JP2006105208A - Double row automatic aligning roller bearing and wind power generator main shaft support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double row automatic aligning roller bearing which achieves long service life of a spherical roller having high load during utilization. <P>SOLUTION: An inner ring 20 has a middle collar 21. End surfaces 11a, 12a of the respective spherical rollers 11, 12 have a protruded spherical shape. In the middle collar 21, one side surface 21b has a recessed curve shape fitted to the protruded spherical shape of the spherical roller 12. The other side surface 21a has a flat surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double-row spherical roller bearing, and more particularly to a double-row spherical roller bearing in which an uneven load is applied to the left and right rows of spherical rollers, and a main shaft support structure of a wind power generator having such a bearing. It is about.

  In recent years, wind power generation that can use clean and inexhaustible energy has attracted attention. In a large-scale wind power generation facility, the generator body equipped with a windmill is installed at a height of several tens of meters from the ground, so maintenance of the bearing that supports the main shaft of the windmill blade involves great effort and danger. . For this reason, a bearing that supports the main shaft of the wind power generator is required to have high reliability and durability.

  A self-aligning roller bearing suitable for rotatably supporting a main shaft of a wind power generator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-11737 (Patent Document 1). As disclosed in this publication, a large double row self-aligning roller bearing 1 as shown in FIG. 1 is often used for a main shaft bearing in a large wind power generator.

  Since the main shaft 2 of the wind turbine of the wind power generator is attached to the housing 4 so as to support the tip end side where the blade 3 is provided, the main shaft 2 can normally support the bending of the main shaft 2 as a bearing for the cantilever support. A large spherical roller bearing 1 is used. When the blade 3 receives wind force, the main shaft 2 rotates together with the blade 3. The rotation of the main shaft 2 is increased by a speed increaser (not shown) and transmitted to the generator to generate power.

  The self-aligning roller bearing 1 includes an inner ring 5, an outer ring 6, and double-row spherical rollers 7 and 8. When power is generated by receiving wind, the main shaft 2 supporting the blade 3 is loaded with an axial load (bearing thrust load) caused by the wind force applied to the blade 3 and a radial load (bearing radial load) due to the blade shaft's own weight. Is done. The double-row self-aligning roller bearing 1 can receive both a radial load and a thrust load at the same time, and has a self-aligning property, so that it can absorb the accuracy error of the housing 4 and the inclination of the spindle 2 due to the mounting error, and can be operated. The bending of the inner main shaft 2 can be absorbed.

The inner ring 5 shown in FIG. 1 has a center flange 9 that comes into contact with the end faces 7a and 8a of the spherical rollers 7 and 8 in the left and right rows. Usually, in order to prevent the skew of the spherical rollers 7 and 8, when the end surfaces of the spherical rollers 7 and 8 are convex spherical shapes, both side surfaces of the center flange 9 are concave shapes that fit the convex spherical shape of the spherical rollers. The curved contact surface increases the contact area between the two.
Japanese Patent Application Laid-Open No. 2004-11737

  In the double-row self-aligning roller bearing 1 for supporting the main shaft of the wind power generator described above, the thrust load becomes larger than the radial load during the rotation of the wind turbine. In this case, of the double-row spherical rollers 7 and 8, the spherical roller 8 in the row farther from the blade 3 receives the radial load and the thrust load at the same time. For the spherical rollers 7 in the row closer to the blade 3, the thrust load is not so much, and only the radial load is received.

  On the other hand, in a windless state, the load applied to the spindle support bearing 1 is exclusively a radial load. Therefore, the spherical rollers 7 in the row closer to the blade 3 receive a larger radial load when the windmill is not rotating than when the windmill is rotating.

  As described above, in the case of the double row self-aligning roller bearing 1 for supporting the main shaft of the wind power generator, the load on the spherical roller 8 in the row farther from the blade 3 is increased, so that the spherical surface in the row closer to the blade 3 is used. Compared with the roller 7, the rolling fatigue life is shortened. In particular, since the convex spherical surface and the concave curved surface are in contact with the side surface of the inner ring 9 of the inner ring 5 and the end surface of the spherical roller 8, the contact surface pressure increases, frictional resistance is generated, and the contact portion rotates. Torque increases. Furthermore, since the contact position is on the upper side of the middle flange, the contact ellipse is cut and edge stress is generated at the upper end portion, and there is a high possibility that problems such as premature wear and peeling will occur in this portion.

  On the other hand, the spherical rollers 7 in the row closer to the blade 3 are lightly loaded, causing slippage between the spherical rollers 7 and the raceway surfaces 5a and 6a of the inner and outer rings 5 and 6, causing surface damage and wear problems. Although it is conceivable to increase the bearing size in order to cope with a large load, the margin becomes too large on the light load side, which is uneconomical.

  An object of the present invention is to provide a double row self-aligning roller bearing capable of extending the life of a spherical roller that is particularly subjected to a high load.

  Another object of the present invention is to provide an economical double-row self-aligning roller bearing that can support the appropriate rollers according to the load in each row, extend the actual life, and has no waste of materials. A main shaft support structure for a wind power generator using this bearing is provided.

  The double-row self-aligning roller bearing according to the present invention has spherical rollers arranged in a double row between an inner ring and an outer ring, and is characterized by the following. That is, the inner ring has a center flange that abuts against the end faces of the double-row spherical rollers. The end surface of each spherical roller in contact with the center flange has a convex spherical shape, and at least one of the side surfaces in contact with the end surface of the double row spherical roller has a flat surface. Have.

  According to the above configuration, since the flat side surface of the center and the spherical roller are in point contact, the contact area is reduced, so that the frictional resistance is reduced and the torque is reduced. Therefore, it is possible to extend the life of the spherical roller that is highly loaded during use.

  In one embodiment, the intermediate flange has a concave curved surface that matches the convex spherical shape of the spherical roller on one side surface, and a flat surface on the other side surface. According to this embodiment, the contact area is increased for one row of spherical rollers in contact with the concave curved surface of the center collar, and the rollers are constrained widely because they contact the roller at the upper end of the center collar. The skew is effectively suppressed, and the frictional resistance is reduced by making point contact with the spherical roller in the other row contacting the flat side surface of the center.

  In the above-described embodiment, preferably, one spherical roller that contacts the concave curved surface of the center has a smaller roller length than the other spherical roller that contacts the flat surface of the center. In this way, if the roller lengths of the left and right rows of spherical rollers are made different, the load capacities of the respective spherical rollers will be different. Therefore, if a spherical roller having a large roller length is used for a row having a large load capacity and a spherical roller having a small roller length is used for a row on the light load side, proper support corresponding to the load can be performed in each row. If the roller length is reduced, the roller skew is likely to occur. However, the skew can be effectively suppressed by bringing the spherical roller having a small roller length into contact with the side surface of the center with a large contact width.

  The spherical roller may be a symmetric roller in which the position of the maximum diameter of the roller is located at the center of the roller length, or an asymmetric roller in which the position of the maximum diameter of the roller is deviated from the center of the roller length. If the position of the maximum roller diameter is an asymmetrical roller that is shifted to the center side from the center of the roller length, a component of the force that presses the roller to the center side during use will be generated, so the roller skew is effective. Can be suppressed.

  Preferably, the height of the side surface of the center flange having a flat surface is larger than the diameter in the height direction of the contact ellipse formed on the contact surface between the side surface and the end surface of the spherical roller. If it is a middle rod having such a height dimension, it can sufficiently withstand the load during use.

  The double-row self-aligning roller bearing having the above-described features is used, for example, in applications in which uneven loads act on the left and right rows of spherical rollers.

  A main shaft support structure of a wind power generator according to the present invention includes a blade that receives wind power, a main shaft that is fixed to the blade and rotating together with the blade, and a double row that is incorporated in a fixed member and rotatably supports the main shaft. Spherical roller bearings are provided. The double row spherical roller bearing includes an inner ring, an outer ring, and a double row spherical roller. The inner ring has a center flange that abuts against the end faces of the double-row spherical rollers. The end face of each spherical roller in contact with the center has a convex spherical shape. One side surface of the intermediate collar has a concave curved surface that conforms to the convex spherical shape of the spherical roller, and the other side surface has a flat surface.

  In the main shaft support structure of the wind power generator configured as described above, the spherical roller and the center of the high load side contact with lower torque, and the spherical roller and the center of the lower load side have a larger contact area. Since they come into contact with each other, it is possible to properly support each row according to the load.

  As described above, according to the double-row self-aligning roller bearing according to the present invention, the flat side surface of the center and the spherical roller are configured to be in point contact with each other. Lowers and lowers torque. Further, in the case of a flat side surface, there is an advantage that the position of the contact point can be easily controlled by the angle. Since it is possible to prevent the contact ellipse from coming off from the side surface of the middle collar even when the load on the middle collar is large, the generation of edge stress can be prevented. In this way, the life of the spherical roller that becomes a high load during use can be extended.

  According to the present invention, proper support according to the load can be provided in each row, and the substantial life can be extended. By applying such a double-row spherical roller bearing to the main shaft support structure of a wind power generator, it is possible to provide proper support according to the characteristics acting on the main shaft, so the main shaft support has high reliability and long life. A structure is obtained.

  With reference to FIG. 2 and FIG. 3, the double row self-aligning roller bearing which concerns on one Embodiment of this invention is demonstrated.

  The double-row self-aligning roller bearing 10 includes an inner ring 20, an outer ring 30, spherical rollers 11 and 12 arranged in a double row between both race rings, and a cage 13 that holds these spherical rollers 11 and 12. Is provided. The cage 13 is provided separately for each column. The raceway surface 30 a of the outer ring 30 is formed in a spherical shape, and the outer peripheral surfaces of the spherical rollers 11 and 12 in each row have a spherical shape along the raceway surface 30 a of the outer ring 30.

  The outer ring 30 has an oil groove 31 at an intermediate position on the outer diameter surface, and further has an oil hole 32 penetrating from the oil groove 31 to the inner diameter surface. The oil holes 32 are provided at one place or a plurality of places in the circumferential direction.

  The inner ring 20 in the illustrated embodiment has outer flanges 22 and 23 at both ends in the width direction and an intermediate flange 21 in the middle. The inner ring 20 has double-row raceway surfaces 20a and 20b having a cross-sectional shape along the outer peripheral surfaces of the spherical rollers 11 and 12 in each row.

  When attention is paid to the roller lengths of the left and right rows of spherical rollers 11, 12, the length L1 of the right side of the spherical rollers 11 in the drawing is larger than the length L2 of the left side of the spherical rollers 12. In the illustrated embodiment, the bearing portions 10a and 10b in the left and right rows have different contact angles θ1 and θ2. In this case, the contact angle θ1 of the bearing portion 10a corresponding to the row of spherical rollers 11 having a large roller length is set to be larger than the contact angle θ2 of the bearing portion 10b of the row of spherical rollers 12 having a small roller length. ing.

  The outer diameters of the spherical rollers 11 and 12 in both rows have the same maximum diameter, for example. As a modification, the outer diameters of the spherical rollers 11 and 12 in both rows may be different from each other. For example, the spherical roller 11 having a larger length may have a larger outer diameter than the spherical roller 12 having a smaller length. Regarding the shape of the spherical rollers 11 and 12 in each row, the roller may be a symmetric roller in which the position of the maximum diameter is located at the center of the roller length, or the position of the maximum diameter of the roller may be from the center of the roller length. It may be an asymmetric roller that is displaced toward the intermediate collar 21 side.

  FIG. 3 shows an enlarged view of a state in which the inner collar 21 of the inner ring 20 is in contact with the spherical rollers 11 and 12 in the left and right rows. As shown in the drawing, the end surfaces 11a and 12a of the spherical rollers 11 and 12 that abut against the intermediate collar 21 have a convex spherical shape.

  The intermediate collar 21 has a flat surface on at least one of the side surfaces 21a and 21b that abut the spherical rollers 11 and 12 in the left and right rows. In the illustrated embodiment, the intermediate flange 21 has a concave curved surface whose one side surface 21 b matches the convex spherical shape of one spherical roller 12, and the other side surface 21 a that contacts the other spherical roller 11 is flat. Has a surface.

  The double-row self-aligning roller bearing 10 having the above-described configuration is used in applications where asymmetric loads act on the left and right rows, for example, one row receives a thrust load and a radial load, and the other row receives only a radial load. It is used for such applications. In this case, the spherical roller 11 having a large roller length is used on the high load row side that receives the thrust load and the radial load, and the spherical roller 12 having a small roller length is used exclusively on the light load side row that receives only the radial load.

  As described above, the spherical roller 11 having a large roller length is arranged in the high load side row, and the spherical roller 12 having a small roller length is arranged in the light load side row, so that the appropriateness corresponding to the load condition of each row is obtained. Support can be made. That is, since the load capacity is increased in the high load side row, the rolling fatigue life is improved. Further, in the light load side row, the contact stress between the spherical roller 12 having a small roller length and the raceway surfaces 30a and 20b is increased, and the roller's own weight is reduced, so that the slip is reduced.

  Further, the spherical roller 12 having a reduced roller length is likely to be skewed. However, the spherical roller 12 is in contact with the intermediate collar 21 by contact between the end surface 12a having a convex spherical shape and the side surface 21b having a concave curved surface. Since the contact area is increased, the skew can be effectively suppressed. On the other hand, with respect to the other spherical roller 11 on the high load side, since the convex spherical end face 11a and the flat side face 21a are brought into point contact with each other, the contact surface pressure is reduced. The torque at the contact portion can be reduced.

  FIG. 4 schematically shows a state in which the end surface 11a of the spherical roller 11 and the flat side surface 21a of the intermediate collar 21 are in contact with each other. When the end surface 11a of the spherical roller 11 and the side surface 21a of the intermediate collar 21 come into contact with each other under load, the contact surface is elastically deformed, and an oval contact surface, that is, a contact ellipse 14 is formed around the contact point. Preferably, in order to keep the edge load at the upper end of the side surface 21a of the center collar 21 low, the height dimension H of the side surface 21a of the center collar 21 is made larger than the diameter A of the contact ellipse 14 in the height direction. .

  FIG. 5 shows a self-aligning roller bearing according to another embodiment of the present invention. Note that the same reference numerals as those in the embodiment shown in FIG. 2 indicate the same or corresponding elements, and detailed description thereof will be omitted. In the embodiment shown in FIG. 5, the outer ring 30 is constituted by two divided outer rings 30A and 30B arranged in the axial direction. Both split outer rings 30A and 30B are provided so that a gap d is formed between them in a natural state, that is, in a state where the raceway surfaces of both split outer rings are located on the same spherical surface.

  As shown in FIG. 5, the preload is preferably applied by the preload applying means 41 so that the gap d between the split outer rings 30 </ b> A and 30 </ b> B on both sides is narrowed. As the preload applying means 41, for example, a spring member, a tightening screw, or the like can be used. When using a spring member, for example, the compression spring is disposed so as to be in contact with the end face of the outer ring 30B at a plurality of locations in the circumferential direction. The preload applying means 41 preferably applies preload from the side of the spherical roller 12 having a small roller length.

  As described above, when the outer ring 30 is divided, the asymmetric outer ring 30 can be easily manufactured. Further, by applying a preload to the outer ring 30, it is possible to positively suppress the slip of the spherical roller 12 having a small roller length. In addition to the split structure of the outer ring, the inner ring 20 may also be constituted by two divided inner rings arranged in the axial direction. In this way, manufacturing of the asymmetric inner ring 20 is facilitated.

  6 and 7 show an example of a main shaft support structure of a wind power generator to which a double row self-aligning roller bearing according to an embodiment of the present invention as shown in FIGS. 2 to 5 is applied. The casing 53 of the nacelle 52 that supports the main components of the main shaft support structure is installed on the support base 50 via a swivel bearing 51 at a high position so as to be horizontally rotatable. A main shaft 56 holding a blade 57 at one end is rotatably supported in a casing 53 of the nacelle 52 via a main shaft support bearing 55 incorporated in a bearing housing 54. The other end of the main shaft 56 is connected to a speed increaser 58, and the output shaft of the speed increaser 58 is coupled to the rotor shaft of the generator 59. The nacelle 52 is turned at an arbitrary angle by the turning motor 60 via the speed reducer 61.

  In the illustrated embodiment, two main shaft support bearings 55 are installed side by side, but may be one. As the main shaft support bearing 55, a double-row self-aligning roller bearing according to an embodiment of the present invention is used. In this case, since a large load is applied to the spherical rollers in the row far from the blade 57, spherical rollers having a large roller width are used. Since only radial load is mainly applied to the spherical rollers in the row closer to the blade 57, spherical rollers having a small roller length are used. The end face of each spherical roller has a convex spherical shape.

  The inner ring of the main shaft support bearing 55 has a center flange that abuts against the end faces of the double row spherical rollers. The intermediate flange has a concave curved surface that matches the convex spherical shape of the spherical roller on one side surface facing the blade 57 side, and a flat surface on the other side surface on the opposite side.

  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 changes can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention can be advantageously used particularly for a double-row self-aligning roller bearing in which an uneven load acts on the left and right rows of spherical rollers and a main shaft support structure of a wind power generator equipped with such a bearing.

It is sectional drawing which shows the prior art example of the spindle support bearing of a wind power generator. It is sectional drawing which shows the double row self-aligning roller bearing which concerns on one Embodiment of this invention. It is sectional drawing which expands and shows the contact part of the inner ring | wheel inner ring | wheel and the spherical roller of a right-and-left row | line | column. It is a figure which shows typically the state which the end surface of a spherical roller and the flat side surface of a center contact | abut. It is sectional drawing which shows the double row self-aligning roller bearing which concerns on other embodiment of this invention. It is a figure which shows an example of the spindle support structure of the wind power generator using the double row self-aligning roller bearing which concerns on this invention. FIG. 7 is a schematic side view of the main shaft support structure of the wind power generator shown in FIG. 6.

Explanation of symbols

10 Double Row Spherical Roller Bearing, 11, 12 Spherical Roller, 11a, 12a End Surface, 13 Cage, 14 Contact Ellipse, 20 Inner Ring, 20a, 20b Raceway Surface, 21 Middle, 21a, 21b Side Surface, 22, 23 Outer bush, 30 Outer ring, 30a Raceway surface, 31 Oil groove, 32 Oil hole, 40 Bearing housing, 41 Preload applying means, 50 Support base, 51 Swivel seat bearing, 52 Nacelle, 53 Casing, 54 Bearing housing, 55 Main shaft support bearing 56 spindles, 57 blades, 58 speed increasers, 59 generators, 60 turning motors, 61 speed reducers.

Claims (7)

In double row spherical roller bearings in which spherical rollers are arranged in double rows between the inner ring and outer ring,
The inner ring has a center abutting against an end surface of the double row spherical roller
The end surface of each spherical roller in contact with the center flange has a convex spherical shape,
The double-row self-aligning roller bearing, wherein at least one side surface of the middle flange has a flat surface among both side surfaces in contact with an end surface of the double-row spherical roller. 2. The center pin according to claim 1, wherein one side surface of the intermediate flange has a concave curved surface that conforms to the convex spherical shape of the spherical roller, and the other side surface has a flat surface. Double row spherical roller bearings. 3. The compound roller according to claim 2, wherein one spherical roller in contact with the concave curved surface of the center flange has a smaller roller length than the other spherical roller in contact with the flat surface of the center flange. Row spherical roller bearings. The double-row self-aligning roller according to any one of claims 1 to 3, wherein each of the spherical rollers is an asymmetric roller in which a position of the maximum diameter of the roller is shifted to the center side from the center of the roller length. bearing. The height of the side surface of the center flange having the flat surface is made larger than the diameter in the height direction of the contact ellipse generated on the contact surface between the side surface and the end surface of the spherical roller. Double row spherical roller bearings according to any of the above. The double row self-aligning roller bearing according to any one of claims 1 to 5, wherein the double row self-aligning roller bearing is used for an application in which an uneven load is applied to the left and right rows of spherical rollers. A blade that receives wind,
One end of which is fixed to the blade and rotates with the blade;
In the main shaft support structure of a wind power generator, which is incorporated in a fixed member and includes a double-row self-aligning roller bearing that rotatably supports the main shaft,
The double-row spherical roller bearing includes an inner ring, an outer ring, and a double-row spherical roller,
The inner ring has a center flange that abuts against an end face of the double row spherical roller;
The end surface of each spherical roller in contact with the center flange has a convex spherical shape,
The main shaft of the wind power generator, characterized in that one side surface of the intermediate flange has a concave curved surface that conforms to the convex spherical shape of the spherical roller, and the other side surface has a flat surface. Support structure.

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