JP2009008019A - Yaw bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a yaw bearing high in weather resistance and long in service life, rotatably supporting a nacelle of a wind turbine generator, and eliminating the need of lubricating material. <P>SOLUTION: The yaw bearing 11 rotatably supports the nacelle 34 of wind turbine generator 31, has a ring-like horizontal sliding plate 12 abutted with a lower face of the nacelle 34 to support a thrust load. The horizontal sliding plate 12 is a polyphenylene sulfide compact using polyphenylene sulfide as base resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a yaw bearing that rotatably supports a nacelle of a wind power generator.

  A yaw bearing that rotatably supports a nacelle of a conventional wind power generator is described in, for example, Japanese Patent Laid-Open No. 8-82277 (Patent Document 1). The yaw bearing described in the publication uses a rolling bearing. A braking brake is provided to stably hold the nacelle against the wind direction.

  Since a rolling bearing which is a conventional yaw bearing has a small rotational resistance, a braking brake having a strong braking force is required to prevent the nacelle from exceeding the stop position due to an inertial force. As a result, there are problems such as increasing the size of braking brakes, installing a large number of brakes, increasing the size and complexity of the device, increasing the weight, and increasing the price. In addition, rolling bearings require maintenance with grease replenishment, and contamination with grease has also been a problem.

  Therefore, a wind power generator that solves the above problem is described in, for example, US Patent Publication No. 2005-196280 (Patent Document 2). The wind power generator described in the publication employs a sliding bearing composed of a plurality of sliding plates as a yaw bearing. As a result, it is described that the braking brake is simplified and the apparatus can be reduced in size and price. Further, it is described that the sliding plate is formed of polyethylene terephthalate (hereinafter referred to as “PET”). Furthermore, Japanese Patent Application Laid-Open No. 2007-51585 (Patent Document 3) discloses polyester, polyurethane, polyamide, acetal, and PET as polymer materials for forming a sliding plate of a yaw bearing.

Japanese Patent Application Publication No. 2003-518594 (Patent Document 4) discloses grease lubrication on an acetal sliding plate.
JP-A-8-82277 US Published Patent No. 2005-196280 JP 2007-51585 A Special table 2003-518594 gazette

  Wind generators are often installed around the coast as a stable geography of wind direction and wind, and are required to have high weather resistance because they continue to be exposed to coastal sea breezes. Also, the wind power generator has a tower that supports the nacelle with a total length of 30 m or more, and is difficult to maintain. Further, the yaw bearing arranged in the nacelle may reach 60 ° C. under the summer sun, and it is necessary that the friction characteristics with respect to the heat change do not vary.

  However, polyester, polyurethane, polyamide, acetal, and PET all have a risk of lowering frictional properties and mechanical strength due to hydrolysis, and in order to prevent problems with wind power generators, periodic replacement of the sliding plate is necessary. It is considered necessary.

  In addition, the sliding properties of polyester, polyurethane, polyamide, acetal, and PET cannot be said to be excellent among synthetic resins, and therefore it is necessary to use a lubricant such as grease. Grease has both a role as a lubricant and a role of preventing hydrolysis of the polymer material by covering the surface of the polymer material to prevent contact with moisture.

  However, the use of a lubricant such as grease is not preferable because maintenance frequency is increased, and if it stays, wear powder or foreign matter may be caught in the sliding surface to cause abnormal wear. Further, the above-described contamination with grease or the like cannot be solved.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a yaw bearing that supports a nacelle of a wind power generator so as to be rotatable, has high weather resistance, has a long life, and does not require a lubricant.

  A yaw bearing according to the present invention is a bearing that rotatably supports a nacelle of a wind power generator, and includes an annular slide plate that abuts against the lower surface of the nacelle and supports a thrust load. The sliding plate is a polyphenylene sulfide resin molded body in which the base resin is polyphenylene sulfide (hereinafter referred to as “PPS”) resin.

  By setting it as the said structure, even if it installs in a coast part, there is no hydrolysis and corrosion by salt water, and a friction characteristic and mechanical strength are stabilized for a long term. Further, since the PPS resin has low friction characteristics, it is possible to eliminate the use of a lubricant such as grease. As a result, maintenance-free for 30 years or more can be achieved.

  Preferably, the PPS resin molding includes at least one of a reinforcing material and a friction modifier. As a result, the wear resistance can be improved and the creep due to the load can be effectively prevented.

  Preferably, the PPS resin molding includes a friction modifier. And the area ratio of the friction modifier exposed to the wall surface of the sliding plate which contacts the nacelle is 5% to 40%. By adding the above additive, the friction stability of the PPS resin molding is improved. As a result, the braking brake can be reduced in size or labor saving.

  Preferably, at least one of the reinforcing material and the friction modifier is made of a non-corrosive substance. As a result, high friction characteristics and mechanical strength can be maintained over a long period of time even when the wind power generator is installed around the coast.

  Preferably, the non-corrosive substance is selected from the group consisting of glass, carbon, silicon carbide, potassium titanate, magnesium borate, zinc oxide, titanium oxide, calcium sulfate, magnesium sulfate, iron oxide, alumina, and wollastonite. At least one type.

  Preferably, the PPS resin molding includes a solid lubricant. The solid lubricant means a solid compound that reduces the friction coefficient of the PPS resin molding by blending with the PPS resin. In one embodiment, the solid lubricant includes any of polytetrafluoroethylene and molybdenum disulfide. Thereby, heat generation on the sliding surface with the nacelle can be effectively suppressed without using a lubricant such as grease. Solid lubricants have a longer lubrication life than liquid lubricants such as lubricating oil and grease. As a result, the maintenance cycle of the yaw bearing can be extended.

  Since the reinforcing material, the friction adjusting material, and the solid lubricant each exhibit different functions, all of them may be blended into the PPS resin molded body, or arbitrary depending on the usage environment of the yaw bearing, etc. You may mix | blend.

  Preferably, the sliding plate is formed by connecting a plurality of arc-shaped sliding members in the circumferential direction. Since the yaw bearing is very large, the above configuration improves the assembly of the yaw bearing and facilitates maintenance.

  Preferably, the yaw bearing is a cylindrical member extending in a direction intersecting with the sliding plate from the inner peripheral surface of the sliding plate, and further includes a second sliding plate that supports a radial load applied to the nacelle. Prepare. The second sliding plate is a PPS resin molded body.

  According to this invention, since the sliding plate of the yaw bearing is the PPS resin molded body, it is possible to effectively prevent hydrolysis and corrosion due to salt water even when installed on the coast. As a result, a yaw bearing having high weather resistance and a long life can be obtained. Further, since the PPS resin itself has a low friction characteristic, it is possible to eliminate the use of a lubricant such as grease. As a result, the maintenance cycle can be extended.

  With reference to FIG. 3 and FIG. 4, the wind power generator 31 which employ | adopted the yaw bearing 11 (it is also mentioned a "swivel seat bearing") which concerns on one Embodiment of this invention is demonstrated. The wind power generator 31 includes a support base 32, a yaw bearing 11, a nacelle 34, a blade 35, a main shaft 36, a speed increaser 37, a generator 38, a bearing housing 39, and a main shaft support bearing 42. The motor 40 for rotation and the reduction gear 41 are provided.

  The nacelle 34 is installed on the support base 32 via the yaw bearing 11, and can be turned horizontally by a turning motor 40 and a speed reducer 41. Moreover, it functions as a housing that accommodates the main shaft 36, the speed increaser 37, the power generator 38, the main shaft support bearing 42, the turning motor 40, the speed reducer 41, and the like, which are the main components of the wind power generator 31.

  The blade 35 is fixed to one end of the main shaft 36 and rotates by receiving wind. One end of the main shaft 36 is connected to the blade 35 and the other end is connected to the speed increaser 37, and the rotation of the blade 35 is transmitted to the generator 38 via the speed increaser 37. Further, it is rotatably supported by a main shaft bearing 42 incorporated in the bearing housing 39.

  Next, the yaw bearing 11 of the wind power generator 31 according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a view showing a yaw bearing 11 according to an embodiment of the present invention, and FIG. 2 is an enlarged view of parts of the yaw bearing 11.

  First, referring to FIG. 1, the yaw bearing 11 includes a horizontal sliding plate 12 and a vertical sliding plate 13. The horizontal sliding plate 12 has an annular shape with a thickness of 2 mm to 10 mm (preferably 2 mm to 5 mm), and constitutes a wall surface on one side in the thickness direction of the yaw bearing. Specifically, the horizontal sliding plate 12 is formed by connecting a plurality of arc-shaped horizontal sliding members 12a in the circumferential direction. The horizontal sliding plate 12 is a thrust sliding bearing that contacts the lower surface of the nacelle 34 of the wind power generator 31 and supports the thrust load.

  The vertical sliding plate 13 is a cylindrical member having a thickness of 2 mm to 5 mm extending from the inner peripheral surface of the horizontal sliding plate 12 in a direction intersecting (in this embodiment, “orthogonal”) with the horizontal sliding plate 12. . Specifically, the vertical sliding plate 13 is formed by connecting a plurality of arc-shaped vertical sliding members 13a in the circumferential direction. The vertical sliding plate 13 is a radial sliding bearing that supports a radial load applied to the nacelle 34 of the wind power generator 31.

  The “horizontal sliding plate” in this specification is the “sliding plate” in the claims, the “horizontal sliding member” is the “sliding member”, and the “vertical sliding plate” is the “second sliding plate”. Respectively. In addition, the term “horizontal” used in the “horizontal sliding plate” in this specification refers to the relative positional relationship with the vertical sliding plate, that is, the horizontal sliding plate and the vertical sliding plate cross each other. It should only be understood as being (orthogonal) and different from “horizontal” in absolute terms. The same applies to the “horizontal sliding member”.

  In this embodiment, the horizontal sliding plate 12 is configured by connecting 12 horizontal sliding members 12a in the circumferential direction. However, the present invention is not limited to this example, and an arbitrary number of horizontal sliding members 12a are provided. The horizontal sliding plate 12 can be configured by the member 12a. For example, the number may be about 4 to 16. The same applies to the case where the vertical sliding plate 13 is constituted by the vertical sliding member 13a.

  Referring to FIG. 2, horizontal sliding member 12 a and vertical sliding member 13 a (hereinafter collectively referred to as “sliding member”) are held by arc-shaped attachment portion 21. And the attaching part 21 which adjoins by a connection means (illustration omitted) is connected to the circumferential direction, and the toroidal yaw bearing 11 as shown in FIG. 1 is comprised. In this embodiment, the horizontal sliding member 12a and the vertical sliding member 13a are integrally formed.

  The horizontal sliding plate 12 and the vertical sliding plate 13 (hereinafter collectively referred to as “sliding plate”) are PPS resin moldings. This PPS resin molded body is an injection molded body of a resin composition in which various compounding materials are mixed with a PPS resin as a base resin.

  PPS resin is a super engineering plastic having a melting point of 285 ° C. PPS resin is a crystalline resin, and its heat resistance and chemical resistance are extremely excellent. The sliding plate formed of PPS resin is not hydrolyzed or corroded by salt water even when installed on the coast, and the friction characteristics and mechanical strength are stable for a long time. As a result, maintenance-free for 30 years or more can be achieved.

  Further, since the PPS resin has low friction characteristics, the yaw bearing 11 can be used in a dry state without using a liquid lubricant such as grease. As a result, contamination by grease is prevented, and maintenance such as intermediate lubrication is unnecessary.

  In order to improve the wear resistance of the sliding plate and prevent creep due to a load, it is desirable to add a reinforcing material to the PPS resin. As the reinforcing material that can be used, any reinforcing material can be used as long as it can appropriately increase the creep resistance of the PPS resin. Specifically, glass fiber, glass bead, carbon fiber, carbon powder, aramid fiber, graphite, spheroidal graphite, iron oxide powder, alumina powder, wollastonite and silicon carbide, potassium titanate, magnesium borate, zinc oxide And various whiskers such as titanium oxide, calcium sulfate and magnesium sulfate, and various powders. Note that the PPS resin containing the reinforcing material is referred to as “reinforced PPS resin”.

  In addition, the yaw bearing 11 is capable of smoothly turning the nacelle 34 and requires a frictional force so that the inertial force does not exceed the stop position when the braking brake is operated. Therefore, in order to give a sufficient frictional force to the PPS resin molded body, it is desirable to blend a friction modifier in the PPS resin. Any friction modifier can be used as long as the friction coefficient of the PPS resin can be appropriately increased. Specifically, glass fiber, glass bead, carbon fiber, carbon powder, aramid fiber, graphite, spheroidal graphite, iron oxide powder, alumina powder, wollastonite and silicon carbide, potassium titanate, magnesium borate, zinc oxide And various whiskers such as titanium oxide, calcium sulfate and magnesium sulfate, and various powders. In addition, as a shape of a friction adjustment material, the isotropic shape in which directionality does not appear in a friction surface is desirable.

  The reinforcing material and the friction modifier are preferably made of a non-corrosive substance that does not cause oxidative degradation, and more preferably a low water-absorbing substance with a low water absorption. Since the non-corrosive substance is not oxidized and deteriorated, the friction characteristics and mechanical strength of the sliding plate can be maintained for a long time even when the wind power generator 31 is installed around the coast.

  Non-corrosive substances having the above properties include, for example, glass, carbon, silicon carbide, potassium titanate, magnesium borate, zinc oxide, titanium oxide, calcium sulfate, magnesium sulfate, iron oxide, alumina, wollastonite, etc. Is exemplified.

  If a reinforcing material or friction modifier is added to the PPS resin, the sliding surface may generate heat depending on circumstances. Therefore, a solid lubricant may be blended with the PPS resin molded body serving as the base resin. The solid lubricant means a solid compound that lowers the coefficient of friction of the PPS resin molding by blending with the PPS resin. Specific examples include polytetrafluoroethylene (PTFE) and molybdenum disulfide.

  Since the PPS resin itself has a low friction characteristic, it is not necessary to use a lubricant such as grease depending on the use conditions even if a solid lubricant is not blended. However, if a solid lubricant is appropriately blended, the generation of heat on the sliding surface with the nacelle 34 can be more effectively suppressed. Further, since the solid lubricant has an extremely long lubrication life compared to the liquid lubricant, the maintenance cycle of the wind power generator 31 can be extended.

  Next, a method for manufacturing the yaw bearing 11 will be described.

  First, pellets for injection molding of a PPS resin composition in which various compounding materials are blended with a PPS resin as a base resin are prepared. Then, a sliding member made of PPS resin is obtained by injection molding. Thus, by adopting injection-moldable PPS resin as the material of the sliding member, the manufacturing efficiency of the yaw bearing is improved.

  Furthermore, it is desirable to form the horizontal sliding member 12a and the vertical sliding member 13a integrally. Specifically, as shown in FIG. 2, the horizontal sliding member 12a and the vertical sliding member 13a may be integrally formed as a member having an L-shaped cross section. As a result, the manufacturing efficiency can be further improved, and the positioning with respect to the mounting portion 21 can be simplified.

  Next, machining such as grinding (polishing) is performed on the surface of the PPS resin molded body, in particular, the wall surface in contact with the nacelle 34. Thereby, while removing a skin layer, a friction adjusting material can be exposed to a processing surface.

  The skin layer refers to a layer having a high content of the resin component present on the surface of the PPS resin molded body formed by injection molding. Since the skin layer has little exposure of the friction modifier, the desired friction characteristics cannot be obtained. Further, when the skin layer on the sliding surface with the nacelle 34 is worn, there is a problem that the friction characteristics of the yaw bearing 11 change. Therefore, by removing the skin layer in advance, the friction characteristics of the sliding plate can be stabilized over a long period of time.

  Moreover, if the area ratio of the friction modifier exposed on the sliding surface is 5% to 40%, an appropriate frictional force can be applied to the sliding member. As a result, when a braking brake (not shown) that stops turning of the nacelle 34 is operated, the nacelle 34 does not exceed the stop position due to inertial force. If the area ratio of the friction modifier exposed on the sliding surface is less than 5%, the friction coefficient becomes too small and a high braking force is required, and if the area ratio exceeds 40%, the sliding resistance increases, so smooth Rotation is difficult.

  Then, the injection-molded sliding member is bonded and fixed to the mounting portion 21 or fixed by fastening means such as a bolt.

  In the above embodiment, the horizontal sliding member 12a and the vertical sliding member 13a are integrally formed. However, the present invention is not limited to this, and both are formed as separate bodies, and each is attached to the mounting portion 21. It may be attached. Thereby, the PPS resin molding which comprises the horizontal sliding member 12a and the vertical sliding member 13a can be made into a mutually different composition. For example, a higher effect can be expected if the base resin and various compounding materials are appropriately combined according to the characteristics of the load applied to the horizontal sliding member 12a and the vertical sliding member 13a.

  In the above embodiment, an example is shown in which both the horizontal sliding plate 12 and the vertical sliding plate 13 are formed of a PPS resin molded body. However, only the horizontal sliding plate 12 is formed of the PPS resin molded body. If configured, the effects of the present invention can be obtained. For example, a radial bearing may be adopted instead of the vertical sliding plate 13.

  Next, a salt spray test and a tensile strength test conducted to confirm the effect of the present invention will be described.

  In each test, three types of test pieces (Examples 1 and 2 and Comparative Example 1) molded into a 5A-type dumbbell shape defined in JIS K7162 (Japan Industrial Standards) were used. Example 1 is a PPS resin molded body in which PPS resin is used as a base resin and 30% by volume of carbon fiber is blended. Example 2 is a PPS resin molding in which PPS resin is used as a base resin and 10% by volume of carbon fiber, 10% by volume of calcium sulfate powder, and 10% by volume of PTFE are blended. Comparative example 1 is PET which is a material of a conventional sliding member.

  First, in order to evaluate the corrosion resistance of a sliding plate, the salt spray test prescribed | regulated to JISZ2371 was implemented. Specifically, 5% saline solution controlled at 35 ° C. was sprayed on the test piece for 2000 hours, and the discoloration of the surface was confirmed visually and with a microscope (× 100).

  As a result, in Examples 1 and 2, no discoloration was observed visually and by microscopic observation. On the other hand, it was confirmed that Comparative Example 1 was slightly cloudy visually. Thereby, it was confirmed that the sliding plate which concerns on this invention has high corrosion resistance compared with the conventional sliding plate.

  Next, in order to confirm the change in mechanical strength before and after the salt spray test of the sliding plate, that is, the weather resistance of the sliding plate, a tensile strength test defined in JIS K7162 was performed.

Specifically, the tensile strength F ₁ (Pa) before the salt spray test and the tensile strength F ₂ (Pa) after the salt spray test of each test piece (Examples 1 and 2 and Comparative Example 1) are measured. Then, the strength reduction rate (F ₁ -F ₂ ) / F ₁ was calculated. For accuracy, each test piece was performed three times, and the average value was used as the test result.

  As a result, the strength reduction rates of Examples 1 and 2 were both 1% to 2%. On the other hand, the strength reduction rate of Comparative Example 1 was 9% to 12%. Thereby, it was confirmed that the sliding plate which concerns on this invention has high weather resistance compared with the conventional sliding plate.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used in a yaw bearing that rotatably supports a nacelle of a wind power generator.

It is a figure which shows the yaw bearing which concerns on one Embodiment of this invention. It is the elements on larger scale of the yaw bearing shown in FIG. It is a figure which shows the wind power generator which employ | adopted the yaw bearing which concerns on one Embodiment of this invention. FIG. 4 is a schematic side view of the wind power generator shown in FIG. 3.

Explanation of symbols

  11 Yaw bearing, 12 Horizontal sliding plate, 12a Horizontal sliding member, 13 Vertical sliding plate, 13a Vertical sliding member, 21 Mounting portion, 31 Wind generator, 32 Support base, 34 Nacelle, 35 Blade, 36 Main shaft, 37 speed increaser, 38 generator, 39 bearing housing, 40 swing motor, 41 speed reducer, 42 spindle support bearing.

Claims (9)

A yaw bearing that rotatably supports a nacelle of a wind power generator,
Provided with an annular sliding plate that contacts the lower surface of the nacelle and supports the thrust load,
The said sliding plate is a yaw bearing which is a polyphenylene sulfide resin molding which uses polyphenylene sulfide resin as a base resin. The yaw bearing according to claim 1, wherein the polyphenylene sulfide resin molded body includes at least one of a reinforcing material and a friction adjusting material. The polyphenylene sulfide resin molding includes a friction modifier,
2. The yaw bearing according to claim 1, wherein an area ratio of the friction modifier exposed on the wall surface of the sliding plate in contact with the nacelle is 5% to 40%. The yaw bearing according to claim 2, wherein at least one of the reinforcing material and the friction modifier is made of a non-corrosive substance. The non-corrosive substance is selected from the group consisting of glass, carbon, silicon carbide, potassium titanate, magnesium borate, zinc oxide, titanium oxide, calcium sulfate, magnesium sulfate, iron oxide, alumina, and wollastonite. The yaw bearing according to claim 4, wherein the yaw bearing is at least one kind. The yaw bearing according to claim 1, wherein the polyphenylene sulfide resin molding includes a solid lubricant. The yaw bearing according to claim 6, wherein the solid lubricant is one of polytetrafluoroethylene and molybdenum disulfide. The yaw bearing according to any one of claims 1 to 7, wherein the sliding plate is formed by connecting a plurality of arc-shaped sliding members in a circumferential direction. The yaw bearing is a cylindrical member extending in a direction intersecting the sliding plate from the inner peripheral surface of the sliding plate, and further includes a second sliding plate that supports a radial load applied to the nacelle. Prepared,
The yaw bearing according to any one of claims 1 to 8, wherein the second sliding plate is the polyphenylene sulfide resin molded body.

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