Roller and needle roller bearings

Abstract

To provide a roller bearing and a needle roller bearing capable of suppressing a reduction in the strength of a pillar part while improving a basic dynamic (static) rated load with an increase in the number of rollers.SOLUTION: To enlarge an area on the pocket inner side, the opposed faces of the pillar part opposed to each other along the peripheral direction are formed as inclined faces to set a roller filling rate on the pitch circle of a roller to be equal to or higher than 93% and lower than 100%. A>(B+rs) is established, where B is the peripheral length of the pillar part on the contact pitch circle between the roller and the pillar part in a site corresponding to a final clearance formed between rollers peripherally neighboring each other on the pitch circle, A is a distance between the rollers neighboring each other along the peripheral direction, and rs is the size of the final clearance. C>D is also established, where D is the peripheral length of the pillar part on the contact pitch circle in a site where the rollers neighboring each other along the peripheral direction contact each other, and C is a distance between the rollers neighboring each other along the peripheral direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roller bearing and a needle roller. [Background technology]

[0002] A conventional roller bearing is a large load capacity roller bearing used for slowing down the rotation of a hydraulic motor installed in a construction machine (Patent Document 1). That is, the roller bearing described in Patent Document 1 has a plurality of rollers 1 arranged circumferentially and held at equal intervals by a cage 2, as shown in Fig. 14.

[0003] That is, as shown in FIG. 15, the retainer 2 has two circular flanges 3a, 3b and a number of column portions 4 connecting the circular flanges 3a, 3b, and the needle rollers 1 are accommodated in pockets 5 formed between adjacent column portions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-46792 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when the bar portions 4 are disposed near the roller PCD (roller pitch circle P), the width dimension of the bar portions 4 near the roller pitch circle P must be smaller than the distance between adjacent rollers along the circumferential direction. By arranging the cage bar portions 4 on the outer diameter side of the roller PCD (roller pitch circle P), the width dimension of the bar portions 4 can be made larger, and moreover, it is possible to increase the number of rollers compared to conventional products.

[0006] However, if an attempt is made to increase the number of rollers in a conventional cage shape to improve the basic dynamic (static) load rating, the radial or circumferential width dimension of the column portion 4 will inevitably become smaller, as shown in Figure 16, resulting in a decrease in the strength of the column portion 4.

[0007] In view of the above situation, the present invention aims to provide a roller bearing and a needle roller bearing in which the cross-sectional shape of the column portion of the retaining member is made to approximate a trapezoid, thereby making effective use of the space between adjacent rollers, thereby increasing the cross-sectional area of ​​the column portion and suppressing a decrease in strength, in order to improve the basic dynamic (static) load rating by increasing the number of rollers. [Means for solving the problem]

[0008] The roller bearing of the present invention has a pair of annular portions spaced apart in the axial direction and a number of column portions extending in the axial direction to connect the annular portions, and has a retaining member in which the rollers are retained in pockets formed between adjacent column portions, and the retaining member has inclined column portion opposing surfaces opposing each other in the circumferential direction so that the inside of the pocket expands, and the roller filling rate on the pitch circle of the rollers is 93% or more and less than 100%, and when the circumferential length of the column portions on the contact pitch circle between the rollers and the column portions of the retaining member at a corresponding portion of the final clearance formed between circumferentially adjacent rollers on the pitch circle is B, the dimension between adjacent rollers in the circumferential direction is A and the dimension of the final clearance is rs, A>(B+rs), and when the circumferential length of the column portions on the contact pitch circle at a portion where adjacent rollers contact in the circumferential direction is D and the dimension between adjacent rollers in the circumferential direction is C, the relationship C>D. Here, the roller packing ratio is the ratio of the rollers to the pitch circle. Roller packing ratio = (Number of rollers x roller diameter) / (Pi x pitch circle diameter) Here, the final clearance is the clearance that ultimately occurs between the last roller and the first roller when the rollers are assembled so that adjacent rollers are in contact with each other in the circumferential direction.

[0009] In the roller bearing of the present invention, the column-part opposing surfaces facing each other in the circumferential direction are inclined so as to expand toward the inside of the pocket, so that the column-part cross-sectional area can be set relatively large even if the column-part is disposed on the outer diameter side or the inner diameter side of the roller pitch circle. Generally, if the pocket clearance is made larger than the final clearance, the circumferential width dimension of the column-part is reduced, and even if the specification is such that the load on the column-part is reduced, the retaining member may not be able to withstand the load. However, by making A>(B+rs) and C>D, the space provided between adjacent rollers in the circumferential direction (the space on the outer diameter side of the roller pitch circle and the space on the inner diameter side of the roller pitch circle) can be effectively used to make the column-part cross-sectional area as large as possible. Moreover, it is possible to arrange the rollers to the same extent as in the so-called full roller state, in which there are parts in contact with adjacent rollers in the circumferential direction.

[0010] It is preferable that the cross-sectional area of ​​the bar portion on the side corresponding to one of the spatial areas on the outer diameter side or inner diameter side of the pitch circle between adjacent rollers in the circumferential direction is 25% to 50%. By setting it in this way, the cross-sectional area of ​​the bar portion is stabilized in terms of strength, and contact between the bar portion and the roller can be effectively suppressed. In other words, if the cross-sectional area exceeds 50%, the pocket clearance becomes smaller than the final clearance, and the roller and the bar portion strongly interfere with each other. The area of ​​the space between the rollers may be on the outer diameter side of the roller pitch circle or on the inner diameter side of the roller pitch circle.

[0011] Also, the spatial area may be on the pitch circle outer diameter side, and the columnar portion may be formed only on the pitch circle outer diameter side. It is preferable that the plate thickness of the columnar portion (radial thickness of the columnar portion) is 10% to 30% of the roller diameter. By setting it in this way, the columnar portion has a stable strength, and further, interference between the roller and the retaining member can be effectively prevented.

[0012] The outer ring guide system can be used. Here, the outer ring guide system refers to a system in which the holding member is positioned by abutting the holding member against the outer ring, and the outer surface serves as a guide surface and abuts against the inner circumference of the outer ring.

[0013] The needle roller bearing of the present invention uses needle rollers for the rollers of the roller bearing. As a result, the cross-sectional area of ​​the column portion can be set relatively large, and a retaining member is used that enables the plate thickness of the column portion (radial thickness of the column portion) to be a thickness that provides stable strength, and the number of rollers can be increased, thereby improving the basic dynamic (static) load rating of the bearing and providing stable strength. Effect of the Invention

[0014] The present invention makes it possible to increase the number of rollers and improve the basic dynamic (static) load rating without causing a decrease in the strength of the column section. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a simplified perspective view of a retaining member of the present invention. [Diagram 2] FIG. 1 is a simplified diagram of a portion where a final clearance is provided. [Diagram 3] 1 is a simplified diagram showing a portion where rollers are in contact with each other. [Figure 4] FIG. 4 is a cross-sectional view of a portion where rollers are in contact with each other. [Diagram 5] 4 is a simplified diagram showing inter-roller spaces generated between adjacent rollers in the circumferential direction. FIG. [Figure 6] FIG. 4 is an enlarged plan view of a corner portion of the pocket. [Figure 7] FIG. 4 is an enlarged perspective view of a corner of the pocket. [Figure 8] 1 is a simplified diagram of a corner of a pocket. [Figure 9] FIG. 4 is a perspective view of a main part showing a process of processing the holding member of the present invention. [Figure 10] 11 is an enlarged cross-sectional view of a main portion showing a pillar portion of a holding member in the middle of being machined; FIG. [Figure 11] 13 is an enlarged cross-sectional view of a main portion showing the post portion of the holding member after machining. FIG. [Figure 12] 13 is a simplified diagram of a portion where a final clearance is provided of another retaining member of the present invention. FIG. [Figure 13]13 is a simplified diagram of a portion where rollers of another retaining member of the present invention are in contact with each other. FIG. [Figure 14] FIG. 1 is a cross-sectional view of a conventional needle roller bearing. [Figure 15] FIG. 1 is a cross-sectional view of a cage of a conventional needle roller bearing. [Figure 16] FIG. 11 is an enlarged cross-sectional view of a main portion of a cage of a conventional needle roller bearing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 13. Figure 1 shows an enlarged perspective view of a main part of a retaining member for a roller bearing of the present invention, and this retaining member 10 has a pair of annular portions 11, 12 spaced apart in the axial direction, and a number of pillar portions 13 extending in the axial direction and connecting the annular portions 11, 12 to each other, and rollers 15 (see Figure 2) are housed in pockets 14 formed between adjacent pillar portions 13.

[0017] In this case, as shown in Figures 2 to 4, the opposing surfaces of the columns facing each other in the circumferential direction are inclined surfaces 16a, 16b so that the pocket inner side expands, that is, so that the pocket expands from the outer diameter to the inner diameter side. Therefore, the cross-sectional shape of the columns 13 is a shape that approximates a trapezoid. The retaining member 10 is disposed on the outer diameter side of the roller pitch circle P1.

[0018] Incidentally, the retaining member 10 is formed by pressing into a molded product S as shown in Fig. 9. In this case, the molded product S has annular portion constituent parts 11A, 12A and a plurality of column portion constituent parts 13A connecting the annular portion constituent parts 11A, 12A with each other, and a pocket portion 14A formed between adjacent column portion constituent parts 13A, 13A. That is, the column portion facing surfaces facing each other in the circumferential direction of the column portion are not inclined surfaces 16a, 16b, but are end surfaces 17a, 17b extending in the radial direction as shown in Fig. 10.

[0019] For this reason, as shown in Fig. 11, the end faces 17a, 17b are cut by cutting or the like to produce inclined faces 16a, 16b. In Fig. 11, the range indicated by the two-dot chain line indicates the removed parts 21a, 21b. In addition, the inclined faces 16a, 16b of the column part 13 may be formed by pressing (surface pressing) processing.

[0020] The method of processing the inclined surfaces 16a, 16b is not limited to pressing, and cutting processes such as broaching and MC milling may be used depending on the production volume and production lead time. Furthermore, if sufficient strength is required, injection molding using resin material or sintering using powder material may be used, and if the size is relatively large, casting may be used. In other words, the material of the retaining member 10 may be metal or synthetic resin that has been conventionally used for retainers, and the molding method may be injection molding, punching (pressing), cutting (machining), etc., depending on the material used.

[0021] At a portion corresponding to the final clearance G formed between the circumferentially adjacent rollers on the roller pitch circle P1, the circumferential length of the bar portion 13 on the contact pitch circle P2 between the roller and the bar portion 13 is B, and the dimension between the adjacent rollers along the circumferential direction is A. Last gap Let rs be the dimension of A > (B + rs). Also, let D be the circumferential length of column portion 13 on contact pitch circle P2 at the portion where adjacent rollers 15 contact in the circumferential direction, and let C be the dimension between adjacent rollers in the circumferential direction, and let C be C > D. Here, the final clearance is the clearance that ultimately occurs between the last roller 15 and the first roller 15 when the rollers 15, 15 are assembled so that they are in contact with each other in the circumferential direction.

[0022] The cross-sectional area of ​​the bar portion 13 between the rollers adjacent in the circumferential direction is set to 25% to 50% of the area of ​​the space 30 between the rollers adjacent in the circumferential direction. Here, the space 30 is the space shown by cross-hatching in FIG. 5, and in this case, it is the range on the outer diameter side of the roller pitch circle between the rollers adjacent in the circumferential direction. The bar portion 13 corresponding to the area of ​​the space 30 is also provided on the outer diameter side of the pitch circle, and corresponds to its cross-sectional area. When the bar portion 13 is provided on the inner diameter side of the pitch circle, the space 30 is also in the range on the inner diameter side. It is preferable that the radial thickness of the bar portion 13 is 10% to 30% of the roller diameter.

[0023] Next, with regard to the preferred ratio of the cross-sectional area of ​​the pillar portion 13 to the area of ​​the space 30 between adjacent rollers in the circumferential direction for the retaining member 10 shown in Figure 1, when the area of ​​the space 30 between adjacent rollers is H and the cross-sectional area of ​​the pillar portion 13 is S1, Table 1 shows S1 / H (%) as less than 20%, 20%, 25%, 30%, 40%, 50%, 55%, and greater than 55%. [Table 1]

[0024] If it is 55% or more, there is a risk of relatively strong interference between the rollers and the bar portion. In this case, it is marked with an X in Table 1. If it is 20% or less, there is a risk of poor roller retention. In this case, it is marked with an X in Table 1. For this reason, it can be said that it is preferable to set the cross-sectional area of ​​the bar portion 13 between adjacent rollers in the circumferential direction, which is marked with an O in Table 1, to 25% to 50% of the spatial area between adjacent rollers in the circumferential direction.

[0025] Next, with respect to the retaining member 10 shown in FIG. 1, preferable ratios of the relationship (T / D) between the thickness (radial thickness of the column portion) T of the retaining member 10 and the roller diameter (roller diameter) D are shown in Table 2 for T / D less than 5%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 35% or more. [Table 2]

[0026] If T / D is 35% or more, the rollers 15 and the column portion 13 will interfere relatively strongly, and it will be necessary to reduce the number of rollers or to set the gap between the rollers large, which may prevent the basic dynamic (static) load rating from being improved. In addition, it will be necessary to reduce the width dimension in the circumferential direction of the retaining member, which may prevent the column portion 13 from maintaining sufficient strength. In this case, it is indicated by an × in Table 2. In addition, if T / D is 5% or less, it may prevent the column portion 13 from maintaining sufficient strength. In this case, it is indicated by an × in Table 2. For this reason, as indicated by an ◯ in Table 2, it can be said that it is preferable to set the plate thickness (radial thickness of the column portion) T of the column portion 13 to 10% to 30% of the roller diameter (roller diameter) D (see FIG. 2).

[0027] As shown in Fig. 6 and Fig. 7, the four corners between the annular portion 11 (12) and the column portion 13 are formed as R-shaped curved surface portions 22. In this case, as shown in Fig. 8, The R shape of the portion located on the outer diameter side is made larger than the R shape of the central portion, and the R shape of the portion located on the inner diameter side is made larger than the R shape of the central portion. Here, a large R shape means a large radius of curvature, and as a result, the distance of the curved surface portion 22 extending from the annular portion 11 (12) to the column portion 13 becomes longer. That is, the radius of curvature of the portion located on the outer diameter side (outer diameter side portion 22a) is set larger than the radius of curvature of the central portion (central portion in the thickness direction 22c). Also, the radius of curvature of the portion located on the inner diameter side (inner diameter side portion 22b) is set larger than the radius of curvature of the central portion (central portion in the thickness direction 22c). In this case, when the radius of curvature of the outer diameter side portion 22a is R1, the radius of curvature of the inner diameter side portion 22b is R2, and the radius of curvature of the central portion in the thickness direction 22c is R3, R1 > R3 and R2 > R3, and the generated stress can be reduced in a state where a load is applied to the column portion 13, and the strength of the holding member 10 can be improved. Also, for example, by setting R1 ≒ R2 and 1.015 < (R1 ≒ R2) / R3 < 1.5, the generated stress can be further reduced in a state where a load is applied to the column portion 13, and the strength of the holding member 10 can be improved. 1.015 < (R1 ≒ R2) / R3 < 1.5 is the case where rolling contact occurs at the radial center of the surfaces of the columns 14a and 14b. On the other hand, there are cases where the rolling contact is set closer to the inner diameter or the outer diameter of the columns 14a and 14b. In this case, by setting 0.6 < R1 / R3 < 1.5 and 0.6 < R2 / R3 < 1.5, the strength of the holding member 10 can be improved.

[0028] In the above embodiment, the retaining member 10 is disposed on the outer diameter side of the roller pitch circle P1, but as shown in Fig. 12 and Fig. 13, the retaining member 10 may be disposed on the inner diameter side of the roller pitch circle P1. In this case, the column portion opposing surfaces opposing along the circumferential direction are inclined surfaces 16a, 16b so that the pocket 14 is expanded from the inner diameter side to the outer diameter side, and the inside of the pocket is expanded, and the column portion cross-sectional shape is made to be a shape that approximates a trapezoid. Then, when the circumferential length of the column portion 13 on the contact pitch circle P2 between the roller and the column portion 13 at the corresponding portion of the final clearance G formed between the circumferentially adjacent rollers on the roller pitch circle P1 is B, the dimension between the adjacent rollers along the circumferential direction is A, and the clearance dimension of the final clearance G is rs, A>(B+rs). In addition, when the circumferential length of the column portion 13 on the contact pitch circle P2 at the location where adjacent rollers 15 contact each other in the circumferential direction is D and the dimension between adjacent rollers in the circumferential direction is C, C>D.

[0029] The cross-sectional area of ​​the bar portion 22 between the circumferentially adjacent rollers is set to 25% to 50% of the area of ​​the space 30 between the circumferentially adjacent rollers. Here, this refers to the range between the space 30 and the roller pitch circle inner diameter side between the circumferentially adjacent rollers. It is preferable that the radial thickness of the bar portion 13 is 10% to 30% of the roller diameter D1.

[0030] In the roller bearing of the present invention, the column portion cross-sectional area can be set relatively large even if the column portion is disposed on the outer diameter side or the inner diameter side of the roller pitch circle P1 by making the column portion opposing surfaces opposed along the circumferential direction inclined surfaces 16a, 16b so that the pocket inner side is expanded. Generally, if the pocket clearance is made larger than the final clearance, the circumferential width dimension of the column portion becomes small, and even if the specification is such that the load on the column portion 13 is reduced, the retaining member may not be able to withstand the load. However, by making A>(B+rs) and C>D, the space provided between adjacent rollers in the circumferential direction (the space on the outer diameter side of the roller pitch circle P1 and the space on the inner diameter side of the roller pitch circle P1) can be effectively used to make the column portion cross-sectional area as large as possible. Moreover, it is possible to arrange the rollers 15 to the same extent as the so-called full roller state, in which there are parts in contact with adjacent rollers 15, 15 in the circumferential direction.

[0031] Therefore, the present invention makes it possible to increase the number of rollers and improve the basic dynamic (static) load rating without causing a decrease in the strength of the column portion.

[0032] 2 and 3, the retaining member 10 is disposed on the outer diameter side of the roller pitch circle P1, so that the roller bearing can be of the outer ring guide type. Here, outer ring guide means that the retaining member 10 is positioned by abutting against the outer ring, and the outer surface serves as a guide surface and abuts against the inner periphery of the outer ring.

[0033] 12 and 13, the retaining member 10 is disposed on the inner diameter side of the pitch circle, so that the roller bearing can be made to have an inner ring guide system. Here, inner ring guide means that the retaining member 10 is positioned by abutting against the inner ring, and the inner surface serves as a guide surface and abuts against the outer periphery of the inner ring.

[0034] It is preferable that the corners between the annular portion 11 (12) and the column portion 13 are formed into R-shaped curved portions 22. By setting them in this way, it is possible to reduce the stress generated in the column portion 13 during processing.

[0035] In the curved surface portion 22, the R shape of the portion located on the outer diameter side is made larger than the R shape of the central portion, and the R shape of the portion located on the inner diameter side is made larger than the R shape of the central portion. That is, the radius of curvature of the portion located on the outer diameter side (outer diameter side portion 22a) is set larger than the radius of curvature of the central portion (central portion in the thickness direction 22c). Also, the radius of curvature of the portion located on the inner diameter side (inner diameter side portion 22b) is set larger than the radius of curvature of the central portion (central portion in the thickness direction 22c). In this case, when the radius of curvature of the outer diameter side portion 22a is R1, the radius of curvature of the inner diameter side portion 22b is R2, and the radius of curvature of the central portion in the thickness direction 22c is R3, R1 > R3 and R2 > R3, and the generated stress can be reduced in a state where a load is applied to the column portion 13, and the strength of the holding member 10 can be improved. Further, for example, by setting R1 ≒ R2 and making 1.015 < (R1 ≒ R2) / R3 < about 1.5, the generated stress can be further reduced in a state where a load is applied to the column portion 13, and the strength of the holding member 10 can be improved. 1.015 < (R1 ≒ R2) / R3 < 1.5 is the case where it rolls and contacts the radial center portion of the surfaces of the columns 14a and 14b. On the other hand, there may be a case where the rolling is set closer to the inner diameter or the outer diameter of the columns 14a and 14b. In this case, by making 0.6 < R1 / R3 < 1.5 and 0.6 < R2 / R3 < about 1.5, the strength of the holding member 10 can be improved.

[0036] The needle roller bearing of the present invention uses the holding member 10. Therefore, in this needle roller bearing, the cross-sectional area of the column portion can be set relatively large, and moreover, a holding member can be used in which the plate thickness (radial thickness of the column portion) of the column portion 13 is set to a thickness that is stable in terms of strength. By increasing the number of rollers, as a bearing, the basic dynamic (static) rated load can be improved, and moreover, it becomes stable in terms of strength.

[0037] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible. The roller bearing may be one in which adjacent rollers face each other with a gap therebetween, or one in which adjacent rollers contact each other in the circumferential direction. The roller bearing is not limited to a needle roller bearing, but may be a cylindrical roller bearing or a tapered roller bearing. The bearing is not limited to a single-row type, but may be a double-row type. The roller bearing in which the retaining member is used is, for example, one used in general industrial machinery, but can be particularly used in those requiring space saving and high load capacity, for example, in automotive machine parts and robot mechanism parts. [Explanation of symbols]

[0038] 10 Retaining member 11,12 Annular section 13 Pillar section 14 Pockets Around 15 16a Slope 16a Slope P1 Pitch circle P2 Contact pitch circle

Claims

1. A roller bearing having a pair of annular portions spaced apart in the axial direction and a plurality of column portions extending in the axial direction to connect the annular portions, the rollers being held in pockets formed between adjacent column portions, a roller bearing comprising: said retaining member having inclined surfaces facing column portions opposed in the circumferential direction so that the inside of the pocket expands; a roller filling rate on the pitch circle of the rollers is 93% or more and less than 100%; a circumferential length of the column portions on a contact pitch circle between the rollers and the column portions of the retaining member at a corresponding portion of an ultimate clearance formed between circumferentially adjacent rollers on the pitch circle is B, a dimension between adjacent rollers in the circumferential direction is A, and a dimension of the ultimate clearance is rs, where A > (B + rs); a circumferential length of the column portions on a contact pitch circle between the rollers and the column portions of the retaining member at a corresponding portion of an ultimate clearance formed between circumferentially adjacent rollers on the pitch circle is D, and a dimension between adjacent rollers in the circumferential direction is C, where C > D; a corner formed between the annular portion and the column portions of the retaining member is an R-shaped curved portion, and the R-shape of a portion of the curved portion located on the outer diameter side is set to be larger than the R-shape of a central portion.

2. A roller bearing having a pair of annular portions spaced apart in the axial direction and a plurality of pillar portions extending in the axial direction to connect the annular portions, the rollers being held in pockets formed between adjacent pillar portions, the roller bearing having a retaining member, a roller bearing comprising: said retaining member having inclined surfaces facing column portions opposed in the circumferential direction so that the inside of the pocket expands; a roller filling rate on the pitch circle of the rollers is 93% or more and less than 100%; a circumferential length of the column portions on a contact pitch circle between the rollers and the column portions of the retaining member at a corresponding portion of an ultimate clearance formed between circumferentially adjacent rollers on the pitch circle is B, a dimension between adjacent rollers in the circumferential direction is A, and a dimension of the ultimate clearance is rs, where A > (B + rs); a circumferential length of the column portions on a contact pitch circle between the rollers and the column portions of the retaining member at a corresponding portion of an ultimate clearance formed between circumferentially adjacent rollers on the pitch circle is D, and a dimension between adjacent rollers in the circumferential direction is C, where C > D; a corner formed between the annular portion and the column portions of the retaining member is an R-shaped curved portion, and the R-shape of a portion of the curved portion located on the inner diameter side is set to be larger than the R-shape of a central portion.

3. A roller bearing according to claim 1 or claim 2, characterized in that the cross-sectional area of ​​the column portion on the side corresponding to one of the spatial areas, either on the outer diameter side or the inner diameter side of the pitch circle between adjacent rollers in the circumferential direction, is 25% to 50%.

4. 4. A roller bearing according to claim 3, wherein the spatial area is on the outer diameter side of the pitch circle, and the pillar portion is formed only on the outer diameter side of the pitch circle.

5. 5. A roller bearing according to claim 1, wherein the radial thickness of the column portion is 10% to 30% of the roller diameter.

6. 6. A roller bearing according to claim 1, which is of an outer ring guide type.

7. A needle roller bearing, characterized in that needle rollers are used as the rollers of the roller bearing according to any one of claims 1 to 6.

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