Multi-gear gearbox lubricating oil composition as well as preparation method and application thereof

Abstract

The invention belongs to the field of lubricating oil, and particularly relates to a multi-gear gearbox lubricating oil composition as well as a preparation method and application thereof. The multi-gear gearbox lubricating oil composition is prepared from the following raw materials in percentage by mass: 2.0 percent to 4.5 percent of a viscosity index improver, 0.01 percent to 0.08 percent of a clearing agent, 4.5 percent to 7.0 percent of a dispersing agent, 0.3 percent to 1.0 percent of an anti-wear reagent at extreme pressure, 0.05 percent to 0.3 percent of an anti-rust agent, 0.3 percent to 1.5 percent of an antioxidant, 0.01 percent to 0.2 percent of a metal deactivator, 0.3 percent to 1.5 percent of a cross-linking agent, 0.01 percent to 0.03 percent of an anti-foaming agent and the balance of base oil. The cross-linking agent of the composition adopts trimethylolpropane tri (1H-imidazole-1-acetate), so that the wear resistance of an oil product is effectively enhanced, the friction coefficient is reduced, and the friction durability is improved, thereby achieving the effects of prolonging the endurance mileage and prolonging the service life of hardware.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil, specifically relating to a multi-speed transmission lubricating oil composition, its preparation method and application, and more specifically to a lubricating oil composition for AT, CVT, DCT transmissions and hybrid DHT transmissions containing a wet clutch, its preparation method and application. Background Technology

[0002] Hybrid electric vehicles (HEVs) have gained popularity due to their combination of the advantages of internal combustion engines and electric motors. Dedicated DHT transmissions for hybrid vehicles require deceleration and torque amplification of the power supplied by the engine and electric motor. During the process of driving the vehicle with these two power sources, the transmission typically uses a wet clutch to interrupt and switch the power sources, ensuring smooth and stable vehicle operation. Combined with traditional AT, CVT, and DCT transmissions, the market share of automatic transmissions using wet clutches has increased significantly. To better meet the performance requirements of different OEMs for transmission fluids, balancing the compatibility of various additives is a crucial aspect of fluid development. Simultaneously, to meet the demands of high-speed and full-life operating conditions, the performance requirements for the lubricant's load-bearing capacity and long service life for gears and bearings have been strengthened. Therefore, a transmission fluid product that balances load-bearing capacity and friction durability is needed.

[0003] Chinese invention patent application CN108218835A discloses the preparation of an extreme pressure anti-wear agent and its application in the transmission oil of new energy electric vehicles. It is formulated with 2-pyrrole dithioacetamido, detergent, ashless dispersant and hydrogenated base oil. The product has low viscosity, low friction, low oil loss and corrosion to metals is far lower than similar products on the market.

[0004] Chinese invention patent application CN113930275A discloses a lubricating oil for an oil-cooled hybrid power gearbox and its application. The lubricating oil comprises the following components by weight percentage: alkyl polysulfides, phosphorus-containing anti-wear agents, viscosity index improvers, pour point depressants, detergent-dispersants, antioxidants, rust inhibitors, metal deactivators, antifoaming agents, hydrotreated base oil, and the balance being synthetic oil; wherein the alkyl polysulfides are polyalkylbenzyl sulfides T324; the phosphorus-containing anti-wear agents are selected from a combination of zinc dialkyl dithiophosphate T204, thiophosphate Irgalube 353, and phosphite T304; the hydrotreated base oil is a Group III hydrotreated base oil; the synthetic oil is a poly-α-olefin synthetic oil; and the viscosity index improver is polymethyl methacrylate. The lubricating oil has the advantages of low viscosity, good compatibility with copper components, and low metal corrosion.

[0005] Chinese invention patent application CN105132107A discloses a lubricating oil composition for a transmission in a pure electric vehicle, comprising the following components by weight percentage: a) at least one viscosity index improver 0.5-25%; b) at least one extreme pressure anti-wear agent 0.05-10%; c) at least one antioxidant 0.5-5%; d) base oil balance. The composition provided by this invention can meet the lubrication requirements of gears and bearings in a pure electric vehicle transmission. The resulting lubricating oil exhibits excellent low-temperature performance, extreme pressure anti-wear properties, antioxidant properties, and rust and corrosion prevention properties, demonstrating superior overall performance. It also features a simple composition and easy manufacturing process.

[0006] None of the above inventions involve the application of trimethylolpropane tris(1H-imidazol-1-acetic acid) in multi-speed transmission lubricating oil containing wet clutches, nor have any related reports been found. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a multi-speed transmission lubricating oil composition, its preparation method, and its application. Specifically, it is an additive and lubricating oil composition that improves the mechanical protection performance and frictional durability of multi-speed transmissions containing wet clutches. The crosslinking agent in this composition is trimethylolpropane tris(1H-imidazolium-1-acetate), which effectively enhances the oil's anti-wear ability, reduces the coefficient of friction, and improves frictional durability, thereby extending driving range and hardware lifespan. The composition exhibits stable performance and meets the lubrication requirements of multi-speed transmissions containing wet clutches.

[0008] To achieve the above-mentioned objectives of this invention, the specific technical solution adopted by this invention is as follows:

[0009] A multi-speed transmission lubricant composition, wherein the raw materials of the multi-speed transmission lubricant composition, by mass percentage, include: 2.0%-4.5% viscosity index improver, 0.01%-0.08% detergent, 4.5%-7.0% dispersant, 0.3%-1.0% extreme pressure anti-wear agent, 0.05%-0.3% rust inhibitor, 0.3%-1.5% antioxidant, 0.01%-0.2% metal passivator, 0.3%-1.5% crosslinking agent, 0.01%-0.03% antifoaming agent, and the balance being base oil.

[0010] Preferably, the viscosity index improver is polymethacrylate.

[0011] Preferably, the detergent is selected from one or two of high-alkalinity alkylphenol salts and thiosulfates.

[0012] Preferably, the dispersant is bis(succinimide).

[0013] Preferably, the extreme pressure anti-wear agent is a mixture of dialkyl dithiophosphate and butyl triphenyl thiophosphate.

[0014] More preferably, the mass ratio of the dialkyl dithiophosphate to the butyl triphenyl thiophosphate is 4-6:1.

[0015] Preferably, the rust inhibitor is selected from one or both of dodecenyl succinic acid and alkenyl succinic acid half ester.

[0016] Preferably, the antioxidant is selected from one or two of octyl / pentyl diphenylamine, octyl-substituted diphenylamine, and high molecular weight phenolic antioxidants.

[0017] Preferably, the metal passivating agent is a 2,5-dithio-1,3,4-thiazolidinediazole derivative.

[0018] Preferably, the crosslinking agent is trimethylolpropane tris(1H-imidazol-1-acetate), with the following structure:

[0019]

[0020] Preferably, the antifoaming agent is a silicone-non-silicone composite T922.

[0021] Preferably, the base oil is one or more of Group II hydrotreated base oil and Group III hydrotreated base oil.

[0022] This invention also relates to a method for preparing the above-mentioned multi-speed transmission lubricating oil composition, comprising the following steps:

[0023] Add the base oil to the mixing tank, then add the remaining raw materials, and stir at 65-75℃ for 2-3 hours to obtain the multi-speed gearbox lubricating oil composition.

[0024] The present invention also relates to the application of the above-mentioned multi-speed transmission lubricating oil composition in the preparation of transmission lubricating oil.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The crosslinking agent of the composition in this invention is trimethylolpropane tri(1H-imidazol-1-acetic acid ester), which effectively enhances the wear resistance of the oil, reduces the coefficient of friction, and improves friction durability, thereby achieving the effect of extending the driving range and the service life of the hardware.

[0027] (2) The composition of the present invention, by adding specific raw materials and optimizing the ratio, makes the performance of the lubricating oil more stable and meets the lubrication requirements of multi-speed gearboxes with wet clutches. Attached Figure Description

[0028] Figure 1Friction durability tests were conducted on each embodiment and comparative example using the test method in Appendix C of GMW 16444 in the NO.2 friction testing machine, characterizing the change of stopping time with the number of cycles;

[0029] Figure 2 The friction durability tests were conducted on each embodiment and comparative example using the test method in Appendix C of GMW 16444 in the NO.2 friction testing machine, characterizing the change of midpoint torque with the number of cycles;

[0030] Figure 3 The friction durability tests were conducted on each embodiment and comparative example using the test method in Appendix C of GMW 16444 on the NO.2 friction testing machine, characterizing the change of maximum torque with the number of cycles. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0032] Example 1

[0033] A multi-speed transmission lubricating oil composition containing a wet clutch, the raw materials and addition amounts are shown in Table 1.

[0034] The base oil is added to the mixing tank, and then various additives are added. The mixture is stirred at 75°C for 2 hours until it is homogeneous, thus obtaining the multi-speed gearbox lubricating oil composition.

[0035] Table 1 Raw materials and dosage

[0036]

[0037]

[0038] Example 2

[0039] A multi-speed transmission lubricating oil composition containing a wet clutch, the raw materials and addition amounts are shown in Table 2.

[0040] The base oil is added to the mixing tank, and then various additives are added. The mixture is stirred at 70°C for 2.5 hours until it is homogeneous, thus obtaining the multi-speed gearbox lubricating oil composition.

[0041] Table 2 Raw materials and dosage

[0042]

[0043] Example 3

[0044] A multi-speed transmission lubricating oil composition containing a wet clutch, the raw materials and addition amounts are shown in Table 3.

[0045] The base oil is added to the mixing tank, and then various additives are added. The mixture is stirred at 65°C for 3 hours until it is homogeneous, thus obtaining the multi-speed gearbox lubricating oil composition.

[0046] Table 3 Raw materials and dosage

[0047]

[0048]

[0049] Comparative Example 1

[0050] A multi-speed transmission lubricating oil composition containing a wet clutch is provided, and the raw materials and dosages are shown in Table 4. The preparation method is the same as in Example 2.

[0051] Table 4 Raw materials and dosage

[0052]

[0053] Comparative Example 2

[0054] A multi-speed transmission lubricating oil composition containing a wet clutch is provided, and the raw materials and dosages are shown in Table 5. The preparation method is the same as in Example 2.

[0055] Table 5 Raw materials and dosage

[0056]

[0057]

[0058] Comparative Example 3

[0059] A multi-speed transmission lubricating oil composition containing a wet clutch is provided, and the raw materials and dosages are shown in Table 6. The preparation method is the same as in Example 2.

[0060] The crosslinking agent used in this comparative example has a similar structure to that in Example 2, and is trimethylolpropane tris(2-methyl-1-azacyclopropane propionate), CAS: 64265-57-2. Its structure is shown below:

[0061]

[0062] Table 6 Raw Materials and Additive Amounts

[0063]

[0064]

[0065] Comparative Example 4

[0066] A multi-speed transmission lubricating oil composition containing a wet clutch is provided, and the raw materials and dosages are shown in Table 7. The preparation method is the same as in Example 2.

[0067] Table 7 Raw Materials and Additive Amounts

[0068]

[0069] Effect test

[0070] The above-mentioned oil products were subjected to FZG load-bearing capacity tests, and the test results are shown in Figure 8 below.

[0071] Table 8. Test Results of FZG Bearing Capacity

[0072]

[0073] The data from the oils prepared in Examples 1-3 and Comparative Examples 1-4 show that the oil blended in Comparative Example 1, without the addition of the crosslinking agent trimethylolpropane tris(1H-imidazol-1-acetate), did not exhibit FZG gear scuffing. In Comparative Example 2, the dosage of the crosslinking agent trimethylolpropane tris(1H-imidazol-1-acetate) was increased to 2.0%, but it failed to have an effective effect. In Comparative Example 3, a structurally similar crosslinking agent trimethylolpropane tris(2-methyl-1-azacyclopropanepropionate) was used at a dosage of 1.0%, but it also failed to have an effective effect. In contrast, Comparative Example 4, which used a structurally similar crosslinking agent, trimethylolpropane tris(2-methyl-1-azacyclopropane propionate), at a dosage of 2.0%, also failed to achieve an effective effect. However, in Examples 1-3, 0.5%, 1.0%, and 1.5% of trimethylolpropane tris(1H-imidazol-1-acetate) were added, respectively, which ensured that the load-bearing capacity of the oil met the technical requirements of mainstream OEM car manufacturers on the market. Among them, the dosage of Examples 2-3 was higher, and its load-bearing capacity was better than that of the main competing products on the market.

[0074] In addition, GMW 16444 Appendix C tests were conducted in the NO.2 friction testing machine to examine the friction characteristics of the oil of this invention. In the 36,000-cycle durability test, the stopping time, midpoint torque, and maximum torque should not exceed the limit requirements. Figures 1-3 The test data show that Comparative Examples 1-4 all had test elements exceeding the limit values. Examples 1-3, however, all met the Dexron VI specifications. With the increase of trimethylolpropane tris(1H-imidazolium-1-acetate) addition, the friction durability characteristics improved. This also indirectly verifies that the addition of a crosslinking agent can not only improve the friction durability of the oil but also improve its load-bearing capacity by reducing the interfacial friction coefficient, thus alleviating surface fatigue and damage.

[0075] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A multi-speed transmission lubricating oil composition, characterized in that, The raw materials of the multi-speed transmission lubricant composition, by weight percentage, include: viscosity index improver 2.0%-4.5%, detergent 0.01%-0.08%, dispersant 4.5%-7.0%, extreme pressure anti-wear agent 0.3%-1.0%, rust inhibitor 0.05%-0.3%, antioxidant 0.3%-1.5%, metal passivator 0.01%-0.2%, crosslinking agent 0.3%-1.5%, antifoaming agent 0.01%-0.03%, and the balance being base oil.

2. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The viscosity index improver is polymethyl methacrylate.

3. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The detergent is selected from one or two of high-alkalinity alkylphenol salts and thiosulfates.

4. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The dispersant is bis(succinimide).

5. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The extreme pressure anti-wear agent is a mixture of dialkyl dithiophosphate and butyl triphenyl thiophosphate.

6. The multi-speed transmission lubricating oil composition according to claim 5, characterized in that, The mass ratio of the dialkyl dithiophosphate to the butyl triphenyl thiophosphate is 4-6:

1.

7. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The rust inhibitor is selected from one or both of dodecenyl succinic acid and alkenyl succinic acid half ester.

8. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The antioxidant is selected from one or two of octyl / pentyl diphenylamine, octyl-substituted diphenylamine, and high molecular weight phenolic antioxidants.

9. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The metal passivating agent is a 2,5-dithio-1,3,4-thiazolidinedione derivative.

10. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The crosslinking agent is trimethylolpropane tris(1H-imidazol-1-acetic acid).

11. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The antifoaming agent is a silicone-non-silicone composite, T922.

12. The multi-speed transmission lubricating oil composition according to claim 1, characterized in that, The base oil is one or more of Group II hydrotreated base oil and Group III hydrotreated base oil.

13. A method for preparing the multi-speed transmission lubricating oil composition according to any one of claims 1-12, characterized in that, Includes the following steps: Add the base oil to the mixing tank, then add the remaining raw materials, and stir at 65-75℃ for 2-3 hours to obtain the multi-speed gearbox lubricating oil composition.

14. The use of the multi-speed transmission lubricating oil composition according to any one of claims 1-12 in the preparation of transmission lubricating oil.

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