JP5595832B2 - Rolling bearings and cages - Google Patents

Description

  The present invention relates to a rolling bearing and a cage applied to a large-sized rolling bearing used for a main bearing of a wind power generator, for example.

  For example, in the case of a large-sized rolling bearing used for a main bearing of a wind turbine generator, it is difficult to manufacture an annular integrated cage. Therefore, a cage divided into a plurality of segments arranged in the circumferential direction is provided. It may be used (for example, patent document 1).

  A segment of this type of rolling bearing cage is shown in FIG. In this segment 30, a plurality of column portions 33 extending in the axial direction are disposed so as to form a pocket 32 that accommodates one rolling element 31, and connecting portions in which both ends of the column portions extend in the circumferential direction. 34 are connected.

Japanese Patent No. 4105750

  However, tensile stress due to separation / concentration of the rolling elements 31 in the operating bearing acts on the column portion 33 of the segment 30, and the stress concentrates on the root of the column portion 33 (the coupling portion with the connecting portion 34). Therefore, the column part 33 cannot be thinned. As a result, the number of rolling elements 31 that can be accommodated in the bearing cannot be increased, which hinders the improvement of the load capacity and the life of the bearing.

  In view of the above circumstances, an object of the present invention is to improve the load capacity and life of a rolling bearing to which a split cage is applied.

  As a result of various studies to solve the above problems, the present inventor has led to a novel idea that tensile stress does not act on the separator by using a separate separator structure that is separated and independent from the cage segment.

As technical means for solving the above problems, the present invention includes an outer ring having a raceway surface formed on an inner periphery, an inner ring having a raceway surface formed on an outer periphery facing the raceway surface of the outer ring, and a track of the outer ring. In a rolling bearing comprising a plurality of rolling elements disposed between a surface and a raceway surface of the inner ring, and a cage for holding the rolling elements, a plurality of cages in which the cage is divided in the circumferential direction A plurality of rolling elements in each cage segment, each of which is formed as a separate and independent piece from the cage segment, and is movable with respect to the cage segment A separator is provided, and the separator is interposed between the rolling elements.

  In this structure, since the tensile stress of a rolling element does not act on the separator used as a substitute for the conventional column part, the circumferential thickness can be reduced. As a result, the number of rolling elements that can be accommodated in the rolling bearing to which the cage of this configuration is applied increases, and the load capacity and life of the bearing can be improved.

  Further, the volume of the cage segment is reduced by the amount of the column part, and the shape of the cage segment is simplified from a ladder shape to a frame shape. Therefore, in this configuration in which the cage segment is formed by resin injection molding, the injection moldability is improved, and a larger cage segment can be molded. As a result, the number of rolling elements that can accommodate one cage segment increases, and the size of the rolling bearing to which the cage having this configuration is applied can be increased.

  Since it is a structure in which a separate separator is interposed in the cage segment, the circumferential gap can be adjusted by managing the circumferential length of each cage segment, so only the rolling elements and the separator The circumferential clearance can be easily adjusted as compared with the above case.

  The cage segment may be formed by resin injection molding. Thereby, it can be set as the cage segment excellent in the mass productivity of the cage segment.

  The cage segment may be configured to be guided by the raceway. Further, the cage segment may be configured to be guided by the inner ring, and a plurality of recesses may be provided in the inner peripheral portion of the cage segment guided by the inner ring. As a result, the behavior of the cage segment during operation can be stabilized, and the lubricant can easily enter and exit between the inner periphery of the cage segment and the outer diameter surface of the inner ring and into the bearing. .

  It is good also as a shape which can accommodate a part of rolling element on the side surface of a separator. Further, the separator may be guided on the raceway surface of the inner ring. Thereby, the behavior of the separator during the operation of the rolling bearing can be stabilized.

  With the separator guided by the rolling element and the separator positioned on the pitch circle of the rolling element, the separator can move radially to the raceway side through the gap between the separator and the outer ring raceway surface and the inner ring raceway surface. It may be larger than the maximum distance. In such a dimensional relationship, the separator is guided in the radial direction by the rolling elements and does not contact the raceway surface of the outer ring or the raceway surface of the inner ring. Thereby, even smoother rotation is possible. Moreover, since the separator does not contact the raceway surface, it is possible to suppress the occurrence of harmful scratches on the separator and the raceway surface.

  A recess may be provided in at least one of the outer diameter side end and the inner diameter side end of the separator, and the separator may be communicated in the circumferential direction. Moreover, you may provide a recessed part in the guide surface of the side surface of a separator. Thereby, holding | maintenance and flow-through performance of a lubrication agent are favorable, and it becomes easy to supply a lubrication agent to the contact surface of a separator and a rolling element, or the contact part of a rolling element and a track surface.

  You may form a separator with resin. The separator can be made excellent in mass productivity and self-lubricating properties. The separator may be formed of a sintered metal. Thereby, a separator can be made excellent in mass productivity. Moreover, since the sintered metal can impregnate the pores with a lubricant, the separator can be excellent in lubricity.

  ADVANTAGE OF THE INVENTION According to this invention, the load capacity and lifetime in a rolling bearing to which a split type cage is applied can be improved.

It is a side view of the rolling bearing which concerns on 1st Embodiment of this invention. It is a perspective view of the holder | retainer segment which concerns on 1st Embodiment of this invention. It is sectional drawing of the rolling bearing which concerns on 1st Embodiment of this invention. It is a perspective view of the holder | retainer segment which concerns on 2nd Embodiment of this invention. It is sectional drawing of the rolling bearing which concerns on 2nd Embodiment of this invention. It is a perspective view of other examples of a cage segment concerning the present invention. It is a perspective view of the conventional cage | basket segment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a rolling bearing according to a first embodiment of the present invention. In this embodiment, the present invention is applied to an N-shaped single row cylindrical roller bearing N29 / 710 (φ710 × φ950 × 140). The cylindrical roller bearing is used, for example, for supporting a main shaft of a wind power generator. It is what is used. The same applies to other embodiments described later.

  The cylindrical roller bearing 1 mainly includes an outer ring 2 as a bearing ring, an inner ring 3 as a bearing ring, a plurality of cylindrical rollers 4 as rolling elements, and a cage 5. The outer ring 2 has a raceway surface 2a on the inner peripheral surface and does not have a collar portion. The inner ring 3 has a raceway surface 3a on the outer peripheral surface, and has flange portions 3b at both ends in the axial direction of the raceway surface 3a. The roller 4 is rotatably interposed between the raceway surface 2a of the outer ring 2 and the raceway surface 3a of the inner ring 3.

  The cage 5 is divided into a plurality of cage segments 6 arranged in the circumferential direction. In the present embodiment, the number of cage segments 6 is six. Each cage segment 6 accommodates six rollers 4, and the rollers 4 are circumferentially separated from each other by five separators 7 interposed between the rollers 4. In the present embodiment, the cage segment 6 is guided by the outer diameter surface of the collar portion 3 b of the inner ring 3. A plurality of recesses 6e are provided on the inner peripheral surface of the cage segment 6 guided by the collar portion 3b to facilitate the entry and exit of the lubricant.

  FIG. 2 is an enlarged perspective view of one cage segment 6 portion. As shown in the drawing, the cage segment 6 is composed of column portions 6a at both ends in the circumferential direction and two connecting portions 6b that connect both ends in the axial direction of these column portions 6a. The connecting portion 6 b of the cage segment 6 is disposed between the outer ring 2 and the inner ring 3, and is curved in an arc shape along the outer peripheral surface of the raceway surface 2 a of the outer ring 2 and the collar portion 3 b of the inner ring 3. Six rollers 4 and five separators 7 are accommodated in a space 6c formed by the column portion 6a and the connecting portion 6b of the cage segment 6. A separator 7 is interposed between the adjacent rollers 4 and 4 in the space 6c. The separator 7 is formed separately from the cage segment 6. In FIG. 2, for ease of understanding, one of the separators 7 is illustrated as being taken out from the space 6c. A plurality of recesses 6e are formed in the inner peripheral surface 6d of the connecting portion 6b of the cage segment 6, and between the inner peripheral surface 6d of the connecting portion 6b of the cage segment 6 and the outer diameter surface of the collar portion 3b of the inner ring 3, and The inside and outside of the lubricant is easy. The circumferential end surfaces 6f of the column portions 6a of the adjacent cage segments 6 are arranged with a space (see FIG. 1), but become surfaces that abut when the adjacent cage segments 6 and 6 approach each other.

  A detailed description will be given based on the separator 7 taken out from the space 6c in FIG. The separator 7 is formed on its side surface with a planar guide surface 8 for guiding the roller 4 and inclined surfaces 9 and 10 that protrude to the inner diameter side and the outer diameter side to prevent the rollers 4 from falling off. Thus, the side surface of the separator 7 has a shape in which a part of the roller 4 is accommodated, and the behavior of the separator 7 during operation can be stabilized. The separator 7 has end surfaces 11, 11 facing the raceway surface 2 a of the outer ring 2 and end surfaces 12, 12 facing the raceway surface 3 a of the inner ring 3. A recess 13 is formed between the end surfaces 11, 11 of the separator 7, and a recess 14 is formed between the end surfaces 12, 12. The recesses 13 and 14 improve the characteristics regarding the retention and flow of the lubricant.

  FIG. 3 is a partial cross-sectional view showing an assembled state of the cylindrical roller bearing of the present embodiment. In this figure, the cross section of the roller 4 is not hatched. A side surface of the separator 7 is formed with a planar guide surface 8 that guides the roller 4, and inclined surfaces 9 and 10 that protrude to the inner diameter side and the outer diameter side thereof to prevent the rollers 4 from falling off. Is shaped to be accommodated. Since the separator 7 has a separate structure from the cage segment 6, tensile stress does not act on the separator 7, so that the circumferential thickness B of the guide surface 8 can be reduced. As a result, the number of rollers 4 that can be accommodated in the roller bearing 1 increases, and a high load capacity can be achieved. Since the side surface of the separator 7 is formed by the planar guide surface 8 and the inclined surfaces 9 and 10, the lubricating oil easily flows between the rollers 4. The separator 7 is guided by the raceway surface 3 a of the inner ring 3. Accordingly, even when the separator 7 moves radially inward and the inner diameter side end face 12 of the separator 7 comes into contact with the raceway surface 3a of the inner ring 3, it is between the inclined surface 10 and the rolling surface of the separator 4. There is a gap left. Since the separator 7 is provided with the recesses 13 and 14, the retention and flow-through performance of the lubricant is good, and the lubricant is supplied to the contact surface of the separator 7 and the contact portion of the roller 4 and the raceway surfaces 2 a and 3 a. It becomes easy to be done.

  Next, a procedure for assembling the cylindrical roller bearing 1 of the present embodiment will be described. The cage segments 6 are arranged on the inner ring 3 having the flange portions 3 b at both ends of the raceway surface 3 a, and the rollers 4, the separators 7, the rollers 4, and the separators 7 are alternately arranged in the space 6 c of the cage segments 6. FIG. 2 shows one separator 7 taken out from the space 6 c of the cage segment 6, but in this state, the roller 4 and the separator 7 are arranged in the space 6 c of the cage segment 6, and then the separator 7 to be assembled lastly. It is the same as the state. In the state shown in FIG. 2, after the rollers 4 and the separators 7 are brought close to the column portions 6 a at both ends in the circumferential direction of the cage segment 6, the last separator 7 is inserted between the rollers 4 and 4. At this time, the circumferential width A of the separator 7 is set to be slightly larger than the accumulated amount of gaps generated between the rollers 4 and 4, and the circumferential width A is overcome by elastic deformation of the separator 7. Inserted. With such a configuration, it is possible to prevent the rollers 4 and the separator 7 from dropping from the cage segment 6. By repeating the above procedure, the rollers 4 and the separators 7 are assembled to all the cage segments 5 around the raceway surface 3 a of the inner ring 3. Thereafter, the raceway surface 2a of the outer ring 2 is fitted onto the roller 4 from the axial direction, and the assembly of the bearing is completed. In FIG. 3, the difference between the circumferential thickness B and the circumferential width A at the guide surface 8 of the separator 7 is shown to be larger than actual, while the gap between the guide surface 8 and 4 is shown to be small. However, the state in which the rollers 4 and the separators 7 are arranged in the cage segment 6 is exaggerated for easy understanding.

  The material of the separator 7 is, for example, a resin, a sintered metal, a metal (including an alloy, and so on). The resin is easy to mold and is suitable for manufacturing the separator 7. In addition, the resin generally has excellent self-lubricating properties, and can smoothly slide the separator 7 with respect to the roller 4, the outer ring 2, and the inner ring 3. The type of resin is not particularly limited, but engineering plastics such as polyphenylsulfide, polyethersulfone, and polyetheretherketone have excellent mechanical strength, heat resistance, and oil resistance, and have stable functions over a long period of time. Demonstrate. In this case, the separator 7 is manufactured by injection molding, and a filler such as glass fiber or carbon fiber may be blended.

  Sintered metal is suitable for the production of the separator 7 because it is easy to mold, like the above-mentioned resin. In addition, since the sintered metal can impregnate the pores with a lubricant, the separator 7 can be smoothly slid relative to the roller 4, the outer ring 2, and the inner ring 3. Furthermore, since the sintered metal has a smaller coefficient of linear expansion than that of the resin, thermal expansion under a high temperature atmosphere can be suppressed. The manufacturing method of the separator 7 made of sintered metal may be solid phase sintering or liquid phase sintering. Solid phase sintering can effectively impregnate the pores with a lubricant. In liquid phase sintering, pores found in solid phase sintering can be filled with a metal having a low melting point, and the strength of the separator 7 can be improved. For example, the sintered base material is copper and the sealing metal is aluminum.

  When the separator 7 is made of metal, the type of metal is not particularly limited, but brass is preferable. The production method is not particularly limited, such as casting, cutting, forging, pressing, etc. However, in terms of production cost, casting and forging typified by lost wax, etc. are preferable. Is preferred.

  The cage segment 6 is preferably formed by resin injection molding, but is not limited thereto. For example, the same material and manufacturing method as the separator 7 may be used.

  With the above configuration, the following effects are obtained in the present embodiment. That is, since the tensile stress of the roller 4 does not act on the separator 7, the circumferential thickness can be reduced. As a result, the number of rollers 3 that can be accommodated in the bearing increases, and the load capacity and life of the bearing can be improved. Specifically, the number of rollers 3 in the bearing is increased from 30 to 36 when the conventional split cage described in FIG. 7 is used, and the load rating of the bearing is 15 as the dynamic load rating. %, Static load rating is improved by 20%.

  Although another embodiment will be described below, the same reference numerals are given to the same components as those in the first embodiment, and the description will be omitted.

  FIG. 4 shows a main part of a cage according to the second embodiment of the present invention. In FIG. 4, for ease of understanding, one of the separators 7 is illustrated as being taken out from the space 6 c of the cage segment 6. In this embodiment, the separator 7 is guided in the radial direction by the rollers 4, and the shape of the separator 7 is different from that of the first embodiment.

  As shown in FIG. 4, the separator 7 has a guide surface 8 that abuts the roller 4 on its side surface, and the guide surface 8 is formed in an arc shape substantially along the rolling surface of the roller 4. ), The radius of curvature of the arc of the guide surface 8 is set slightly larger than the radius of the rollers 4. In this configuration, the separator 7 is sandwiched and restrained by the adjacent rollers 4 and 4, and the separator 7 does not come into contact with the raceway surfaces 2 a and 3 a, so that harmful damage to the separator 7 and the raceway surfaces 2 a and 3 a is suppressed. be able to. Moreover, it becomes easy for lubricating oil to enter between the roller 4 and the guide surface 8. Grooves 7 b 2 (concave portions) spaced apart in the axial direction of the rollers 4 are formed on the guide surface 8. A notch 7 b 1 is provided on the outer diameter side of the guide surface 8, while a notch 7 b 3 is provided on the inner diameter side of the guide surface 8. Since the notches 7b1 and 7b3 are connected by the groove 7b2, a passage in the radial direction of the lubricating oil is formed, and the lubricant is more easily supplied to the contact portion between the guide surface 8 and 4. Further, recesses 7a1, 7a2, 7a3 are provided at the inner diameter side end of the separator 7, and recesses 7a4, 7a5 are provided at the outer diameter side end. These recesses 7a1, 7a2, 7a3, 7a4 and 7a5 provide good retention and flow-through performance of the lubricant, and the lubricant is supplied to the contact surface of the separator 7 and the contact surface of the roller 4 and the raceway surfaces 2a and 3a. It becomes easy.

  FIG. 5 is a partial cross-sectional view showing an assembled state of the cylindrical roller bearing of the present embodiment. FIG.5 (b) is the figure which expanded the part enclosed with the dashed-two dotted line of Fig.5 (a). As shown in FIG. 5B, the separator 7 has a guide surface 8 that abuts the roller 4 on its side surface, and the guide surface 8 is formed in an arc shape substantially along the rolling surface of the roller 4. The radius of curvature of the arc of the surface 8 is set slightly larger than the radius of the roller 4. FIG. 5 shows the separator 7 positioned on the pitch circle of the rollers 4. Further, in the state of FIG. 5, the separators 7 and 4 other than the separator 7 (separator 7 enlarged in FIG. 5B) surrounded by a two-dotted line in FIG. In this state, the cage segment 6 is brought close to the column portions 6a at both ends. That is, the separator 7 and the rollers 4 on both sides thereof are in the most separated state. In this state, the gap between the separator 7 and the raceway surfaces 2a and 3a can be moved in the radial direction toward the raceway surfaces 2a and 3a on the outer diameter side and the inner diameter side of the pitch circle of the roller 4, respectively. It is set larger than the maximum distance.

  This will be described in detail with reference to FIG. With the separator 7 positioned on the pitch circle of the roller 4, the gap between the end surface 11 on the radially outer diameter side of the separator 7 and the raceway surface 2a is g1, and the separator 7 is movable in the radial direction toward the raceway surface 2a. When the maximum distance is d1, the relationship g1> d1 is satisfied. On the other hand, when the gap between the end surface 12 on the radially inner diameter side of the separator 7 and the raceway surface 3a is g2, and the maximum distance that the separator 7 can move radially toward the raceway surface 3a is d2, the relationship of g2> d2 is satisfied. Meet. Because of this dimensional relationship, the separator 7 is guided in the radial direction by the rollers 4 and does not contact the raceway surface 2 a of the outer ring 2 or the raceway surface 3 a of the inner ring 3. Thereby, the cylindrical roller bearing of this embodiment can be rotated more smoothly.

  Since the procedure of assembling the cylindrical roller bearing 1 of the present embodiment is the same as that of the first embodiment described above, the description thereof is omitted. 5A and 5B, as in the first embodiment, the difference between the circumferential thickness B and the circumferential width A of the portion of the guide surface 8 of the separator 7 is greatly represented. Although the gap between the guide surface 8 and 4 is shown small, the state where the rollers 4 and the separator 7 are arranged in the cage segment 5 is exaggerated for easy understanding. However, because of the dimensional relationship described above, the separator 7 is guided in the radial direction by the rollers 4 and is set so as not to contact the raceway surface 2 a of the outer ring 2 and the raceway surface 3 a of the inner ring 3.

  In the said embodiment, although the separator 7 is a complicated shape, this invention is not limited to this, The separator 7 should just be isolate | separated from the holder | retainer segment 6. FIG. For example, it may be a simple flat plate as shown in FIG.

  In the said embodiment, although the cylindrical roller bearing was demonstrated to the example, this invention is not limited to this, If it is a rolling bearing, it is applicable. For example, the present invention may be applied to other types of rolling bearings such as other types of roller bearings such as tapered roller bearings and ball bearings such as deep groove ball bearings.

  The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Cylindrical roller bearing 2 Outer ring 2a Raceway surface 3 Inner ring 3a Raceway surface 4 Cylindrical roller (rolling element)
5 Retainer 6 Retainer segment 6e Recess 7 Separator 7a Recess 13 Recess 14 Recess g1, g2 Clearance d1, d2 Maximum distance

Claims (13)

An outer ring having a raceway surface on the inner periphery, an inner ring having a raceway surface on the outer periphery facing the raceway surface of the outer ring, and a plurality of members arranged between the raceway surface of the outer ring and the raceway surface of the inner ring In a rolling bearing comprising a rolling element and a cage for holding the rolling element,
The cage is composed of a plurality of cage segments divided in the circumferential direction, each cage segment contains a plurality of rolling elements, and is formed as a separate and independent piece from the cage segment. A rolling bearing comprising: at least one separator movable with respect to the cage segment ; and the separator interposed between the rolling elements.   The rolling bearing according to claim 1, wherein the cage segment is formed by injection molding of resin.   The rolling bearing according to claim 1, wherein the cage segment is configured to be guided by a raceway ring.   The rolling bearing according to claim 3, wherein the cage segment is configured to be guided by an inner ring, and a plurality of concave portions are provided in an inner peripheral portion of the cage segment guided by the inner ring.   The rolling bearing according to any one of claims 1 to 4, wherein a side surface of the separator is shaped to accommodate a part of a rolling element.   With the separator guided by the rolling element and the separator positioned on the pitch circle of the rolling element, the separator can move radially to the raceway side through the gap between the separator and the outer ring raceway surface and the inner ring raceway surface. The rolling bearing according to claim 1, wherein the rolling bearing is larger than a maximum distance.   The rolling bearing according to claim 1, wherein the separator is guided on a raceway surface of an inner ring.   The rolling according to any one of claims 1 to 7, wherein a concave portion is provided in at least one of an outer diameter side end and an inner diameter side end of the separator and communicated in the circumferential direction via the concave portion. bearing.   The rolling bearing according to claim 1, wherein a concave portion for forming a gap between the separator and a rolling element is provided on a side surface of the separator.   The rolling bearing according to claim 1, wherein the separator is made of a resin.   The rolling bearing according to claim 1, wherein the separator is made of a sintered metal.   The rolling bearing according to claim 1, wherein the rolling bearing is a cylindrical roller bearing.   The cage | basket which consists of a cage | basket segment which interposed the separator used for the rolling bearing of any one of Claims 1-12.

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