JP4708221B2 - Cylindrical roller bearing for wind power generator - Google Patents

Description

  The present invention relates to a cylindrical roller bearing, and more particularly to a cylindrical roller bearing for a speed increaser of a wind power generator.

  Since wind turbine generators have a large initial investment in equipment, their depreciation period often exceeds 10 years, and they are installed in high places and are difficult to maintain. A long life of 20 years is required.

  The speed-up gear incorporated to increase the rotation of the rotor is no exception. Especially, the bearing used in the same device requires high reliability and long life. In recent years, wind turbines have been increasing in size for the purpose of improving power generation efficiency, but in contrast, the need for lighter and smaller nacelles for the purpose of reducing equipment costs has increased. Speed machines are also required to be compact.

Most of the speed increasers of wind power generators are composed of a planetary gear unit and a multistage speed increaser behind the planetary gear unit. In the former, a total rolling element type cylindrical roller bearing is used. As the free side bearing, a cylindrical roller bearing with a cage is often used.
JP 2005-36880 A Japanese Patent No. 3549530

  The rolling element type cylindrical roller bearing is a bearing that incorporates more rollers by eliminating the cage, so it is compact and has a very high rated load, but the adjacent rollers contact each other in reverse rotation. In addition to being liable to hinder roller rotation, surface damage such as galling and smearing tends to occur. In particular, under conditions where the rotational speed is low as in a planetary gear device, the damage is more prominent because an oil film is not formed by a lubricant at each contact portion in the bearing. On the other hand, cylindrical roller bearings with cages do not come in contact with each other like full rolling element bearings, and the allowable rotational speed is high, but the rated load is low, so the size of the bearing must be increased. It is a factor that prevents the device from being made compact.

  The main object of the present invention is to provide a cylindrical roller bearing that is compact, has a high rated load and high rigidity, and has reduced surface damage, and contributes to the downsizing and longevity of the speed increaser of the wind power generator.

The cylindrical roller bearing according to the present invention is characterized in that a spacer is interposed between adjacent rollers, and extended portions facing the roller end faces are provided at both axial ends of the spacer.
That is, the invention according to claim 1 is a cylindrical roller bearing comprising a plurality of rollers that are freely rollable between an inner ring raceway surface and an outer ring raceway surface, and a plastic spacer positioned between adjacent rollers. In this case, there are integrally extended portions facing the roller end surfaces at both ends in the axial direction of the spacer, the expanded portion occupies a position closer to the outer ring, and the surface of the expanded portion facing the inner ring collar surface is the curvature of the outer ring collar inner diameter. A convex curved surface having a smaller radius of curvature than the radius, a surface facing the roller rolling surface of the spacer is a concave shape extending across the pitch circle of the roller, and the spacer is sandwiched between adjacent rollers In this case, it is a cylindrical roller bearing for a wind turbine speed increaser having a gap between the extension portion and the raceway.
The invention of claim 2 is a cylindrical roller bearing comprising a plurality of rollers that are movably interposed between an inner ring raceway surface and an outer ring raceway surface, and a plastic spacer located between adjacent rollers. It has an extension part that faces the roller end face at both ends in the axial direction of the spacer, the extension part occupies a position near the inner ring, and the surface of the extension part that faces the outer diameter surface of the inner ring collar is the curvature of the outer diameter of the inner ring collar. A concave curved surface with a radius of curvature larger than the radius, the surface facing the roller rolling surface of the spacer is a concave shape extending across the pitch circle of the roller, and the spacer is sandwiched between adjacent rollers In this case, it is a cylindrical roller bearing for a wind turbine speed increaser having a gap between the extension portion and the raceway.
By adopting such a configuration, it is possible to avoid the tensile stress caused by the discrete set of rollers found in conventional cages, so more rollers can be incorporated into the bearing, which is compact and has a rated load. High cylindrical roller bearings can be provided. In addition, unlike total rolling element bearings, it is possible to avoid contact between adjacent rollers, and the rollers do not slide in reverse rotation, so that the rotation of the rollers is less likely to be hindered, such as galling and smearing. Damage can be greatly reduced.
Further, the spacer extension portion engages with the end face of the roller to restrict the axial movement of the spacer, and also exhibits a guiding action between the outer ring collar inner diameter surface or the inner ring collar outer diameter surface. However, since the expansion portion of the spacer occupies the position near the outer ring or the inner ring, the influence on the axial flow of the lubricating oil is reduced, which is advantageous in maintaining a good lubricating state.

  In addition, by providing extension portions facing the roller end faces at both ends in the axial direction of the spacer, the movement of the spacer in the axial direction can be restricted by the end faces of the extension portions, and the movement in the radial direction can be reduced. It can be regulated by the rolling surface or inner ring collar outer diameter or outer ring collar inner diameter. That is, since the inner ring and outer ring raceway surfaces and flange side surfaces are not used as spacer movement restricting means, there is no need to interpose the spacer over a wide area between adjacent rollers, and the stirring resistance of the lubricating oil can be suppressed. Moreover, the smooth flow of the lubricating oil is not prevented in the vicinity of the rolling surface. Further, when the spacer is guided to the inner ring collar outer diameter or the outer ring collar inner diameter, the expansion portion also exerts an effect of expanding the guide area, so that an oil film is easily formed on the guide surface.

  In the cylindrical roller bearing described in Patent Document 2, since the movement of the spacer is restricted by the raceway surface and the flange side surface of the inner ring and the outer ring, a spacer having the same size as the radial cross section of the roller is inevitably required. Therefore, the lubricating oil stirring resistance tends to be large. Furthermore, since the spacer is slid on the raceway surface of the inner ring or the outer ring, smooth oil film formation on the rolling surface may be impaired.

A concave rolling surface and the facing surface roller before SL between seat extends across the pitch circle of the rollers and the spacers are guided by the inner ring flange outer diameter or outer ring flange inner diameter, while in rollers adjacent The following operation and effect can be obtained by adopting a structure in which there is a gap between the spacer and the raceway when the seat is sandwiched. When the spacer is sandwiched between rollers on the raceway surface, the radial position of the spacer is determined with the concave bottom as a contact position. At that time, by setting the clearance between the spacer and the raceway, it is possible to avoid a state in which the spacer is pressed against the raceway by adjacent rollers. That is, with the above settings, the spacer is basically a roller guide, and only the spacer positioned in the circumferential clearance is released from the restraint of the adjacent rollers, and the released spacer has other than its own weight and centrifugal force. Since no radial force acts, heat generation and wear on the guide surface of the spacer can be reduced.

The invention of claim 1, the outer ring flange inner diameter surface and facing the surface of the extension portion of the front Symbol spacer is characterized in that a curvature smaller radius of curvature of the convex surface than the radius of the outer ring flange inner diameter. The invention of claim 2 is that the surface facing the inner ring flange outer diametric surface of the extension portion of the front Symbol spacer, characterized in that a concave surface of radius of curvature greater than the radius of curvature of the inner ring flange outer diameter It is. By adopting such a configuration, a so-called “wedge effect” (an effect in which fluid is drawn into the wedge-shaped gap narrowing in the direction of motion by viscosity to generate pressure, that is, load capacity) is obtained, and the spacer Heat generation and wear on the guide surface can be reduced.

According to a third aspect of the present invention, in the cylindrical roller bearing for wind power generators of the first or second aspect , the keystone effect is exhibited by the roller and the spacer. By adopting such a configuration, it is possible to create a specification in which the rollers and the spacer are not dropped even if the inner ring is removed, and the inner ring and the outer ring can be assembled separately. That is, it is possible to assemble such that the sub-assembly at the outer ring is assembled to the housing in advance with the inner ring as the shaft, and the inner ring is inserted along with the shaft. That is, it is possible to assemble in the same manner as a cylindrical roller bearing with a cage that is frequently used in a multistage speed increaser of a wind power generator.

According to a fourth aspect of the present invention, in the cylindrical roller bearing for wind power generators of the first or second aspect , the keystone effect is exhibited by the roller and the spacer, and the outer diameter surface of the shaft is used as the inner ring raceway surface. It is a feature. By adopting such a configuration, it is possible to downsize the speed increaser of the wind power generator, and it is possible to improve the rigidity of the shaft and the housing. Or it can be set as the cylindrical roller bearing with a higher rated load which increased the roller diameter by the space of the omitted inner ring, and can contribute to the extension of the life of the speed increaser. The cylindrical roller bearing has two or more types of spacers with different wall thicknesses manufactured in advance, and the circumferential clearance can be easily adjusted by a combination of the number of the spacers. Keystone can be established without severely managing the roller diameter. That is, the keystone effect can be obtained at a lower cost than the total rolling element bearing.

A fifth aspect of the present invention is the cylindrical roller bearing for a wind turbine speed increaser according to any one of the first to fourth aspects, characterized in that a recess is provided in the spacer for the purpose of retaining lubricating oil. It is. By adopting such a configuration, the lubricating oil can be held in the concave portion, and it can contribute to the extension of the life of the bearing and thus the speed increaser. Wind turbine generators may stop operating for a long time depending on wind conditions. Especially in planetary gear units, the lubricating oil flows down from the bearings in the planetary gears that are not immersed in the oil bath, and most of them are lost. . When the operation is resumed from the state due to a change in the wind condition, the bearing may be poorly lubricated, and smooth rotation may be impaired. This leads to a decrease in power generation efficiency and also hinders the extension of the bearing life.

A sixth aspect of the present invention is the cylindrical roller bearing for a wind turbine speed increaser according to the first aspect , wherein the expansion portion is located on the outer ring side of the pitch circle of the rollers . A seventh aspect of the present invention is the cylindrical roller bearing for a wind turbine speed increaser according to the second aspect, characterized in that the expansion portion is located closer to the inner ring than the pitch circle of the rollers .

  According to the present invention, it is possible to provide a cylindrical roller bearing that is compact, has a high rated load, and has reduced surface damage, and can contribute to the downsizing and extending the life of the step-up gear of the wind power generator.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a step-up gear for wind power generator provided with the planetary gear device shown in FIGS. 7 and 8 will be described. This speed increaser includes a planetary gear device 12 and a secondary speed increase device 14 disposed in a common casing 10. The planetary gear unit 12 plays a role of increasing the rotation of the input shaft 16 and transmitting it to the low-speed shaft 18. The secondary speed increasing device 14 plays a role of further increasing the rotation of the low speed shaft 18 and transmitting it to the output shaft 20. The input shaft 16 is connected to a main shaft (not shown) of a windmill (not shown) and the output shaft 20 is connected to a generator (not shown).

  The planetary gear device 12 includes a gear train including a sun gear 22, a planetary gear 24, and an internal gear 26. The planetary gear 24 meshes with both the sun gear 22 and the internal gear 26. The internal gear 26 may be formed directly on the casing 10 or may be fixed separately to the casing 10. The sun gear 22 is a member serving as an output shaft in the planetary gear device 12, and is attached to the low speed shaft 18. The low speed shaft 18 is supported by bearings 28 and 30 and is rotatable with respect to the casing 10.

  The planetary gear 24 is carried by a carrier 32. The carrier 32 is a member that serves as an input portion in the planetary gear device 12, and is formed integrally with the input shaft 16 or integrally coupled. The carrier 32 is supported by bearings 34 and 36 at the portion of the input shaft 16 and is rotatable with respect to the casing 10. A plurality of (3 in FIG. 8) planetary shafts 38 are arranged in the circumferential direction of the carrier 32, and the planetary gear 24 is rotatably supported on each planetary shaft 38 via a bearing 40. Although two bearings 40 of each planetary gear 24 are arranged in the illustrated example, one bearing may be used.

  The secondary speed increasing device 14 is constituted by a gear train. In the illustrated example, the gear 42 fixed to the low speed shaft 18 meshes with the small diameter side gear 46 of the intermediate shaft 44, and the large diameter side gear 48 provided on the intermediate shaft 44 meshes with the gear 50 of the output shaft 20. The intermediate shaft 44 and the output shaft 20 are supported by bearings 52 and 54, respectively, and are rotatable with respect to the casing 10.

  The lower part of the casing 10 is a part forming an oil bath 56 of lubricating oil, and the oil level L of the oil bath 56 is a height at which the bearing 40 supporting the planetary gear 24 enters and exits by turning of the carrier 32.

  The operation of the above configuration will be described. When the input shaft 16 rotates, the carrier 32 integral with the input shaft 16 turns, and the planetary gear 24 carried on the carrier 32 revolves. At this time, each planetary gear 24 revolves while revolving while meshing with the fixed internal gear 26 to cause rotation. The planetary gear 24 that rotates while revolving is meshed with the sun gear 22, so that the sun gear 22 is rotated at an increased speed with respect to the input shaft 16. The sun gear 22 serving as the output unit of the planetary gear device 12 is provided on the low speed shaft 18 of the secondary speed increasing device 14, and the rotation of the sun gear 22 is increased by the secondary speed increasing device 14 to the output shaft 20. Reportedly. As described above, the rotation of the windmill main shaft (not shown) input to the input shaft 16 is significantly increased by the planetary gear device 12 and the secondary speed increasing device 20 and is transmitted to the output shaft 20. From 20, high-speed rotation capable of generating power is obtained.

Next, the bearing 40 that supports each planetary gear 24 will be described. In the embodiment shown in FIG. 1, a cylindrical roller bearing in which a plurality of cylindrical rollers 6 are interposed between the inner ring 2 and the outer ring 4. This cylindrical roller bearing does not use a normal cage, but instead has a spacer 8 interposed between adjacent cylindrical rollers 6. The inner ring 2 has one collar, and the outer ring 4 has both collars. As shown in FIG. 2, the spacer 8 has a roller contact surface 8a in contact with the rolling surface 6a of the cylindrical roller 6 extending in the axial direction of the bearing, and an extended portion 8b facing the roller end surface 6b at both ends thereof. Is provided. The expansion portion 8b interferes with the roller end surface 6b, thereby restricting the movement of the spacer 8 in the axial direction of the bearing. Movement of the spacer 8 in the radial direction of the bearing is restricted by the roller rolling surface 6 a or the outer ring flange inner diameter.

  As shown in FIG. 3, the surface of the spacer 8 that faces the roller rolling surface 6 a, that is, the roller contact surface 8 a has a concave shape that extends across the pitch circle of the roller 6. Here, the case where the cross section is a concave arc is shown as an example of the concave shape. The spacer 8 is guided by the inner diameter of the outer ring collar, and when the spacer 8 is sandwiched between the adjacent rollers 6, there is a clearance Sr between the spacer 8 and the outer ring 4. As shown in FIG. 4, when the spacer 8 is sandwiched between the rollers 6 on the raceway surface of the outer ring 4, the radial position of the spacer 8 is determined using the concave bottom of the outer ring collar as a contact position. At that time, by setting so that the clearance Sr exists between the spacer 8 and the outer ring 4, it is possible to avoid a state in which the spacer 8 is pressed against the outer ring by the adjacent rollers 6 (see FIG. 4). . That is, the spacer 8 basically serves as a roller guide by the above setting, and only the spacer 8 located in the circumferential clearance is released from the restraint of the adjacent roller 6, and the released spacer has its own weight, centrifugal force. Since no radial force other than the force acts, heat generation and wear on the guide surface of the spacer 8 can be reduced.

  As can be seen from FIG. 3, the surface of the spacer 8 that faces the inner diameter surface of the outer ring collar is a convex curved surface having a curvature radius R <b> 1 that is smaller than the curvature radius R <b> 2 of the inner diameter of the outer ring collar. In addition, although illustration was abbreviate | omitted, when arrange | positioning the expansion part of a spacer to an inner ring collar outer diameter side, the curvature radius larger than the curvature radius of the inner ring collar outer diameter is the surface facing the inner ring collar outer diameter surface of the spacer 8 Or a concave curved surface. By adopting such a configuration, a so-called “wedge effect” (an effect in which fluid is drawn into the wedge-shaped gap narrowing in the direction of motion by viscosity to generate pressure, that is, load capacity) is obtained, and the spacer Heat generation and wear on the guide surface can be reduced.

The embodiment shown in FIG. 5 is a cylindrical roller bearing in which a keystone effect is exhibited by the cylindrical roller 6 and the spacer 8 and the inner ring is omitted, and the outer diameter surface of the planetary shaft is substituted for the inner ring raceway surface. Is. In the same figure, the symbol Sc represents the clearance of the roller row before pushing the last one cylindrical roller 6 and the pair of spacers 8, and the symbol A represents the sum of the thickness of the cylindrical roller 6 and the pair of spacers 8. Represents. By setting the dimensions so that the relationship between the two is Sc <A, if the last one cylindrical roller 6 and the pair of spacers 8 are pushed in, the entire roller row will fall off radially outward from the outer ring. No (Keystone effect). In this cylindrical roller bearing, two or more types of spacers with different wall thicknesses are manufactured in advance, and the circumferential clearance can be easily adjusted by the combination (matching). Keystone can be established without management.

  The spacer 8 may be provided with a lubricating oil holding portion having various shapes such as a recess and a through hole for holding the lubricating oil on the roller contact surface 8a, the inner diameter surface, the outer diameter surface, and the like. By doing so, it is possible to contribute to the extension of the life of the bearing, and thus the speed increaser. Some examples of such lubricating oil retaining portions are shown in FIG. FIG. 6A shows a lubricating oil holding portion 8 c formed on the roller contact surface 8 a of the spacer 8 and having a recess shape independent of each other. FIG. 6B shows a lubricating oil holding portion 8 c formed on the roller contact surface 8 a of the spacer 8 and in the form of a groove extending in the axial direction of the bearing. FIG. 6C shows a groove-like lubricating oil retaining portion 8 c formed on the roller contact surface 8 a of the spacer 8 and cut from the inner diameter side to the outer diameter side of the bearing. FIG. 6D shows a groove-like lubricating oil retaining portion 8c formed on the inner side of the extended portion 8b of the spacer 8, that is, on the surface facing the roller end surface 6b, cut from the inner diameter side to the outer diameter side of the bearing. ing. FIG. 6E shows a lubricating oil holding portion 8 c in the form of a through hole provided in the roller contact surface 8 a of the spacer 8. FIG. 6F shows a lubricating oil retaining portion 8c formed by cutting out a part of the spacer 8 in the circumferential direction and the radial direction of the bearing.

  The material of the spacer 8 is preferably engineering plastic or sintered alloy. Plastics are generally self-lubricating and sintered alloys can have their pores impregnated with lubricating oil. Therefore, by adopting such a configuration, it is possible to contribute to the extension of the life of the bearing and thus the speed increaser.

Broken perspective view showing an embodiment of a bearing The perspective view of the spacer in the bearing of FIG. Partial side view of the bearing of FIG. Partial side view of the bearing of FIG. Cross section showing another embodiment of bearing Perspective view showing various modifications of the spacer Vertical sectional view showing an embodiment of the planetary gear device Cross-sectional view of the planetary gear device of FIG.

Explanation of symbols

2 Inner ring 4 Outer ring 6 Cylindrical roller 6a Rolling surface 6b Roller end surface 8 Spacer 8a Roller contact surface 8b Expanding portion 8c Lubricating oil holding portion 10 Casing 12 Planetary gear device 14 Secondary speed increasing device 16 Input shaft 18 Low speed shaft 20 Output shaft 22 sun gear 24 planetary gear 26 internal gear 28 bearing 30 bearing 32 carrier 34 bearing 36 bearing 38 planetary shaft 40 bearing 42 gear 44 intermediate shaft 46 small diameter side gear 48 large diameter side gear 50 gear 52 bearing 54 bearing 56 oil bath 14 2 Next gearbox

Claims (7)

In cylindrical roller bearings having a plurality of rollers that are freely rollable between an inner ring raceway surface and an outer ring raceway surface, and a plastic spacer located between adjacent rollers, both ends in the axial direction of the spacer It has an extended part that faces the roller end face, and the extended part is arranged on the outer ring side, and the surface of the extended part that faces the inner ring surface of the outer ring collar is a convex curved surface having a curvature radius smaller than the radius of curvature of the outer ring collar inner diameter. And the surface of the spacer facing the roller rolling surface has a concave shape extending across the pitch circle of the roller, and when the spacer is sandwiched between adjacent rollers, the extension portion and the raceway Cylindrical roller bearings for wind generator gearboxes with a gap between them. In cylindrical roller bearings having a plurality of rollers that are freely rollable between an inner ring raceway surface and an outer ring raceway surface, and a plastic spacer located between adjacent rollers, both ends in the axial direction of the spacer An expansion portion that faces the roller end surface is integrally provided, the expansion portion is disposed on the inner ring side, and a surface of the expansion portion that faces the outer diameter surface of the inner ring collar is a recess having a radius of curvature larger than the curvature radius of the outer diameter of the inner ring collar. A curved surface, a surface facing the roller rolling surface of the spacer is a concave shape extending across the pitch circle of the roller, and when the spacer is sandwiched between adjacent rollers, Cylindrical roller bearing for wind generator gearbox with clearance between raceway and ring.   The cylindrical roller bearing for wind power generators according to claim 1 or 2, wherein a keystone effect is exhibited by the roller and the spacer.   The cylindrical roller bearing for a wind power generator gearbox according to claim 1 or 2, wherein the keystone effect is exhibited by the roller and the spacer, and the outer diameter surface of the shaft is used as the inner ring raceway surface.   The cylindrical roller bearing for wind power generators according to any one of claims 1 to 4, wherein the spacer is provided with a recess intended to retain lubricating oil. The cylindrical roller bearing for wind turbine speed increaser according to claim 1, wherein the expansion portion is located on the outer ring side of the pitch circle of the rollers. The cylindrical roller bearing for wind power generator gearboxes according to claim 2, wherein the extension portion is located on the inner ring side of the pitch circle of the rollers.

Images