CN115058278A

CN115058278A - Gearbox oil and preparation method and application thereof

Info

Publication number: CN115058278A
Application number: CN202210789369.XA
Authority: CN
Inventors: 乔传威; 王静礼; 梁浩勇; 孙彦; 郑金周; 陈铁旦
Original assignee: Zhengzhou Oupushi Technology Co ltd
Current assignee: Zhengzhou Oupushi Technology Co ltd
Priority date: 2022-07-05
Filing date: 2022-07-05
Publication date: 2022-09-16
Anticipated expiration: 2042-07-05
Also published as: CN115058278B

Abstract

The invention provides gearbox oil, and belongs to the technical field of automobiles. The extreme pressure agent and the antiwear agent adopted by the invention are both ashless antiwear agents, and are matched with two ashless friction modifiers in a good proportion, so that a low friction coefficient can be obtained for a long time, and long-acting antiwear protection is ensured. Specifically, the ashless anti-wear system adopts an amine phosphate mixture, and the alkyl chain is longer, belongs to chemical adsorption and has better anti-wear performance. And through the two compounded ashless amide friction modifiers, a lower friction coefficient can be ensured at a lower temperature through physical adsorption, and along with the temperature rise, the friction modifier is formed by initially forming a monomolecular film and connecting self polar groups into a dimer through hydrogen bonds and Debye induced stress, so that polymolecular layer adsorption is repeatedly formed, a stable and compact protective film can be formed on the friction surface at a low temperature and a high temperature in a boundary and mixed lubrication state, a long-term lower friction coefficient is obtained, and long-term wear resistance protection is ensured.

Description

Gearbox oil and preparation method and application thereof

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to gearbox oil as well as a preparation method and application thereof.

Background

In recent years, the sales volume of new energy automobiles in China is increased explosively. At present, a new energy electric automobile adopts traditional fuel vehicle gearbox oil. However, the new energy automobile comprises a motor structure, and when the existing gearbox oil is applied to the electric axle gearbox of the new energy automobile, pitting abrasion of a meshing gear set and a bearing caused by insufficient wear resistance can occur.

Disclosure of Invention

The invention aims to provide gearbox oil and a preparation method and application thereof.

The invention provides a gearbox oil which comprises the following components in percentage by mass: 4 to 5.5 percent of viscosity index improver, 0.25 to 0.35 percent of detergent, 2.7 to 3.3 percent of dispersant, 0.4 to 0.6 percent of antioxidant, 0.15 to 0.25 percent of extreme pressure agent, 0.25 to 0.35 percent of antiwear agent, 0.28 to 0.32 percent of friction improver, 0.5 to 1.0 percent of seal expanding agent, 0.15 to 0.25 percent of metal deactivator, 0.01 to 0.02 percent of anti-foaming agent and the balance of mixed coal base oil;

the extreme pressure agent is nonyl triphenyl thiophosphate or amine phosphate; the antiwear agent is an amine phosphate mixture or phosphite triester; the friction modifier is oleic acid diethanolamide and a liquid high-molecular-weight multi-effect single agent; the mass ratio of the oleic diethanolamide to the liquid high-molecular-weight multi-effect single agent is 1: 2.

preferably, the viscosity index improver comprises polymethacrylate.

Preferably, the detergent comprises a polyetheramine; the dispersant comprises boronated polyisobuteneimide or an ashless phosphate.

Preferably, the antioxidant comprises two of octyl butyl diphenylamine, an antioxidant POUPC 5002 and methyl benzotriazole.

Preferably, the kinematic viscosity of the base oil prepared from the mixed coal is 3.2-3.5 mm ² /s。

Preferably, the seal swell agent comprises trimethylolpropane oleate or monopentaerythritol oleate.

Preferably, the metal deactivator includes a thiadiazole derivative or a methylbenzotriazole derivative.

Preferably, the anti-foaming agent comprises dimethicone or methyl silicone ester.

The invention also provides a preparation method of the gearbox oil, which comprises the following steps:

diluting the anti-foaming agent by using light solvent oil to obtain a diluent of the anti-foaming agent;

heating mixed coal base oil, and mixing with a viscosity index improver and a diluent of an anti-foaming agent to obtain a mixed solution;

mixing the mixed solution with a detergent, a dispersant, an antioxidant, an extreme pressure agent, an antiwear agent, a friction modifier, a seal expanding agent and a metal deactivator to obtain transmission oil;

the invention also provides application of the gearbox oil prepared by the scheme or the preparation method of the scheme in a gearbox of a new energy automobile.

The invention provides a gearbox oil which comprises the following components: 4 to 5.5 percent of viscosity index improver, 0.25 to 0.35 percent of detergent, 2.7 to 3.3 percent of dispersant, 0.4 to 0.6 percent of antioxidant, 0.15 to 0.25 percent of extreme pressure agent, 0.25 to 0.35 percent of antiwear agent, 0.28 to 0.32 percent of friction improver, 0.5 to 1.0 percent of seal expanding agent, 0.15 to 0.25 percent of metal deactivator, 0.01 to 0.02 percent of anti-foaming agent, 0.1 to 0.2 percent of light solvent oil, and the balance of mixed coal base oil; the extreme pressure agent is nonyl triphenyl thiophosphate or amine phosphate; the antiwear agent is an amine phosphate mixture or phosphite triester; the friction modifier comprises oleic acid diethanolamide and a liquid high-molecular-weight multi-effect single agent; the mass ratio of the oleic diethanolamide to the liquid high-molecular-weight multi-effect single agent is 1: 2. the extreme pressure agent and the antiwear agent adopted by the invention are ashless antiwear agents, and are matched with two ashless friction modifiers in a good proportion, so that a low friction coefficient can be obtained for a long time, and long-acting antiwear protection is ensured. Specifically, an ashless anti-wear system adopts a phosphoric ester-amine mixture, the alkyl chain is longer, the chemical adsorption is realized, the anti-wear performance is better, but the thermal stability and the anti-wear durability need to be complemented; especially, in the low temperature state of the initial operation and the later state of the long-term high temperature operation, the anti-wear and anti-friction performance needs to be complemented. Therefore, the two compounded ashless amide friction modifiers can ensure a lower friction coefficient at a lower temperature through physical adsorption, and the friction modifiers are formed by initially forming a monomolecular film to connect self polar groups into a dimer through hydrogen bonds and Debye induced stress along with the rise of the temperature, so that the polymolecular layer adsorption is repeatedly formed, a stable and compact protective film can be formed on the friction surface at a low temperature and a high temperature under the boundary and mixed lubrication state, a long-term lower friction coefficient is obtained, and long-term wear resistance protection is ensured. The embodiment result shows that the maximum non-seizing load of the gearbox oil is 250KG, the sintering load is 250KG, the diameter of a grinding spot is 0.42-0.45 mm, the pitting corrosion of FZG is 209-227 hrs, the abrasion of the FZG low-speed gear is 10-12 mg, the pitting corrosion of an FE8 bearing is 269-273 h, and the abrasion loss (roller) of the FE8 bearing is 1 mg.

Furthermore, in the formula of the traditional oil-fired vehicle transmission oil, a detergent, an antioxidant and a friction modifier are all metal salt ion types, which are currently widely applied schemes, but the defects are that the metal ions can also be used as a catalyst while playing a role, so that oil products are aged too fast and oxidized to generate dirt such as oil sludge, and the metal salt compounds are the causes of the oil sludge. The transmission oil does not contain metal ions, three ashless antioxidants of octyl butyl diphenylamine, an antioxidant POUPC 5002 and methyl benzotriazole are selected, and the proportion of the two antioxidants is adjusted to ensure that the antioxidant effect reaches the optimal state, so that the transmission oil does not generate excessive greasy filth and other dirt which have influence on the electric conductivity in the long-term use process, and the low electric conductivity is maintained for a long time. The embodiment results show that the increase rate of the kinematic viscosity of the transmission oil at 40 ℃ is 10.65-14.52%, the increase rate of the kinematic viscosity at 100 ℃ is 8.79-13.44%, the acid value is changed to 1.33-1.44 mgKOH/g, and the conductivity of the transmission oil before and after oxidation is slightly increased.

Furthermore, the extreme pressure agent adopts ashless sulfur-phosphorus agent-nonyl triphenyl thiophosphate which has good copper sheet corrosion protection, and simultaneously has excellent liquid phase and gas phase copper corrosion protection performance by matching with proper metal deactivator. The embodiment result shows that the copper content of the transmission oil disclosed by the invention is 35-40 ppm in a liquid-phase copper corrosion test and the transmission oil passes a gas-phase copper corrosion test.

Furthermore, the mixed coal base oil has extremely high viscosity index, ensures that the base oil has better oil film thickness at high temperature to ensure lubrication, and has better fluidity at low temperature to prevent low-temperature abrasion. And the coal-based base oil belongs to fully synthetic base oil, has high thermal conductivity and specific heat capacity, and can quickly dissipate heat. The example results show that the transmission oil of the present invention has excellent specific heat capacity and thermal conductivity.

In addition, the mixed coal base oil adopted by the invention has a shrinkage effect on the sealing material, so that the sealing expanding agent with a reasonable proportion is compounded in a formula system, and the compatibility of the sealing expanding agent with a nylon (PA66) material is ensured. The results of the examples show that after soaking nylon (PA66) in the transmission oil of the present invention at a temperature of 150 ℃ for 240 hours, the tensile strength change rate is 5% to 6%, the change rate extending to a fracture is-3%, and the appearance is free from cracks.

Drawings

FIG. 1 is a graph showing the thermal conductivity of transmission oils of examples 1 to 4 and comparative examples 1 to 2;

FIG. 2 is a graph of the specific heat capacity of the transmission oils of examples 1-4 and comparative examples 1-2;

FIG. 3 shows the insulation voltage test results of the transmission fluids of example 1 and comparative examples 1-2;

FIG. 4 shows the results of conductivity tests on transmission fluids of example 1 and comparative examples 1-2;

FIG. 5 is a graph of the electrical performance test results for example 1 and comparative example 1 transmission fluids before and after a DKA oxidation test;

FIG. 6 is a copper sheet after a vapor phase copper corrosion test with the transmission oil of example 1;

FIG. 7 is a copper sheet after vapor phase copper corrosion testing with the transmission oil of example 2;

FIG. 8 is a copper sheet after a vapor phase copper corrosion test with the transmission oil of example 3;

FIG. 9 is a copper sheet after a vapor phase copper corrosion test with the transmission oil of example 4;

FIG. 10 is a copper sheet after a vapor phase copper corrosion test with the transmission oil of comparative example 1;

fig. 11 is a copper sheet after a vapor phase copper corrosion test with the transmission oil of comparative example 2.

Detailed Description

The invention provides a gearbox oil which comprises the following components in percentage by mass: 4 to 5.5 percent of viscosity index improver, 0.25 to 0.35 percent of detergent, 2.7 to 3.3 percent of dispersant, 0.4 to 0.6 percent of antioxidant, 0.15 to 0.25 percent of extreme pressure agent, 0.25 to 0.35 percent of antiwear agent, 0.28 to 0.32 percent of friction improver, 0.5 to 1.0 percent of seal expanding agent, 0.15 to 0.25 percent of metal deactivator, 0.01 to 0.02 percent of anti-foaming agent, 0.1 to 0.2 percent of light solvent oil, and the balance of mixed coal base oil;

the transmission oil comprises 4-5.5% of viscosity index improver, preferably 4.5-5% by mass percent. In the present invention, the viscosity index improver preferably comprises polymethacrylate. The preferable kinematic viscosity of the polymethacrylate at 100 ℃ is 245.7-275.5 mm ² And s. The source of the polymethacrylate is not particularly limited in the present invention, and the above kinematic viscosity can be satisfied. Specifically, the polymethacrylate can be Hitec 5769, a Yaofton chemical industry (Suzhou) Co., Ltd., or TK-chem V6350, a Dalian New York Co., Ltd. In the invention, the polymethacrylate has excellent shear resistance, and the side chain of the structure has a modified dispersing group, so that the polymethacrylate has excellent capacity of dispersing oil sludge. The modified dispersing groups can form thicker barrier membranes at multiple positions among ions, so that oil sludge ions peptized to reach 100nm are uniformly dispersed in oil, a suspension state is maintained, an oil way is not blocked, the pressure is kept stable, the high temperature of an oil product is prevented, and the purpose of controlling oxidation is achieved.

The gearbox oil comprises 0.25-0.35% of detergent, preferably 0.3-0.32% of detergent in percentage by mass. In the present invention, the detergent preferably comprises a polyetheramine. The polyether amine is preferably amber liquid, and the transportation of the polyether amine at 40 DEG CThe kinematic viscosity is preferably 121.7mm ² The flash point is preferably 200 ℃. The source of the polyether amine is not particularly limited, and the kinematic viscosity and the flash point are satisfied. Specifically, in the embodiment of the invention, the polyether amine is powerzo of luobo additive (pearl sea) limited ^TM 9522D. The polyether amine has multiple effects of cleaning, dispersing, demulsifying, corrosion inhibiting, resisting oxidation and the like, is an ashless additive, is different from the traditional metal salt detergent, and can ensure that the transmission oil has lower conductivity and conductivity after aging.

The transmission oil comprises 2.7-3.3% of dispersing agent, preferably 3.0-3.2% by mass. In the present invention, the dispersant preferably comprises a borated polyisobuteneimide or an ashless phosphate. The preferable kinematic viscosity of the boronated polyisobuteneimide is 130-250 mm at 100 DEG C ² (ii) s, more preferably 150 to 200mm ² The total base number is preferably 15 to 30mgKOH/g, more preferably 20 to 25 mgKOH/g. The source of the boronated polyisobuteneimide is not particularly limited, and the kinematic viscosity and the total base number are satisfied. Specifically, in the embodiment of the present invention: the boronated polyisobutenoyl imide is RF1154B from Refeng New materials GmbH, New county, N.J.. In the invention, the boronized polyisobutenyl imide has the function of dispersing oil sludge and has the functions of resisting oxygen and resisting wear.

The transmission oil comprises 0.4-0.6% of antioxidant, preferably 0.45-0.5% by mass. In the invention, the antioxidant is preferably two of octyl butyl diphenylamine, an antioxidant POUPC 5002 and methyl benzotriazole ester; when the antioxidant is octyl butyl diphenylamine and an antioxidant POUPC 5002, the mass ratio of the octyl butyl diphenylamine to the antioxidant POUPC 5002 is preferably 1: 1-1.5, and more preferably 1: 1.2-1.4. When the antioxidant is methyl phenyl triazole ester and octyl butyl diphenylamine, the mass ratio of the methyl phenyl triazole ester to the octyl butyl diphenylamine is preferably 1-1.5: 1, and more preferably 1: 1.2-1.4. When the antioxidant is methyl benzotriazole and antioxidant POUPC 5002, the mass ratio of the methyl benzotriazole to the antioxidant POUPC 5002 is preferably 1-1.5: 1, and more preferably 1: 1.2-1.4. The sources of the octyl butyl diphenylamine, the antioxidant POUPC 5002 and the methyl benzotriazole ester are not particularly limited, and the products are commercially available. Specifically, in the embodiment of the present invention: octyl butyl diphenylamine is an antioxidant L57 from BASF (China) Co., Ltd, and antioxidant POUPC 5002 was purchased from Pacific Union (Beijing) petrochemical Co., Ltd. Octyl butyl diphenylamine, an antioxidant POUPC 5002 and methyl benzotriazole ester are all ashless composite high-temperature antioxidants, and can effectively inhibit high-temperature oxidation of oil products and control the generation of oil sludge when the temperature is usually in the range of 100-150 ℃. Octyl butyl diphenylamine and antioxidant POUPC 5002 in a weight ratio of 1: 1-1.5, can ensure the antioxidant effect to reach the optimal state.

The transmission oil comprises, by mass, 0.15-0.25% of extreme pressure agent, preferably 0.18-0.20%. In the invention, the extreme pressure agent is nonyl triphenyl thiophosphate or amine phosphate. The kinematic viscosity of the nonyl triphenyl thiophosphate at 40 ℃ is preferably 3000mm ² The sulfur content is preferably 4.5% and the phosphorus content is preferably 4.3%. The source of the nonyl triphenyl thiophosphate is not particularly limited, and the kinematic viscosity, the sulfur content and the phosphorus content can be met. Specifically, in the embodiment of the present invention: the nonyl triphenyl thiophosphate is Runlube211 from Schterner chemical Co., Ltd. in Hangzhou. The amine salt of a phosphoric acid ester is preferably P120 of shenyang deluxe lubricating oil additives ltd. In the invention, nonyl triphenyl phosphorothioate has excellent extreme pressure performance and wear resistance.

The transmission oil comprises 0.25-0.35% of antiwear agent, preferably 0.3-0.32% by mass. In the invention, the antiwear agent is an amine phosphate mixture or a phosphorous triester. The kinematic viscosity of the amine phosphate mixture at 40 ℃ is preferably 2390mm ² The phosphorus content is preferably 4.8% and the nitrogen content is preferably 2.7%. The source of the amine phosphate mixture is not particularly limited, and the kinematic viscosity, the sulfur content and the phosphorus content are satisfied. In particular, in the bookIn the embodiment of the invention: the amine phosphate mixture is Irgalube 349 from Basff (China) Inc. The phosphite triester is preferably Iragafos 168 from Basff.

The transmission oil comprises 0.28-0.32% of friction modifier, preferably 0.29-0.30% of friction modifier. In the invention, the friction modifier is oleic acid diethanolamide and a liquid high-molecular-weight multi-effect single agent; the mass ratio of the oleic diethanolamide to the liquid high-molecular-weight multi-effect single agent is 1: 2. the sources of the oleic acid diethanolamide and the liquid high-molecular-weight multi-effect single agent are not particularly limited, and the oleic acid diethanolamide and the liquid high-molecular-weight multi-effect single agent can be obtained by a commercially available product. Specifically, in the embodiment of the present invention: oleic diethanolamide is Hitec 3191, Yafuton chemical (Suzhou) Co., Ltd, and the liquid high molecular weight multi-effect mono-agent is Irgalube F10A, Basff (China) Co., Ltd. In the invention, the friction modifier type adopts two types of friction modifiers to be compounded and used cooperatively, and has excellent wear-resistant and friction-reducing performances especially in the presence of a sulfur-containing extreme pressure agent.

The extreme pressure agent and the antiwear agent adopted by the invention are both ashless antiwear agents, and are matched with two ashless friction modifiers in a good proportion, so that a low friction coefficient can be obtained for a long time, and long-acting antiwear protection is ensured. Specifically, the ashless anti-wear system adopts a phosphate amine mixture, has a longer alkyl chain, belongs to chemical adsorption, and has better anti-wear performance, but the thermal stability and the anti-wear durability need to be complemented; especially, in the low temperature state of the initial operation and the later state of the long-term high temperature operation, the anti-wear and anti-friction performance needs to be complemented. Therefore, the two compounded ashless amide friction modifiers can ensure a lower friction coefficient at a lower temperature through physical adsorption, and the friction modifiers are formed by initially forming monomolecular films and connecting self polar groups into dimers through hydrogen bonds and Debye induced stress along with the temperature rise, so that polymolecular layer adsorption is repeatedly formed, a stable and compact protective film can be formed on the friction surface at a low temperature and a high temperature in a boundary and mixed lubrication state, a long-term lower friction coefficient is obtained, and long-term wear resistance protection is ensured.

The transmission oil comprises 0.5-1.0% of sealing expanding agent, preferably 0.6-0.8% of sealing expanding agent. The seal swell agent preferably comprises trimethylolpropane oleate or monopentaerythritol oleate. The trimethylolpropane oleate preferably has a kinematic viscosity of 22.51mm at 40 DEG C ² S, the kinematic viscosity at 100 ℃ is preferably 4.75mm ² The viscosity index is preferably 134/s. In the present invention, the source of the trimethylolpropane oleate is not particularly limited, and the kinematic viscosity and the viscosity index may be satisfied. Specifically, in the embodiment of the present invention: the trimethylolpropane oleate is TRS0812 of Hangzhou Youmi chemical Co. Trimethylolpropane oleate has excellent polarity, has an expansion effect on sealing material nylon (PA66), and can compensate the contraction effect caused by the mixed base oil.

The transmission oil comprises 0.15-0.25% of metal deactivator, preferably 0.18-0.2% by mass percent. In the present invention, the metal deactivator preferably includes a thiadiazole derivative or a methylbenzotriazole derivative. The thiadiazole derivative is not specially limited in source, and can be obtained from commercial products. Specifically, in the embodiment of the present invention: the thiadiazole derivative is POUPC 6001-9 of Pacific Union (Beijing) petrochemical Co. The methylbenzotriazole derivative is preferably POUPC 7001 from Pacific (Beijing) petrochemical Co. The methyl benzotriazole derivatives and the thiadiazole derivatives are ashless metal deactivators, have multiple effects of metal deactivation, oxidation resistance and wear resistance, have strong inhibiting effect on copper corrosion, and can eliminate the negative influence of sulfur-containing extreme pressure agents on the copper corrosion.

The transmission oil comprises 0.01-0.02% of anti-foaming agent by mass percent. In the present invention, the antifoaming agent preferably includes dimethylsilicone oil or methylsilicone oil ester. The source of the dimethyl silicone oil is not specially limited, and the dimethyl silicone oil can be sold in the market. Specifically, in the embodiment of the invention, the simethicone is T901 of the company of GmbH (petroleum additives) emerging in Jinzhou. The methyl silicone oil ester is preferably T903 of the company llc, emerging petroleum additives, nj. The anti-foaming agent has good compatibility with other additives. The additive amount is small, the oil is suitable for an integral gearbox oil system, the oil has the most excellent anti-foaming characteristic, and the air release performance is not influenced due to the small viscosity of the integral oil.

The transmission oil comprises the balance of mixed coal base oil, preferably 88.5-93.5% by mass, and more preferably 90-92% by mass. In the invention, the kinematic viscosity of the base oil prepared from the mixed coal is preferably 3.2-3.5 mm ² (ii) s, more preferably 3.3 to 3.4mm ² And s. The blended coal base oil preferably includes a first base oil and a second base oil. The mixed coal base oil comprises 74.5-77.5% of first base oil and 14-16% of second base oil in percentage by mass. The kinematic viscosity of the first base oil at 40 ℃ is preferably 11.01mm ² S, kinematic viscosity at 100 ℃ is preferably 3.042mm ² The viscosity index is preferably 140. In the present invention, the source of the first base oil is not particularly limited, and the kinematic viscosity and the viscosity index described above may be satisfied. Specifically, in the examples of the present invention, the first base oil is lu' an CTL No. 3. In the present invention, the kinematic viscosity of the second base oil at 40 ℃ is preferably 31.05mm ² The kinematic viscosity at 100 ℃ is preferably 6.180mm ² The viscosity index is preferably 152 per second. In the present invention, the source of the second base oil is not particularly limited, and the kinematic viscosity and the viscosity index described above may be satisfied. Specifically, in the examples of the present invention, the second base oil was lu' an CTL No. 6. The mixed coal base oil has extremely high viscosity index, ensures that the base oil has better oil film thickness at high temperature to ensure lubrication, and has better fluidity at low temperature to prevent low-temperature abrasion. And the coal-based base oil belongs to fully synthetic base oil, has very high thermal conductivity and specific heat capacity, and can quickly dissipate heat.

the extreme pressure agent is nonyl triphenyl thiophosphate; the antiwear agent is a phosphoric acid amine mixture; the friction modifier is oleic acid diethanolamide and a liquid high-molecular-weight multi-effect single agent; the mass ratio of the oleic diethanolamide to the liquid high-molecular-weight multi-effect single agent is 1: 2.

the invention dilutes the anti-foaming agent with light solvent oil to obtain the diluted solution of the anti-foaming agent. In the present invention, the mass ratio of the antifoaming agent to the light solvent oil is preferably 1: 10. the light solvent oil is preferably aviation kerosene. The time and the mode of the dilution are not specially limited, and the dilution is uniform. The light solvent oil is preferably aviation kerosene or D60 solvent oil. In the invention, the light solvent oil is used for diluting the anti-foaming agent and improving the dispersibility of the anti-foaming agent. During the mixing process, the light solvent oil will evaporate.

After the diluent of the anti-foaming agent is obtained, the mixed coal base oil is heated and then mixed with the viscosity index improver and the diluent of the anti-foaming agent to obtain a mixed solution. In the invention, the temperature of the heated mixed coal base oil is preferably 55-65 ℃. The mixing temperature is preferably 55-65 ℃. The invention has no special limitation on the mixing mode and time, and the mixing is uniform. Specifically, in the practice of the present invention, stirring is carried out for 30 min.

After the mixed solution is obtained, the mixed solution is mixed with a detergent, a dispersant, an antioxidant, an extreme pressure agent, an antiwear agent, a friction modifier, a seal swelling agent and a metal deactivator to obtain the transmission oil. The method and the time for mixing the mixed solution with the detergent, the dispersant, the antioxidant, the extreme pressure agent, the antiwear agent, the friction modifier, the seal expanding agent and the metal deactivator are not specially limited, and the mixed solution is uniformly mixed. Specifically, in the implementation of the invention, the stirring is carried out for 40-60 min.

For further explanation of the present invention, the transmission oil provided by the present invention, its preparation method and application will be described in detail below with reference to the accompanying drawings and examples, which should not be construed as limiting the scope of the present invention.

Example 1

Mixing the anti-foaming agent aviation kerosene according to the proportion of 1: 10 to obtain a diluent of the anti-foaming agent;

heating the mixed base oil to 55-65 ℃, sequentially adding a viscosity index improver and a diluent of an antifoaming agent, and stirring for 30min to obtain a mixed solution;

and (2) adding a detergent, a dispersant, an antioxidant, an extreme pressure agent, an antiwear agent, a friction modifier, a seal expanding agent and a metal deactivator into the mixed solution in sequence, and stirring for 40-60 min to obtain the transmission oil.

The specific types and amounts of the mixed base oil, viscosity index improver, the diluent of the anti-foaming agent, the detergent, the dispersant, the antioxidant, the extreme pressure agent, the anti-wear agent, the friction modifier, the seal swelling agent and the metal deactivator are detailed in table 1.

TABLE 1 compositions of example 1-4 Transmission oils

Examples 2 to 4

Examples 2 to 4 differ from example 1 only in the amount of each component, and the details are shown in table 1, and the rest are the same as example 1.

The physical and chemical indexes of the transmission oil of examples 1 to 4 were measured, and the results are shown in table 2.

TABLE 2 physicochemical indices of Transmission oils of examples 1 to 4

Comparative example 1

ToyotaWS, Toyota was used as comparative example 1.

Comparative example 2

The daily produced Matic S is used as comparative example 2.

Experiment of thermal conductivity and specific Heat

The gearbox oil of examples 1-4 and comparative examples 1-2 were subjected to thermal conductivity and specific heat capacity tests, and the test results are shown in tables 3-4, fig. 1 and fig. 2.

TABLE 3 thermal conductivity of Transmission oils of examples 1-4 and products of comparative examples 1-2

TABLE 4 specific heat capacity of Transmission oil of examples 1-4 and products of comparative examples 1-2

As can be seen from tables 3 to 4 and fig. 1 and 2, the transmission oil of the present invention has higher specific heat capacity and thermal conductivity than the transmission oils of comparative examples 1 to 2.

DKA oxidation test

DKA oxidation tests were performed on the transmission oils of examples 1-4 and the transmission oils of comparative examples 1-2 by high-temperature oxidation at 170 ℃ for 192 hours, respectively. The test results are shown in table 5. (the smaller the increase rate of kinematic viscosity and the change in acid value, the better the oxidation stability)

TABLE 5 DKA oxidation test results for the transmission oils of examples 1-4 and comparative examples 1-2

As can be seen from Table 5, the transmission oil of the present invention has a small kinematic viscosity increase rate and a small value of acid value change in the DKA oxidation test, which indicates that the transmission oil of the present invention has good oxidation stability.

Insulation voltage test and conductivity test

The transmission fluids of example 1 and comparative examples 1-2 were tested for insulation voltage and conductivity on a BAUR DPA 75C (breakdown voltage test equipment) according to ASTM D1816-12, with the results shown in tables 6-7 and FIGS. 3-4:

TABLE 6 insulating Voltage test results for Transmission oils of example 1 and comparative examples 1-2

TABLE 7 results of conductivity tests on the transmission oils of example 1 and comparative examples 1-2

As can be seen from tables 6 to 7 and FIGS. 3 to 4, the transmission oil of example 1 of the present invention has a lower conductivity and a higher insulation voltage.

Electrical performance testing of transmission oil before and after DKA oxidation test

The electrical performance tests were performed on the transmission oils of example 1 and comparative examples 1 to 2 before and after the DKA oxidation test, and the test results are shown in tables 8 to 9 and fig. 5.

TABLE 8DKA electrical Performance test of Transmission oils of example 1 and comparative examples 1-2 prior to DKA oxidation test

TABLE 9 Electrical Performance testing of example 1 and comparative examples 1-2 Transmission oils after DKA oxidation test

As can be seen from tables 8-9 and FIG. 5, the conductivity increase before and after oxidation of the transmission oil of the present invention is small, and it can be concluded that a low conductivity can be maintained throughout the life cycle.

Liquid phase copper sheet corrosion test and gas phase copper corrosion test

Setting test conditions (168h, 150 ℃) according to an ASTM D130 copper corrosion test method, and carrying out long-term liquid phase copper sheet corrosion test on the copper sheet by using the transmission oil of examples 1-4 and comparative examples 1-2 as a liquid phase; and a gas phase copper corrosion test was performed, and test conditions (48h, 100 ℃, circuit board) were set, and the results are shown in table 10 below and fig. 6 to 11. FIGS. 6 to 11 show copper sheets after vapor phase copper corrosion tests were performed on transmission oils of examples 1 to 4 and comparative examples 1 to 2, respectively;

TABLE 10 results of corrosion test on liquid-phase copper sheet and corrosion test on gas-phase copper sheet

As can be seen from Table 10 and FIGS. 6-11, the transmission oil of the present invention has a lower copper content, less effect on copper corrosion and better protection over the transmission oils of comparative examples 1-2 during the entire life cycle.

Material compatibility testing

And (3) testing material compatibility: nylon (PA66) was soaked in the transmission oil of examples 1 to 4 and comparative examples 1 to 2 under soaking conditions (150 ℃ C., 240 hours). After soaking, the parameters were measured and the results are shown in Table 11.

TABLE 11 results of testing material compatibility of transmission oils of examples 1 to 4 and comparative examples 1 to 2

As can be seen from table 11, the transmission oil of the present invention has very excellent nylon material compatibility.

Extreme pressure wear-resisting experiment

The maximum seizure-free load, the sintering load and the wear scar diameter (1500rpm, 40kg, 60min, 75 ℃) of the transmission oil of examples 1 to 4 and comparative examples 1 to 2 were measured according to GB/T3142-2019 "determination of lubricant carrying capacity", and FZG pitting corrosion and FZG low-speed gear wear (120h) were performed according to an FZG testing method, and FE8 bearing pitting corrosion and FE8 bearing wear amount (roller) were performed according to an FE8 bearing testing method.

The extreme pressure wear test was carried out as standard, and the results are shown in Table 12.

TABLE 12 extreme pressure wear test results for Transmission oils of examples 1 to 4 and comparative examples 1 to 2

As can be seen from Table 12, the transmission oil of the present invention has excellent extreme pressure antiwear properties and more excellent wear protection capability for gears and bearings.

Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and all of the embodiments belong to the protection scope of the present invention.

Claims

1. The gearbox oil is characterized by comprising the following components in percentage by mass: 4 to 5.5 percent of viscosity index improver, 0.25 to 0.35 percent of detergent, 2.7 to 3.3 percent of dispersant, 0.4 to 0.6 percent of antioxidant, 0.15 to 0.25 percent of extreme pressure agent, 0.25 to 0.35 percent of antiwear agent, 0.28 to 0.32 percent of friction improver, 0.5 to 1.0 percent of seal expanding agent, 0.15 to 0.25 percent of metal deactivator, 0.01 to 0.02 percent of anti-foaming agent and the balance of mixed coal base oil;

2. the transmission fluid of claim 1, wherein the viscosity index improver comprises polymethacrylate.

3. The transmission fluid of claim 1, wherein the detergent comprises a polyetheramine; the dispersant comprises boronated polyisobuteneimide or an ashless phosphate.

4. The transmission oil of claim 1, wherein the antioxidant comprises two of octyl butyl diphenylamine, the antioxidants POUPC 5002, and methyl phenyl triazole ester.

5. The gearbox oil of claim 1, wherein the kinematic viscosity of the mixed coal base oil is 3.2-3.5 mm ² /s。

6. The transmission fluid of claim 1, wherein the seal swell agent comprises trimethylolpropane oleate or monopentaerythritol oleate.

7. The transmission oil of claim 1, wherein the metal deactivator comprises a thiadiazole derivative or a methylbenzotriazole derivative.

8. The transmission fluid of claim 1, wherein the anti-foaming agent comprises dimethicone or methyl silicone oil ester.

9. The method for preparing the gearbox oil as recited in any of claims 1 to 8, characterized by comprising the following steps:

the extreme pressure agent is nonyl triphenyl thiophosphate or phosphate amine salt; the antiwear agent is an amine phosphate mixture or phosphite triester; the friction modifier is oleic acid diethanolamide and a liquid high-molecular-weight multi-effect single agent; the mass ratio of the oleic diethanolamide to the liquid high-molecular-weight multi-effect single agent is 1: 2.

10. the application of the gearbox oil as defined in any one of claims 1 to 8 or the gearbox oil prepared by the preparation method as defined in claim 9 in a gearbox of a new energy automobile.