Grease for cleaning and method for cleaning bearing waste grease

Abstract

The embodiment of the invention provides lubricating grease for cleaning, the lubricating grease for cleaning comprises the following components: base oil, the mass fraction of the base oil is 60-90%, the kinematic viscosity at 40 DEG C is 10-100 mm < 2 > / s, the base oil comprises synthetic ester oil; a thickening agent, wherein the mass fraction of the thickening agent is 5%-20%; and a surfactant, wherein the mass fraction of the surfactant is 1%-20%. The lubricating grease for cleaning can be used for cleaning waste grease and has a good cleaning effect.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating grease, and in particular to a lubricating grease for cleaning and a method for cleaning waste bearing grease. Background Art

[0002] The operation of the wind turbine main shaft bearing requires grease to reduce the wear of the bearing during operation. As time goes by, the grease tends to dry up and clump, and it is difficult to remove. If it is not cleaned in time, it will cause poor lubrication of the main shaft bearing, resulting in main shaft bearing damage, abnormal wear, high bearing temperature and other problems.

[0003] Depending on the use of grease, the original grease needs to be cleaned and replaced with fresh grease regularly or irregularly. Traditional cleaning methods include manual removal, but there are problems such as low efficiency, incomplete cleaning, and long time consumption; or using tank trucks to transport cleaning solvents to clean the main shaft bearings, which has high cleaning costs and takes a long time. These two methods require the wind turbine to be shut down for cleaning of the main shaft bearings, which will affect the power generation efficiency of the wind turbine. Summary of the invention

[0004] In order to more efficiently clean waste grease and achieve the cleaning target, the embodiment of the present disclosure provides a cleaning grease for cleaning waste grease, wherein the cleaning grease comprises: a base oil, wherein the mass fraction of the base oil is 60% to 90%, and the kinematic viscosity at 40°C is 10 to 100 mm 2 / s, the base oil comprises synthetic ester oil; a thickener, the mass fraction of the thickener is 5% to 20%; a surfactant, the mass fraction of the surfactant is 1% to 20%.

[0005] In some embodiments, the synthetic ester oil comprises at least one of a polyol ester and a phenyl ester, wherein the phenyl ester has the following structural formula:

[0006]

[0007] Wherein, R1 is a straight chain or branched chain alkyl group having 8 to 10 carbon atoms, and n is 3 or 4.

[0008] In some embodiments, the synthetic ester oil includes at least one of trimellitic acid ester, pyromellitic acid ester, trimellitic acid ester, trimellitic acid ester, pentaerythritol ester, dipentaerythritol ester and isopentaerythritol ester.

[0009] In some embodiments, the base oil further comprises mineral oil and / or polyalphaolefin.

[0010] In some embodiments, the mass fraction of the synthetic ester oil in the cleaning grease is 20% to 40%.

[0011] In some embodiments, the mass fraction of the mineral oil in the cleaning grease is 20% to 40%, and the mass fraction of the polyalphaolefin in the cleaning grease is 20% to 40%.

[0012] In some embodiments, the thickener comprises silica aerogel.

[0013] In some embodiments, the surfactant is a polyoxyethylene fatty alcohol ether having the following structural formula: R2O(CH2CH2O) m H, wherein R2 is a hydrocarbon group having 9 to 11 carbon atoms, and m is an integer of 1-5.

[0014] In some embodiments, the mass fraction of the thickener is 5% to 10%, and the mass fraction of the surfactant is 5% to 15%.

[0015] In some embodiments, the cleaning grease further comprises an extreme pressure anti-wear additive, and the mass fraction of the extreme pressure anti-wear additive is 0.5% to 5%.

[0016] In some embodiments, the extreme pressure and anti-wear additives include: thiophosphate and ammonium phosphate.

[0017] In some embodiments, according to the DIN51350 standard, the welding load of the cleaning grease is above 1300N; and / or according to method E of part 5 of the DIN51350 standard, a load of 1000N is applied at room temperature for 60s, and the diameter of the wear spot of the cleaning grease is less than 2mm.

[0018] An embodiment of the present disclosure also provides a method for cleaning waste bearing grease, the cleaning method comprising: adding any of the above cleaning greases into the bearing to clean the waste grease in the bearing; after the waste grease is cleaned and removed, adding new grease to the bearing.

[0019] In some embodiments, when the waste grease in the bearing is cleaned, the bearing is in a normal operating state.

[0020] In some embodiments, the bearing is a bearing of a wind turbine.

[0021] Compared with the prior art, the technical solution of the embodiment of the present disclosure has the following beneficial effects:

[0022] The cleaning grease of the embodiment of the present disclosure comprises a base oil with a mass fraction of 60% to 90%, a thickener with a mass fraction of 5% to 20%, and a surfactant with a mass fraction of 1% to 20%. The base oil comprises a synthetic ester oil, which has a certain polarity and can dissolve and remove polar substances in waste grease. The kinematic viscosity of the base oil at 40°C is 10 to 100 mm 2 / s, which has a good effect of promoting the flow and removing waste grease. The cleaning grease has a good cleaning effect on waste grease.

[0023] The method for cleaning waste grease of a bearing in an embodiment of the present disclosure includes cleaning the waste grease of the bearing with cleaning grease, and can achieve cleaning of the waste grease when the bearing is operating normally. After the waste grease is cleaned, new grease is added, and the cleaning efficiency is high without affecting the normal operation of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features and advantages of the present disclosure will be better understood through the following detailed description of the optional embodiments in conjunction with the accompanying drawings, in which the same reference numerals represent the same or similar components, wherein:

[0025] Figure 1 shows a photograph of a spindle bearing before cleaning according to an embodiment of the present disclosure;

[0026] Figure 2 The cleaning grease cleaning method of Comparative Example 1 in the specific embodiment of the present disclosure is shown. Figure 1 Photo of the bearing after the spindle bearing

[0027] Figure 3-Figure 4 The cleaning grease cleaning method using Examples 1 to 2 of the specific embodiments of the present disclosure is shown. Figure 1 Photo of the bearing after the spindle bearing. DETAILED DESCRIPTION

[0028] Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and cannot be understood as limiting the present disclosure.

[0029] Waste grease is usually difficult to remove and may even dry up and clump. In order to more efficiently clean the waste grease and achieve the cleaning goal, the specific embodiments of the present disclosure provide a cleaning grease for cleaning waste grease. The waste grease includes a variety of greases that are waste during use. In some specific embodiments, the waste grease includes grease, and the grease can be used for lubricating bearings or other components.

[0030] The components of the cleaning grease of the specific embodiment of the present disclosure include: base oil, thickener, and surfactant. The mass fraction of the base oil is 60% to 90%, and specifically, for example, it can be 60%, 65%, 70%, 75%, 77%, 80% or 90%, etc. The mass fraction of the thickener is 5% to 20%, and specifically, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, etc. The mass fraction of the surfactant is 1% to 20%, and specifically, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, etc.

[0031] The main component of waste grease is oily organic matter, which usually has a relatively high viscosity. In order to better remove waste grease, the viscosity of the cleaning grease needs to be controlled within a certain range so that the cleaning grease has good low-temperature flow properties. The viscosity of the cleaning grease is mainly determined by the base oil. In some specific embodiments, the kinematic viscosity of the base oil at 40°C is 10 to 100 mm 2 / s, for example, 10 mm 2 / s, 20mm 2 / s, 30mm 2 / s, 40mm 2 / s, 50mm 2 / s, 60mm 2 / s, 70mm 2 / s, 80mm 2 / s, 90mm 2 / s or 100mm 2 In some embodiments, the kinematic viscosity of the base oil at 40° C. is 30 to 40 mm 2 / s, for example, 30 mm 2 / s, 35mm 2 / s or 40mm 2 / s and so on.

[0032] In the cleaning grease according to a specific embodiment of the present disclosure, the base oil includes synthetic ester oil.

[0033]

[0034] In some embodiments, the synthetic ester oil includes at least one of a polyol ester and a phenyl ester, wherein the phenyl ester has the following structural formula:

[0035] Wherein, R1 is a straight chain or branched chain alkyl group having 8 to 10 carbon atoms, and n is 3 or 4.

[0036] In some specific embodiments, the synthetic ester oil includes polyol esters, and specifically may be at least one of triethylolpropane ester, trimethylolpropane ester, pentaerythritol ester, dipentaerythritol ester, or isopentaerythritol ester.

[0037] In some specific embodiments, the pentaerythritol ester is selected from monopentaerythritol octanoate, monopentaerythritol nonanoate, or monopentaerythritol decanoate.

[0038] In some specific embodiments, the dipentaerythritol ester is selected from dipentaerythritol hexa-C5-9 acid esters.

[0039] In some specific embodiments, the synthetic ester oil includes at least one of trimellitic acid ester, pyromellitic acid ester, trimellitic acid ester, trimellitic acid ester, pentaerythritol ester, dipentaerythritol ester and isopentaerythritol ester.

[0040] In some specific embodiments, the trimellitic acid ester is selected from trioctanol trimellitate, trinonanol trimellitate, tridecyl trimellitate or decyloctyl 1,2,4-benzenetricarboxylate.

[0041] In some specific embodiments, the synthetic ester oil is selected from tri(n-octyl-n-decyl) trimellitate (CAS No.: 67989-23-5).

[0042] In some specific embodiments, the synthetic ester oil is selected from dipentasrythrityl hexa C5-9 acid ester (CAS No.: 67762-52-1).

[0043] In the cleaning grease of the specific embodiments of the present invention, since the polarity of synthetic ester oil is relatively high, the polarity of the cleaning grease is adjusted by adjusting the amount of synthetic ester oil, so that the cleaning grease has similar polarity and good compatibility with waste greases of different polarities. In some specific embodiments, the mass fraction of synthetic ester oil in the cleaning grease is 20% to 40%, for example, it can be 20%, 27%, 28%, 30% or 40%, etc.

[0044] In some specific embodiments of the cleaning grease according to the specific embodiments of the present disclosure, the base oil further comprises mineral oil and / or poly-alpha-olefin.

[0045] In some embodiments, the base oil is composed of synthetic ester oil and mineral oil. In some embodiments, the base oil is composed of synthetic ester oil and polyalphaolefin. In some embodiments, the base oil is composed of synthetic ester oil, mineral oil and polyalphaolefin.

[0046] In the cleaning grease of the specific embodiment of the present disclosure, the polarity of mineral oil and polyalphaolefin is relatively low. By adjusting the appropriate ratio of mineral oil, polyalphaolefin and synthetic ester oil, the cleaning grease has a good removal effect on both polar and non-polar waste grease. In some specific embodiments, the mass fraction of the mineral oil in the cleaning grease is 20% to 40%, and specifically, for example, it can be 20%, 22%, 26%, 28%, 30%, 39% or 40%, etc.; the mass fraction of the polyalphaolefin in the cleaning grease is 20% to 40%, and specifically, for example, it can be 20%, 22%, 23%, 25%, 30%, 38% or 40%, etc. In some specific embodiments, the mineral oil includes Class II mineral oil and Class III mineral oil, which can be purchased from the market, such as from PetroChina, etc.; the polyalphaolefin includes traditional polyalphaolefin (PAO) and metallocene-catalyzed polyalphaolefin (mPAO), which can be purchased from the market, such as from Chevron, INEOS, etc.

[0047] In the cleaning grease of the specific embodiments of the present disclosure, in some specific embodiments, the thickener includes an organic aerogel or an inorganic aerogel. In some specific embodiments, the thickener includes a silica aerogel, which has the function of thickening and reducing viscosity. The silica aerogel has a relatively small particle size, and has a grinding effect on hardened and coked waste grease, and has a good removal effect. In some specific embodiments, the thickener includes a lipophilic silica aerogel, and the lipophilic silica aerogel can be purchased from, for example, Evonik. In some specific embodiments, the particle size of the lipophilic silica aerogel is less than 50 μm, and the BET specific surface area is 90 to 130 m 2 / g.

[0048] In the cleaning grease of the specific embodiments of the present disclosure, in some specific embodiments, the mass fraction of the thickener is 5% to 10%, for example 5%, 6%, 7%, 8%, 9% or 10%, etc.

[0049] In the cleaning grease of the specific embodiment of the present disclosure, in some specific embodiments, the surfactant is a non-ionic surfactant. In some specific embodiments, the surfactant is a polyoxyethylene fatty alcohol ether, and the polyoxyethylene fatty alcohol ether has the following structural formula:

[0050] R2O(CH2CH2O) m H

[0051] Wherein, R2 is a hydrocarbon group having 5 to 11 carbon atoms, further, R2 is a hydrocarbon group having 9 to 11 carbon atoms, R2 is a straight-chain hydrocarbon group or a branched hydrocarbon group, in some specific embodiments, R is a saturated hydrocarbon group, in some specific embodiments, R is an unsaturated hydrocarbon group; in some specific embodiments, m is an integer of 1 to 5.

[0052] In the cleaning grease of the specific embodiments of the present disclosure, in some specific embodiments, the mass fraction of the surfactant is 5% to 15%, for example 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%, etc.

[0053] In order to make the cleaning grease of the specific embodiments of the present disclosure have good extreme pressure and anti-wear properties, in some specific embodiments, the components of the cleaning grease also include extreme pressure and anti-wear additives, and the mass fraction of the extreme pressure and anti-wear additives is 0.5% to 5%, for example, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.6%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc.

[0054] In some embodiments, the extreme pressure anti-wear additive includes an organic sulfur phosphorus compound. In some embodiments, the extreme pressure anti-wear additive includes thiophosphate and ammonium phosphate, and the mass ratio of thiophosphate to ammonium phosphate can be 1:2 to 2:1, for example 1:2, 1:1 or 2:1.

[0055] In order to make the cleaning grease have anti-oxidation or anti-corrosion properties and to make the properties of the cleaning grease more stable, without affecting the cleaning performance of the cleaning grease, in some specific embodiments, the cleaning grease also includes other additives, and the mass fraction of the other additives in the cleaning grease is 0.5% to 6%, for example, it can be 0.5%, 3%, 3.8%, 5% or 6%, etc.

[0056] In some specific embodiments, other additives may include at least one of antioxidants, anti-corrosion additives, copper corrosion inhibitors, and pour point depressants. Other additives are only examples and do not limit the effects and types of additives. Those skilled in the art can select the types of additives according to the requirements for the performance of the cleaning grease.

[0057] In some specific embodiments, in order to make the cleaning grease have antioxidant properties and help keep the cleaning grease itself from being oxidized during the process of cleaning waste grease, other additives include antioxidants. In some specific embodiments, the antioxidant includes at least one of hindered amines and hindered phenols; in some specific embodiments, the antioxidant includes: at least one of diphenylamine, naphthylamine, and p-phenylenediamine.

[0058] In some embodiments, in order to make the cleaning grease have anti-corrosion and anti-rust properties, other additives include anti-corrosion additives. In some embodiments, the anti-corrosion additives include at least one of barium petroleum sulfonate, calcium petroleum sulfonate, and succinic acid semi-lipid compounds. In some embodiments, the anti-corrosion additive is a succinic acid semi-lipid compound.

[0059] In some embodiments, to prevent the copper or copper alloy parts from being corroded at the place where the waste grease is cleaned, other additives include a copper corrosion inhibitor. In some embodiments, the copper corrosion inhibitor includes at least one of benzotriazole (BTA), 2-mercaptobenzimidazole (MBI), and 2-mercaptobenzothiazole. In some embodiments, the copper corrosion inhibitor is benzotriazole.

[0060] In some embodiments, to further improve the low temperature fluidity and viscosity index of the cleaning grease, other additives include an anticoagulant. In some embodiments, the anticoagulant includes polyalkyl methyl acrylate.

[0061] In some specific embodiments, in order to maintain the structural stability of the cleaning grease and prevent it from softening or liquefying, other additives include a structural stabilizer. In some specific embodiments, the structural stabilizer includes water, glycerol, and a low-molecular organic acid salt.

[0062] In some specific embodiments of the cleaning grease disclosed in the present invention, the components of the cleaning grease include: 60% to 90% by mass of base oil, 5% to 20% by mass of thickener, 1% to 20% by mass of surfactant, 0.5% to 5% by mass of extreme pressure anti-wear additive, and 0.5% to 6% by mass of other additives. The cleaning grease has a good removal effect on waste grease, can soften and remove dried, agglomerated, and coked waste grease, and the cleaning is relatively thorough and has a good cleaning effect.

[0063] The cleaning grease of the specific embodiment of the present disclosure has good load performance. According to the fourth part of the DIN51350 standard, the welding load of the cleaning grease is tested, and the welding load of the cleaning grease is measured to be above 1300N, that is, the cleaning grease can withstand higher loads and speeds, and will not be damaged by friction or lose performance due to excessive loads, and has good extreme pressure performance.

[0064] The cleaning grease of the specific embodiment of the present disclosure has good anti-wear performance. According to method E of part 5 of DIN51350 standard, a load of 1000N is applied at room temperature for 60s, and the diameter of the steel ball wear spot of the cleaning grease is less than 2mm, and the cleaning grease has good anti-wear performance.

[0065] In some specific embodiments of the cleaning grease according to the specific embodiments of the present disclosure, the working cone penetration of the cleaning grease is measured to be 00 grade according to the DIN ISO 2137 standard.

[0066] The cleaning grease of the specific embodiment of the present disclosure is used for cleaning waste grease in some specific embodiments, wherein the waste grease comprises 50% to 80% of base oil by mass, 5% to 20% of thickener by mass, 1% to 10% of additive by mass, etc., wherein the mass fraction is the mass fraction of each component in the waste grease. The cleaning grease has a good cleaning effect on a variety of waste greases, and also has excellent infiltration, softening and cleaning effects on dried, agglomerated and coked waste greases.

[0067] The specific embodiment of the present disclosure also provides a method for preparing cleaning grease, which is used to prepare the cleaning grease of any of the above embodiments. The preparation method comprises: adding base oil, extreme pressure anti-wear additives, thickeners, surfactants and other additives into a reaction kettle and stirring.

[0068] The preparation method of the cleaning grease of the specific embodiment of the present disclosure, in some specific embodiments, comprises: adding a part of the base oil to the reactor, controlling the temperature in the reactor to 80-90°C; adding the antioxidant and the extreme pressure anti-wear additive to the reactor for stirring and dissolving; adding the remaining part of the base oil to the reactor, cooling the temperature in the reactor to 50-70°C; adding the thickener to the reactor, and continuing to stir for 20-80 minutes; adding the surfactant and at least one other additive to the reactor, stirring for 100-200 minutes and then cooling the reactor to room temperature; performing homogenization, degassing and filtering to obtain the cleaning grease. The cleaning grease can be canned as a finished product.

[0069] In the method for preparing cleaning grease according to the specific embodiments of the present disclosure, in some specific embodiments, the raw materials for preparing the cleaning grease have a base oil mass fraction of 60% to 90%, a thickener mass fraction of 5% to 20%, a surfactant mass fraction of 1% to 20%, an extreme pressure and anti-wear additive mass fraction of 0.5% to 5%, and other additives mass fraction of 0.5% to 6%.

[0070] In a specific embodiment, the preparation method includes: adding about half of the base oil to a reactor and controlling the temperature in the reactor to 80-90°C; adding an antioxidant (hindered amine) and an extreme pressure anti-wear additive (a mixture of thiophosphate and ammonium phosphate) to the reactor for stirring and dissolving; adding the remaining base oil to the reactor and cooling the temperature in the reactor to about 60°C; adding a thickener (silicon dioxide aerogel) to the reactor and continuing to stir for 30 minutes; adding a surfactant (polyoxyethylene fatty alcohol ether) and at least one other additive to the reactor, stirring for 120 minutes and then cooling the reactor to room temperature; performing homogenization, degassing and filtering to obtain a cleaning grease.

[0071] The specific embodiments of the present disclosure also provide a method for cleaning waste bearing grease, which includes: adding the cleaning grease of any of the above specific embodiments into the bearing to clean the waste grease in the bearing; after the waste grease is cleaned and removed, adding new grease to the bearing.

[0072] The cleaning method of the specific embodiment of the present disclosure uses cleaning grease to clean waste grease, has a good removal effect on waste grease and agglomerated or coked waste grease, has a good cleaning effect, and can achieve the cleaning goal.

[0073] The cleaning method of the specific embodiment of the present disclosure, in some specific embodiments, refers to online cleaning of the bearing, that is, when the bearing is operating normally, the waste grease of the bearing is cleaned and discharged, and then new grease is added, so that the cleaning and removal of the waste grease and the addition of new grease are completed without stopping the bearing equipment, and the operating efficiency of the bearing is not affected.

[0074] The waste grease of the main shaft bearings of wind turbines is the grease whose performance decreases or dries up, lumps or cokes as the service time increases. Its lubricating effect decreases and it needs to be cleaned and replaced with new grease in time to avoid problems such as abnormal wear of the main shaft bearings or excessive bearing temperature caused by poor lubrication, which will affect the normal operation of the wind turbine. Therefore, it is necessary to clean the waste grease of the main shaft bearings of wind turbines.

[0075] In some specific embodiments, the cleaning grease of the specific embodiment of the present disclosure is used to clean the waste grease of the main shaft bearing of the wind turbine set, which specifically includes: when the wind turbine set is in normal operation, the cleaning grease is added to the main shaft bearing of the wind turbine set, the cleaning grease contacts and rubs with the waste grease and softens the waste grease, drives the waste grease to flow, and the waste grease and the cleaning grease are discharged from the main shaft bearing together, and after the waste grease is cleaned and removed, new grease is added to the main shaft bearing, thereby completing the online cleaning process and achieving the replacement of the waste grease with the new grease. The method for cleaning the waste grease of the bearing of the specific embodiment of the present disclosure is an online cleaning process throughout the whole process, and the cleaning of the waste grease and the injection of the new grease are a continuous process. Both the cleaning process and the injection of the new grease do not require the operation of the wind turbine set to be stopped. Compared with the wind turbine set that needs to be shut down for cleaning, it has a lower cleaning economic cost and a higher convenience of cleaning operation.

[0076] The cleaning grease used in the method for cleaning waste bearing grease of the specific embodiment of the present disclosure has good compatibility with different grease products from multiple manufacturers, has a good removal effect on waste grease formed by grease products, and has excellent wetting, softening and cleaning effects on dried, agglomerated and coked waste grease.

[0077] The present invention is further described below by means of specific examples.

[0078] Example

[0079] Test Method Description

[0080] (1) Kinematic viscosity: The kinematic viscosity of the base oil is tested according to GB / T 265-1988 Kinematic viscosity determination and dynamic viscosity calculation of petroleum products;

[0081] (2) Working cone penetration: The working cone penetration of cleaning grease is tested according to DIN ISO 2137;

[0082] (3) Low temperature flow pressure: According to DIN51805 standard, the low temperature flow pressure of cleaning grease is tested at -20°C;

[0083] (4) Welding load: According to the fourth part of DIN51350 standard, the welding load of the cleaning grease is tested by the four-ball machine method. The welding load represents the extreme pressure performance of the cleaning grease;

[0084] (5) Wear spot diameter: According to method E of part 5 of DIN51350 standard, the wear spot diameter of the cleaning grease is tested by applying a load of 1000N for 60s at room temperature using a four-ball tester. The wear spot diameter represents the anti-wear performance of the cleaning grease.

[0085] (6) Cleaning effect: The waste grease of the main shaft bearing of the wind turbine generator set makes the bearing unable to rotate freely. The components of the waste grease of the main shaft bearing of the wind turbine generator set include 50% to 80% by mass of base oil, 5% to 20% of thickener, and 1% to 10% of additives. The waste grease is cleaned by using the EMCOR bearing corrosion test bench with cleaning grease. After cleaning, the degree of coking and softening on the bearing surface and whether it can be wiped off, as well as whether the bearing can rotate freely, are judged. The cleaning effect evaluation criteria are detailed in Table 1.

[0086] Table 1 Evaluation of cleaning effect of spindle bearings

[0087]

[0088] Example 1

[0089] According to the ratio in Table 2 below, a part of the base oil is added to the reactor, and the temperature in the reactor is controlled to be 80-90°C; the antioxidant and the extreme pressure and anti-wear additive are added to the reactor and stirred and dissolved; the remaining part of the base oil is added to the reactor, and the temperature in the reactor is cooled to 50-70°C; the silica aerogel is added to the reactor in an amount of 8% by mass, and the stirring is continued for 20-80 minutes; the surfactant and at least one other additive are added to the reactor, and the reactor is cooled to room temperature after stirring for 100-200 minutes; homogenization, degassing and filtering are performed to obtain cleaning grease 1#.

[0090] The performance test of cleaning grease 1# and the cleaning effect evaluation of waste grease are carried out. The performance test results and cleaning effect evaluation are recorded in Table 3. The photos of the bearings after cleaning are shown in Figure 3 .

[0091] Example 2

[0092] According to the ratio in Table 2 below, a part of the base oil is added to the reactor, and the temperature in the reactor is controlled to be 80-90°C; the antioxidant and the extreme pressure and anti-wear additive are added to the reactor and stirred and dissolved; the remaining part of the base oil is added to the reactor, and the temperature in the reactor is cooled to 50-70°C; the silica aerogel is added to the reactor in an amount of 8% by mass, and the stirring is continued for 20-80 minutes; the surfactant and at least one other additive are added to the reactor, and the reactor is cooled to room temperature after stirring for 100-200 minutes; homogenization, degassing and filtering are performed to obtain cleaning grease 2#.

[0093] The performance test of cleaning grease 2# and the cleaning effect evaluation of waste grease are carried out. The performance test results and cleaning effect evaluation are recorded in Table 3. The photos of the bearings after cleaning are shown in Figure 4 .

[0094] Comparative Example 1

[0095] According to the ratio in Table 2 below, a part of the base oil is added to the reactor, and the temperature in the reactor is controlled to be 80-90°C; the antioxidant and the extreme pressure and anti-wear additive are added to the reactor and stirred and dissolved; the remaining part of the base oil is added to the reactor, and the temperature in the reactor is cooled to 50-70°C; the silica aerogel is added to the reactor in an amount of 8% by mass, and the stirring is continued for 20-80 minutes; the surfactant and at least one other additive are added to the reactor, and the reactor is cooled to room temperature after stirring for 100-200 minutes; homogenization, degassing and filtration are performed to obtain cleaning grease 3#.

[0096] The performance test of cleaning grease 3# and the cleaning effect evaluation of waste grease are carried out. The performance test results and cleaning effect evaluation are recorded in Table 3. The photos of the bearings after cleaning are shown in Figure 2 .

[0097] Table 2 Components and mass fractions of cleaning greases of Examples 1 to 2 and Comparative Example 1

[0098]

[0099] Table 3 Performance of cleaning grease of Examples 1 to 2 and Comparative Example 1

[0100]

[0101] As shown in Table 3, the working cone penetration of cleaning grease 1#, cleaning grease 2# and cleaning grease 3# is 00 grade, that is, it is close to liquid and has good fluidity. Cleaning grease 1#, cleaning grease 2# and cleaning grease 3# all have relatively low low-temperature flow pressure, that is, they have good fluidity at low temperatures. The welding load of cleaning grease 1#, cleaning grease 2# and cleaning grease 3# is 1300N, that is, they can withstand higher loads and speeds, and will not cause the bearing spindle friction pair to wear and fail under high loads due to excessive loads, and have good extreme pressure performance. The diameter of the steel ball wear spot of cleaning grease 1# and cleaning grease 2# is less than 2mm, which is smaller than the steel ball wear spot diameter of 2mm of cleaning grease 3#, so cleaning grease 1# and cleaning grease 2# have better anti-wear performance.

[0102] Figure 1 shows a photograph of a spindle bearing before cleaning according to an embodiment of the present disclosure; Figure 2 The cleaning grease cleaning method of Comparative Example 1 in the specific embodiment of the present disclosure is shown. Figure 1 Bearing photo after the spindle bearing in the; Figure 3-Figure 4 The cleaning grease cleaning method using Examples 1 to 2 of the specific embodiments of the present disclosure is shown. Figure 1Photo of the bearing after the spindle bearing.

[0103] refer to Figure 1 , the waste grease in the main shaft bearing of the wind turbine unit is aged and coked, and the bearing cannot rotate freely and needs to be cleaned. Figure 2 After cleaning the waste grease of the main shaft bearing with cleaning grease 3#, the rolling element of the bearing regained its gloss, the coking lubrication on the bearing surface could only be partially wiped off, the bearing could rotate freely, and the cleaning effect was not up to standard. Figure 3 After cleaning the waste grease of the main shaft bearing with grease 1#, the rolling elements of the bearing are bright, the coke on the bearing surface is softened and can be completely wiped off, the bearing can rotate freely, and the cleaning effect is excellent. Figure 4 After cleaning the waste grease of the main shaft bearing with grease 2#, the rolling elements of the bearing are bright, the coke on the bearing surface is softened and can be basically wiped off, the bearing can rotate freely, and the cleaning effect is good.

[0104] From the cleaning effect evaluation of cleaning grease 1#, cleaning grease 2# and cleaning grease 3#, it can be seen that cleaning grease 3# failed to achieve the cleaning effect. The base oils of cleaning grease 1# and cleaning grease 2# include synthetic ester oil, which increases the polarity of the base oil and promotes the removal of polar grease in waste grease. Compared with cleaning grease 2#, since the synthetic ester oil in the components of cleaning grease 1# is a dipentaerythritol hexa C5-9 acid ester with higher polarity, cleaning grease 2# has a better cleaning effect.

[0105] The above is only an exemplary embodiment used to illustrate the principle of the present disclosure, and is not intended to limit the protection scope of the present disclosure. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also within the protection scope of the present disclosure.

Claims

1. A cleaning grease, characterized in that: Used for cleaning waste grease, the cleaning grease comprises: Base oil, the mass fraction of the base oil is 60% to 90%, and the kinematic viscosity at 40°C is 10 to 100 mm 2 / s, the base oil comprises synthetic ester oil; A thickener, wherein the mass fraction of the thickener is 5% to 20%; The surfactant has a mass fraction of 1% to 20%.

2. The cleaning grease according to claim 1, characterized in that: The synthetic ester oil comprises at least one of a polyol ester and a phenyl ester, and the phenyl ester has the following structural formula: Wherein, R1 is a straight chain or branched chain alkyl group having 8 to 10 carbon atoms, and n is 3 or 4.

3. The cleaning grease according to claim 2, characterized in that: The synthetic ester oil comprises at least one of trimellitic acid ester, pyromellitic acid ester, trimellitic acid ester, trimellitic acid ester, pentaerythritol ester, dipentaerythritol ester and isopentaerythritol ester.

4. The cleaning grease according to claim 1, characterized in that: The base oil also includes mineral oil and / or polyalphaolefin.

5. The cleaning grease according to claim 4, characterized in that: The mass fraction of the synthetic ester oil in the cleaning grease is 20% to 40%.

6. The cleaning grease according to claim 5, characterized in that: The mass fraction of the mineral oil in the cleaning grease is 20% to 40%, and the mass fraction of the polyalphaolefin in the cleaning grease is 20% to 40%.

7. The cleaning grease according to claim 1, characterized in that: The thickener includes silica aerogel.

8. The cleaning grease according to claim 1, characterized in that: The surfactant is a polyoxyethylene fatty alcohol ether having the following structural formula: R2O(CH2CH2O) m H Wherein R2 is a hydrocarbon group having 9 to 11 carbon atoms, and m is an integer of 1 to 5.

9. The cleaning grease according to claim 1, characterized in that: The mass fraction of the thickener is 5% to 10%, and the mass fraction of the surfactant is 5% to 15%.

10. The cleaning grease according to claim 1, characterized in that: The cleaning grease also comprises an extreme pressure anti-wear additive, and the mass fraction of the extreme pressure anti-wear additive is 0.5% to 5%.

11. The cleaning grease according to claim 10, characterized in that: The extreme pressure and anti-wear additives include: thiophosphate and ammonium phosphate.

12. The cleaning grease according to any one of claims 1 to 11, characterized in that: i) According to DIN51350 standard, the welding load of the cleaning grease is above 1300N; and / or ii) According to method E of part 5 of DIN 51350 standard, a load of 1000N is applied for 60s at room temperature, and the diameter of the wear spot of the cleaning grease is less than 2mm.

13. A method for cleaning waste bearing grease, characterized in that: include: Adding the cleaning grease as claimed in any one of claims 1 to 12 into the bearing to clean the waste grease in the bearing; After the waste grease has been cleaned away, new grease is added to the bearing.

14. The cleaning method according to claim 13, characterized in that: When the waste grease in the bearing is cleaned, the bearing is in a normal operating state.

15. The cleaning method according to claim 13, characterized in that: The bearing is a bearing of a wind turbine generator set.

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