Lubricating agent for reduction gearbox of electric automobile and preparation method of lubricating agent

Abstract

The invention belongs to the technical field of lubricants, and particularly relates to a lubricant for a reduction gearbox of an electric vehicle and a preparation method. The invention relates to a lubricant for a reduction gearbox of an electric vehicle. The lubricant is prepared by uniformly mixing the following components in percentage by weight: 15-50% of deionized water, 30-80% of an antifriction and antiwear basic lubricant and 0.01-0.05% of a defoaming agent. The lubricant provided by the invention has ultralow friction coefficient (less than 0.01) and excellent thermal conductivity, and can realize efficient cooling and super lubrication, thereby prolonging the service life of a reduction gearbox and improving the overall efficiency of an electric automobile.

Description

Technical Field

[0001] The present invention belongs to the technical field of lubricants, and particularly relates to a lubricant for an electric vehicle reduction gearbox and a preparation method thereof. Background Art

[0002] Currently, environmental pollution and the depletion of fossil fuels have become increasingly severe global challenges. Against this backdrop, electric vehicles, as a type of green and environmentally friendly new energy vehicle, have received increasing attention. Compared with traditional internal combustion engine vehicles, electric vehicles have significant advantages such as zero emissions, low noise, and high energy utilization efficiency. However, the high-speed operation of the electric vehicle reduction gearbox poses a huge challenge to the lubrication system. High-speed rotation generates a large amount of heat inside the reduction gearbox, leading to a sharp rise in temperature. If the lubricating oil cannot effectively dissipate the heat, it will accelerate the aging of the lubricating oil, reduce its lubricating performance, and thus accelerate component wear. Therefore, developing a special lubricant for the reduction gearbox with excellent cooling performance is crucial for ensuring the long-term stable operation of the electric vehicle reduction gearbox. At the same time, high-speed operation also causes serious friction and wear problems. Due to the absence of a traditional internal combustion engine "oil circulation pump" in electric vehicles, the fluidity of the lubricating oil in the reduction gearbox is poor, and the oil film is extremely easy to be damaged under high-load and high-shear rate working conditions. Therefore, reducing the friction of the reduction gearbox has become another major challenge that needs to be solved urgently. Summary of the Invention

[0003] The present invention discloses a lubricant for an electric vehicle reduction gearbox and a preparation method thereof. This lubricant has both an ultra-low friction coefficient (less than 0.01) and excellent thermal conductivity, enabling efficient cooling and super lubrication, thereby extending the service life of the reduction gearbox and improving the overall efficiency of the electric vehicle.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] A lubricant for an electric vehicle reduction gearbox is formed by uniformly mixing the following components in weight percentage: deionized water 15 - 50%, friction-reducing and anti-wear base lubricant 30 - 80%, defoaming agent 0.01 - 0.05%.

[0006] A preparation method of a lubricant for an electric vehicle reduction gearbox includes: adding deionized water, friction-reducing and anti-wear base lubricant, and defoaming agent into a flask according to a certain weight percentage and stirring for 1 - 2 hours to make them uniformly mixed, thus obtaining the lubricant for an electric vehicle reduction gearbox.

[0007] Preferably, the preparation of the friction-reducing and anti-wear base lubricant includes the following steps: dropping polyamine into an aqueous solution of phytate, and then performing ultrasonic treatment for 10 - 30 minutes to make them fully mixed and react, obtaining the friction-reducing and anti-wear base lubricant.

[0008] Preferably, the mass ratio of the polyamine to the aqueous solution of phytate is 0.5-5:1.

[0009] Preferably, the polyamine is one or a mixture of more than one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine.

[0010] Preferably, the phytate is a mixed solution of one or more of sodium phytate, iron phytate, aluminum phytate, magnesium phytate, lithium phytate, etc.

[0011] Preferably, in the aqueous solution of phytate, the weight percentage content of phytate is 40%-80%.

[0012] Preferably, the defoaming agent is one of polyether-modified polysiloxane and silicone.

[0013] The beneficial effects of a lubricant for an electric vehicle speed reducer and a preparation method thereof according to the present invention are as follows: 1. The selected phytate is a natural compound, which will not cause pollution to the environment, and is relatively safe for users and not easily sensitizing. 2. The prepared liquid lubricant can achieve superlubricity on the surface of the bearing steel friction pair, and its running-in period is shorter. 3. The preparation method is simple. Only by compounding phytate and polyamine in a certain proportion can the basic lubricant be obtained, and the reaction can occur at room temperature without any catalyst. 4. The use cost is low and it is easy to mass-produce. 5. The prepared liquid lubricant not only has good friction reduction and anti-wear properties, but also can effectively prevent the corrosion of the metal material surface. 6. The liquid superlubricating material prepared by the present invention has broad application prospects in the fields of industrial processing, transportation, aerospace, etc. Description of the Drawings

[0014] Figure 1 It is a graph showing the change of the friction coefficient of the water-based lubricant for an electric vehicle speed reducer provided in Example 11 with time;

[0015] Figure 2 It is a graph showing the change of the friction coefficient of the water-based lubricant for an electric vehicle speed reducer provided in Example 12 with time;

[0016] Figure 3 It is a graph showing the change of the friction coefficient of the water-based lubricant for an electric vehicle speed reducer provided in Example 13 with time. Detailed Embodiments

[0017] The following is only a preferred embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0018] The following embodiments can be understood as separately representing a part of the local structure or method of the present invention, or can also be understood as the combination of embodiments explaining the connotation of the structure or method of a larger scope of the present invention.

[0019] Embodiment 1

[0020] A lubricant for an electric vehicle reduction gearbox is prepared by uniformly mixing the following components in weight percentage: deionized water 15%, friction-reducing and anti-wear base lubricant 30%, defoaming agent 0.01%.

[0021] Embodiment 2

[0022] A lubricant for an electric vehicle reduction gearbox is prepared by uniformly mixing the following components in weight percentage: deionized water 50%, friction-reducing and anti-wear base lubricant 80%, defoaming agent 0.05%.

[0023] Embodiment 3

[0024] Based on Embodiment 1, this embodiment discloses: A preparation method of a lubricant for an electric vehicle reduction gearbox, including: adding deionized water, friction-reducing and anti-wear base lubricant, and defoaming agent into a flask according to the weight percentages provided in Embodiment 1 and stirring for 1 h to make them uniformly mixed, thus obtaining the lubricant for an electric vehicle reduction gearbox.

[0025] Embodiment 4

[0026] Based on Embodiment 2, this embodiment discloses: A preparation method of a lubricant for an electric vehicle reduction gearbox, including: adding deionized water, friction-reducing and anti-wear base lubricant, and defoaming agent into a flask according to the weight percentages provided in Embodiment 2 and stirring for 2 h to make them uniformly mixed, thus obtaining the lubricant for an electric vehicle reduction gearbox.

[0027] Embodiment 5

[0028] Based on Embodiments 1 - 4, this embodiment discloses: The preparation of the friction-reducing and anti-wear base lubricant includes the following steps: dropping polyamine into an aqueous solution of phytate, and then performing ultrasonic treatment for 10 minutes to make them fully mixed and react, thus obtaining the friction-reducing and anti-wear base lubricant.

[0029] The mass ratio of the polyamine to the aqueous solution of phytate is 0.5:1.

[0030] Embodiment 6

[0031] Based on Embodiments 1 - 4, this embodiment discloses: The preparation of the friction-reducing and anti-wear base lubricant includes the following steps: dropping polyamine into an aqueous solution of phytate, and then performing ultrasonic treatment for 30 minutes to make them fully mixed and react, thus obtaining the friction-reducing and anti-wear base lubricant.

[0032] The mass ratio of the polyamine to the aqueous solution of phytate is 5:1.

[0033] Example 7

[0034] Based on Example 6, this example discloses various embodiments of polyamines, specifically as follows: The polyamine is (A1) diethylenetriamine; (A2) triethylenetetramine; (A3) tetraethylenepentamine; (A4) pentaethylenehexamine; where (A1) to (A4) are the numbers of specific embodiments, and the operator can select one or a mixture of multiple ones.

[0035] Example 8

[0036] Based on Example 6, this example discloses various embodiments of phytates, specifically as follows: The phytate is (B1) sodium phytate, (B2) iron phytate, (B3) aluminum phytate, (B4) magnesium phytate, (B5) lithium phytate; where (B1) to (B5) are the numbers of specific embodiments, and the operator can select one or a mixture of multiple ones.

[0037] Example 9

[0038] Based on Example 8, this example discloses that in the aqueous solution of phytate, the weight percentage of phytate is 40%; the defoaming agent is polyether-modified polysiloxane.

[0039] Example 10

[0040] Based on Example 8, this example discloses that in the aqueous solution of phytate, the weight percentage of phytate is 80%, and the defoaming agent is silicone.

[0041] Example 11

[0042] Preparation of friction-reducing and anti-wear base lubricant:

[0043] Slowly drop 100 g of triethylenetetramine into 50 g of an aqueous solution of sodium phytate, where the mass fraction percentage of sodium phytate in the aqueous solution of sodium phytate is 60%, stir and ultrasonicate for 30 min to make them fully mixed and react, then the friction-reducing and anti-wear base lubricant can be obtained.

[0044] Preparation of lubricant for electric vehicle gearbox:

[0045] According to the following mass percentages, add 39.95% deionized water, 60% friction-reducing and anti-wear base lubricant, and 0.05% defoaming agent into a flask and stir for 2 h to make them evenly mixed, then the water-based lubricant for electric vehicle gearbox can be obtained.

[0046] Tribological property test:

[0047] The tribological properties of the water-based lubricant for electric vehicle reduction gearboxes were evaluated using a ball-disk friction and wear tester (TRB-3, Anton Paar). Both the upper and lower friction pairs were made of AISI 52100 steel, the friction mode was reciprocating sliding, the load applied in the experiment was 3 N, and the frequency was 4 Hz. The friction coefficient of the water-based lubricant for electric vehicle reduction gearboxes prepared in this example is as Figure 1 shown. The measured average friction coefficient was approximately 0.008, indicating that the water-based lubricant for electric vehicle reduction gearboxes can achieve an ultra-lubricated state. In addition, compared with commercial lubricating oil through testing, the temperature rise was reduced by approximately 40%, demonstrating its excellent cooling performance.

[0048] Example 12

[0049] Preparation of the friction-reducing and anti-wear base lubricant:

[0050] 150 g of tetraethylenepentamine was slowly added dropwise to 50 g of an aqueous sodium phytate solution, where the mass fraction of sodium phytate in the aqueous sodium phytate solution was 50%. Stir and sonicate for 30 min to allow them to react fully and uniformly, and the friction-reducing and anti-wear base lubricant can be obtained.

[0051] Preparation of the lubricant for electric vehicle reduction gearboxes:

[0052] 49.98% of deionized water, 50% of the friction-reducing and anti-wear base lubricant, and 0.02% of the defoamer were added to a flask and stirred for 2 h to mix them evenly, and the water-based lubricant for electric vehicle reduction gearboxes can be obtained.

[0053] Tribological property testing:

[0054] The tribological properties of the water-based lubricant for electric vehicle reduction gearboxes were evaluated using a ball-disk friction and wear tester (TRB-3, Anton Paar). Both the upper and lower friction pairs were made of AISI 52100 steel, the friction mode was reciprocating sliding, the load applied in the experiment was 2 N, and the frequency was 4 Hz. The friction coefficient of the water-based lubricant for electric vehicle reduction gearboxes prepared in this example is as Figure 2 shown. The measured average friction coefficient was approximately 0.007, indicating that the water-based lubricant for electric vehicle reduction gearboxes can achieve an ultra-lubricated state. In addition, compared with commercial lubricating oil through testing, the temperature rise was reduced by approximately 45%, demonstrating its excellent cooling performance.

[0055] Example 13

[0056] Preparation of the friction-reducing and anti-wear base lubricant:

[0057] 200 g of diethylenetriamine was slowly added dropwise to 50 g of an aqueous aluminum phytate solution, where the mass fraction of aluminum phytate in the aqueous aluminum phytate solution was 70%. Stir and sonicate for 30 min to allow them to react fully and uniformly, and the friction-reducing and anti-wear base lubricant can be obtained.

[0058] Preparation of Lubricant for Electric Vehicle Reduction Gearbox:

[0059] Add 19.97% deionized water, 80% friction-reducing and anti-wear base lubricant, and 0.03% defoamer into a flask and stir for 2 h to make them evenly mixed, then the water-based lubricant for electric vehicle reduction gearbox can be obtained.

[0060] Tribological Property Test:

[0061] The tribological properties of the water-based lubricant for electric vehicle reduction gearbox were evaluated by a ball-disk friction and wear tester (TRB-3, Anton Paar). The upper and lower friction pairs were both AISI 52100 steel, the friction mode was reciprocating sliding, the load applied in the experiment was 2 N, and the frequency was 5 Hz. The friction coefficient of the water-based lubricant for electric vehicle reduction gearbox prepared in this example is as Figure 3 shown. The measured average friction coefficient is about 0.006, indicating that the water-based lubricant for electric vehicle reduction gearbox can achieve superlubrication state. In addition, compared with commercial lubricating oil through testing, the temperature rise is reduced by about 32%, proving its excellent cooling performance.

[0062] The water-based lubricant for electric vehicle reduction gearbox provided by the present invention can achieve macro-scale liquid superlubrication on the surface of the bearing steel friction pair, and its required running-in period is shorter. The reason is that there is a strong hydrogen bond interaction between phytate and polyamine molecules, which can enable the lubricant to bear a large load, and can fix water molecules between the friction pairs as a shear layer to reduce the frictional resistance during the sliding process.

[0063] The friction-reducing and anti-wear base lubricant prepared by the present invention has excellent friction-reducing and anti-wear properties and will not cause corrosion to the metal friction pair. Therefore, there is no need to add extreme pressure anti-wear agents, preservatives, etc. additionally, which greatly reduces the preparation cost of the lubricant.

Claims

1. A lubricant for an electric vehicle reduction gearbox, characterized by: The invention is prepared by uniformly mixing the following components in percentage by weight: 15-50% of deionized water, 30-80% of friction-reducing and anti-wear basic lubricant, and 0.01-0.05% of defoaming agent.

2. The method for preparing a lubricant for an electric vehicle reduction box according to claim 1, characterized in that it comprises: Deionized water, antifriction and anti-wear base lubricant and defoaming agent are added into a flask according to a certain weight percentage and stirred for 1-2 hours to make them evenly mixed to obtain a lubricant for an electric vehicle reduction box.

3. The method for preparing a lubricant for an electric vehicle reduction box according to claim 2, characterized in that: The preparation of the friction-reducing and anti-wear basic lubricant comprises the following steps: adding polyamine dropwise into a phytate aqueous solution, and then subjecting the solution to ultrasonic treatment for 10-30 minutes to allow the solution to be fully mixed and reacted to obtain the friction-reducing and anti-wear basic lubricant.

4. The method for preparing a lubricant for an electric vehicle reduction box according to claim 3, characterized in that: The mass ratio of the polyamine to the phytate aqueous solution is 0.5-5:

1.

5. The method for preparing a lubricant for an electric vehicle reduction box according to claim 3, characterized in that: The polyamine is a mixture of one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

6. The method for preparing a lubricant for an electric vehicle reduction box according to claim 3, characterized in that: The phytate is a mixture of one or more of sodium phytate, iron phytate, aluminum phytate, magnesium phytate, lithium phytate and the like.

7. The method for preparing a lubricant for an electric vehicle reduction box according to claim 3, characterized in that: In the phytate aqueous solution, the weight percentage of phytate is 40% to 80%.

8. A method for preparing a lubricant for an electric vehicle reduction box according to any one of claims 2 to 7, characterized in that: The defoamer is one of polyether modified polysiloxane and organic silicon.

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