Motor lubricating grease composition

Abstract

The application discloses a motor lubricating grease composition, which comprises a thickening agent, base oil and an additive, and specifically, the thickening agent is 10-15%, the base oil is 85-90%, and the sum of the mass percentages of the two is 100%; the additive is additionally added in a proportion of 1-5%; the thickening agent is composed of mixture A and mixture B; a) the mixture A is a reactant of dodecahydroxy stearic acid, organic dibasic acid and saturated aqueous solution of lithium hydroxide monohydrate, and the molar ratio of the dodecahydroxy stearic acid to the organic dibasic acid is 1:0.1-1; b) the mixture B is an amide compound, and the amide compound is a mixture of one or more of dodecanamide, hexadecanamide, octadecanamide, octadecenoic acid amide, docosanamide, docosenoic acid amide, N,N-dimethyl dodecanamide and N,N'-ethylene bis-stearamide in an arbitrary ratio. The application can effectively prolong the service life of the lubricating grease, prolong the grease replenishing period and prolong the service life of the motor.

Description

Technical Field

[0001] This invention belongs to the field of lubricating grease technology, and specifically relates to a motor lubricating grease composition. Background Technology

[0002] Electric motors, as crucial equipment in modern manufacturing processes, are used across numerous industries. With the increasing demand for continuous equipment operation, the ability of motors to operate safely and stably for extended periods has become a vital factor in generating profits and enhancing competitiveness. 40% of motor bearing failures are caused by poor lubrication; improving the quality of lubricating grease can extend bearing life by 2-5 times. Proper bearing lubrication is a key guarantee for the safe and stable operation of motors, thereby helping to extend equipment life and minimize downtime for maintenance.

[0003] In many cases, the heat generated by the motor has a greater impact on the life of the lubricating grease than the load on the bearings on the mechanical life. Temperature is the most significant factor affecting grease life; higher bearing temperatures accelerate grease oxidation and increase volatility. Furthermore, as temperature rises, the grease tends to soften and may become a fluid, leaking from the bearing housing.

[0004] Invention patent CN201810538230 discloses a motor bearing grease and its preparation method. The motor bearing grease comprises the following components by weight percentage: 35-50 parts diester oil, 40-48 parts polyalphaolefin, 10-14 parts dodecyl stearic acid, and 1-4 parts additives, wherein the additives include polyethylene glycol and α-phenylnaphthylamine. CN201510065423 discloses a special grease for low-speed motor bearings and its preparation method, prepared from the following raw materials by weight: 60 parts dodecyl stearic acid, 40 parts stearic acid, 38 parts lithium hydroxide, 3 parts calcium hydroxide, 10 parts azelaic acid, 10 parts sebacic acid, 10 parts dimethyl disulfide T322 additive, 5 parts T406 additive, and 108 parts base oil. CN201110105616 discloses a submarine motor bearing grease and its preparation method, using a mixed lithium soap and a high-viscosity complex ester thickener. The submarine motor bearing grease has excellent shear stability: the use of dual-ester synthetic base oil with low viscosity results in low temperature rise of the bearing after operation; the use of mixed rust inhibitors ensures the bearing's rust prevention in the presence of seawater. The resulting product has good performance in terms of corrosion resistance, lubrication stability and load-bearing capacity when used in submarine motor bearings.

[0005] Existing technologies mainly focus on selecting suitable base oils or additives to improve the performance of greases and extend the life of motor bearings. The thickeners used are all ordinary and conventional components, and no improvements have been made to the thickener components to reduce the temperature rise of motor bearings and improve lubrication life. Summary of the Invention

[0006] The purpose of this invention is to provide a motor grease composition that can effectively improve grease life, extend grease replenishment cycle, and increase the service life of the motor.

[0007] The technical solution adopted in this invention is an electric motor lubricating grease composition, comprising a thickener, a base oil, and additives, specifically: the thickener is 10% to 15%, the base oil is 85% to 90%, and the sum of their mass percentages is 100%; the additives are added at a ratio of 1% to 5%.

[0008] The thickener consists of mixture A and mixture B:

[0009] a) Mixture A is a reactant of 12-hydroxystearic acid, an organic dicarboxylic acid and a saturated aqueous solution of lithium hydroxide monohydrate, wherein the molar ratio of 12-hydroxystearic acid to the organic dicarboxylic acid is 1:0.1 to 1;

[0010] b) Mixture B is an amide compound, wherein the amide compound is one or more of dodecanoamide, hexadecanoamide, octadecanoamide, octadecenoamide, docosamide, docosamide, N,N-dimethyldodecanoamide, and N,N'-ethylidene bis-stearamide in any proportion.

[0011] The invention is further characterized in that,

[0012] Mixture A comprises 80% to 90% of the total mass of the thickener.

[0013] The organic dicarboxylic acid in mixture A is one or more of C4 to C12 in any proportion.

[0014] Mixture B comprises 10% to 20% of the total mass of the thickener.

[0015] The base oil is one or more of mineral oil, poly-α-olefin, and ester oil in any proportion, and the viscosity grade of the base oil ranges from ISO 46 to ISO 320.

[0016] The additives are one or more of the following: sulfurized animal and vegetable oils, organic molybdenum compounds, fatty amine derivatives, organic borate esters, or borates.

[0017] When the additive is sulfurized animal or vegetable oil, the proportion of sulfurized animal or vegetable oil added is 0.5% to 2%;

[0018] When the additive is an organic molybdenum compound, the proportion of the organic molybdenum compound added is 1% to 5%;

[0019] When the additive is a fatty amine derivative, the proportion of the fatty amine derivative added is 0.5% to 2%;

[0020] When the additive is borate, the proportion of borate added is 1% to 3%.

[0021] The beneficial effects of this invention are:

[0022] This invention provides a motor grease composition that maintains a sufficiently low coefficient of friction between motor bearing friction pairs over a long period, suppresses temperature rise during motor bearing operation, and reduces starting torque at low temperatures. This effectively improves grease life, extends grease replenishment cycles, and extends the service life of the motor. The motor grease composition uses metal soaps and amide compounds as a thickener, and adds friction-reducing agents for synergistic effect, effectively reducing the coefficient of friction between friction pairs and lowering bearing temperature rise. This invention's motor grease composition exhibits outstanding low-temperature starting torque, excellent performance in suppressing bearing temperature rise, and outstanding long-life durability. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments.

[0024] This invention provides an electric motor grease composition comprising a thickener, a base oil, and additives, specifically: the thickener is 10% to 15%, the base oil is 85% to 90%, and the sum of their mass percentages is 100%; the additives are added at a ratio of 1% to 5% (the additives account for 1% to 5% of the sum of the mass of the thickener and the base oil).

[0025] The thickener consists of mixture A and mixture B:

[0026] a) Mixture A is a reactant of 12-hydroxystearic acid, an organic dicarboxylic acid and a saturated aqueous solution of lithium hydroxide monohydrate, with a molar ratio of 12-hydroxystearic acid to organic dicarboxylic acid of 1:0.1 to 1; Mixture A accounts for 80% to 90% of the total mass of the thickener.

[0027] The organic dicarboxylic acid in mixture A is one or more of C4 to C12 in any proportion;

[0028] b) Mixture B is an amide compound, wherein the amide compound is one or more of dodecanoamide, hexadecanoamide, octadecanoamide, octadecenoamide, docosamide, docosamide, N,N-dimethyldodecanoamide, and N,N'-ethylenebisstearamide in any proportion; mixture B accounts for 10% to 20% of the total mass of the thickener; the base oil is one or more of mineral oil, poly-α-olefin, and ester oil in any proportion, and the viscosity grade of the base oil is in the range of ISO 46 to ISO 320;

[0029] The additives are one or more of the following: sulfurized animal and vegetable oils, organic molybdenum compounds, fatty amine derivatives, organic borate esters, or borates;

[0030] When the additive is sulfurized animal or vegetable oil, the proportion of sulfurized animal or vegetable oil added is 0.5% to 2%;

[0031] When the additive is an organic molybdenum compound, the proportion of the organic molybdenum compound added is 1% to 5%;

[0032] When the additive is a fatty amine derivative, the proportion of the fatty amine derivative added is 0.5% to 2%;

[0033] When the additive is borate, the proportion of borate added is 1% to 3%.

[0034] Example 1

[0035] 12900g of poly-α-olefin (viscosity 100mm) 2 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly raised to 210℃ and held for 10 minutes. The temperature was then slowly lowered to 185℃, and 450g of amide compound 1 was added and sheared and dispersed for 40 minutes. The temperature was then further lowered to approximately 80℃, and all additives (alkyl molybdenum thiophosphate) were added and stirred for 1.5 hours. The mixture was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0036] Example 2

[0037] 12900g of poly-α-olefin (viscosity 100mm) 2 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly increased to 210℃ and held for 10 minutes. The temperature was then slowly decreased to 185℃, and 450g of amide compound 2 was added and sheared and dispersed for 40 minutes. The temperature was then further decreased to approximately 80℃, and all additives (alkyl molybdenum thiophosphate) were added and stirred for 1.5 hours. The mixture was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0038] Example 3

[0039] 12900g of poly-α-olefin (viscosity 100mm) 21701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly raised to 210℃ and held for 10 minutes. The temperature was then slowly lowered to 185℃, and 150g of amide compound 2 was added and sheared and dispersed for 40 minutes. The temperature was then further lowered to approximately 80℃, and all additives (alkyl molybdenum thiophosphate) were added and stirred for 1.5 hours. The mixture was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0040] Comparative Example 1

[0041] 12900g of poly-α-olefin, 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. The mixture was then heated to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly increased to 210℃ and held for 10 minutes. The temperature was then slowly decreased to 185℃ and sheared for 40 minutes. The temperature was further decreased to approximately 80℃, and all additives were added and stirred for 1.5 hours. The mixture was then removed from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0042] Comparative Example 2

[0043] 12900g of poly-α-olefin, 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly raised to 210℃ and held for 10 minutes. The temperature was then slowly lowered to 185℃, and 450g of amide compound 2 was added and sheared and dispersed for 40 minutes. The temperature was then further lowered to approximately 80℃, all additives were added, and the mixture was stirred for 1.5 hours. The product was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0044] Comparative Example 3

[0045] 12900g of poly-α-olefin, 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly raised to 210℃ and held for 10 minutes. The temperature was then slowly lowered to 185℃, and 450g of amide compound 2 was added and sheared and dispersed for 40 minutes. The temperature was then further lowered to approximately 80℃, all additives were added, and the mixture was stirred for 1.5 hours. The product was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0046] Comparative Example 4

[0047] 12900g of poly-α-olefin, 1701g of dodecyl stearic acid, 400g of lithium hydroxide monohydrate, 344g of sebacic acid, and 1500g of water were added to a reaction vessel and heated to 80℃, stirring until homogeneous. Then, the temperature was raised to approximately 135℃ and saponified at this temperature for 45 minutes. The temperature was further increased to 146℃ while simultaneously depressurizing and dehydrating. After depressurization, the pressure relief valve was closed, and the temperature was rapidly raised to 210℃ and held for 10 minutes. The temperature was then slowly lowered to 185℃, and 450g of amide compound 2 was added and sheared and dispersed for 40 minutes. The temperature was then further lowered to approximately 80℃, all additives were added, and the mixture was stirred for 1.5 hours. The product was then discharged from the vessel and ground to obtain the desired product. Sample performance data are shown in Table 1.

[0048] Test method:

[0049] The lubricating grease composition of the present invention was evaluated by the following test methods to assess the composition's ability to suppress bearing temperature rise, reduce torque, and resist wear.

[0050] Bearing temperature rise

[0051] A grease composition was installed in an actual motor bearing, and a bearing temperature rise test was conducted under the following conditions: with fixed axial and radial loads, the rotational speed was increased in a stepwise manner, and the temperature rise of the bearing at each speed was examined. The time period for each speed was controlled to be approximately one hour after the temperature stabilized. Temperature sensors transmitted and recorded the temperatures of two bearings, and the temperature rise data was calculated by subtracting the room temperature from the temperatures of the two bearings at the highest speed.

[0052]

[0053] (2) Wear resistance

[0054] The anti-wear performance was evaluated according to the method of SH / T 0204 by measuring the wear scar diameter of the steel ball.

[0055] Low temperature torque

[0056] The evaluation is conducted according to the method of SH / T 0338, and the low torque performance is evaluated by measuring the operating torque of the bearing at low temperature.

[0057] Table 1 Comparison of the properties of lubricating grease compositions

[0058]

[0059] As shown in Table 1, the grease composition of the present invention, in Examples 1-3, which contain amide compounds (Amide 1 being octadecenoamide and Amide 2 being docosenoamide) and alkyl molybdenum thiophosphate, significantly reduces bearing temperature rise and torque, exhibiting excellent anti-wear properties. Comparative Example 1, which does not contain amide compounds, has no significant effect on suppressing bearing temperature rise. Comparative Examples 2-4, which contain other types of friction reducers, show insufficient anti-wear performance. The grease composition of the present invention, by using metal soap and amide compounds as a mixed thickener and adding friction reducers for synergistic effect, effectively reduces motor bearing temperature rise, exhibits significant anti-wear effect, and thus extends motor service life.

Claims

1. A motor lubricating grease composition, characterized in that, It includes thickener, base oil, and additives, specifically: thickener 10%–15%, base oil 85%–90%, the sum of their mass percentages being 100%; and additives added at a rate of 1%–5%. The thickener is composed of mixture A and mixture B. composition: a) Mixture A is a reactant of dodecyl stearic acid, an organic dicarboxylic acid and a saturated aqueous solution of lithium hydroxide monohydrate, wherein the molar ratio of dodecyl stearic acid to organic dicarboxylic acid is 1:0.1 to 1; b) Mixture B is an amide compound, wherein the amide compound is one or more of dodecanoamide, hexadecanoamide, octadecanoamide, octadecenoamide, docosamide, docosamide, N,N-dimethyldodecanoamide, and N,N'-ethylenebisstearamide in any proportion; The mixture A accounts for 80% to 90% of the total mass of the thickener; The organic dicarboxylic acid in mixture A is one or more of C4 to C12 in any proportion; The mixture B accounts for 10% to 20% of the total mass of the thickener; The base oil is one or more of mineral oil, poly-α-olefin, and ester oil in any proportion; the viscosity grade of the base oil is in the range of ISO 46 to ISO 320. The additive is an organic molybdenum compound, and the proportion of the organic molybdenum compound added is 1% to 5%.

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