Lubricating composition with multi-synergistic effect, spline lubricating grease and preparation method thereof

Abstract

The invention discloses a lubricating composition with a multi-synergistic effect, spline lubricating grease and a preparation method of the spline lubricating grease. The lubricating composition comprises composite calcium sulfonate lubricating grease, an organic antiwear agent and an organic antifriction agent, the spline lubricating grease comprises the following components: the lubricating composition, base oil, a thickening agent, an antioxidant, an anti-rust agent and a solid anti-seizing additive. The preparation method of the spline lubricating grease comprises the following steps: dissolving the thickening agent in the base oil, shearing and filtering the obtained mixture to adjust the consistency, homogenizing the mixture, uniformly mixing the homogenized mixture with the lubricating composition, the antioxidant, the antirust agent and the solid anti-sticking additive, degassing, and filtering to obtain the spline lubricating grease. Through the multi-synergistic effect generated among the components in the lubricating composition, the lubricating performance of the lubricating composition can be improved, and when the lubricating composition is used in spline lubricating grease, the friction coefficient and the damping performance of a material can be remarkably reduced, the wear resistance of the material is improved, and abnormal wear and loss in the use process of splines are effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of lubricating grease, and in particular to a lubricating composition with multiple synergistic effects, a spline lubricating grease and a preparation method thereof. Background Art

[0002] As the integration of electric drive systems of new energy pure electric vehicles becomes higher and higher, the motor and reducer are highly integrated, generally connected by splines. Since the torque transmitted here is large and it is an alternating load, the spline connection between the clutch and the transmission input shaft of traditional fuel vehicles has changed from a flexible connection to a rigid connection, with a higher speed and the need to withstand back-torque. Due to the high speed, high temperature and fast power response of the pure electric vehicle drive motor, the impact force of the spline between the motor and the reducer is large. If there is no good lubrication, the spline between the motor and the reducer will wear too quickly, resulting in reduced spline durability and reliability, poor NVH performance, low efficiency and affecting the power transmission effect of the motor.

[0003] At present, new energy pure electric vehicles use imported grease to lubricate splines, which leads to serious spline wear problems. The main problem is that a large amount of solid lubricants are added to the imported grease, which can improve its high temperature resistance and NHV performance, but at the same time it brings high friction coefficient, poor anti-wear performance, and solid lubricants are easy to settle, resulting in structural instability. Summary of the invention

[0004] Purpose of the invention: The first purpose of the present invention is to provide a lubricating composition with multiple synergistic effects. The second purpose of the present invention is to provide a spline grease comprising the lubricating composition, which has excellent extreme pressure and anti-wear properties, a low friction coefficient, and impact resistance, and can reduce the wear of the spline surface. The third purpose of the present invention is to provide a method for preparing the spline grease.

[0005] Technical solution: The lubricating composition with multiple synergistic effects provided by the present invention comprises a composite calcium sulfonate grease, an organic antiwear agent and an organic friction reducer, wherein the mass ratio of the composite calcium sulfonate grease to the organic friction reducer is 1.6-5:1, and the mass ratio of the organic antiwear agent to the organic friction reducer is 1:1-3.

[0006] Furthermore, the organic friction reducer is dibutyl dithiocarbamate molybdenum; and the organic antiwear agent is dialkyl dithiophosphate zinc.

[0007] The spline grease provided by the present invention comprises the following components by mass percentage: 9-14wt% of the above-mentioned lubricating composition, 66.37-78.31wt% of base oil, 9.36-10.08wt% of thickener, 0.3-0.5wt% of antioxidant, and 0.03-0.05wt% of rust inhibitor.

[0008] Furthermore, the kinematic viscosity of the base oil at 40°C is 200-1000 mm 2 / s, preferably 350-450mm 2 / s.

[0009] More preferably, the base oil is synthetic oil high viscosity polyalphaolefin PAO40.

[0010] Furthermore, in the spline grease, the mass percentage of the composite calcium sulfonate grease is 5-10wt%, and the mass percentage of the organic friction reducer is 1.5-2.5wt%.

[0011] Furthermore, the thickener is a reaction product of an organic acid and lithium hydroxide, wherein the organic acid is one or more of 12-hydroxystearic acid, azelaic acid or stearic acid; preferably, the organic acid is a combination of 12-hydroxystearic acid and azelaic acid; and the lithium hydroxide is lithium hydroxide monohydrate, which meets the requirements of industrial-grade lithium hydroxide.

[0012] Furthermore, the antioxidant is one or a combination of hindered amine antioxidants and phenolic antioxidants; the hindered amine antioxidant is one or more of diphenylamine, naphthylamine or p-phenylenediamine.

[0013] Furthermore, the rust inhibitor is one or more of benzotriazole, 2-mercaptobenzimidazole or 2-mercaptobenzothiazole, which is used to reduce the corrosion of grease on copper-containing parts that may exist in the mechanical structure; the solid anti-seizure additive is one or more of graphite, calcium oxide, calcium carbonate, calcium fluoride, calcium stearate, molybdenum disulfide, boron nitride or tungsten disulfide; preferably, the solid anti-seizure additive is a combination of graphite, calcium carbonate and tungsten disulfide, which can withstand impact load or vibration load or high load conditions at room temperature or high temperature, has a reinforcing function, improves its lubricity and extreme pressure wear resistance at high temperature, and prevents overheating, abnormal wear or seizure of friction parts.

[0014] The preparation method of the above-mentioned spline grease provided by the present invention comprises the following steps: firstly dissolving a thickener in a base oil, adjusting the consistency of the obtained mixture by shearing and filtering, then uniformly mixing the mixture with a lubricating composition, an antioxidant, a rust inhibitor and a solid anti-seizure additive after homogenization, and then degassing and filtering to obtain the spline grease.

[0015] Principle of the invention: In the present invention, the composite calcium sulfonate grease, organic antiwear agent and organic friction reducer in the lubricating composition have multiple synergistic effects. The composite calcium sulfonate grease itself has good extreme pressure anti-wear properties and has good synergistic effects with the organic friction reducer. At the same time, the organic antiwear agent and the organic friction reducer also have synergistic effects with each other.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The lubricating composition has multiple synergistic effects, which significantly improves the lubrication performance of the entire composition; (2) The lubricating composition is added to the spline grease, and then combined with the base oil, thickener, antioxidant, rust inhibitor and solid anti-seizure additive. The components cooperate with each other to improve the anti-wear performance of the spline grease, reduce the friction coefficient, and shock absorption and damping performance. At the same time, it can also effectively reduce the wear problem in its application, and solve the problem of severe wear of the spline parts caused by impact, vibration and different torque conditions under different working conditions during the driving of existing passenger cars. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with specific embodiments.

[0018] Example 1: The lubricating composition provided in this example includes a calcium sulfonate composite grease, an organic antiwear agent, molybdenum dibutyl dithiocarbamate, and zinc dialkyl dithiophosphate T202 in a mass ratio of 5:2:2.

[0019] The spline grease provided in this embodiment includes the following components by mass: 78.31wt% of PAO40, 9.36wt% of thickener (including 6.5wt% of 12-hydroxystearic acid, 1.3wt% of sebacic acid, and 1.56wt% of lithium hydroxide monohydrate), 0.3wt% of diphenylamine, an antioxidant, 0.03wt% of benzotriazole, a rust inhibitor, 9wt% of a lubricating composition (including 5wt% of composite calcium sulfonate grease, 2wt% of dibutyl dithiocarbamate molybdenum, an organic friction reducer, and 2wt% of organic antiwear agent T202), and 3wt% of a solid anti-seizure additive (including 1wt% of graphite, 1wt% of nano-calcium carbonate, and 1wt% of tungsten disulfide).

[0020] The steps of the preparation method of the above-mentioned spline grease are as follows:

[0021] (1) PAO40 base oil was put into a reactor through a 1 μm bag filter, and then 12-hydroxystearic acid was added to the reactor and heated to 75-80° C. until it was completely dissolved;

[0022] (2) Then, 3 times of water is used to dissolve the lithium hydroxide aqueous solution, and then 50% of the lithium hydroxide is slowly added to the reaction kettle to react completely with 12-hydroxystearic acid. The temperature is controlled at 95-105° C. and stirred for 1.5-2 hours. After completion, sebacic acid is added and the temperature is raised to 120-130° C., and the remaining 50% of lithium hydroxide is slowly added to the reaction and stirred for 1-1.5 hours. The temperature is continued to be raised to 130-140° C. for dehydration. After dehydration, a sample is taken to measure the free alkali content, and the free alkali content is controlled at 0.05-0.15%, and then the temperature is raised to 200-210° C. for high-temperature refining for 3-5 minutes;

[0023] (3) slowly adding 15-25% of the total amount of base oil, controlling the rapid cooling to 170-180° C., and stirring at a constant temperature for 30 minutes, then adding the remaining part of the base oil, and continuing to cool to 140-150° C.;

[0024] (4) Transfer to the intermediate kettle, circulate shear filtration for 2 hours, thicken, and add other components in sequence after homogenization, stir evenly, degas, filter through a 200-mesh stainless steel filter to obtain the finished spline grease.

[0025] The preparation methods of Examples 2-3 and Comparative Examples 1-7 are the same as those of Example 1. The specific formulas are shown in Table 1 below.

[0026] Table 1 Component formula of Example 1-Example 3 and Comparative Example 1-Comparative Example 7

[0027]

[0028]

[0029] Table 2 Performance test table of spline grease obtained from Example 1 to Example 3 and Comparative Example 1 to Comparative Example 7

[0030]

[0031] The performance test results of the materials prepared in Examples 2 to 3 and Comparative Examples 1 to 7 are shown in Table 2 above.

[0032] As can be seen from Table 2, by comparing Examples 1 to 3, Comparative Example 1 (without adding composite calcium sulfonate grease) and Comparative Example 2 (without adding organic anti-wear agent dibutyl dithiocarbamate molybdenum), it can be seen that the simultaneous addition of composite calcium sulfonate and organic molybdenum friction reducer - dibutyl dithiocarbamate molybdenum can effectively reduce the friction coefficient and anti-wear performance.

[0033] By comparing Examples 1 to 3, Comparative Example 3 (the anti-wear agent T309 is used instead of the anti-wear agent T202) and Comparative Example 4 (the anti-wear agent T306 is used instead of the anti-wear agent T202), it can be seen that compared with other anti-wear agents T309 and T306, T202 has a better synergistic effect when used in combination with composite calcium sulfonate and organic molybdenum friction reducer.

[0034] From the comparison of Examples 1 to 3, Comparative Example 5 (using anhydrous calcium-based grease to replace composite calcium sulfonate grease), Comparative Example 6 (using polyurea grease to replace composite calcium sulfonate grease) and Comparative Example 7 (using composite aluminum-based grease to replace composite calcium sulfonate grease), it can be seen that compared with other greases, composite calcium sulfonate has better extreme pressure and anti-wear properties, and has better synergistic effect when added to the formula.

[0035] The preparation method of Examples 4-9 and Comparative Examples 8-10 is the same as that of Example 1, except that the mass ratio and mass percentage of the composite calcium sulfonate grease and the organic friction reducer are changed, and the performance of the prepared spline grease is tested. The results are shown in Table 3 below.

[0036] Table 3 Performance test table of spline grease at different mass ratios and mass percentages of composite calcium sulfonate grease and organic friction reducer for Example 4-Example 9 and Comparative Example 8-Comparative Example 10

[0037]

[0038] It can be seen from Table 3 that, compared with Comparative Examples 8 to Comparative Examples 10, when the mass ratio of composite calcium sulfonate grease to dibutyl dithiocarbamate molybdenum is between 5-10:2-3 in Examples 4 to 6, the friction coefficient is small and the anti-wear performance is optimal. When the amount of organic friction reducer in Comparative Examples 8 to 10 is less than 2wt% or no composite calcium sulfonate grease is added, the friction coefficient is about 1.5 times that of Examples 4 to 8, and the anti-wear performance is poor.

Claims

1. A lubricating composition having multiple synergistic effects, characterized in that: The invention comprises a composite calcium sulfonate grease, an organic anti-wear agent and an organic friction reducer, wherein the mass ratio of the composite calcium sulfonate grease to the organic friction reducer is 1.6-5:1, and the mass ratio of the organic anti-wear agent to the organic friction reducer is 1:1-3.

2. The lubricating composition with multiple synergistic effects according to claim 1, characterized in that: The organic friction reducer is molybdenum dibutyl dithiocarbamate.

3. The lubricating composition with multiple synergistic effects according to claim 1, characterized in that: The organic anti-wear agent is zinc dialkyl dithiophosphate.

4. A spline grease, characterized in that: The following components are included by mass percentage: The lubricating composition with multi-synergistic effects as claimed in claim 1 comprises 6-20 wt%, 60-80 wt% of base oil, 9-11 wt% of thickener, 0.3-0.5 wt% of antioxidant, 0.03-0.05 wt% of rust inhibitor and 3-9 wt% of solid anti-seizure additive.

5. The spline grease according to claim 4, characterized in that: The base oil has a kinematic viscosity of 200-1000 mm at 40°C. 2 / s.

6. The spline grease according to claim 4, characterized in that: In the spline grease, the mass percentage of the composite calcium sulfonate grease is 5-10wt%, and the mass percentage of the organic friction reducer is 1.5-2.5wt%.

7. The spline grease according to claim 4, characterized in that: The thickener is a reaction product of an organic acid and lithium hydroxide, wherein the organic acid is one or more of 12-hydroxystearic acid, azelaic acid or stearic acid; and the lithium hydroxide is lithium hydroxide monohydrate.

8. The spline grease according to claim 4, characterized in that: The antioxidant is one or a combination of hindered amine antioxidants and phenolic antioxidants; the hindered amine antioxidant is one or more of diphenylamine, naphthylamine or p-phenylenediamine.

9. The spline grease according to claim 4, characterized in that: The rust inhibitor is one or more of benzotriazole, 2-mercaptobenzimidazole or 2-mercaptobenzothiazole; the solid anti-seizure additive is one or more of graphite, calcium oxide, calcium carbonate, calcium fluoride, calcium stearate, molybdenum disulfide, boron nitride or tungsten disulfide.

10. A method for preparing the spline grease according to any one of claims 4 to 9, characterized in that: The following steps are involved: Firstly, the thickener is dissolved in the base oil, the obtained mixture is sheared and filtered to adjust the consistency, then homogenized and mixed evenly with the lubricating composition, antioxidant, rust inhibitor and solid anti-seize additive, and then degassed and filtered to obtain the spline grease.

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