JP2007247849A - Cylindrical roller bearing with aligning ring for agitator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical roller bearing with aligning ring for agitator with high load rating and reduced surface damage of rollers. <P>SOLUTION: The cylindrical roller bearing with aligning ring for agitator comprises: an inner ring 12; an outer ring 14 having an outer diameter face in a projecting spherical shape; an aligning ring 20 including the outer ring 14 and having an inner diameter face in a recessed spherical shape; a plurality of rollers 16 inter posed freely rotatably between an inner ring raceway surface and an outer ring raceway surface; and spacers 18 interposed between adjacent rollers 16. Extended parts 18b having a surface facing roller end surface 16b are disposed at both ends in axial direction of the spacers 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylindrical roller bearing with a centering ring suitable for supporting a stirring shaft of a large stirrer.

  Large stirrers used for kneading and stirring chemical substances such as polyethylene generally have a long stirring shaft and a long distance between the support bearings, and therefore the stirring shaft tends to be greatly bent during operation. For this reason, the support bearing for the stirring shaft is required to have alignment enough to allow the shaft to bend. Furthermore, since the temperature inside the stirring tank is as high as about 150 ° C., it is necessary to allow thermal expansion of the shaft. Therefore, as the support bearing for the stirring shaft, there is a cylindrical roller bearing with an aligning ring as shown in Patent Document 1, which has the aligning property of a self-aligning roller bearing and the ability to move the cylindrical roller bearing in the axial direction. It is used a lot.

  As shown in FIG. 7, the roller bearing with a centering ring described in Patent Document 1 has a structure in which a centering ring is added to the outer periphery of the cylindrical roller bearing. That is, the inner ring 2, the outer ring 4, the plurality of cylindrical rollers 6, the cage 8, and the aligning ring 10 are included. The inner ring 2 has a cylindrical shape, and a track is formed on the outer periphery of the cylindrical shape. The outer ring 4 is formed with ribs on both sides of the inner circumferential track, and the outer circumferential surface is partially spherical. Between the race of the inner ring 2 and the race of the outer ring 4, a cylindrical roller 6 is interposed so as to be able to roll and is held at a predetermined interval by a cage 8. The aligning ring 10 is in spherical contact with the partial spherical outer peripheral surface of the outer ring 4 at the partial spherical inner peripheral surface. Therefore, it is possible to move in the axial direction between the inner ring 2 and the cylindrical roller 6, and furthermore, a centering action can be exerted between the outer ring 4 and the aligning ring 10.

Patent Document 2 describes a cylindrical roller bearing that employs a spacer instead of a cage.
JP 2001-271832 A Japanese Patent No. 3549530

Cylindrical roller bearings with aligning rings require a space to provide aligning rings in addition to the inner and outer rings, so the roller diameter cannot be increased, and the rated load is significantly inferior to that of self-aligning roller bearings of the same size. . Here, since the rotational speed of the stirring shaft is as low as several min ⁻¹ , the cylindrical roller bearing with the aligning ring can increase the rated load by using a total rolling element bearing. Since adjacent rollers contact each other by reverse rotation, there is a risk of causing surface damage called smearing on the rollers. In particular, bearings close to agitation tanks are exposed to high temperatures, so the grease in the bearings tends to soften, and in combination with the conditions of low-speed rotation, an oil film is unlikely to form on the rolling surface and smearing damage is likely to occur. There is a tendency. Further, since the rolling element bearing does not have a cage, the place where either the outer ring or the inner ring is removed is dropped, so the aligning ring + outer ring + roller subassembly and inner ring (or inner ring + roller sub) The assembly and the aligning ring + outer ring subassembly) cannot be separately attached to the apparatus, and the handling is not good.

  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 provided. In addition to being able to hold a large amount of lubricant between the rollers, there is a risk that the spacer will stretch between the flange side surfaces of the raceway ring due to thermal expansion during operation. Furthermore, since the spacer is slid on the raceway surface of the inner ring or the outer ring, there is a possibility that smooth oil film formation on the rolling surface is impaired.

  A main object of the present invention is to provide a cylindrical roller bearing with a centering ring for a stirrer having a high rated load and reduced surface damage of the roller.

  The cylindrical roller bearing with an aligning ring for a stirrer of the present invention includes an inner ring, an outer ring having a convex spherical outer surface, a aligning ring containing the outer ring and a concave spherical inner surface, an inner ring raceway surface and an outer ring raceway. In a cylindrical roller bearing with a centering ring that includes a plurality of rollers that are movably interposed between the rollers and a spacer between adjacent rollers, an extended portion that faces the roller end surface at both axial ends of the spacer. It is characterized by providing. By adopting such a configuration, more rollers can be incorporated in the bearing, and a cylindrical roller bearing with a centering ring having a high rated load 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 not easily inhibited, and surface damage such as galling and smearing. Can be greatly reduced.

  In addition, by providing the extension portions having surfaces facing the roller end surfaces at both ends in the axial direction of the spacer, the movement of the spacers in the axial direction can be restricted by the extension portions and the end surfaces. The radial movement can be regulated by the roller rolling surface, the inner ring collar outer diameter or the outer ring collar inner diameter. That is, since the raceway surface and the collar side surface of the inner ring and outer ring are not used as spacer movement restricting means, it is not necessary to interpose the spacer over a wide area between adjacent rollers, and a large amount of lubricant is held between the rollers. be able to. Further, even when the bearing is exposed to a high temperature, the gap between the extended portion of the spacer and the end surface is not crushed. Furthermore, when the spacer is guided to the outer diameter of the inner ring collar or the inner diameter of the outer ring collar, the expansion portion also exerts an effect of expanding the guide area, so that an oil film is easily formed on the guide surface.

  The invention of claim 2 is a cylindrical roller bearing with a centering ring for a stirrer according to claim 1, wherein 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 guided by the inner ring collar outer diameter surface or outer ring collar inner diameter surface, and when the spacer is sandwiched between adjacent rollers, there is a clearance between the spacer and the inner ring collar outer diameter surface or outer ring collar inner diameter surface. It is characterized by. When the spacer is sandwiched between rollers on the raceway surface, the position of the spacer in the bearing radial direction is determined with the concave bottom as a contact position. At that time, by setting so that there is a gap between the spacer and the bearing ring, it is possible to avoid a state in which the spacer is pressed against the bearing ring by adjacent rollers. That is, with the above settings, the spacer is basically a roller guide, and only the spacer located in the circumferential clearance of the bearing is released from the restraint of the adjacent roller. If it is low, the specification is guided to the rollers. Since the released spacer has no force in the bearing radial direction other than its own weight and centrifugal force, heat generation and wear on the guide surface of the spacer can be reduced. In particular, when used in grease lubrication, the inner ring collar outer diameter surface or the spacer guide surface in contact with the outer ring collar inner diameter surface is liable to suffer from poor lubrication, so that the application of the present invention is desirable.

  According to a third aspect of the present invention, in the cylindrical roller bearing with an aligning ring for the stirrer according to the first or second aspect, the surface of the spacer facing the inner ring surface of the outer ring collar is convex with a curvature radius smaller than the curvature radius of the outer ring collar inner diameter. It is characterized by a curved surface. According to a fourth aspect of the present invention, in the cylindrical roller bearing with a centering ring for an agitator according to the first or second aspect, the surface of the spacer facing the outer diameter surface of the inner ring collar is larger than the radius of curvature of the outer diameter of the inner ring collar. It is a concave curved surface with a radius of curvature. By adopting such a configuration, a so-called “wedge film effect” (an effect in which fluid is drawn into the wedge-shaped gap narrowing in the moving direction by viscosity to generate pressure, that is, load capacity) is obtained. Heat generation and wear on the seat guide surface can be reduced.

  According to a fifth aspect of the present invention, in the cylindrical roller bearing with an aligning ring for agitator according to any one of the first to fourth aspects, 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 when the inner ring is removed, and the inner ring can be assembled separately. In other words, it is possible to assemble the inner ring with the inner ring as a shaft, the aligning ring and the outer ring sub-assemblies attached to the housing in advance, and the inner ring inserted with the shaft. That is, the same assembly as a conventional cylindrical roller bearing with a cage is possible.

  A sixth aspect of the present invention is the cylindrical roller bearing with a centering ring for agitator according to any one of the first to fifth aspects, wherein the inner ring and the outer ring are heat-treated. By adopting such a configuration, it is possible to suppress changes in the dimensions of the bearing in a high temperature atmosphere. As a specific example of the heat treatment, high-temperature tempering after quenching can be mentioned.

  A seventh aspect of the invention is the cylindrical roller bearing with an aligning ring for agitator according to any one of the first to sixth aspects, wherein silicon-based grease or fluorine-based grease is enclosed. By adopting such a configuration, it is possible to extend the life of grease under a high temperature atmosphere, and thus it is possible to extend the life of the bearing.

  According to an eighth aspect of the present invention, in the cylindrical roller bearing with an aligning ring for an agitator according to any one of the first to seventh aspects, a lubricant retaining portion is provided in the spacer. The lubricant holding part is intended to hold the lubricant, and may take various forms such as a bottomed recess, a groove, a through hole, and the like.

  A ninth aspect of the present invention is the cylindrical roller bearing with an aligning ring for an agitator according to any one of the first to eighth aspects, wherein the spacer is formed of silicon resin or fluororesin. By adopting such a configuration, surface damage such as galling or smearing of the roller rolling surface can be greatly reduced. The resin material is not only suitable for manufacturing the spacer, but generally has excellent self-lubricating properties and smoothly slides on the roller rolling surface. Especially, since a silicon resin and a fluororesin are excellent in heat resistance, the strength reduction in a high temperature atmosphere can be suppressed.

  According to a tenth aspect of the present invention, in the cylindrical roller bearing with an aligning ring for a stirrer according to any one of the first to eighth aspects, the spacer is formed of a sintered alloy. By adopting such a configuration, surface damage such as galling or smearing of the roller rolling surface can be greatly reduced. Similar to the above-mentioned resin, the sintered alloy is suitable for the production of the spacer, and since the pores can be impregnated with the lubricant, the sintered alloy slides smoothly on the roller rolling surface. Furthermore, since the linear expansion coefficient is relatively small, thermal expansion in a high temperature atmosphere can be suppressed.

  According to the present invention, a cylindrical roller bearing with a centering ring having a high rated load and reduced roller surface damage can be provided as a support bearing for a stirring shaft of a large stirrer. Can contribute to improvement.

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

  The cylindrical roller bearing with aligning ring shown in FIG. 1 includes an inner ring 12, an outer ring 14, a cylindrical roller 16, a spacer 18, and an aligning ring 20 as main components. The inner ring 12 is cylindrical, and the outer peripheral surface of the cylindrical shape is a raceway surface. The outer ring 14 has both collars, and collars are formed on both sides of the track. The cylindrical roller 16 can roll between the track of the inner ring 12 and the track of the outer ring 14, and the rolling surface is indicated by reference numeral 16a. The end surface 16b of the cylindrical roller 16 is in contact with the inner surface of the collar of the outer ring 14. The outer peripheral surface of the outer ring 14 is partially spherical, while the inner peripheral surface of the aligning ring 20 is also partially spherical, and the two are spherically fitted.

  By subjecting the inner ring 12, the outer ring 14 and the cylindrical roller 16 to a heat-resistant treatment, for example, high temperature tempering after quenching, it is possible to suppress changes in the dimensions of the bearing in a high temperature atmosphere. In addition, by enclosing silicon-based grease or fluorine-based grease, it is possible to extend the grease life under a high temperature atmosphere, and thus extend the bearing life. Examples of silicone greases include “FS345 No. 2” manufactured by Dow Corning and “SH33L” manufactured by Toray Silicone. Examples of fluorine-based grease include “Varielta L55 / 2” manufactured by NOK Kluber. Can be mentioned.

  A spacer 18 is interposed between the adjacent cylindrical rollers 16. The spacer 18 is generally plate-shaped, and a surface that contacts the rolling surface 16a of the cylindrical roller 16, that is, a roller contact surface is indicated by reference numeral 18a. The cross-sectional shape of the roller contact surface 18a is a concave shape that receives the rolling surface 16a of the cylindrical roller 16, for example, a concave arc shape. When assembled in the bearing, the roller contact surface 18a of the spacer 18 extends in the bearing radial direction across the pitch circle of the cylindrical roller 16. Accordingly, the spacer 18 can be guided only by the cylindrical roller 16, that is, a roller guide. However, in the following embodiment, as shown in FIG. 4, specifications for guiding the inner diameter surface of the collar of the outer ring 14 will be described. .

  As shown in FIG. 2, extended portions 18 b are formed at both ends in the longitudinal direction of the spacer 18, and the inner surfaces of the extended portions 18 b facing each other face the end surface 16 b of the cylindrical roller 16 in a state where they are assembled in the bearing. . Thus, the movement of the spacer 18 in the bearing axial direction is restricted by the interference between the extended portion 18 b of the spacer 18 and the cylindrical roller 16. The upper surface of the expansion portion 18 of the spacer 18, that is, the surface facing the radially outer side of the bearing when incorporated in the bearing faces the inner diameter surface of the collar of the outer ring 14 as shown in FIG. 4. As described above, the spacer 18 can be guided by the inner diameter surface of the collar of the outer ring 14 during the operation of the bearing. The surface of the spacer 18 facing the inner diameter surface of the outer ring 14 is a convex curved surface, and its radius of curvature is set smaller than the radius of curvature of the inner diameter surface of the outer ring 14. Therefore, a wedge film effect of the lubricating oil is generated between the spacer 18 and the collar of the outer ring 14, and wear of the spacer 18 is reduced. In addition, it is desirable to provide chamfering at the edge of the extended portion 18b facing the circumferential direction of the bearing in order to avoid edge contact with the flange inner diameter surface of the outer ring 14.

  The roller contact surface 18 a of the spacer 18 has a concave shape extending across the pitch circle of the cylindrical roller 16, and the spacer 18 is guided by the flange inner diameter surface of the outer ring 14. In this case, when the spacer 18 is sandwiched between the cylindrical rollers 16 on the raceway surface of the outer ring 14, the position of the spacer 18 in the bearing radial direction is determined with the bottom of the concave roller contact surface 18a as the contact position. At that time, by setting so that there is a clearance Sr (FIG. 4) between the spacer 18 and the inner ring surface of the race ring, here the outer ring 14, the cylinder 18 adjacent to the spacer 18 as shown in FIG. A state where the roller 16 is pressed against the race ring 14 can be avoided. That is, the spacer 18 basically serves as a roller guide by the above setting, and only the spacer 18 located in the circumferential clearance of the bearing is released from the restraint of the adjacent cylindrical roller 16, and when the rotational speed is high, the outer ring In the inner diameter surface of the collar 14, the specification is such that it is guided to the rollers when it is low. Since no force in the bearing radial direction acts on the released spacer 18 other than its own weight and centrifugal force, heat generation at the guide surface of the spacer 18 (the surface contacting the inner diameter surface of the inner ring collar or the inner diameter surface of the outer ring collar) Wear is reduced.

  As shown in FIG. 4, in the case of the outer ring guide, the surface of the spacer 18 that faces the inner diameter surface of the outer ring 14 is a convex curved surface having a curvature radius R1 that is smaller than the curvature radius R2 of the inner diameter surface of the outer ring 14. Is preferred. Although illustration is omitted, in the case of the inner ring guide, the surface of the spacer 18 facing the outer diameter surface of the inner ring 12 is a concave curved surface having a radius of curvature larger than the radius of curvature of the outer diameter surface of the inner ring 12. Is preferred. By adopting such a configuration, a so-called “wedge film effect” (an effect in which a fluid is drawn into a wedge-shaped clearance narrowing in the direction of motion by viscosity to generate pressure, that is, a load capacity) is obtained. Heat generation and wear on the guide surface of the seat 18 (the inner ring collar outer diameter surface or the outer ring collar inner diameter surface) are reduced.

  By making the cylindrical roller 16 and the spacer 18 exhibit the keystone effect, it is possible to create a specification in which the cylindrical roller 16 and the spacer 18 are not dropped even if the inner ring 12 is removed. Accordingly, the inner ring 12 can be assembled separately, that is, the inner ring 12 can be assembled in advance by attaching the sub-assembly of the aligning ring 20, the outer ring 14 and the cylindrical roller 16 to the housing and inserting the inner ring 12 together with the shaft. . That is, by setting the circumferential clearance S (the clearance that is generated in the circumferential direction when the rolling elements are brought into contact with the adjacent rolling elements) within a predetermined range, the circumferential clearance is increased by increasing the temperature during operation. Further, the keystone effect is exhibited by the cylindrical roller 16 and the spacer 18 so that the cylindrical roller 16 and the spacer 18 are not dropped from the outer ring 14 even when the inner ring 12 is pulled out. As shown in FIG. 5, the condition for exhibiting the keystone effect is that the cylindrical rollers 16 and the spacers 18 are alternately arranged on the inner periphery of the outer ring 14, and the last one cylindrical roller 16 is arranged. When the sum of the diameter and the thickness of the pair of spacers 18 that should be positioned on both sides of the diameter is A and the distance between the ends of the arranged roller rows is Sc, A> Sc.

  FIG. 5 illustrates an assembling process of the cylindrical roller bearing with the aligning ring. The assembly procedure will be described with reference to the embodiment of FIG. 1 as an example. The rollers 16 and the spacers 18 are alternately arranged on the inner periphery of the outer ring 14, and the bearings 18 on the rolling surfaces 16 a of the rollers 16 on which the spacers 18 to be positioned on both sides of the roller 16 to be assembled are arranged. The roller 16 is assembled while sliding the spacer 18 on both sides by pushing the last roller 16 toward the outer ring 14 along the side. The surface of the spacer 18 facing the roller rolling surface 16a, that is, the roller contact surface 18a has a concave shape for receiving the roller rolling surface 16a. In addition, when inserting the last roller 16 toward the outer ring | wheel 14, since the expansion part 18b of the both ends of the spacer 18 can be hooked on the roller end surface 16b, the spacer 18 is also during the time the spacer 18 is slid. Does not shift in the axial direction, and workability is significantly improved.

  FIG. 6 shows various modifications in which the spacer 18 is provided with a lubricant holding portion 18c for the purpose of holding the lubricant. FIG. 6A shows an example in which the roller contact surface 18a is provided with a lubricant holding portion 18c in the form of recesses independent of each other. FIG. 6B shows an example in which the lubricant contact portion 18c in the form of two grooves extending in the longitudinal direction of the spacer 18, in other words, in the bearing axial direction, is provided on the roller contact surface 18a. FIG. 6C shows an example in which a lubricant holding portion 18c in the form of two grooves extending in the bearing radial direction and spaced apart in the bearing axial direction is provided on the roller contact surface 18a. FIG. 6D shows an example in which a lubricant retaining portion 18c in the form of a groove extending in the bearing radial direction is provided on the inner surface of the expanded portion 18b. FIG. 6E shows an example in which a lubricant holding portion 18c in the form of a through hole is provided on the roller contact surface 18a. FIG. 6F shows an example in which a lubricant holding portion 18c in the form of a notch is provided on the upper and lower portions of the roller contact surface 18a, in other words, on the outer side and the inner side in the bearing radial direction. The lubricant holding portions exemplified here can be employed separately or in appropriate combinations.

  The material of the spacer 18 may be a resin or a metal. When the spacer 18 is formed of silicon resin or fluororesin, surface damage such as galling or smearing of the roller rolling surface can be greatly reduced. The resin material is not only suitable for the production of the spacer 18, but generally has an excellent self-lubricating property and slides smoothly on the roller rolling surface 16a. Especially, since a silicon resin and a fluororesin are excellent in heat resistance, the strength reduction in a high temperature atmosphere can be suppressed.

  When the spacer 18 is formed of a sintered alloy, surface damage such as galling or smearing of the roller rolling surface can be greatly reduced. Similar to the above-mentioned resin, the sintered alloy is suitable for the production of the spacer 18, and since the pores can be impregnated with a lubricant, the sintered alloy slides smoothly on the roller rolling surface 16a. Furthermore, since the linear expansion coefficient is relatively small, thermal expansion in a high temperature atmosphere can be suppressed. The method for producing the sintered alloy may be solid phase sintering or liquid phase sintering. In the case of solid phase sintering, the pores can be effectively impregnated with the lubricant. In the case of liquid phase sintering, the climate seen in solid phase sintering can be filled with a metal having a low melting point, and the strength of the spacer can be improved. For example, the sintered base material is iron and the sealing metal is copper.

Broken perspective view of cylindrical roller bearing with aligning ring showing an embodiment An enlarged perspective view of a spacer in the bearing of FIG. Partial side view of cylindrical roller bearing without aligning ring Partial side view of the bearing of FIG. 1 without the aligning ring 1 is a cross-sectional view showing the assembly process of the bearing of FIG. Perspective view showing various modifications of the spacer Cross-sectional view of cylindrical roller bearing with aligning ring showing conventional technology

Explanation of symbols

12 Inner ring 14 Outer ring 16 Roller 16a Rolling surface 16b End surface 18 Spacer 18a Roller contact surface 18b Expansion portion 18c Recess 20 Centering ring

Claims (10)

  An inner ring, an outer ring having a convex spherical outer surface, an aligning ring that includes the outer ring and having a concave spherical inner surface, and a plurality of rollers that are rotatably disposed between the inner ring raceway surface and the outer ring raceway surface. And a cylindrical roller bearing with a centering ring having a spacer between adjacent rollers, and a cylindrical roller bearing with a centering ring for a stirrer provided with an extended portion facing the roller end surface at both axial ends of the spacer.   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 guided by the inner ring collar outer diameter surface or the outer ring collar inner diameter surface, The cylindrical roller bearing with an aligning ring for an agitator according to claim 1, wherein there is a gap between the spacer and the inner ring collar outer diameter surface or the outer ring collar inner diameter surface when the spacer is sandwiched.   The cylindrical roller bearing with an aligning ring for a stirrer according to claim 1 or 2, wherein a surface of the spacer facing the inner diameter surface of the outer ring collar is a convex curved surface having a curvature radius smaller than the curvature radius of the inner diameter of the outer ring collar.   The cylindrical roller bearing with a centering ring for an agitator according to claim 1 or 2, wherein a surface of the spacer facing the outer diameter surface of the inner ring collar is a concave curved surface having a radius of curvature larger than that of the inner ring collar.   The cylindrical roller bearing with a centering ring for an agitator according to any one of claims 1 to 4, wherein a keystone effect is exhibited by the roller and the spacer.   The cylindrical roller bearing with an aligning ring for a stirrer according to any one of claims 1 to 5, wherein the inner ring and the outer ring are heat-treated.   The cylindrical roller bearing with an aligning ring for a stirrer according to any one of claims 1 to 6, wherein silicon-based grease or fluorine-based grease is enclosed.   The cylindrical roller bearing with an aligning ring for an agitator according to any one of claims 1 to 7, wherein a lubricant retaining portion is provided in the spacer.   The cylindrical roller bearing with an aligning ring for an agitator according to any one of claims 1 to 8, wherein the spacer is formed of silicon resin or fluorine resin.   The cylindrical roller bearing with a centering ring for an agitator according to any one of claims 1 to 8, wherein the spacer is formed of a sintered alloy.

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