Composite lubricating oil for large tile of riding wheel and preparation method of composite lubricating oil

Abstract

The invention relates to the technical field of lubricating oil, in particular to riding wheel large tile compound lubricating oil and a preparation method thereof. The composite lubricating oil for the riding wheel large tile comprises the following raw materials in parts by mass: 70-120 parts of base oil, 20-40 parts of a thickening agent, 5-10 parts of graphene oxide, 1-3 parts of zirconium oxychloride, 1-2 parts of citric acid, 0.1-1 part of a silane coupling agent, 1-2 parts of amino-terminated polyamidoamine, 1-2 parts of nano molybdenum disulfide, 1-3 parts of an antioxidant, 0.1-1 part of a metal deactivator, 1-2 parts of an antirust agent and 0.1-0.5 part of an anti-foaming agent, and 1-2 parts of a wear-resistant agent. Under the extreme working conditions of high temperature, high load, shaft deviation and the like, the stable lubricating performance can still be kept, the service life of the riding wheel bearing bush is remarkably prolonged, and the maintenance cost caused by lubrication failure is reduced.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and in particular to a composite lubricating oil for roller bearings and its preparation method. Background Technology

[0002] Currently, with the cement industry developing towards larger scale and higher efficiency, the capacity of rotary kilns has increased significantly. Consequently, the thermal load, material load, and weight borne by the roller bearings have also increased significantly, placing higher demands on the performance of lubricating oils. As a core piece of equipment in cement production, the lubrication performance of the rotary kiln's roller bearings directly affects the stability and economy of the equipment's operation.

[0003] Currently, many cement plants use asphalt-based heavy oil or cylinder oil as the lubricating medium for roller bearings. However, these oils perform poorly under complex conditions such as high temperature, high load, and shaft misalignment. Their viscosity-temperature properties are poor; when the shaft temperature rises due to misalignment, the oil's kinematic viscosity and oil film thickness decrease sharply, leading to deterioration of lubrication and ineffective heat dissipation, easily causing bearing failure. Simultaneously, these oils lack sufficient oxidative stability, easily forming carbon deposits and further exacerbating wear. Furthermore, at low temperatures, the oil tends to harden and become brittle, even detaching from the gear surface, severely affecting lubrication.

[0004] To address the aforementioned issues, insufficient high-temperature resistance leads to the decomposition and failure of lubricating oil at high temperatures, making it impossible to maintain a stable oil film thickness. Poor anti-wear performance fails to effectively reduce direct contact between the bearing bush and the roller shaft, accelerating equipment wear. Poor adhesion results in insufficient retention of lubricating oil on the bearing bush surface, leading to easy leakage and reduced lubrication effectiveness. Therefore, providing a composite lubricating oil that combines high-temperature resistance, anti-wear properties, and excellent adhesion to extend bearing bush service life, reduce maintenance costs, and improve economic efficiency is of great significance. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a composite lubricating oil for bearing rollers and its preparation method.

[0006] A composite lubricating oil for roller bearings, comprising the following raw materials by weight: 70-120 parts base oil, 20-40 parts thickener, 5-10 parts graphene oxide, 1-3 parts zirconium oxychloride, 1-2 parts citric acid, 0.1-1 parts silane coupling agent, 1-2 parts amino-terminated polyamide amine, 1-2 parts nano molybdenum disulfide, 1-3 parts antioxidant, 0.1-1 parts metal passivator, 1-2 parts rust inhibitor, 0.1-0.5 parts antifoaming agent, and 1-2 parts wear-resistant agent.

[0007] Preferably, the base oil includes: bright oil, polyalphaolefin, and dipentaerythritol ester.

[0008] More preferably, the mass ratio of bright oil, polyalphaolefin, and dipentaerythritol ester is 5-10:1-3:1-2.

[0009] More preferably, the kinematic viscosity of the polyα-olefin at 100°C is 60-100 mm. 2 / s.

[0010] More preferably, the kinematic viscosity of the bright oil at 40°C is 130-155 mm. 2 / s.

[0011] Preferably, the thickener is at least one of polymethacrylate and polyurea.

[0012] Preferably, the antioxidant is at least one of dialkyldiphenylamine and hindered phenolic antioxidants.

[0013] Preferably, the metal passivating agent is at least one of benzotriazole derivatives, zinc dioctyl dithiophosphate, and imidazoline compounds.

[0014] Preferably, the rust inhibitor is calcium dinonylnaphthalenesulfonate.

[0015] Preferably, the antifoaming agent is a polyether-modified siloxane.

[0016] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to water, add citric acid, stir at 80-90℃ for 1-2 hours, add graphene oxide and stir evenly, adjust the pH of the system to 8-9 while stirring, stir for 10-30 minutes, let stand at room temperature for 20-30 hours, add silane coupling agent, stir at 70-80℃ for 5-10 hours, add terminal amino polyamide amine and continue stirring for 1-2 hours, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, thickener, and wear-resistant graphene evenly to obtain a premix; mix the antioxidant, metal passivator, rust inhibitor, antifoaming agent, polytetrafluoroethylene micro powder, and nano molybdenum disulfide evenly, add them to the premix, and stir under vacuum for 10-30 minutes.

[0017] Preferably, in S2, the vacuum stirring temperature is 60-70℃ and the vacuum degree is 50-150Pa. Beneficial effects

[0018] This invention utilizes the synergistic effect of wear-resistant graphene and nano-molybdenum disulfide. By depositing a zirconium-containing protective layer in the graphene oxide sheets, the wear-resistant graphene not only forms a physical barrier at high temperatures but also exhibits excellent thermal stability and conductivity, effectively slowing down the thermal decomposition of the base oil. Its layered structure effectively disperses heat, preventing localized overheating that could lead to a sudden drop in viscosity. Combined with the effect of nano-molybdenum disulfide, a molybdenum disulfide film with low shear strength can be formed on the friction surface at high temperatures. Together with the physical barrier of graphene, this maintains the oil film thickness, reducing the risk of direct contact between the bearing and the roller shaft. In conjunction with the base oil system, it ensures that sufficient kinematic viscosity is maintained at high temperatures, preventing lubrication failure due to temperature fluctuations.

[0019] Wear-resistant graphene can be effectively embedded in micro-protrusions on metal surfaces, effectively reducing the contact area of ​​friction pairs and lowering the wear rate. Its surface contains active amino groups, which can interact with the metal surface to enhance the adhesion of the lubricating film and inhibit metal oxidation and corrosion. Combined with the action of nano-molybdenum disulfide, it forms a solid lubricating film with a low coefficient of friction, significantly reducing wear. Moreover, the long-chain structure of terminal amino polyamide amine can wrap around the metal surface to form a strong adsorption layer. Combined with the action of thickeners, it significantly improves the retention capacity of lubricating oil on the bearing surface.

[0020] This invention maintains stable lubrication performance even under extreme conditions such as high temperature, high load, and shaft misalignment, significantly extending the service life of the roller bearing and reducing maintenance costs due to lubrication failure. Attached Figure Description

[0021] Figure 1 This is a comparison chart of the kinematic viscosity and viscosity index at 100°C of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3.

[0022] Figure 2 The image shows a comparison of the flash point and pour point of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3.

[0023] Figure 3 The graph shows a comparison of the maximum non-seizure load and the maximum non-seizure load at 70°C for the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3. Detailed Implementation

[0024] The present invention will be further explained below with reference to specific embodiments.

[0025] The polyalphaolefin used below was purchased from Shenzhen Derun Petroleum Technology Co., Ltd., and its kinematic viscosity at 100°C was 100 mmHg. 2 / s. The bright oil used below was purchased from Shandong Mouyou Lubrication Technology Co., Ltd., and its kinematic viscosity at 40℃ is 152.6 mm. 2 / s. The dipentaerythritol ester used below was purchased from Jinan Mouao Chemical Co., Ltd. The polyether-modified siloxane used below was purchased from Hubei Mousheng Sihai New Materials Co., Ltd., model SH-G1045, with a viscosity (25℃) of 15000-35000cp. The polymethacrylate used below was purchased from Jinzhou Mouhua New Materials Co., Ltd., model T-6-310.

[0026] Example 1 A composite lubricating oil for roller bearings, comprising the following raw materials: 70g base oil, 20g polymethacrylate, 5g graphene oxide, 1g zirconium oxychloride, 1g citric acid, 0.1g KH550 coupling agent, 1g amino-terminated polyamide amine, 1g nano molybdenum disulfide, 1g 2,6-di-tert-butyl-p-cresol, 0.1g zinc dioctyl dithiophosphate, 1g calcium dinonylnaphthalene sulfonate, 0.1g polyether-modified siloxane, and 1g polytetrafluoroethylene micropowder.

[0027] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 5:1:1.

[0028] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 30g of deionized water, add citric acid, stir at 80℃ for 1h, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 10min, let stand at room temperature for 20h, add KH550 coupling agent, stir at 70℃ for 5h, add terminal amino polyamide amine and continue stirring for 1h, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, zinc dioctyl dithiophosphate, calcium dinonylnaphthalene sulfonate, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 10 minutes at a stirring speed of 50 r / min, a stirring temperature of 60℃, and a vacuum degree of 50 Pa.

[0029] Example 2 A composite lubricating oil for roller bearings, comprising the following raw materials: 120g base oil, 40g polymethacrylate, 10g graphene oxide, 3g zirconium oxychloride, 2g citric acid, 1g KH550 coupling agent, 2g amino-terminated polyamide amine, 2g nano molybdenum disulfide, 3g 2,6-di-tert-butyl-p-cresol, 1g zinc dioctyl dithiophosphate, 2g calcium dinonylnaphthalene sulfonate, 0.5g polyether-modified siloxane, and 2g polytetrafluoroethylene micropowder.

[0030] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 10:3:2.

[0031] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 60g of deionized water, add citric acid, stir at 90℃ for 2h, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 30min, let stand at room temperature for 30h, add KH550 coupling agent, stir at 80℃ for 10h, add amino-terminated polyamide amine and continue stirring for 2h, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, zinc dioctyl dithiophosphate, calcium dinonylnaphthalene sulfonate, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 30 minutes at a stirring speed of 150 r / min, a stirring temperature of 70℃, and a vacuum degree of 150 Pa.

[0032] Example 3 A composite lubricating oil for roller bearings, comprising the following raw materials: 90g base oil, 35g polymethacrylate, 7g graphene oxide, 2.5g zirconium oxychloride, 1.2g citric acid, 0.8g KH550 coupling agent, 1.3g amino-terminated polyamide amine, 1.7g nano molybdenum disulfide, 1.5g 2,6-di-tert-butyl-p-cresol, 0.8g metal passivator T551, 1.2g dinonylnaphthalenesulfonate calcium, 0.4g polyether-modified siloxane, and 1.5g polytetrafluoroethylene micro powder.

[0033] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 7:2.5:1.2.

[0034] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 50g of deionized water, add citric acid, stir at 82℃ for 100min, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 15min, let stand at room temperature for 28h, add KH550 coupling agent, stir at 73℃ for 9h, add terminal amino polyamide amine and continue stirring for 80min, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, dinonylnaphthalenesulfonate calcium, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 25 minutes at a stirring speed of 80 r / min, a stirring temperature of 66℃, and a vacuum degree of 80 Pa.

[0035] Example 4 A composite lubricating oil for roller bearings, comprising the following raw materials: 110g base oil, 25g polymethacrylate, 9g graphene oxide, 1.5g zirconium oxychloride, 1.8g citric acid, 0.2g KH550 coupling agent, 1.7g amino-terminated polyamide amine, 1.3g nano molybdenum disulfide, 2.5g 2,6-di-tert-butyl-p-cresol, 0.2g metal passivator T551, 1.8g dinonylnaphthalenesulfonate calcium, 0.2g polyether-modified siloxane, and 1.5g polytetrafluoroethylene micro powder.

[0036] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 9:1.5:1.8.

[0037] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 40g of deionized water, add citric acid, stir at 88℃ for 80min, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 25min, let stand at room temperature for 22h, add KH550 coupling agent, stir at 77℃ for 7h, add terminal amino polyamide amine and continue stirring for 100min, filter, wash, and vacuum dry to obtain wear-resistant graphene; S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, dinonylnaphthalenesulfonate calcium, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 15 minutes at a stirring speed of 120 r / min, a stirring temperature of 64℃, and a vacuum degree of 120 Pa.

[0038] Example 5 A composite lubricating oil for roller bearings, comprising the following raw materials: 100g base oil, 30g polymethacrylate, 8g graphene oxide, 2g zirconium oxychloride, 1.5g citric acid, 0.5g KH550 coupling agent, 1.5g amino-terminated polyamide amine, 1.5g nano molybdenum disulfide, 2g 2,6-di-tert-butyl-p-cresol, 0.5g metal passivator T551, 1.5g dinonylnaphthalenesulfonate calcium, 0.3g polyether-modified siloxane, and 1.5g polytetrafluoroethylene micro powder.

[0039] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 8:2:1.5.

[0040] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 45g of deionized water, add citric acid, stir at 85℃ for 90min, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 20min, let stand at room temperature for 25h, add KH550 coupling agent, stir at 75℃ for 8h, add terminal amino polyamide amine and continue stirring for 90min, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, dinonylnaphthalenesulfonate calcium, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 20 minutes at a stirring speed of 100 r / min, a stirring temperature of 65℃, and a vacuum degree of 100 Pa.

[0041] Comparative Example 1: A composite lubricating oil for roller bearings, comprising the following raw materials: 100g base oil, 30g polymethyl methacrylate, 10g graphene oxide, 1.5g citric acid, 0.5g KH550 coupling agent, 1.5g amino-terminated polyamide amine, 1.5g nano molybdenum disulfide, 2g 2,6-di-tert-butyl-p-cresol, 0.5g metal passivator T551, 1.5g dinonylnaphthalenesulfonate calcium, 0.3g polyether-modified siloxane, and 1.5g polytetrafluoroethylene micro powder.

[0042] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 8:2:1.5.

[0043] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add citric acid to 45g of deionized water, add graphene oxide and stir evenly. Let stand at room temperature for 25h, add KH550 coupling agent, stir at 75℃ for 8h, add terminal amino polyamide amine and continue stirring for 90min, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, dinonylnaphthalenesulfonate calcium, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 20 minutes at a stirring speed of 100 r / min, a stirring temperature of 65℃, and a vacuum degree of 100 Pa.

[0044] Comparative Example 2: A composite lubricating oil for roller bearings, comprising the following raw materials: 100g base oil, 30g polymethyl methacrylate, 9.5g graphene oxide, 2g zirconium oxychloride, 1.5g citric acid, 0.5g KH550 coupling agent, 1.5g nano molybdenum disulfide, 2g 2,6-di-tert-butyl-p-cresol, 0.5g metal passivator T551, 1.5g dinonylnaphthalenesulfonate calcium, 0.3g polyether-modified siloxane, and 1.5g polytetrafluoroethylene micro powder.

[0045] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 8:2:1.5.

[0046] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 45g of deionized water, add citric acid, stir at 85℃ for 90min, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 20min, let stand at room temperature for 25h, add KH550 coupling agent, stir at 75℃ for 8h, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, dinonylnaphthalenesulfonate calcium, polyether-modified siloxane, polytetrafluoroethylene micro powder, and nano-molybdenum disulfide evenly, add them to the premix, and vacuum stir for 20 minutes at a stirring speed of 100 r / min, a stirring temperature of 65℃, and a vacuum degree of 100 Pa.

[0047] Comparative Example 3: A composite lubricating oil for roller bearings, comprising the following raw materials: 100g base oil, 30g polymethyl methacrylate, 8g graphene oxide, 2g zirconium oxychloride, 1.5g citric acid, 0.5g KH550 coupling agent, 1.5g amino-terminated polyamide amine, 2g 2,6-di-tert-butyl-p-cresol, 0.5g metal passivator T551, 1.5g dinonylnaphthalenesulfonate calcium, 0.3g polyether-modified siloxane, and 3g polytetrafluoroethylene micro powder.

[0048] The base oil is composed of bright oil, polyalphaolefin, and dipentaerythritol ester in a mass ratio of 8:2:1.5.

[0049] The preparation method of the above-mentioned composite lubricating oil for bearing rollers includes the following steps: S1. Add zirconium oxychloride to 45g of deionized water, add citric acid, stir at 85℃ for 90min, add graphene oxide and stir evenly, add 12% ammonia water dropwise to adjust the pH of the system to 8-9 while stirring, stir for 20min, let stand at room temperature for 25h, add KH550 coupling agent, stir at 75℃ for 8h, add terminal amino polyamide amine and continue stirring for 90min, filter, wash, and vacuum dry to obtain wear-resistant graphene. S2. Mix the base oil, polymethyl methacrylate, and wear-resistant graphene evenly to obtain a premix; mix 2,6-di-tert-butyl-p-cresol, metal passivator T551, calcium dinonylnaphthalene sulfonate, polyether-modified siloxane, and polytetrafluoroethylene micro powder evenly, add them to the premix, and vacuum stir for 20 minutes at a stirring speed of 100 r / min, a stirring temperature of 65℃, and a vacuum degree of 100 Pa.

[0050] The kinematic viscosity at 100°C of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3 was determined according to GB / T 265-1988 "Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity of Petroleum Products". The viscosity index of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3 was determined according to GB / T 2541-1981 "Table for Calculating Viscosity Index of Petroleum Products".

[0051] like Figure 1 As shown, the composite lubricating oil obtained in Example 5 has the highest kinematic viscosity and viscosity index at 100°C, which is significantly better than the comparative example.

[0052] The flash points of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3 were determined according to GB / T 3536-2008 "Determination of Flash Point and Ignition Point of Petroleum Products - Cleveland Open Cup Method". The pour points of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3 were determined according to GB / T 510-2018 "Determination of Pour Point of Petroleum Products".

[0053] like Figure 2 As shown, the composite lubricating oil obtained in Example 5 has the highest flash point and the lowest pour point, which is significantly better than the comparative example.

[0054] The maximum non-seize load and the maximum non-seize load at 70°C of the composite lubricating oils obtained in Example 5 and Comparative Examples 1-3 were determined according to GB / T 3142-2019 "Determination of Carrying Capacity of Lubricants - Four-Ball Method".

[0055] like Figure 3 As shown, the maximum non-jamming load and the maximum non-jamming load at 70°C obtained in Example 5 are the highest, which are significantly better than the comparative example.

[0056] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A roller bearing large shoe composite lubricating oil, characterized by, The raw materials include, by mass fraction: base oil 70-120 parts, thickening agent 20-40 parts, graphene oxide 5-10 parts, zirconium oxychloride 1-3 parts, citric acid 1-2 parts, silane coupling agent 0.1-1 part, amino-terminated polyamide amine 1-2 parts, nanometer molybdenum disulfide 1-2 parts, antioxidant 1-3 parts, metal deactivator 0.1-1 part, anti-rust agent 1-2 parts, anti-foaming agent 0.1-0.5 parts, wear-resistant agent 1-2 parts.

2. The complex lubricating oil of claim 1, wherein The base oil includes: bright stock, poly-alpha-olefin, dipentaerythritol ester; The mass ratio of the bright stock, poly-alpha-olefin, and dipentaerythritol ester is 5-10:1-3:1-2.

3. The complex lubricating oil of claim 2, wherein The polyalphaolefin has a kinematic viscosity at 100°C of 60-100 mm 2 / s; Bright stock 40 130-155 mm 2 / s.

4. The complex lubricating oil of claim 1, wherein The thickening agent is at least one of polymethyl acrylate and polyurea.

5. The complex lubricating oil of claim 1, wherein The antioxidant is at least one of dialkyldiphenylamine and hindered phenolic antioxidant.

6. The complex lubricating oil of claim 1, wherein The metal deactivator is at least one of benzotriazole derivative, zinc dioctyldithiophosphate, and imidazoline compound.

7. The complex lubricating oil of claim 1, wherein The anti-rust agent is calcium dinonylnaphthalene sulfonate.

8. The complex lubricating oil of claim 1, wherein The anti-foaming agent is polyether-modified siloxane.

9. A method of preparing a roller bearing complex lubricating oil as claimed in any one of claims 1 to 8, characterized in that, The method includes the following steps: S1, adding zirconium oxychloride to water, adding citric acid, stirring at 80-90°C for 1-2h, adding graphene oxide and stirring uniformly, adjusting the pH value of the system to 8-9 under stirring, stirring for 10-30min, standing at room temperature for 20-30h, adding silane coupling agent, stirring at 70-80°C for 5-10h, adding amino-terminated polyamide amine and continuing to stir for 1-2h, filtering, washing, vacuum drying to obtain wear-resistant graphene; S2, mixing the base oil, thickening agent, and wear-resistant graphene uniformly to obtain a premix; mixing the antioxidant, metal deactivator, anti-rust agent, anti-foaming agent, polytetrafluoroethylene powder, and nanometer molybdenum disulfide uniformly, and adding them to the premix and stirring under vacuum for 10-30min.

10. The method of claim 9, wherein the preparation of the composite lubricating oil for a roller bearing is characterized by, In S2, the vacuum stirring temperature is 60-70°C, and the vacuum degree is 50-150Pa.

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