer shell surface is grafted with phosphate ester ionic liquid.

2. The core-shell structured borate extreme pressure agent according to claim 1, characterized in that, The phosphate ester ionic liquid is any one of tetrabutylammonium phosphate, trihexyltetradecylphosphonium phosphate diethyl ester, 1-butyl-3-methylimidazolium phosphate dihydrogen ester, tetrabutylammonium phosphate tributyl ester, and methyltrioctylammonium phosphate triethyl ester.

3. The core-shell structured borate extreme pressure agent according to claim 1, characterized in that: The preparation method of the core-shell structured borate extreme pressure agent includes the following steps: ① Provide tungsten-containing compounds and lanthanum-containing compounds as raw materials; ② The tungsten-containing compound, lanthanum-containing compound, boron source and sulfur source are placed in a hydrothermal reactor and reacted at 210-230℃ and 5-7MPa for 10-14 hours to obtain a core-shell structured precursor with tungsten disulfide as the core and lanthanum borate as the shell; ③ The core-shell structure precursor is surface-modified using a phosphate ester ionic liquid to obtain the core-shell structured borate extreme pressure agent.

4. A wide-temperature-range industrial lubricating grease, characterized in that, Based on the total mass of the grease, it comprises the following components: Base oil: 70%–85%; Thickener: 8%–15%; Core-shell structured borate extreme pressure agent as described in any one of claims 1-3: 5%-10%; Dispersant enhancer: 0.5%–5%; Antioxidants: 0.5%–3%.

5. The wide-temperature-range industrial grease according to claim 4, characterized in that, The base oil is an alkylnaphthalene base oil, and its kinematic viscosity at -50°C is not higher than 2800 cSt.

6. The wide-temperature-range industrial grease according to claim 4, characterized in that, The thickener is a composite lithium-based thickener, which is a three-dimensional fiber network structure formed by the compounding of lithium 12-hydroxystearate and lithium sebacate.

7. The wide-temperature-range industrial grease according to claim 5, characterized in that, The wide-temperature-range industrial grease has a low-temperature starting torque of no more than 7.5 N·m at -50℃, a high-temperature evaporation loss of no more than 5.0% at 180℃ for 24 hours, and a dropping point of more than 300℃.

8. The application of a wide-temperature-range industrial grease as described in any one of claims 4-7 in the lubrication and repair of gear transmission components, characterized in that, The core-shell structured borate extreme pressure agent in the grease functions at the friction interface through the following mechanism: ①The tungsten disulfide core provides layered shear lubrication, reducing frictional resistance; ② The lanthanum borate shell releases active boron atoms at temperatures above 300°C, which react with iron-based materials to form an Fe2B ceramic repair layer with a hardness of not less than HV 1500, in order to repair micropitting damage.

9. The application of the wide-temperature-range industrial grease according to claim 8 in the lubrication and repair of gear transmission components, characterized in that, The application includes the following steps: ① Real-time monitoring of vibration signals or wear particle concentration during gearbox operation; ② When the monitored signal value exceeds the preset safety threshold, the wide temperature range industrial grease is injected into the gearbox lubrication system through a high-pressure injection device, with an injection pressure of not less than 15 MPa; ③ The wide-temperature-range industrial grease forms a lubrication and repair film on the gear meshing surface, enabling online repair of worn parts.

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