JP4751807B2 - Spindle support device for wind power generation and double row self-aligning roller bearing used in the device - Google Patents

Description

  The present invention relates to a main shaft support device for wind power generation and a double-row self-aligning roller bearing that supports the main shaft for wind power generation.

  As a bearing for a wind turbine main shaft in a large wind power generator, a rolling bearing, particularly a large double row self-aligning roller bearing 21 as shown in FIG. 4 is often used. The main shaft 20 is a shaft to which the blade 19 is attached. The main shaft 20 is rotated by receiving wind force, and the rotation is increased by a speed increaser (not shown) to rotate the generator to generate power. When power is generated by receiving wind, the main shaft 20 supporting the blade 19 is loaded with an axial load (bearing thrust load) due to wind force applied to the blade 19 and an axial radial load (bearing radial load). The double-row self-aligning roller bearing 21 can simultaneously apply a radial load and a thrust load and has alignment, so that it can absorb an accuracy error of the bearing housing 18 and an inclination of the spindle 20 due to an installation error, and The bending of the main shaft 20 during operation can be absorbed. Therefore, it is a bearing suitable for a main shaft bearing for wind power generation, and is used (Non-Patent Document 1).

  However, in the wind turbine, the thrust load is larger than the radial load, and the roller 24 in the row receiving the thrust load out of the double row rollers 24 and 25 is exclusively subjected to the radial load and the thrust load at the same time. Become. Therefore, the rolling fatigue life is shortened. Further, since a thrust load is applied, there has been a problem that sliding motion occurs at the collar portion and wear occurs. In addition, there is a problem that the opposite row is lightly loaded, and the rollers 25 slip on the raceway surfaces 22a and 23a of the inner and outer rings 22 and 23, thereby causing surface damage and wear. For this reason, the problem is dealt with by increasing the bearing size. However, the margin is too large on the light load side, which is uneconomical. In addition, in a main shaft bearing for wind power generation that is installed unattended or is installed at a high place because the blade 19 is large, it is desired that the bearing be simple in terms of lubrication in order to be maintenance-free.

For such a problem, a main shaft bearing for wind power generation is known in which frictional wear is reduced by adding a bismuth compound to grease to be enclosed (see Patent Document 1). However, since the main shaft bearing for wind power generation is used outdoors, rainwater may enter during rainy weather. In addition, it is often installed on the ocean, and is exposed to water vapor from the sea surface. Further, condensation may occur inside the bearing due to a temperature difference due to temperature change.
When water enters the bearing, the following problems arise. When water droplets enter the load area, the oil film is interrupted, which is disadvantageous in terms of lubricity. When the oil film is interrupted, metal contact occurs, and there is a risk that wear, surface-origination type peeling, and early peeling occur on the rolling surface of the bearing. Premature peeling refers to peeling accompanied by a white structure change near the surface, or peeling in which cracks develop near the surface in the direction opposite to the rolling direction of the rolling element. In addition, rust is generated inside the bearing depending on the state of water in the bearing.

In addition, a double row cylindrical roller bearing often used for a main shaft bearing for wind power generation is likely to slip, and when an oil film breakage occurs at this portion, the wear becomes severe and a large amount of wear powder is generated. These wear powders deteriorate the lubrication performance of the grease and promote the peeling of the bearing.
NTN catalog “New generation wind turbine bearings” A65. CAT. No. 8404/04 / JE, issued May 1, 2003 JP 2006-161624 A

  The present invention has been made to cope with such a problem, and can effectively prevent separation on the rolling surface caused by water intrusion, and is a double row self-aligning roller excellent in long-term durability. An object of the present invention is to provide a bearing and a spindle support device for wind power generation using the bearing.

The spindle support device for wind power generation according to the present invention is a spindle support device for wind power generation in which a spindle to which a blade is attached is supported by at least one rolling bearing installed in a bearing housing, and the rolling bearing is A rolling bearing comprising an inner ring, an outer ring, and a rolling element interposed between the inner ring and the outer ring, in which grease is sealed around the rolling element. The grease is made up of a non-aqueous base oil and a thickener. And a non-water base oil comprising at least one oil selected from poly-α-olefin oil and mineral oil. As a funnel, an alicyclic-aromatic urea compound obtained by reaction of an aromatic diisocyanate with an alicyclic monoamine and an aromatic monoamine, or an aromatic It consists of an aromatic urea compound obtained by reaction of diisocyanate with an aromatic monoamine alone, and the water dispersant contains Ca sulfonate having a base number of 50 to 500, and the amount of the water dispersant is the same as that of the water resistant grease. It is characterized in that the saturated water content is set to 30% to 60% by weight.

The water dispersant contains sorbitan monooleate. Further, it is characterized by containing 0.5 to 2 parts by weight of the Ca sulfonate and 0.2 to 1 part by weight of the sorbitan monooleate with respect to 100 parts by weight of the base grease.
The thickener is characterized by comprising the alicyclic-aromatic urea compound .

  The double-row self-aligning roller bearing of the present invention includes an inner ring, an outer ring, and a double-row roller interposed between the inner ring and the outer ring, and an axial raceway surface of the outer ring and an outer periphery of the roller in the axial direction. A double-row self-aligning system in which the outer peripheral surface of the roller is disposed along the raceway surface of the outer ring and the water-resistant grease is sealed around the roller by making the surface into a spherical shape having the same radius of curvature. It is a roller bearing, Comprising: This double row self-aligning roller bearing is a rolling bearing used for the said spindle support apparatus for wind power generation, It is characterized by the above-mentioned.

The double-row self-aligning roller bearing used in the spindle support device for wind power generation according to the present invention has a water-resistant grease sealed in the bearing as a fine particle in a base grease composed of a non-aqueous base oil and a thickener. Since a water dispersant that can disperse the water in the grease is blended, the water that has entered the bearing can be dispersed as fine particles. Therefore, even if water is mixed in the water-resistant grease of this bearing, it is possible to suppress the action of moisture that inhibits oil film formation. As a result, metal contact on the rolling surface is suppressed, early peeling can be prevented, and long-term durability is required under conditions where water easily enters due to exposure to rainwater or water vapor from the seawater surface. It can utilize suitably for the spindle support apparatus for wind power generation.
Regarding the rust prevention action, the contact between the steel constituting the bearing and the massive water component can be reduced, so that the generation of rust can be suppressed.

  As a result of investigating the durability of double row spherical roller bearings used in locations where water may enter, the amount of saturated water can be reduced by adding a water dispersant that can disperse water as fine particles in grease. It has been found that the double-row spherical roller bearing filled with the controlled water-resistant grease can be maintained without deterioration of the lubrication performance of the rolling contact portion even when water enters. This is because grease with controlled saturated water content breaks down the oil film formed by the grease because the infiltrated water becomes fine water particles that are uniformly dispersed in the grease and trapped in the continuous phase grease. Therefore, it is considered that the durability of the double row spherical roller bearing is improved. The present invention is based on such knowledge.

  The spindle support device for wind power generation of this invention is demonstrated from FIG. 1 and FIG. FIG. 1 is a schematic diagram of the entire wind power generator including the main shaft support device for wind power generation, and FIG. 2 is a diagram illustrating the main shaft support device for wind power generation of FIG. As shown in FIG. 1 or FIG. 2, the wind power generator 1 rotatably supports a main shaft 3 to which a blade 2 serving as a windmill is attached by a bearing 5 installed in a bearing housing 15 in the nacelle 4. A speed increaser 6 and a generator 7 are installed in the nacelle 4. The speed increaser 6 increases the rotation of the main shaft 3 and transmits it to the input shaft of the generator 7. The nacelle 4 is installed on the support base 8 through a swivel seat bearing 17 so as to be turnable, and is turned through the speed reducer 10 by driving the turning motor 9 shown in FIG. The turning of the nacelle 4 is performed in order to make the direction of the blades 2 face the wind direction. Two spindle support bearings 5 are provided in the example of FIG. 2, but may be one.

  The installation structure of the bearing 5 for supporting the main shaft will be described with reference to FIG. FIG. 3 is a view showing the installation structure of the spindle support bearing 5 in the spindle support apparatus for wind power generation according to the present invention. The bearing 5 includes an inner ring 11 and an outer ring 12 that are a pair of race rings, and a plurality of rolling elements 13 interposed between the inner and outer rings 11 and 12. The bearing 5 may be a radial bearing capable of thrust load, and may be an angular ball bearing, a tapered roller bearing, a deep groove ball bearing, or the like in addition to the self-aligning roller bearing. Among these, the spindle support bearings for wind power generators that operate in a wide load range from light loads to heavy loads during gusts and with the wind direction constantly changing absorb the deflection of the spindle due to operation. Spherical roller bearings that can be made are preferred. The double-row spherical roller bearing of the present invention in which water resistant grease is sealed in a double-row spherical roller bearing capable of handling even if the load capacity applied to the double-row roller bearing is different for each row is a radial As a main shaft support bearing for wind power generation, which has a larger thrust load than the load and has a larger load capacity than the bearing part of the row closer to the bearing part far from the blade, it is durable and long-term durability It can be used suitably.

The outer ring 12 of the bearing 5 has a spherical raceway surface 12a, and each rolling element 13 has a spherical roller whose outer peripheral surface is along the outer ring raceway surface 12a. The inner ring 11 has a collared structure having the raceway surfaces 11a and 11a in each row individually. The rolling elements 13 are held by a holder 14 for each row.
The outer ring 12 is fitted to the inner diameter surface of the bearing housing 15 and the inner ring 11 is fitted to the outer periphery of the main shaft 3 to support the main shaft 3. In the bearing housing 15, a seal 16 such as a labyrinth seal is formed between the side wall 15 a that covers both ends of the bearing 5 and the main shaft 3. Since the sealing performance is obtained by the bearing housing 15, the bearing 5 has a structure without a seal. The bearing 5 is a main shaft bearing for wind power generation according to an embodiment of the present invention.

The water resistant grease used in the present invention is a water resistant grease obtained by blending an additive containing a water dispersing agent capable of dispersing water into a base grease composed of a non-aqueous base oil and a thickener, and enters a bearing. It has a certain affinity for incoming water. A numerical value indicating this affinity was called “saturated water content” and defined as the following formula.

Saturated water content (wt%) = maximum water content dispersible in grease x 100 / (grease weight + maximum water content dispersible in grease)

In the water resistant grease used in the present invention, the blending amount of the water dispersant is such an amount that the saturated moisture content of the grease represented by the above formula can be made 30 to 60% by weight, preferably 40 to 50% by weight. Within this range, inhibition of oil film formation due to moisture can be suppressed.
If the amount of the water dispersant is less than 30% by weight, it becomes difficult for water to be taken in, and the infiltrated water exists as large water droplets inside the bearing and inhibits oil film formation. On the other hand, if the blending amount is more than 60% by weight, a large amount of moisture is retained inside the bearing, and rust is generated.

  In addition, the amount of the water dispersant should be such that the particle size of the water dispersed by the water dispersant measured at a water content of 20% by weight is 50 μm or less with respect to the total amount of grease and the total amount of water. Is preferred. If the water droplets are 50 μm or less, the water does not inhibit the formation of the oil film by the water-resistant grease. Preferably it is 30 micrometers or less, More preferably, it is the range of 5-25 micrometers. If it exceeds 50 μm, oil film formation is inhibited and the bearing life is extremely shortened. The water particle diameter in the present invention is a numerical value obtained by measuring the diameter of water droplets dispersed in a base grease having a water content of 20% by weight spread on a glass plate under a load of 600 N with a microscope. .

In the present invention, a surfactant can be used as the water dispersant capable of controlling the saturated water content. Surfactant makes water harmless by dispersing water in grease so that oil film does not break or rust even if water enters the double row spherical roller bearing of the spindle support device for wind power generation. Used for. The water that has entered the grease is dispersed in the grease as fine water particles by the surfactant. Since grease can exist as a continuous phase, it is thought that oil film breakage does not occur.
Similarly, water particles, which are discontinuous phases confined in grease, which is a continuous phase, have a very low and low probability of contact with the steel constituting the double row spherical roller bearing body of the spindle support device for wind power generation. Thus, it is considered that the water particles adhering to the steel cannot be rusted because the continuous phase grease is immediately replaced by the rotation of the rolling elements in conjunction with the rotation of the bearing body.

  The surfactant that can be used in the present invention is a W / O (water phase dispersed in an oil phase (grease)) type interface that easily traps water particles as a discontinuous phase in a grease that is a continuous phase. The HLB (Hydrophilic-Lipophilic Balance) value representing the degree of affinity of the surfactant for water and oil is preferably in the range of 5-18.

  Specific examples of the surfactant used in the present invention include glycol surfactants such as polyalkylene glycols, carboxylic acid alkylene glycols, and carboxylic acid polyalkylene glycols, glycerin glycerin, and polyoxyalkyl carboxylates. Glycerin surfactants such as glycerin and glyceryl carboxylates, glyceryl surfactants such as polyglyceryl carboxylates and polyoxyalkylene glyceryl carboxylates, polyoxyalkylene alkyl ethers, and polyoxyalkylene alkyl ether carboxylates Ether surfactants such as carboxylic acid polyoxyalkylene alkyl ether diesters and sorbitan ester surfactants, polyoxyalkylene hardened castor oil, carboxylic acid polyoxyal Castor oil surfactants such as alkylene hydrogenated castor oil-based, carboxylic acid polyoxyalkylene Rent trimethylolpropane-based surfactant, metal sulfonate surfactant, sorbitan ester surfactant and the like. These surfactants may be used alone or in combination of two or more.

In the present invention, among the above surfactants, it is preferable to use a metal sulfonate surfactant, a carboxylic acid polyalkylene glycol surfactant, or a sorbitan ester surfactant. Particularly preferred are Ca sulfonate, polyethylene glycol stearate, sorbitan monooleate and the like.
The metal sulfonate surfactant, carboxylic acid polyalkylene glycol surfactant, or sorbitan ester surfactant can control the saturated water content within the range of 30 to 60% by weight within the range of the following blending amount. it can.

  The amount of the surfactant (aqueous dispersant) that can be used in the present invention is such an amount that the saturated water content of the grease can be adjusted to 30 to 60% by weight as described above. Specifically, it is increased with the non-aqueous base oil. The amount is preferably 0.4 to 4 parts by weight with respect to 100 parts by weight of the base grease comprising the agent. More preferably, it is 1 to 4 parts by weight. If the amount is less than 0.4 parts by weight, the saturated water content may not be 30% by weight or more, and it is difficult to obtain the desired effect sufficiently. If the amount exceeds 4 parts by weight, the saturated water content may exceed 60% by weight, and the desired effect such as oil film formation rate will reach its peak, reducing the grease characteristics such as bearing life.

The Ca sulfonate that can be used in the present invention preferably has a base number in the range of 50 to 500. A base number shows the quantity of the basic substance contained in 1 molecule, and becomes a high numerical value, when there is much quantity of Ca which an additive contains. Basic Ca sulfonate can not only provide rust prevention performance but also extreme pressure performance.
For example, in the present invention, when 0.5 to 2 parts by weight of Ca sulfonate is blended with 100 parts by weight of the base grease, the extreme pressure performance becomes insufficient when the base number is less than 50, and the base number exceeds 500. No further effect can be expected.

  The sorbitan monooleate that can be used in the present invention is a nonionic surfactant, has an HLB value of about 9 indicating the degree of affinity of the surfactant with water and oil, and has lipophilic properties. Have The sorbitan monooleate is preferably used in combination with the Ca sulfonate.

In the present invention, the combination amount of Ca sulfonate and sorbitan monooleate as the surfactant is 0.5 to 2 parts by weight of Ca sulfonate and 0.2 to 1 part by weight of sorbitan monooleate with respect to 100 parts by weight of the base grease. Part.
Moreover, when using these independently, it is preferable to mix | blend Ca sulfonate 1.5-4 weight part and sorbitan monooleate 0.4-2 weight part.
By using both in the above range, the saturated moisture content of the water-resistant grease can be controlled to 30 to 60% by weight. In addition, the desired effect such as the oil film formation rate has reached its peak, and there is no fear that the grease characteristics such as the bearing life will deteriorate.

Non-aqueous base oils that can be used in the present invention are mineral oils such as spindle oil, refrigerating machine oil, turbine oil, machine oil, dynamo oil, highly refined mineral oil, liquid paraffin oil, GTL oil synthesized by Fischer-Tropsch method, polybutene oil , Poly-α-olefin (hereinafter referred to as “PAO”) oil, alkylnaphthalene oil, hydrocarbon synthetic oil such as alicyclic compound, or natural oil, polyol ester oil, phosphate ester oil, polymer ester oil, aromatic Non-hydrocarbon synthetic oils such as group ester oil, carbonate ester oil, diester oil, polyglycol oil, silicone oil, polyphenyl ether oil, alkyl diphenyl ether oil, alkylbenzene oil, and fluorinated oil can be used. These non-aqueous base oils can be used alone or in combination of two or more.
In consideration of lubrication performance and price, it is preferable to use mineral oil and PAO oil among these non-aqueous base oils.

The non-aqueous base oil that can be used in the present invention is liquid at room temperature and has a kinematic viscosity at 40 ° C. of 20 to 200 mm ² / sec. Preferably, it is 30-120 mm < ² > / sec. If it is less than 20 mm ² / sec, the non-aqueous base oil deteriorates in a short time, and the produced degradation product promotes the deterioration of the entire non-aqueous base oil, so the durability of the bearing is reduced and the life is shortened. On the other hand, if it exceeds 200 mm ² / sec, the temperature rise of the bearing due to the increase in rotational torque becomes large, which is not preferable.

In the water-resistant grease used in the present invention, the blending ratio of the non-aqueous base oil in 100 parts by weight of the base grease is preferably 60 to 99 parts by weight, more preferably 70 to 95 parts by weight.
When the blending ratio of the non-aqueous base oil is less than 60 parts by weight, the grease is hard and the lubricity at low temperatures is poor. If it exceeds 99 parts by weight, it will be soft and leaky.

  Thickeners that can be used in the present invention include benton, silica gel, fluorine compounds, lithium soap, lithium complex soap, strong lucium soap, calcium complex soap, aluminum soap, aluminum complex soap, and other soaps, diurea compounds, polyurea compounds, etc. These urea compounds are mentioned. In consideration of heat resistance, cost, and the like, a urea compound is desirable.

式中においてＲ² は、炭素原子数 6〜15 の芳香族炭化水素基を、Ｒ¹ およびＲ³ は、互いに同一であっても異なっていてもよく、それぞれ炭素原子数 6〜12 の芳香族炭化水素基または炭素原子数 6〜20 の脂環族炭化水素基およびまたは炭素原子数 6〜20 の脂肪族炭化水素基から選ばれた少なくとも一つの基を、それぞれ示す。
ウレア系化合物は、イソシアネート化合物とアミン化合物とを反応させることにより得られる。反応性のある遊離基を残さないため、イソシアネート化合物のイソシアネート基とアミン化合物のアミノ基とは略当量となるように配合することが好ましい。 The urea compound is represented, for example, by the following formula (1).

In the formula, R ² is an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R ¹ and R ³ may be the same or different from each other, and each of them is an aromatic group having 6 to 12 carbon atoms. At least one group selected from a hydrocarbon group or an alicyclic hydrocarbon group having 6 to 20 carbon atoms and / or an aliphatic hydrocarbon group having 6 to 20 carbon atoms is shown.
A urea compound is obtained by reacting an isocyanate compound and an amine compound. In order not to leave a reactive free radical, the isocyanate group of the isocyanate compound and the amino group of the amine compound are preferably blended so as to be approximately equivalent.

The diurea compound represented by the formula (1) can be obtained, for example, by reaction of diisocyanate and monoamine. Diisocyanates include phenylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 2,4-tolylene diisocyanate, 3,3-dimethyl-4,4-biphenylene diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate. Examples of the monoamine include octylamine, dodecylamine, hexadecylamine, stearylamine, oleylamine, aniline, p-toluidine, cyclohexylamine and the like.
In the present invention, an alicyclic-aromatic urea compound or an aromatic urea compound obtained by a reaction of an aromatic diisocyanate with an alicyclic monoamine and an aromatic monoamine, or an aromatic monoamine alone is preferable. Particularly preferably, cyclohexylamine is used as the alicyclic monoamine and aniline is used as the aromatic monoamine.

For example, after sufficiently reacting monoamine acid and diisocyanate in a non-aqueous base oil at about 70 to 120 ° C., the temperature is raised and maintained at 120 to 180 ° C. for about 1 to 2 hours, and then cooled. , Homogenizers, three roll mills, etc. are used to obtain a base grease for blending various compounding agents.
In the present invention, the blending ratio of the thickener in 100 parts by weight of the base grease is preferably 1 to 40 parts by weight, more preferably 3 to 25 parts by weight. If the blending ratio of the thickener is less than 1 part by weight, the thickening effect will be reduced and it will be difficult to make grease, and if it exceeds 40 parts by weight, the grease will be too hard and the desired effect will not be obtained.

  To the water-resistant grease used in the present invention, known additives other than the above-mentioned surfactant (water dispersing agent) can be added as necessary within the range not impairing the function. Examples of additives include extreme pressure agents such as organic zinc compounds and organic molybdenum compounds, antioxidants such as amine-based, phenol-based and sulfur-based compounds, anti-wear agents such as sulfur-based and phosphorus-based compounds, and polyhydric alcohols. Examples thereof include rust preventives such as esters, viscosity index improvers such as polymethacrylate and polystyrene, solid lubricants such as molybdenum disulfide and graphite, and oily agents such as esters and alcohols. Moreover, metal fine powders, such as molybdate, an organic acid salt, aluminum, and copper, can also be mix | blended as an additive which suppresses early peeling with a white structure | tissue change. These can be added alone or in combination of two or more.

  Among the above additives, the water resistant grease used in the present invention preferably contains an extreme pressure agent for imparting extreme pressure performance and an antioxidant for suppressing oxidative degradation. It is particularly preferable to use zinc dithiophosphate as the extreme pressure agent and an amine antioxidant as the antioxidant.

式中においてＲ は、アルキル基を示す。アルキル基としては、一級アルキル基、二級アルキル基およびアリール基が挙げられるが、水に対する安定性や摩耗防止性等のバランスのよい二級アルキル基を用いることが好ましい。 Examples of zinc dithiophosphate include zinc dialkyldithiophosphate represented by the following formula (2), which is added to impart extreme pressure performance of grease.

In the formula, R 1 represents an alkyl group. Examples of the alkyl group include a primary alkyl group, a secondary alkyl group, and an aryl group, but it is preferable to use a secondary alkyl group having a good balance such as stability against water and wear resistance.

  The compounding amount of zinc dithiophosphate is preferably 0.5 to 2.0 parts by weight based on 100 parts by weight of the base grease. Most preferably, it is 2.0 parts by weight with respect to 100 parts by weight of the base grease. If the amount is less than 0.5 parts by weight, the extreme pressure performance becomes insufficient, and it becomes difficult to obtain the desired effect sufficiently. Can not.

Examples of amine antioxidants include phenyl-1-naphthylamine, phenyl-2-naphthylamine, diphenyl-p-phenylenediamine, dipyridylamine, phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, and 3,7-dioctylphenothiazine. , P, p′-dioctyldiphenylamine, N, N′-diisopropyl-p-phenylenediamine, and the like.
The compounding amount of the amine antioxidant is preferably 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the base grease. When the amount is less than 0.5 parts by weight, the antioxidant performance becomes insufficient, and it becomes difficult to obtain the desired effect sufficiently, and even if added over 2.0 parts by weight, no further effect can be expected. Most preferably, it is 1 part by weight per 100 parts by weight of the base grease.

The present invention will be specifically described with reference to examples and comparative examples, but is not limited to these examples.
Example 1, Example 2, Example 4 to Example 9, Reference Example 1 to Reference Example 3, and Comparative Example 1 to Comparative Example 6
A mineral oil / urea base grease (JIS consistency No. 2 grade, consistency: 265 to 295) in which a urea compound is uniformly dispersed as a thickener in a mineral oil which is a non-aqueous base oil was prepared.
In 2000 g of mineral oil (Nippon Oil Co., Ltd. turbine 100, kinematic viscosity at 40 ° C .: 100 mm ² / sec), 2000 g of diphenylmethane-4,4′-diisocyanate, 86.2 g of aniline and 91.7 g of cyclohexylamine And the resulting urea compound was uniformly dispersed to obtain a base grease. Additives were added to the base grease in the formulation shown in Table 1 to obtain a test grease.

  The obtained grease for testing was subjected to an oil film formation rate test, a bearing life test, and a saturated water content measurement described below, and an oil film formation rate, a bearing life time, a saturated water content, and whether or not rust was generated were measured. The results are also shown in Table 1.

<Oil film formation rate test>
Bearing used: Angular ball bearing 7006ADLLB (outer ring: S53C, inner ring: SUJ2) was used as a wind turbine main shaft bearing.
Test conditions: 1.0 g of the obtained grease for test is sealed in an angular ball bearing 7006ADLLB and rotated at a radial load of 8000 N, an axial load of 3000 N, and a bearing rotational speed of 1000 rpm. The oil film formation rate of the test grease when water was poured for 10 hours was measured. The oil film formation rate was measured by the electric resistance method.

<Bearing life test>
Bearing used: An angular ball bearing 7006ADLLB was used as a wind turbine main shaft bearing.
Test conditions: 1.0 g of the obtained grease for test is sealed in an angular ball bearing 7006ADLLB, and is rotated at a radial load of 8000 N, an axial load of 3000 N, and a bearing rotational speed of 1000 rpm. The bearing life when water was poured was measured. The bearing life was defined as the time until one of the outer ring rolling surface, inner ring rolling surface, and steel ball was damaged and the vibration increased.

<Saturated water content measurement>
Add a fixed amount of water to the test grease by changing the mixing ratio of water by 5% by weight, and manually stir using a microspatel to obtain the maximum amount of water that could disperse the added water. The saturated water content was calculated using the formula. To determine whether it was dispersed, collect test grease on a glass plate, place a spacer shim with a thickness of 0.025 mm on both ends of the glass plate, and sandwich it with another glass plate from above. When the test grease was spread and observed with a microscope, the largest water droplets present in the grease were considered to be dispersed when the particle size was 50 μm or less.

Saturated water content (wt%) = maximum water content dispersible in grease x 100 / (weight of test grease + maximum water content dispersible in grease)

Example 3
In a reaction vessel, 231.7 g of diphenylmethane-4,4′-diisocyanate and 86.2 g of aniline in 1600 g of PAO oil (Nippon Chemical Co., Ltd., Sinfluid 801: Kinematic viscosity at 40 ° C .: 46 mm ² / sec) Then, 91.7 g of cyclohexylamine was reacted, and the resulting urea compound was uniformly dispersed to obtain a base grease. Additives were added to the base grease in the formulation shown in Table 1 to obtain a test grease. The same items as in Example 1 were measured for the obtained test grease. The results are also shown in Table 1.

Reference example 4
Add lithium soap (lithium stearate) as a thickener to mineral oil (Nippon Oil Co., Ltd. turbine 100, kinematic viscosity at 40 ° C: 100 mm ² / sec) in a reaction vessel, and use a three-roll mill. The base grease was obtained by the chemical treatment. Further, an additive was added at a ratio shown in Table 1 to prepare a test grease. The same items as in Example 1 were measured for the obtained test grease. The results are also shown in Table 1.

As shown in Table 1, a high oil film formation rate is obtained in a region where the saturated water content is 30 to 60% by weight (particularly 40 to 50% by weight).
When water is mixed in, grease with saturated water content of less than 30% by weight or grease with more than 60% by weight impairs the formation of an oil film, which causes metal contact and rust. If it is 30 to 60% by weight, an oil film can be formed, so there is little risk of metal contact, so the bearing life is long and the occurrence of rust can be suppressed.

  The double-row spherical roller bearing used in the spindle support device for wind power generation according to the present invention encloses water-resistant grease that can control the saturated water content to 30 to 60% by weight. Even if it is mixed, by suppressing the action of moisture that causes the oil film formation of the grease to be inhibited, early damage of the bearing can be suppressed, and a long life can be obtained even if the lubrication conditions become severe. Therefore, it can be suitably used as a bearing for a main shaft support device for wind power generation that is required to have long-term durability as well as wear resistance in an environment in which water may enter.

It is a schematic diagram of the whole wind power generator containing the spindle support apparatus for wind power generation of this invention. It is a figure which shows the spindle support apparatus for wind power generation of this invention. It is a figure which shows the installation structure of the bearing for spindle support in the spindle support apparatus for wind power generation of this invention. It is a figure which shows the installation structure of the bearing for spindle support in the conventional wind power generator.

Explanation of symbols

1 Wind power generator 2 Blade 3 Spindle 4 Nacelle 5 Bearing (rolling bearing)
6 Speed increaser 7 Generator 8 Support base 9 Motor 10 Reduction gear 11 Inner ring 12 Outer ring 13 Rolling body 14 Cage 15 Bearing housing 16 Seal 17 Swivel seat bearing 18 Bearing housing 19 Blade 20 Main shaft 21 Double row self-aligning roller bearing 22 Inner ring 23 Outer ring 24 Double row roller 25 Double row roller

Claims (5)

A main shaft support device for wind power generation in which a main shaft to which a blade is attached is supported by at least one rolling bearing installed in a bearing housing,
The rolling bearing is a rolling bearing comprising an inner ring, an outer ring, and a rolling element interposed between the inner ring and the outer ring, in which grease is sealed around the rolling element,
The grease is a water-resistant grease obtained by blending an additive containing at least a water dispersant with a base grease composed of a non-aqueous base oil and a thickener,
The non-aqueous base oil comprises at least one oil selected from poly-α-olefin oil and mineral oil;
The thickener is an alicyclic-aromatic urea compound obtained by a reaction of an aromatic diisocyanate with an alicyclic monoamine and an aromatic monoamine, or a reaction of an aromatic diisocyanate with an aromatic monoamine alone. It consists of an aromatic urea compound obtained,
The water dispersant contains Ca sulfonate having a base number of 50 to 500, and the amount of the water dispersant is such that the saturated moisture content of the water resistant grease is set to 30 to 60% by weight. Spindle support device for wind power generation.   The spindle support device for wind power generation according to claim 1, wherein the water dispersant contains sorbitan monooleate.   The spindle support device for wind power generation according to claim 2, wherein 0.5 to 2 parts by weight of the Ca sulfonate and 0.2 to 1 parts by weight of the sorbitan monooleate are included with respect to 100 parts by weight of the base grease. 4. The main shaft support device for wind power generation according to claim 1, wherein the thickener comprises the alicyclic-aromatic urea compound .   An inner ring, an outer ring, and a double-row roller interposed between the inner ring and the outer ring, and the axial raceway surface of the outer ring and the axial outer peripheral surface of the roller have a spherical shape having the same radius of curvature. A double-row self-aligning roller bearing in which the outer peripheral surface of the roller is disposed along the raceway surface of the outer ring, and the water-resistant grease is sealed around the roller. A double-row self-aligning roller bearing, wherein the roller bearing is used in the main shaft support device for wind power generation according to any one of claims 1 to 4.

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