JP2007198589A - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing with a higher allowable rotational frequency by providing a smooth transverse flow of lubricant in a rolling surface vicinity, and reducing agitating resistance of the lubricant due to spacers, in a rolling bearing with the spacers interposed between rollers. <P>SOLUTION: The rolling bearing is provided with a plurality of rollers 16 interposed so as to freely roll between an inner ring raceway surface and an outer ring raceway surface, and the spacers 18 positioned between adjacent rollers 16. Axial both ends of the spacer 18 have extension parts 18a extended over roller end faces 16b, and contacting the roller end faces 16b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a roller bearing, more specifically, a roller bearing having a spacer interposed between the rollers, and can be used in applications requiring a high load rating, such as a speed increaser for a wind power generator.

Patent Document 1 describes a roller bearing in which a spacer is interposed between rollers. In this type of roller bearing, interposing a spacer in place of the cage allows more rollers to be incorporated into the bearing, and unlike full roller bearings, contact between the rollers can be avoided. It is possible to provide a roller bearing having a load capacity and a relatively high permissible rotational speed. Moreover, since it is not necessary to use a hollow roller unlike a pin type cage, the strength of the roller does not decrease, and welding is not used for assembly, so that the manufacturing cost can be suppressed.
Japanese Patent No. 3549530

  In the roller bearing described in Patent Document 1, 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. Therefore, the agitation resistance of the lubricating oil is large and unsuitable for high-speed rotation. 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 may be hindered.

  The main object of the present invention is to enable a smooth flow of lubricating oil in the vicinity of the rolling surface in a roller bearing having a spacer interposed between the rollers, and to reduce the stirring resistance of the lubricating oil by the spacer. An object of the present invention is to provide a roller bearing having a higher allowable rotational speed.

  The roller bearing according to the present invention is a roller bearing comprising a plurality of rollers rotatably interposed between an inner ring raceway surface and an outer ring raceway surface, and a spacer positioned between adjacent rollers. Both ends in the direction extend beyond the roller end face and have an extended portion in contact with the roller end face. The extended portion is formed, for example, by expanding the end portion of the spacer in the circumferential direction or tangential direction of the roller pitch circle.

  The expansion portion restricts the movement of the spacer in the axial direction, and the radial movement is restricted by the rolling surface of the roller, the outer diameter of the inner ring collar, or the inner diameter of the outer ring collar. In other words, since the inner ring or outer ring raceway surface or collar side surface is not used as the spacer movement restricting means, it is not necessary 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 in the vicinity of the rolling surface is not hindered. As a result, it is possible to provide a roller bearing with a high allowable rotational speed that suppresses heat generation during operation.

  Further, when the spacer is guided by the inner ring collar outer diameter surface or the outer ring collar inner diameter surface, the extended portion serves as a guide surface, so that the guide area is expanded and an oil film is formed on the guide surface compared to the case where the spacer is not expanded. Since it becomes easy, wear of the spacer can be reduced.

  The invention of claim 2 is the roller bearing of claim 1, wherein the circumferential clearance S (see FIG. 1) is 0.001 × Dw × Z ≦ S ≦ when the roller diameter is Dw and the number of rollers is Z. It is within the range of 0.01 × Dw × Z. By adopting such a configuration, it is possible to stabilize the behavior of the spacer while avoiding the disappearance of the circumferential clearance due to the thermal expansion of the spacer and rollers during operation of the bearing, and to suppress vibrations. Can do.

  According to a third aspect of the present invention, in the roller bearing of the first or second aspect, when the maximum value L (see FIG. 4) of the length of the expansion portion of the spacer is 0.2 × Dw when the roller diameter is Dw ≦ L ≦ 0.9 × Dw. The reason why the lower limit is set to 0.2 × Dw is to bring the extended portion into contact with the flat portion that avoids chamfering of the roller end face. The reason why the upper limit is set to 0.9 × Dw is to prevent adjacent spacers from interfering with each other.

  According to a fourth aspect of the present invention, in the roller bearing of any one of the first to third aspects, the spacer extends from the inner diameter side to the outer diameter side of the pitch circle of the roller, and contacts the rolling surface of the roller of the spacer. The cross-sectional shape of the surface to be rolled is a concave shape that receives the rolling surface of the roller. By adopting such a configuration, the movement of the spacer in the radial direction can be restricted only by the roller rolling surface. In other words, it is possible to restrict the movement of the spacer in the radial direction by simply pinching the spacer with rollers without sliding the spacer on the inner ring or the outer ring.

  According to a fifth aspect of the present invention, in the roller bearing of any one of the first to fourth aspects, the spacer is guided by a flange inner diameter surface of the outer ring. According to a sixth aspect of the present invention, in the roller bearing according to any one of the first to fourth aspects, the spacer is guided by a flange outer diameter surface of the inner ring. As described above, the spacer may only be sandwiched between rollers, but the behavior is further stabilized by guiding the spacer to the inner diameter of the outer ring or the outer diameter of the inner ring. If it is only pinched with rollers, the behavior of the spacer located next to the circumferential clearance becomes unstable.

  According to a seventh aspect of the present invention, in the roller bearing according to any one of the first to sixth aspects, an oil groove is provided on a surface (roller contact surface) that contacts the roller of the spacer. By providing an oil groove on the roller contact surface of the spacer, the lubricating oil around the roller can easily enter and exit, and the cooling efficiency of the bearing by the lubricating oil is improved.

  The invention of claim 8 is characterized in that, in the roller bearing according to any one of claims 1 to 7, a concave portion for retaining lubricating oil is provided on a surface (roller contact surface) that contacts the spacer roller. To do. Here, the concave portion includes both a bottomed one and a through hole. By adopting such a configuration, the lubricating oil can be held in the recess, and is particularly suitable for holding grease.

  According to a ninth aspect of the present invention, in the roller bearing according to any one of the first to eighth aspects, the extended portion is provided with a convex portion facing the roller end face. By adopting such a configuration, only the tip of the convex portion comes into contact with the roller end surface, so that the lubricating oil near the roller end surface can be smoothly flowed, and the oil film breakage of the roller end surface can be prevented. Can be suppressed. In other words, the contact area of the end face at the spacer is reduced, and a space is created around the convex part, so that the lubricating oil can flow smoothly, and the lubricating oil is abundant between the roller end face and the raceway collar side face. Since it can be supplied, the occurrence of galling and heat generation can be suppressed.

  According to a tenth aspect of the present invention, in the roller bearing of the ninth aspect, the convex portion faces a portion of the roller end face that avoids a region in contact with the collar of the raceway ring. By adopting such a configuration, the lubricating oil can flow smoothly, and the occurrence of galling and heat generation can be suppressed, and there is no functional damage on the roller end face. Moreover, by providing the contact portion closer to the center of the roller end surface, the sliding speed is reduced, and wear of the tip of the convex portion of the spacer can be reduced.

  The invention of claim 11 is the roller bearing of claim 9 or 10, characterized in that the spacer is made of resin and the convex portion extends perpendicularly to the parting surface of the mold. It is. By adopting such a configuration, the manufacturing cost of the spacer can be suppressed. That is, by avoiding the undercut shape, a complicated mechanism such as a loose core or a slide core is not required, and the mold cost can be simplified by reducing the mold cost.

  According to a twelfth aspect of the invention, in the roller bearing of any one of the ninth to eleventh aspects, the tip of the convex portion is a curved surface. By adopting such a configuration, edge contact with the roller end face can be avoided, and occurrence of oil film breakage can be suppressed.

  According to a thirteenth aspect of the present invention, in the roller bearing according to any one of the first to twelfth aspects, the guide surface provided on the surface of the extended portion of the spacer facing the inner ring surface of the outer ring collar is formed from the inner ring surface of the outer ring collar. Is formed with a small convex shape. When the convex shape is formed by two planes, the radius of curvature refers to the radius of curvature of an arc connecting the intersection of the two planes and the end points of each plane (see FIG. 21. FIG. 21 is a collar portion on the inner ring). This is a diagram of an N type product having a symbol, but is substituted for convenience) By adopting such a configuration, a so-called “wedge film effect” (an effect in which a fluid is drawn into the wedge-shaped gap narrowing in the movement direction by viscosity to generate pressure, that is, load capacity) is adopted in the guide surface. And the occurrence of oil film breakage on the guide surface can be suppressed.

  In addition, as described above, since it is not necessary to slide the spacer on the raceway surface of the inner ring or the outer ring, the formation of the oil film on the rolling surface is not hindered. The area is not restricted by the clearance between the rollers.

  Here, the load capacity of the oil film obtained by the wedge film effect is larger as the guide surface is wider. For example, when the movement direction of the guide surface, that is, the length of the extended portion in the circumferential direction is doubled, the load capacity of the oil film is increased. Can be increased by a factor of four. That is, the expansion part of the spacer has another advantage of expanding the area of the guide surface in addition to the role of regulating the movement of the spacer in the axial direction.

The invention of claim 14 is the roller bearing according to claim 13, when the curvature radius of the outer ring flange inner surface and the _{R 1,} the radius of curvature _{R 2} is 0.3 × _R 1 of said convex _<R 2 <0. it is characterized in that the 6 × is within represented by R _1. By adopting such a configuration, it is possible to suppress the occurrence of oil film breakage on the guide surface. Here, the upper limit is set to 0.6 × R ₁ in order to avoid the edge contact on the guide surface and generate the wedge film effect even if the behavior of the spacer is disturbed. In this type of roller bearing, the behavior of the spacer located next to the circumferential clearance becomes unstable. That is, since the spacer released from the rolling surfaces of the adjacent rollers can move and rotate within the circumferential clearance, the approach angle (wedge angle) of the guide surface is not always constant. Therefore, if the radius of curvature of the convex curved surface of the spacer is too large, in other words, if the wedge angle is too small, depending on the behavior of the spacer, the end portion of the expansion portion may be in edge contact with the inner surface of the outer ring collar or the wedge film. Problems such as ineffectiveness may occur. The reason why the lower limit is set to 0.3 × R ₁ is to ensure the load capacity of the oil film due to the wedge film effect. If the curvature radius of the convex curved surface of the spacer is too small, in other words, if the wedge angle is too large, the load capacity of the oil film obtained by the wedge film effect will be reduced.

  According to a fifteenth aspect of the present invention, in the roller bearing of any one of the first to twelfth aspects, the guide surface provided on the surface of the extended portion of the spacer facing the inner ring collar outer surface is formed in a convex shape. It is a feature. By adopting such a configuration, a “wedge film effect” is generated on the guide surface, and the occurrence of oil film breakage on the guide surface can be suppressed. Further, the edge contact between the end portion of the guide surface of the spacer and the collar outer surface of the inner ring can be avoided.

  The invention according to claim 16 is the roller bearing according to any one of claims 13 to 15, characterized in that a flat portion is provided on the top of the convex shape of the spacer formed by injection molding of a resin material. To do. By adopting such a configuration, it is possible to suppress oil film breakage and wear powder generation on the guide surface.

  In order to reduce the mold cost and make it easy to control the opening and closing of the mold during molding, the parting surface of the mold is a position where the shape of the spacer is bisected symmetrically and the undercut shape is avoided Will be provided. That is, in the case of the spacer, a parting line is provided at a position that passes through the apex of the convex shape and bisects the spacer in the axial direction. However, since parting lines are accompanied by burrs and steps, abrasion powder may be generated due to sliding with the inner surface of the outer ring collar, or oil film may be cut. Therefore, by providing a flat portion at the apex of the convex shape, contact between the parting line of the spacer and the inner surface of the outer ring collar can be avoided.

  The invention of claim 17 is the roller bearing of claim 16, wherein the parting line passes through the flat portion and a position shifted from the center line that bisects the width of the spacer. It is. By adopting such a configuration, the spacer after injection molding can be reliably released from the mold. In order to release the product after injection molding, when the mold is opened, the product needs to be fixed to the core plate (movable mold) side having the protruding pins. However, if the parting line of the mold is provided at a position that bisects the product bilaterally, when the mold is opened, the product may stick to the cavity plate (fixed side mold), There is a problem that the product cannot be released. Therefore, the parting line is slightly shifted from the center line toward the cavity plate, and the contact area between the spacer and the mold is (core plate side)> (cavity plate side). The seat can be securely fixed to the core plate side.

  According to the present invention, the movement of the spacer in the axial direction can be restricted by the expansion portion of the spacer, and the movement in the radial direction can be restricted by the rolling surface of the roller, the inner ring collar outer diameter surface or the outer ring collar inner diameter surface. Therefore, it is not necessary to interpose a spacer between adjacent rollers over a wide area, the stirring resistance of the lubricating oil can be suppressed, and the smooth flow of the lubricating oil near the rolling surface is not hindered. That is, it is possible to provide a roller bearing with a high allowable rotational speed that suppresses temperature rise. In addition, when the spacer is guided by the outer diameter surface of the inner ring collar or the inner diameter surface of the inner ring collar, the extended portion of the spacer serves as a guide surface, so the guide area is expanded and an oil film is formed on the guide surface compared to the case where the spacer is not expanded. Therefore, wear of the spacer can be reduced.

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

  The embodiment shown in FIGS. 1 and 2 is an example applied to a cylindrical roller bearing, and includes an outer ring 12, an inner ring 14, a cylindrical roller 16, and a spacer 18. The cylindrical roller 16 rolls on the raceway surface of the outer ring 12 and the raceway surface of the inner ring 14 on its rolling surface 16a. A spacer 18 is interposed between the adjacent cylindrical rollers 16.

  As can be seen from FIG. 2, the spacer 18 has extended portions 18a at both ends. The extended portion 18a extends in the roller pitch circle tangential direction. The cross-sectional shape of a surface 18b (hereinafter referred to as a roller contact surface) 18b of the spacer 18 that is in contact with the cylindrical roller 16 is slightly larger than the radius of curvature of the rolling surface 16a of the roller 16, as shown in FIG. It is a concave arc with a radius of curvature. As can be seen from FIG. 1, the roller contact surface 18b extends across the roller pitch circle indicated by the alternate long and short dash line, that is, from the inner diameter side to the outer diameter side of the roller pitch circle. Therefore, the movement of the spacer 18 in the radial direction is restricted only by the rolling surface 16 a of the roller 16.

  In the embodiment shown in FIGS. 4 and 5, the extended portion 18 a of the spacer 18 is guided by the inner diameter surface of the collar 12 a of the outer ring 12. Thereby, the behavior of the spacer 18 is stabilized. That is, by supporting the outer diameter of the extended portion 18a of the spacer 18 with the inner peripheral surface of the collar 12a of the outer ring 12, the movement of the spacer 18 in the radial direction is restricted and the behavior is stabilized. The outer peripheral surface of the extended portion 18a is a partial cylindrical surface. Further, the roller contact surface 18b and the inner diameter surface (lower surface) of the spacer 18 are provided with notches 20 for improving the cooling efficiency of the bearing by the lubricant.

If the material of the spacer 18 is 66 nylon (natural) and applied to NJ2324E (φ120 × φ260 × 86), the circumferential clearance S is 1.5 mm. × Dw × Z. The minimum thickness of the spacer 18 is 1.8 mm. At this time, even if the temperature of the bearing rises by 100 ° C., the total thermal expansion of the roller 16 and the spacer 18 is about 1 mm, and the circumferential clearance S (see FIG. 1) is not crushed. Can withstand use under temperature conditions. Incidentally, the linear expansion coefficient of the cylindrical roller (bearing steel) is 12.5 × 10 ⁻⁶ (° C.), and the linear expansion coefficient of the spacer (66 nylon (N)) is 9 × 10 ⁻⁵ (° C.). Moreover, the maximum value L (see FIG. 4) of the length of the end portion of the spacer 18 expanded in the pitch circle tangential direction is 20 mm, and L = 0.5 × Dw in terms of a mathematical expression. At this time, the extended portion 18a comes into contact with the roller end surface 16b at a position beyond the chamfering of the roller 16, and adjacent spacers 18 do not interfere with each other.

Table 1 shows the results of comparing the number of rollers and the bearing life ratio of the example applied to NJ2324E (φ120 × φ260 × 86) and the comparative example (with the machined cage).

FIG. 6 shows a modification of the spacer 18. In this case, as is clear from comparison with FIG. 3, the roller contact surface 18b of the spacer 18 has a concave shape constituted by a combination of straight surfaces. As shown in FIG. 6B, the cross-sectional shape of the roller contact surface 18b is a combination of straight lines.

  When applied to a tapered roller bearing, the roller contact surface of the spacer preferably has a concave slope shape (see FIG. 6C).

  When applied to a spherical roller bearing, the roller contact surface of the spacer is preferably a concave spherical shape (see FIG. 6D).

  FIG. 7 shows a modification of the spacer 18 provided with oil grooves. 7A shows an oil groove 18c provided on the roller contact surface 18b of the spacer 18, and FIG. 7B shows an oil groove 18d provided on the inner surface of the extended portion 18a of the spacer 18. Both oil grooves 18c, 18d can be provided in one spacer 18. The number of oil grooves may be singular or plural and may or may not be parallel to the radial direction of the bearing. Two or more oil grooves may intersect.

  FIG. 8 shows a modification of the spacer 18 provided with a recess for retaining lubricating oil. 8A shows the dimple-like recesses 18e provided on the roller contact surface 18b, and FIG. 8B shows a groove-like recess 18f extending in the longitudinal direction of the roller contact surface 18Bb.

  The oil grooves 18c and 18d and the recesses 18e and 18f can have various cross-sectional shapes. 9A to 9F illustrate the case of V shape, rectangle, trapezoid, arc, and elliptic arc.

  FIG. 10 shows a modification of the spacer 18 provided with the through holes 18g and 18h. A through hole 18g shown in FIG. 10 (A) opens in the roller contact surface 18b of the spacer 18, and a through hole 18h shown in FIG. 10 (B) penetrates the extended portion 18a in the axial direction. The through holes 18g and 18h may be provided at one place or two or more places, and may have various shapes such as a quadrangle, a triangle, a trapezoid, a circle, an ellipse and the like.

  The oil grooves 18c and 18d, the recesses 18e and 18f, and the through holes 18g and 18h provided in the spacer 18 are solid lubricants mainly composed of grease and resin, such as polylube (trade name: NTN Corporation). May be buried.

  The depths of the oil grooves 18c and 18d and the recesses 18e and 18f provided on the roller contact surface 18b of the spacer 18 are set so that the roller diameter is set to Dw in order to avoid the breakage of the spacer 18 and from the requirement of the lubricant retaining property. , It is preferable to set within the range of 0.001 × Dw to 0.1 × Dw, more preferably within the range of 0.01 × Dw to 0.1 × Dw.

  In order to avoid edge contact with the rollers 16, chamfering is preferably provided at the opening edges of the oil grooves 18c and 18d, the recesses 18e and 18f, and the through holes 18g and 18h.

  The occupied area of the oil grooves 18c, 18d, the recesses 18e, 18f and the through holes 18g, 18h is 50% or less of the roller contact area when they are not provided in order to prevent the contact surface pressure at the spacer 18 from increasing. It is preferable to set it to 30% or less.

  The minimum thickness in the cross section perpendicular to the axial direction of the spacer 18 is 0.03 Dw to 0% when the roller diameter is Dw in order to achieve both the avoidance of breakage of the spacer 18 and the high load capacity of the bearing. It is preferable to be within the range of 0.20 Dw. Regarding the lower limit of the numerical range, if it is thinner than 0.03 Dw, there is a risk of breakage, so 0.03 × Dw is set as the lower limit. As for the upper limit, 0.20 Dw corresponds to the thickness of the pillar in the conventional cage, but if it exceeds this, the load capacity decreases, so 0.20 Dw is the upper limit.

  The spacer 18 may be made of resin or metal. Injection molding is preferred as a method for producing the resin spacer. The method for producing the metal spacer is not particularly limited, such as casting, cutting, forging, pressing, etc. However, in terms of production cost, precision casting represented by lost wax or the like is preferable, and forging is particularly highly accurate. It is preferable to perform additional machining by cutting or manufacture from scratch.

  In the case where the spacer 18 is made of metal, a copper-based alloy having relatively good sliding characteristics is preferable than general steel. Carbon steel for mechanical structure such as S30C can also be used. The copper-based alloy used for the spacer is preferably brass, and among these, hexagonal brass and high-strength brass are preferred. High-strength brass is one in which manganese (Mn) is added to hexagonal brass in an amount of 0.1 to 5.0% by weight, and in some cases, components such as Al, Fe, Sn, Ni, etc. are added in some cases. It becomes stronger by solid solution in the α phase and β phase, and the corrosion resistance and wear resistance are also increased.

  When the spacer 18 is made of resin, it is preferable that the resin be injection-moldable, and it is sufficient that the resin composition is injection-moldable even if fibers and other fillers are mixed. In general, a resin material is considered to be preferable as a spacer material because it is lightweight, self-lubricating and has a small friction coefficient. Examples of the resin suitable for the spacer are as follows.

  Polycarbonate (PC), polyamide 6 (PA6), polyamide 66 (PA66), polyacetal (POM), modified polyphenylene ether (modified PPE), polybutylene terephthalate (PBT), GF reinforced polyethylene terephthalate (GF-PET), ultra high molecular weight General-purpose engineering plastics such as polyethylene (UHMW-PE)

  Polysulfone (PSF), Polyethersulfone (PES), Polyphenylene sulfide (PPS), Polyarylate (PAR), Polyamideimide (PAI), Polyetherimide (PEI), Polyetheretherketone (PEEK), Liquid crystal polymer (LCP) ), Thermoplastic polyimide (TPI), polybenzimidazole (PBI), polymethylpentene (TPX), poly 1,4-cyclohexanedimethylene terephthalate (PCT), polyamide 46 (PA46), polyamide 6T (PA6T), polyamide 9T (PA9T), polyamide 11,12 (PA11,12), polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene- Styrene copolymer (ETFE) super engineering plastics typified by

  The above-mentioned general-purpose engineering plastics, super engineering plastics, and phenol resins with cloth are preferable in terms of mechanical strength, oil resistance, and heat resistance.

  In the above-described embodiment, the movement of the spacer 18 in the axial direction is restricted by providing the extended portion 18 a having a surface facing the roller end face at the axial end of the spacer 18. For this reason, the expansion part 18a is in sliding contact with the end face 16b of the roller 16 during operation of the bearing. In particular, when the contact surface is flat, smooth flow of the lubricating oil on the roller end surface 16b is prevented, and the oil film on the roller end surface 16b may be cut by the edge portion of the contour. As a result, there is a shortage of lubricating oil between the roller end surface 16b and the raceway collar surface, which may lead to galling or heat generation. In view of such a problem, in the spacer modification described below, in order to enable smooth flow of the lubricating oil in the vicinity of the roller end face and to suppress the occurrence of oil film breakage on the roller end face, the roller of the spacer 18 The convex part 52 is provided in the contact part with an end surface. As a result, it is possible to provide a roller bearing that reduces the shortage of lubricating oil between the roller end face and the raceway collar face and suppresses the occurrence of galling and heat generation.

  First, in the modified example shown in FIG. 11, a convex portion 52 having a hemispherical tip is provided on the surface of the extended portion 18a of the spacer 18 facing the roller end surface 16b. In this case, the spacer 18 comes into point contact because it contacts the roller end surface 16b at the tip of the convex portion 52, and a space is created around the convex portion 52, so that the lubricating oil can flow smoothly and the oil film breaks. Can be suppressed.

  The modification shown in FIG. 12 is an example in which a convex portion 52 is provided in a portion of the roller end surface 16b that avoids a region (shaded portion) that contacts the collar surface of the raceway, that is, near the center of the roller end surface 16b. is there.

  The modification shown in FIG. 13 is a case where it is applied to a resin spacer produced by injection molding. The convex portion 52 has a substantially semicircular cross-sectional shape, and the longitudinal direction of the convex portion 52 extends perpendicular to the parting surface of the molding die. In this case, as shown in FIG. 14, the spacer 18 can be easily taken out only by opening the upper mold 64 and the lower mold 60 in one direction, that is, in the illustrated vertical direction. In FIG. 14, the parting surfaces of the upper mold 64 and the lower mold 60 are indicated by reference numerals 66 and 62, respectively.

  Note that the number of convex portions 52 may be one or two or more. Or it is good also as a convex part 52 by providing crowning to the whole surface which faces the roller end surface 16b of the expansion part 18a.

  By the way, in this type of roller bearing in which the spacer 18 is interposed between the adjacent rollers 16, when the spacer 18 is brought into contact with the raceway surface of the outer ring 12 or the inner ring 14 and guided to the raceway, an oil film is formed on the rolling surface. May be disturbed. Further, in this type of roller bearing, after the rollers 16 and the spacers 18 are alternately arranged on the inner periphery of the outer ring 12, the last remaining spacer 18 is press-fitted between the rollers 16 for assembly. For this reason, the thickness of the spacer 18 that greatly exceeds the clearance between the rollers 16 cannot be used due to the press-fitting margin, and the area of the guide surface (surface that slides in contact with the raceway surface) of the spacer 18 is inevitably narrow. Become. Therefore, since the load capacity of the oil film due to the so-called “wedge film effect” on the guide surface of the spacer 18 is reduced, the oil film is cut off, which may lead to heat generation of the bearing and abnormal wear of the spacer 18. Therefore, by devising the shape of the spacer 18, smooth flow of the lubricating oil in the vicinity of the rolling surface is possible, and furthermore, by suppressing the occurrence of oil film breakage on the guide surface of the spacer 18, heat generation of the bearing, There is a need to provide a roller bearing with a high permissible rotational speed that avoids abnormal wear of the spacer.

  In the embodiment shown in FIGS. 15 and 16, the guide surface 54 provided on the surface of the extended portion 18 a of the spacer 18 facing the inner diameter surface of the collar 12 a of the outer ring 12 is provided, and the radius of curvature is the inner diameter of the collar 12 a of the outer ring 12. It is formed with a convex curved surface smaller than the surface. In the embodiment shown in FIGS. 20 and 21, the guide surface 54 provided on the surface of the extended portion 18a of the spacer 18 facing the outer diameter surface of the collar 14a of the inner ring 14 is formed in a convex shape. is there. By adopting such a configuration, the lubricating oil can flow smoothly in the vicinity of the rolling surface, and the so-called “wedge film effect” (the wedge-shaped gap narrowing in the direction of motion) (The effect of generating pressure, that is, load capacity) due to viscosity being drawn, and the occurrence of oil film breakage on the guide surface 54 can be suppressed.

  Further, since it is not necessary to slide the spacer 18 on the raceway surface of the inner ring 14 or the outer ring 12, the formation of an oil film on the rolling surface is not hindered. Further, the area of the guide surface 54 is determined by the clearance between the rollers 16. There are no restrictions (see FIG. 15). Here, the load capacity of the oil film obtained by the wedge film effect is larger as the guide surface is wider. For example, when the movement direction of the guide surface, that is, the length of the extended portion in the circumferential direction is doubled, the load capacity of the oil film is increased. Can be increased by a factor of four. In other words, the expansion portion of the spacer has another advantage of expanding the area of the guide surface in addition to the role of regulating the movement of the spacer in the axial direction (see FIG. 16). In addition, as shown in FIG. 16, it is desirable to chamfer the end portion of the extended portion 18a, in particular, the outer diameter side end edge portion facing the circumferential direction of the bearing.

Further, the length of the extended portion 18 is set such that adjacent spacers do not interfere with each other while ensuring the load capacity of the oil film on the guide surface 54. As a specific example, when the roller diameter is Dw, the length L of the expanded portion is preferably within the range represented by the following formula.
0.5 × Dw ≦ L ≦ 0.9 × Dw

The radius of curvature R ₂ of the guide surface (convex curved surface) 54 of the spacer 18 is 0.3 × R ₁ <R ₂ <0.6 ×, where R ₁ is the radius of curvature of the inner diameter surface of the collar 12 b of the outer ring 12. preferably within the range represented by R _1. FIG. 17 shows the behavior of the spacer 18 located next to the circumferential clearance. The radius of curvature R ₂ of the guide face 54 that within the above range, even if disturbed orientation of the spacer 18 at the spacer 18 is the guide surface 54 into contact with the radially inner surface of the outer ring 12 collar 12b can do. The upper limit is set to 0.6 × R ₁ in order to avoid the edge contact on the guide surface 54 and generate the wedge film effect even when the behavior of the spacer 18 is disturbed. In this type of roller bearing, as indicated by a two-dot chain line in FIG. 17, the behavior of the spacer 18 located next to the circumferential clearance becomes unstable. That is, since the spacer 18 released from the rolling surfaces of the adjacent rollers 16 can move and rotate in the circumferential clearance, the approach angle (wedge angle) of the guide surface 54 is not always constant. . Thus, the radius of curvature R ₂ of the guide surface (convex surface) 54 of the spacer 18 is too large, the approach angle when (a wedge angle) is too small, depending on the behavior of the spacer 18 distal portion of the extension portion 18a in other words In some cases, the outer ring collar may come into edge contact with the inner diameter surface, or the wedge film effect may not be obtained. The reason why the lower limit is set to 0.3 × R ₁ is to ensure the load capacity of the oil film due to the wedge film effect. If the radius of curvature of the guide surface (convex curved surface) of the spacer 18 is too small, in other words, if the approach angle (wedge angle) is too large, the load capability of the oil film obtained by the wedge film effect is reduced.

  FIG. 18 shows the positions (parting lines) of the parting surfaces 62 and 66 of the molds 60 and 64 when the spacer 18 is formed by injection molding. As illustrated, an undercut shape can be avoided by providing a parting line at the center of the width of the guide surface (convex curved surface) 54.

  In the embodiment shown in FIG. 19, a flat portion 56 is provided at the apex of the guide surface (convex curved surface) 54 of the spacer 18. By providing the flat portion 56, a space is created between the outer ring collar inner diameter surface, and therefore, sliding between the burr existing on the parting line 58 and the outer ring collar inner diameter surface can be avoided. The occurrence of oil film breakage and wear powder on the (curved surface) 54 can be suppressed. In order to reduce the mold cost and facilitate the mold opening and closing control at the time of molding, the parting surfaces 62 and 66 of the molds 60 and 64 bisect the shape of the spacer 18 bilaterally, And it will provide in the position which avoided the undercut shape. That is, as will be described with reference to FIG. 19, a parting line is provided at the position of the two-dot chain line that passes through the apex of the guide surface (convex curved surface) 54 and bisects the width of the spacer 18. However, since parting lines are accompanied by burrs and steps, abrasion powder may be generated due to sliding with the inner surface of the outer ring collar, or oil film may be cut. Therefore, by providing the flat portion 56 at the apex of the guide surface (convex curved surface) 54, it is possible to avoid contact between the parting line of the spacer 18 and the inner surface of the outer ring collar.

  Further, as shown in FIG. 19, the parting line 58 is slightly shifted from the center line (two-dot chain line) in the flat portion 54 and the width of the spacer 18 into two parts. The spacer 18 after injection molding can be reliably released from the molds 60 and 64 while avoiding the cut shape. In order to release the product after injection molding, when the mold is opened, the product needs to be fixed to the core plate (movable mold) side having the protruding pins. However, if the parting line of the mold is provided at a position that bisects the product bilaterally, when the mold is opened, the product may stick to the cavity plate (fixed side mold), There is a problem that the product cannot be released. Therefore, the parting line is slightly shifted from the center line toward the cavity plate, and the contact area between the spacer and the mold is (core plate side)> (cavity plate side). The seat can be securely fixed to the core plate side.

Schematic diagram of a roller bearing showing an embodiment of the present invention Broken perspective view of the roller bearing of FIG. (A) is a perspective view of a spacer, (B) is a sectional view of the spacer of FIG. 3 (A). Front view of a roller bearing showing another embodiment (A) is a cutaway perspective view of the roller bearing of FIG. 4, (B) is a perspective view of a spacer. (A) is a perspective view showing a modification of the spacer, (B) is a sectional view of the spacer of FIG. 6 (A), (C) is a perspective view showing a modification of the spacer, and (D) is a spacer. The perspective view which shows the modification of The perspective view which shows the modification of a spacer The perspective view which shows the modification of a spacer An enlarged cross-sectional view illustrating the cross-sectional shape of the oil groove and recess The perspective view which shows the modification of the spacer provided with the through-hole (A) is a plan view showing a modification of the spacer, (B) is a perspective view The perspective view which shows another modification of a spacer The perspective view which shows another modification of a spacer Exploded perspective view of the spacer and mold shown in FIG. Broken perspective view of a roller bearing showing another embodiment The perspective view of the spacer in FIG. Partial side view of the roller bearing of FIG. Perspective view of spacer mold release process Enlarged side view of the spacer Longitudinal sectional view showing an embodiment applied to an N type cylindrical roller bearing (A) is a partially broken side view of the cylindrical roller bearing of FIG. 20, (B) is a partially enlarged view.

Explanation of symbols

12 outer ring 12a collar 12b annular step part 14 inner ring 14a collar 16 roller 16a rolling surface 16b end face 18 spacer 18a expansion part 18b roller contact surface 18c oil groove 18d oil groove 18e recess 18f recess 18g through hole 52h notch through hole 52 notch Convex part 54 Guide surface (convex surface)
56 Flat part 58 Parting line 60, 64 Mold 62, 66 Parting surface

Claims (17)

  In a roller bearing that includes a plurality of rollers that are freely rollable between an inner ring raceway surface and an outer ring raceway surface, and a spacer that is positioned between adjacent rollers, both axial ends of the spacer exceed the roller end face. A roller bearing having an extended portion extending in contact with the roller end surface.   The roller bearing according to claim 1, wherein the circumferential clearance S is in a range of 0.001 × Dw × Z ≦ S ≦ 0.01 × Dw × Z, where Dw is the roller diameter and Z is the number of rollers.   3. The roller bearing according to claim 1, wherein the maximum value L of the length of the expanded portion is in a range of 0.2 × Dw ≦ L ≦ 0.9 × Dw when the roller diameter is Dw.   The spacer extends from an inner diameter side to an outer diameter side of a pitch circle of the roller, and a cross-sectional shape of a surface of the spacer that contacts the roller rolling surface is a concave shape that receives the roller rolling surface. 1 to 3 roller bearings.   The roller bearing according to any one of claims 1 to 4, wherein the spacer is guided by a flange inner diameter surface of an outer ring.   The roller bearing according to claim 1, wherein the spacer is guided by a flange outer diameter surface of an inner ring.   7. The roller bearing according to claim 1, wherein an oil groove is provided on a surface of the spacer that contacts the roller.   The roller bearing according to any one of claims 1 to 7, wherein a concave portion for retaining lubricating oil is provided on a surface of the spacer that contacts the roller.   The roller bearing according to claim 1, wherein the extended portion is provided with a convex portion facing the roller end face.   The roller bearing according to claim 9, wherein the convex portion faces a portion of the roller end face that avoids a region in contact with a collar of the race.   The roller bearing according to claim 9 or 10, wherein the spacer is made of resin, and the convex portion extends perpendicularly to the parting surface of the mold. The roller bearing according to claim 9, wherein a tip of the convex portion is a curved surface.   The roller bearing according to any one of claims 1 to 12, wherein a guide surface provided on a surface of the expansion portion of the spacer facing the inner surface of the outer ring collar is formed in a convex shape having a smaller radius of curvature than the inner surface of the outer ring collar. When the curvature radius of the outer ring flange inner surface and the _{R 1,} claim curvature radius _{R 2} of the convex is within the range expressed by _{0.3 × R 1 <R 2 <} 0.6 × R 1 13 Roller bearings.   The roller bearing according to any one of claims 1 to 12, wherein a guide surface provided on a surface facing the outer diameter surface of the inner ring collar of the expansion portion of the spacer is formed in a convex shape.   The roller bearing according to any one of claims 13 to 15, wherein a flat portion is provided at the top of the convex shape of the spacer formed by injection molding of a resin material.   The roller bearing according to claim 16, wherein the parting line passes through a position shifted from the center line that bisects the width of the spacer in the flat portion.

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