A lubricating oil composition for a plug-in hybrid electric vehicle gearbox and a preparation method thereof

Abstract

The present invention relates to the field of lubricating oils, and in particular to a lubricating oil composition for a plug-in hybrid electric vehicle gearbox and a preparation method thereof. The lubricating oil composition of the present invention comprises a friction modifier, and the friction modifier is one or more of oleic acid, glycerol dioleate, dioleyl phosphite, amide, and subamide; the content of the friction modifier is 0.2-5wt%. The lubricating oil composition of the present invention can make the lubricating oil have good electrochemical properties and thermal conductivity, excellent compatibility with motor materials, especially insulating materials, and good friction performance.

Description

Technical Field

[0001] The present invention relates to the field of lubricating oils, and in particular to a lubricating oil composition for a plug-in hybrid electric vehicle gearbox and a preparation method thereof. Background Art

[0002] Plug-in hybrid vehicles are closer to pure electric vehicles in structure because they can obtain electricity from the external power grid as energy to drive the vehicle. They have a longer pure electric range and better fuel economy and emissions.

[0003] For plug-in hybrid electric vehicles, the gearbox is a transmission system that couples the power of the engine and the drive motor in a certain way and can achieve speed and torque conversion. As far as current technology is concerned, the gearbox of a plug-in hybrid electric vehicle integrates one or more electric motors into the gearbox to form an automatic transmission system with an electric motor, which has the advantages of high integration, compact structure, energy saving and high efficiency. Due to the integrated coupling of the electric motor and the transmission, the lubricating oil must not only ensure the lubrication and cooling of the mechanical transmission parts, but also take into account the lubrication and cooling requirements of the motor. Therefore, the oil must have good electrochemical properties and thermal conductivity, and must have excellent compatibility with motor materials, especially insulating materials. In addition, hybrid gearboxes usually have friction clutches, and lubricating oil products must also have good friction properties. Providing a lubricating oil composition that can be applied to the gearbox of a plug-in hybrid electric vehicle is an important issue that the industry needs to solve urgently. Summary of the invention

[0004] The present invention provides a lubricating oil composition for a plug-in hybrid electric vehicle gearbox and a preparation method thereof, so as to solve the defect that there is a lack of a lubricating oil composition for a plug-in hybrid electric vehicle gearbox with excellent performance in the prior art. The lubricating oil composition provided by the present invention has good low-temperature flowability, extreme pressure and anti-wear performance, oxidation stability, and anti-rust and anti-corrosion performance, and has excellent electrochemical performance and motor material compatibility, as well as good friction performance, and is suitable for a plug-in hybrid electric vehicle gearbox with friction property requirements.

[0005] The present invention provides a lubricating oil composition, which contains a friction modifier, wherein the friction modifier is one or more of oleic acid, dioleyl glycerol, dioleyl phosphite, amide, and subamide; the content of the friction modifier is 0.2-5wt%. The friction modifier of the present invention can make the lubricating oil have good friction performance.

[0006] According to the lubricating oil composition provided by the present invention, the lubricating oil composition further comprises a detergent and a dispersant; the detergent is one or more of sulfonate, alkylphenol, sulfurized alkylphenol, alkyl salicylate, thiophosphate, and cyclopentaneate, and the content of the detergent is 0.5-10wt%; the dispersant is one or more of polyisobutylene imide, polyisobutylene ester, bis-succinimide, and polyolefin succinic acid polyhydroxy alcohol ester, and the content of the dispersant is 0.1-15wt%. The detergent and dispersant of the present invention are used in combination with the above-mentioned friction modifier to enable the lubricating oil composition to have very good electrochemical properties.

[0007] The lubricating oil composition provided by the present invention further comprises one or more of an extreme pressure anti-wear agent, an antioxidant, a metal deactivator, a viscosity index improver, and an anti-foaming agent.

[0008] The extreme pressure anti-wear agent is one or more of phosphate amine salt, thiophosphate amine salt, thiophosphate, thiophosphite, and derivatives thereof.

[0009] The antioxidant is one or two or more of tert-butylphenol, tert-butyl-p-cresol, alkyl dimethylphenol, α-naphthylamine and alkyl diphenylamine.

[0010] The metal deactivator is one or more of benzotriazole and its derivatives, thiadiazole and its derivatives, benzimidazole and benzothiazole.

[0011] The viscosity index improver is one or more of polymethacrylate and polyisobutylene.

[0012] The antifoaming agent is one or more of polysiloxane, fluorosilicone, organic silicate and composite antifoaming agent.

[0013] Preferably, the content of the extreme pressure anti-wear agent is 0.5-11wt%; the content of the antioxidant is 0.01-5wt%; the content of the metal deactivator is 0.005-0.2wt%; the content of the viscosity index improver is 0.2-10wt%; the content of the anti-foaming agent is 0.005-0.6wt% (preferably 0.005-0.1wt%).

[0014] According to the lubricating oil composition provided by the present invention, the extreme pressure anti-wear agent is thiophosphate and / or thiophosphite; the antioxidant is a mixture of tert-butylphenol and alkyl diphenylamine; the metal deactivator is a thiadiazole derivative; the detergent is calcium alkyl salicylate; the dispersant is poly(ethylene glycol ester); the friction modifier is a mixture of amide and imide; the viscosity index improver is polymethacrylate; the anti-foaming agent is fluorosilicone; preferably, the base oil of the lubricating oil composition is Class III hydrogenated base oil.

[0015] According to the lubricating oil composition provided by the present invention, based on the total weight of the lubricating oil composition: the content of the extreme pressure anti-wear agent is 1-8wt%; the content of the antioxidant is 0.01-3wt%; the content of the metal deactivator is 0.01-0.15wt%; the content of the detergent is 0.5-5wt%; the content of the dispersant is 0.5-12wt%; the content of the friction modifier is 0.2-4wt%; the content of the viscosity index improver is 0.2-8wt%; the content of the anti-foaming agent is 0.005-0.6wt%, and the balance is base oil.

[0016] According to the lubricating oil composition provided by the present invention, the lubricating oil composition comprises 2.8-3.4wt% of extreme pressure anti-wear agent thiophosphite, 0.2-0.4wt% of antioxidant tert-butylphenol, 0.08-0.12wt% of metal deactivator thiadiazole derivative, 0.7-0.9wt% of detergent calcium alkyl salicylate, 2.4-2.8wt% of dispersant polyisobutylene ester, 1.1-1.4wt% of friction modifier imide, 4-5wt% of viscosity index improver polymethacrylate, and 0.02-0.04wt% of anti-foaming agent fluorosilicone.

[0017] Or, the lubricating oil composition comprises 2.8-3.4wt% of extreme pressure anti-wear agent thiophosphite, 0.2-0.4wt% of antioxidant tert-butylphenol, 0.08-0.12wt% of metal deactivator thiadiazole derivative, 0.7-0.9wt% of detergent calcium alkyl salicylate, 2.4-2.8wt% of dispersant polyisobutylene imide, 1.1-1.4wt% of friction modifier amide, 4-5wt% of viscosity index improver polymethacrylate, and 0.02-0.04wt% of anti-foaming agent fluorosilicone.

[0018] Or, the lubricating oil composition comprises 2.8-3.4wt% of extreme pressure anti-wear agent thiophosphite, 0.2-0.4wt% of antioxidant tert-butylphenol, 0.08-0.12wt% of metal deactivator thiadiazole derivative, 0.7-0.9wt% of detergent calcium alkyl salicylate, 2.4-2.8wt% of dispersant polyisobutylene ester, 1.1-1.4wt% of friction modifier amide, 4-5wt% of viscosity index improver polymethacrylate, and 0.02-0.04wt% of anti-foaming agent fluorosilicone. The lubricating oil prepared by combining the types and proportions of the extreme pressure anti-wear agent, antioxidant, metal deactivator, detergent, dispersant, friction modifier, viscosity index improver, and anti-foaming agent has extremely excellent effect.

[0019] According to the lubricating oil composition provided by the present invention, the base oil of the lubricating oil composition is mineral oil and / or synthetic oil;

[0020] Preferably, the mineral oil is a Class II hydrogenated base oil and / or a Class III hydrogenated base oil, and the synthetic oil is one or more of poly-α-olefins, polyol esters, diesters, and complex esters.

[0021] The present invention also provides a method for preparing the lubricating oil composition, wherein the lubricating oil composition is heated and stirred to obtain the lubricating oil for the plug-in hybrid electric vehicle gearbox.

[0022] Preferably, after mixing extreme pressure anti-wear agent, antioxidant, metal deactivator, detergent, dispersant, friction modifier and viscosity index improver, base oil is added and stirred until the mixture is uniform and transparent; anti-foaming agent is added to the obtained mixture, and the lubricating oil composition is obtained after mixing and stirring.

[0023] In some embodiments, the preparation method is to mix an extreme pressure anti-wear agent, an antioxidant, a metal deactivator, a detergent, a dispersant, a friction modifier, and a viscosity index improver in an unrestricted order of addition, and then add a Class III hydrogenated base oil and stir until the mixture is uniform and transparent; add an anti-foaming agent to the obtained mixture, and after mixing and stirring, obtain a lubricating oil composition for a plug-in hybrid electric transmission.

[0024] According to the method for preparing the lubricating oil composition provided by the present invention, the stirring is heating stirring.

[0025] Preferably, the heating and stirring temperature is 45-80° C., and the stirring time is 1-3 hours.

[0026] Preferably, the stirring is mechanical stirring and / or pulse stirring.

[0027] According to the preparation method of the lubricating oil composition provided by the present invention, 3.2% of extreme pressure anti-wear agent thiophosphite, 0.3% of antioxidant tert-butylphenol, 0.1% of metal deactivator thiadiazole derivative, 0.8% of detergent calcium alkyl salicylate, 2.6% of dispersant polyisobutylene ester, 1.25% of friction modifier amide, 4.5% of viscosity index improver polymethacrylate are added to API III hydrogenated base oil in percentage by mass, and stirred at 75°C for 2h until the mixture is uniform and transparent; 0.03% of anti-foaming agent fluorosilicone is added to the obtained mixture, and stirred at 75°C for 1h to obtain the lubricating oil composition.

[0028] Alternatively, by weight percentage, 3.2% of extreme pressure anti-wear agent thiophosphite, 0.3% of antioxidant tert-butylphenol, 0.1% of metal deactivator thiadiazole derivative, 0.8% of detergent calcium alkyl salicylate, 2.6% of dispersant polyisobutylene imide, 1.25% of friction modifier amide, and 4.5% of viscosity index improver polymethacrylate are added to API III hydrogenated base oil, and stirred at 75° C. for 2 hours until the mixture is uniform and transparent; 0.03% of anti-foaming agent fluorosilicone is added to the obtained mixture, and stirred at 75° C. for 1 hour to obtain the lubricating oil composition.

[0029] Alternatively, by weight percentage, 3.2% of extreme pressure anti-wear agent thiophosphite, 0.3% of antioxidant tert-butylphenol, 0.1% of metal deactivator thiadiazole derivative, 0.8% of detergent calcium alkyl salicylate, 2.6% of dispersant polyisobutylene ester, 1.25% of friction modifier amide, and 4.5% of viscosity index improver polymethacrylate are added to API III hydrogenated base oil, and stirred at 75° C. for 2 hours until the mixture is uniform and transparent; 0.03% of anti-foaming agent fluorosilicone is added to the obtained mixture, and stirred at 75° C. for 1 hour to obtain the lubricating oil composition.

[0030] The lubricating oil composition and the preparation method of the lubricating oil composition provided by the present invention are used in a gearbox.

[0031] The application provided by the present invention is used for an automobile gearbox; preferably, it is used for a plug-in hybrid vehicle gearbox.

[0032] Beneficial effects of the present invention:

[0033] (1) By optimizing additives and base oil, the lubricating oil of the present invention has good electrochemical properties and thermal conductivity, excellent compatibility with motor materials, especially insulating materials, and good friction properties.

[0034] (2) Through the coordination of the components, the lubricating oil composition of the present invention can exhibit good low-temperature fluidity, extreme pressure and anti-wear properties, oxidation stability, and anti-rust and anti-corrosion properties, and can provide good lubrication protection for gearbox gears and bearings, thereby extending the service life of the oil product; the lubricating oil composition has excellent electrochemical properties and motor material compatibility, and can be used for lubrication and cooling of motors, providing good insulation properties, and ensuring the normal operation of motors; at the same time, the lubricating oil composition has good friction properties, and is suitable for plug-in hybrid electric vehicle gearboxes with friction property requirements.

[0035] (3) The preparation method of the lubricating oil composition of the present invention is simple and suitable for industrial production.

[0036] (4) The lubricating oil composition of the present invention has good effect when applied to the gearbox of plug-in hybrid electric vehicles and is superior to ordinary commercially available lubricating oil products. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] The preparation method of the plug-in hybrid electric vehicle transmission oil composition of the present embodiment comprises: adding, by weight percentage, 3.2% of an extreme pressure anti-wear agent thiophosphite, 0.3% of an antioxidant tert-butylphenol, 0.1% of a metal deactivator thiadiazole derivative, 0.8% of a detergent calcium alkyl salicylate, 2.6% of a dispersant polyisobutylate, 1.25% of a friction modifier imide, and 4.5% of a viscosity index improver polymethacrylate, to an API III hydrogenated base oil, and stirring at 75° C. for 2 hours until the mixture is uniform and transparent; adding 0.03% of an anti-foaming agent fluorosilicone to the obtained mixture, and stirring at 75° C. for 1 hour to obtain the lubricating oil composition for the plug-in hybrid electric transmission.

[0040] Example 2

[0041] The preparation method of the plug-in hybrid electric vehicle transmission oil composition of the present embodiment comprises: adding, by weight percentage, 3.2% of an extreme pressure anti-wear agent thiophosphite, 0.3% of an antioxidant tert-butylphenol, 0.1% of a metal deactivator thiadiazole derivative, 0.8% of a detergent calcium alkyl salicylate, 2.6% of a dispersant polyisobutylene imide, 1.25% of a friction modifier amide, and 4.5% of a viscosity index improver polymethacrylate, to an API III hydrogenated base oil, and stirring at 75° C. for 2 hours until the mixture is uniform and transparent; adding 0.03% of an anti-foaming agent fluorosilicone to the obtained mixture, and stirring at 75° C. for 1 hour to obtain the lubricating oil composition for the plug-in hybrid electric transmission.

[0042] Example 3

[0043] The preparation method of the plug-in hybrid electric vehicle transmission oil composition of the present embodiment comprises: adding, by weight percentage, 3.2% of an extreme pressure anti-wear agent thiophosphite, 0.3% of an antioxidant tert-butylphenol, 0.1% of a metal deactivator thiadiazole derivative, 0.8% of a detergent calcium alkyl salicylate, 2.6% of a dispersant polyisobutylene ester, 1.25% of a friction modifier amide, and 4.5% of a viscosity index improver polymethacrylate, to an API III hydrogenated base oil, and stirring at 75° C. for 2 hours until the mixture is uniform and transparent; adding 0.03% of an anti-foaming agent fluorosilicone to the obtained mixture, and stirring at 75° C. for 1 hour to obtain the lubricating oil composition for the plug-in hybrid electric transmission.

[0044] Comparative Examples 1-2

[0045] Comparative Example 1 and Comparative Example 2 are commercially available hybrid transmission oil products.

[0046] Comparative Example 3

[0047] Comparative Example 3 was carried out in the same manner as in Example 1, except that the friction modifier imide in Example 1 was replaced with dioleyl phosphite, to obtain a lubricating oil composition for a plug-in hybrid transmission fluid.

[0048] The test results of the lubricating oil composition for plug-in hybrid electric vehicles (Examples 1-3) obtained according to the embodiment of the present invention and the transmission oil prepared by Comparative Examples 1 to 3 are shown in Table 1.

[0049] Table 1 Test results of Examples 1 to 3 and Comparative Examples 1 to 3

[0050]

[0051]

[0052] The data analysis results of Table 1 show that, compared with Comparative Examples 1 to 3, Examples 1 to 3 have excellent oxidation stability and copper sheet corrosion performance; Example 1 has the most excellent electrochemical performance, with a breakdown voltage of 75 kV, a volume resistivity of 32 MOhm·m, and a dielectric constant of 2.12; the motor materials of Examples 1 to 3 have good compatibility and meet the insulation performance requirements of the motor; at the same time, the friction performance μ0 / μd values ​​of Examples 1 to 3 are all between 1.0 and 1.05, meeting the friction characteristics requirements of the gearbox.

[0053] The lubricating oil composition provided by the present invention has good low-temperature fluidity, extreme pressure and anti-wear properties, oxidation stability, and anti-rust and anti-corrosion properties, and also has excellent electrochemical properties and motor material compatibility, and has good friction properties, and is suitable for plug-in hybrid electric vehicle gearboxes with friction property requirements.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Application of a lubricating oil composition in a plug-in hybrid electric vehicle gearbox, characterized in that: The lubricating oil composition comprises, by weight percentage, 2.8-3.4 wt % of an extreme pressure anti-wear agent thiophosphite, 0.2-0.4 wt % of an antioxidant tert-butylphenol, 0.08-0.12 wt % of a metal deactivator thiadiazole derivative, 0.7-0.9 wt % of a detergent calcium alkyl salicylate, 2.4-2.8 wt % of a dispersant polyisobutylene ester, 1.1-1.4 wt % of a friction modifier imide, 4-5 wt % of a viscosity index improver polymethacrylate, and 0.02-0.04 wt % of an anti-foaming agent fluorosilicone, and the balance is API III class hydrogenated base oil; The friction performance μ0 / μd value of the lubricating oil composition is between 1.0 and 1.

05.

2. Application of a lubricating oil composition in a plug-in hybrid electric vehicle gearbox, characterized in that: The lubricating oil composition comprises, in percentage by mass, 2.8-3.4 wt % of an extreme pressure anti-wear agent thiophosphite, 0.2-0.4 wt % of an antioxidant tert-butylphenol, 0.08-0.12 wt % of a metal deactivator thiadiazole derivative, 0.7-0.9 wt % of a detergent calcium alkyl salicylate, 2.4-2.8 wt % of a dispersant polyisobutylene ester, 1.1-1.4 wt % of a friction modifier amide, 4-5 wt % of a viscosity index improver polymethacrylate and 0.02-0.04 wt % of an anti-foaming agent fluorosilicone, and the balance is API Class III hydrogenated base oil; The friction performance μ0 / μd value of the lubricating oil composition is between 1.0 and 1.

05.

3. Use of the lubricating oil composition according to any one of claims 1 to 2 in a plug-in hybrid electric vehicle gearbox, characterized in that: The preparation method of the lubricating oil composition comprises: mixing an extreme pressure anti-wear agent, an antioxidant, a metal deactivator, a detergent, a dispersant, a friction modifier, and a viscosity index improver, and then adding a base oil and stirring until the mixture is uniform and transparent; adding an anti-foaming agent to the obtained mixture, and mixing and stirring to obtain the lubricating oil composition.

4. The use of the lubricating oil composition according to claim 3 in a plug-in hybrid electric vehicle gearbox, characterized in that: The stirring is heating stirring.

5. The use of the lubricating oil composition according to claim 4 in a plug-in hybrid electric vehicle gearbox, characterized in that: The heating and stirring temperature is 45-80° C., and the stirring time is 1-3 hours.

6. The use of the lubricating oil composition according to claim 4 in a plug-in hybrid electric vehicle gearbox, characterized in that: The stirring is mechanical stirring and / or pulse stirring.

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