Radial roller bearing retainer

Abstract

The present invention comprises: a pair of annular rim parts; a plurality of column parts which connect the pair of rim parts and are provided at a prescribed interval in the circumferential direction; and a plurality of pockets formed from the adjacent column parts and pair of rim parts, and hold rollers in a rollable manner. The column parts each have: a column center part which is positioned relatively radially inward in an axial center part region; a column end part which is positioned relatively radially outward in an axial end part region; and a column connection part which is positioned between the column center part and the column end part. A chamfered part is formed on an inner-circumferential side edge part between a circumferential side surface and the inner-circumferential surface of the column end part.

Description

Cage for radial roller bearings

[0001] The present invention relates to a cage for radial roller bearings.

[0002] Recently, cage and rollers and radial roller bearings have been widely used in rotating parts such as transmissions of various industrial machinery and automobiles. For example, even in radial roller bearings used in transmissions, along with the increase in output and speed of automobiles, they are increasingly used under high-speed rotation conditions and low-viscosity lubricants, and bearing specifications that can be used under severe lubrication conditions are required.

[0003] In Patent Document 1, a plurality of pillar parts connecting a pair of ring parts to each other have a central pillar part, a pair of pillar end parts, and a pair of inclined pillar parts. A cylindrical member is compressed in the axial direction, such that the wall thickness at the boundary between adjacent parts is made larger than the wall thickness of each of the central pillar part, the pair of pillar end parts, and the pair of inclined pillar parts. A plurality of pockets for accommodating rollers are formed on the circumferential surface of the cylindrical member by punching, and roller retaining portions for preventing the rollers from falling out are formed on the wall surfaces of the pillar parts facing the pockets. A cage for a roller bearing is disclosed.

[0004] Japanese Patent No. 5597747

[0005] Patent Document 1 aims to increase the strength of the boundary portions between the central pillar portion, the pair of pillar end portions, and the pair of inclined pillar portions, where stress concentration is relatively likely to occur, by means of roller retaining, thereby making the cage less prone to damage. However, since the roller retaining portions are formed by ironing the central pillar portion and the pair of pillar end portions, they do not utilize the thickness of the material of the pillar portions themselves, and there is a problem that the processing takes time and costs.

[0006] In addition, if the amount of protrusion of the rollers accommodated in the pockets is small, the cage may restrain the rollers. Therefore, in general, in order to prevent the amount of protrusion of the rollers from the pockets from becoming too small, it is necessary to adjust the amount of protrusion of the rollers by increasing the width of the pockets or cutting the outer diameter surface of the cage. At this time, there is a problem that the wall thickness of the pillar end portions becomes thin, which may reduce the strength of the cage more than necessary.

[0007] The present invention has been made in view of the aforementioned problems, and its purpose is to provide a cage for radial roller bearings that allows the amount of roller protrusion from the cage pocket to be adjusted with simple and low-cost processing without reducing the strength of the cage.

[0008] The above object of the present invention is achieved by the following configuration: (1) A cage for a radial roller bearing comprising: a pair of annular rim portions; a plurality of column portions connected between the pair of rim portions and provided at predetermined intervals in the circumferential direction; and a plurality of pockets formed by adjacent column portions and the pair of rim portions for holding rollers so as to be able to roll; wherein each column portion has a column central portion located radially inward relative to the axial central portion region, a column end portion located radially outward relative to the axial end portion region, and a column connecting portion located between the column central portion and each of the column end portions; and a chamfered portion is formed on the inner circumferential edge portion between the circumferential side surface and the inner circumferential surface of the column end portion.

[0009] According to the present invention, the amount of protrusion of the rollers from the pockets of the retainer can be adjusted with simple and low-cost processing without reducing the strength of the retainer.

[0010] Figure 1 is a cross-sectional view illustrating one embodiment of a radial roller bearing to which the present invention is applied. Figure 2 is a side view showing a cage to which the present invention is applied holding cylindrical rollers. Figure 3 is a side view showing the cage. Figure 4 is a perspective view of the main part showing the radially outer side of the cage. Figure 5 is a perspective view of the main part showing the radially inner side of the cage. Figure 6 is an enlarged view of the main part of Figure 5 showing the column end. Figure 7 is a model diagram showing an example of a chamfering apparatus. Figure 8(A) is a model diagram showing the state of the chamfering before processing, and Figure 8(B) is a model diagram showing the state after processing the chamfering. Figure 9 is a partial cross-sectional view showing a cage in which cylindrical rollers are housed in pockets.

[0011] Hereinafter, an embodiment of a cage-and-roller radial roller bearing to which the cage for radial roller bearings according to the present invention is applied will be described in detail with reference to the drawings. Figure 1 is a cross-sectional view illustrating an embodiment of a cage-and-roller to which the present invention is applied. Figure 2 is a side view showing the cage to which the present invention is applied holding cylindrical rollers.

[0012] In the following explanation, the axial direction refers to the direction of the rotational axis of the cylindrical roller bearing (left-right direction in Figure 1), the radial direction refers to the direction perpendicular to the rotational axis of the cylindrical roller bearing (up-down direction in Figure 1), the roller axial direction refers to the direction of the rotation axis of the cylindrical roller, and the roller radial direction refers to the direction perpendicular to the rotation axis of the cylindrical roller.

[0013] As shown in Figure 1, the cage and roller 10 of this embodiment comprises a plurality of cylindrical rollers 13 as rolling elements and a metal cage 14 that holds the plurality of cylindrical rollers 13 at approximately equal intervals in the circumferential direction. The cage and roller 10 is used by being inserted between the inner circumferential surface of a housing (not shown) and the outer circumferential surface of a rotating shaft.

[0014] The cylindrical roller 13 has a cylindrical rolling surface 13a which is the circumferential surface of the cylindrical roller 13, and a circular planar roller end surface 13b which is the axial outer end surface of the cylindrical roller 13.

[0015] Next, the specific configuration of the retainer 14 will be described based on Figures 3 to 6. Figure 3 is a side view showing the retainer. Figure 4 is a perspective view of the main part showing the radially outer side of the retainer. Figure 5 is a perspective view of the main part showing the radially inner side of the retainer. Figure 6 is an enlarged view of the main part of Figure 5 showing the column end.

[0016] The retainer 14 has a pair of ring-shaped rim portions 15 arranged coaxially, a plurality of column portions 16 that connect the pair of rim portions 15 in the axial direction and are provided at approximately equal intervals in the circumferential direction, and pockets 17 that are formed between adjacent column portions 16 in the circumferential direction, surrounded by the pair of rim portions 15, and that hold the cylindrical roller 13 so that it can roll. The pair of rim portions 15 have flange portions 19 that are formed radially inward and have a radial width smaller than the diameter of the end face of the cylindrical roller 13.

[0017] The retainer 14 is made of metal and is a welded retainer manufactured by welding the ends of a steel plate rolled into an annular shape together. The retainer 14 has a pair of rim portions 15 arranged coaxially, and both ends of a column portion 16 extending along the axial direction are connected to the rim portion 15. Multiple column portions 16 are arranged along the ring-shaped rim portion 15 at predetermined intervals.

[0018] The column portion 16 has a central column portion 16A located radially inward relative to the axial central region and holding the inner diameter side of the cylindrical roller 13, a column end portion 16B located radially outward relative to the axial end region and holding the outer diameter side of the cylindrical roller 13, and a column connecting portion 16C located between the central column portion 16A and the column end portion 16B, respectively. The column connecting portion 16C is inclined diagonally from the radial end of the central column portion 16A toward the column end portion 16B. In this embodiment, the column portion 16 is formed in an M shape by bending the central region of an axially extending plate-like member radially inward.

[0019] Specifically, the central part 16A of the column is located radially inward from the pitch circle diameter PCD of the cylindrical roller 13, and the end part 16B of the column is located radially outward from the pitch circle diameter PCD of the cylindrical roller 13. Note that the central part 16A and the end part 16B of the column may partially overlap with the pitch circle diameter PCD.

[0020] The column section 16 has different external dimensions in the axial central region and the end region, respectively, in the width direction perpendicular to the axial and radial directions (hereinafter referred to as the circumferential size: column width). Specifically, as shown in Figure 9, the column width w of the column end 16B is larger than the column width of the column central section 16A and the column connection section 16C.

[0021] In this embodiment, there is no gap (recess) in the corner (connection portion) formed between the column portion 16 and the rim portion 15. For this reason, the column end portion 16B is formed such that the circumferential width gradually and smoothly widens towards the rim portion 15 at the base side connected to the rim portion 15. This configuration can be seen in Figure 6, etc. With this configuration, the column width at the base side of the column portion 16 becomes larger, so the strength of the boundary portion between the column portion 16 and the rim portion 15, where stress tends to concentrate, becomes higher.

[0022] As shown in Figures 5 and 6, the inner circumferential edge of the column end 16B between the circumferential side surface and the inner circumferential surface has a chamfered portion 20 that contacts the radially outer circumferential surface of the cylindrical roller 13 held in the pocket 17.

[0023] Next, a specific method for forming the chamfered portion 20 will be described based on Figures 7 and 8. Figure 7 is a model diagram showing an example of a chamfered portion forming apparatus. Figure 8(A) is a model diagram showing the state of the chamfered portion before processing, and Figure 8(B) is a model diagram showing the state after processing the chamfered portion.

[0024] In this embodiment, a face-pressing punch 30, which is formed in a U-shape with one end open and has a pair of inclined surfaces 31 at its end, was used as a processing tool to form a chamfered portion 20 on the column portion 16. Specifically, as shown in Figures 7 and 8, a chamfered portion 20 is formed on the column portion 16B by pressing the inclined surfaces 31 of the face-pressing punch 30 against the corner of the column end portion 16B.

[0025] In this embodiment, the chamfered portion 20 is not limited to the above configuration, and only needs to be cut out to chamfer the corners formed at both ends in the width direction of the radially inner end of the column end portion 16B, which is the base side of the column portion 16. The chamfered portion 20 is a gently curved surface along the circumferential surface of the cylindrical roller 13, but it may also be a flat surface.

[0026] (Function and Effects) Figure 9 is a partial cross-sectional view showing a retainer in which cylindrical rollers are housed in pockets. As shown in Figure 9, the retainer 14 described above maintains the strength of the column portion 16 while adjusting the amount of roller protrusion h, which is the portion that the cylindrical rollers 13 held in the pockets 17 of the retainer 14 protrude radially outward from the outer diameter surface of the retainer 14 (rim portion 15). Specifically, by increasing the amount of notches at both ends in the width direction of the column end 16B and making the chamfer portion 20 larger, the amount of roller protrusion h of the cylindrical rollers 13 held in the retainer 14 can be increased. Refer to Figure 9 for this configuration.

[0027] If the amount of protrusion h of the cylindrical roller 13 held by the retainer 14 is too small, the retainer 14 may restrain the cylindrical roller 13, so it is necessary to ensure that the amount of protrusion h of the cylindrical roller 13 is sufficient. In order to increase the amount of protrusion h of the cylindrical roller 13 held by the retainer 14, it is generally necessary to widen the circumferential width of the pocket 17 by making the width of the column portion 16 narrower, or to make the thickness of the column portion 16 thinner, which tends to reduce the strength of the retainer 14.

[0028] In contrast, with the retainer 14 of this embodiment, the amount of roller protrusion h of the cylindrical roller 13 is adjusted by the chamfered portion 20 formed on the inner circumferential edge of the column end portion 16B, so there is no need to reduce the thickness t of the column end portion 16B on the base side of the column portion 16 and the column width w. In other words, the amount of roller protrusion h of the cylindrical roller 13 held by the retainer 14 can be increased without reducing the strength of the column portion 16.

[0029] Furthermore, the present invention is not limited to the embodiments described above, and can be modified, improved, etc., as appropriate.

[0030] As described above, the following is disclosed in this specification: (1) A cage for a radial roller bearing comprising: a pair of annular rim portions; a plurality of column portions connected between the pair of rim portions and provided at predetermined intervals in the circumferential direction; and a plurality of pockets formed by adjacent column portions and the pair of rim portions for holding rollers so as to be able to roll, wherein the column portions have a column central portion located radially inward relative to the axial central portion region, a column end portion located radially outward relative to the axial end portion region, and a column connecting portion located between the column central portion and the column end portion, respectively, and a chamfer is formed on the inner circumferential edge portion between the circumferential side surface and the inner circumferential surface of the column end portion. With this configuration, since the chamfered portion does not require reducing the thickness or width of the column portions, the amount of roller protrusion from the pockets of the cage can be adjusted with simple and low-cost processing without reducing the strength of the cage.

[0031] (2) The chamfered portion is formed by pressing, the cage for the radial roller bearing described in (1). With this configuration, the amount of roller protrusion can be adjusted by simple processing, and therefore manufacturing costs can be kept low.

[0032] (3) The column end is wider in the circumferential direction than the central part of the column, and the column end is connected to the rim while gradually widening in the circumferential direction, as described in (1) or (2). With this configuration, the column end can be made wider in the part where stress concentration is likely to occur, thereby improving the rigidity of the cage.

[0033] (4) A welded cage for a radial roller bearing as described in any one of (1) to (3). With this configuration, there is no need to form a recess at the base of the column that is welded to the rim, so the base of the column can be made thicker. This makes it possible to widen the column in areas where stress concentration is likely to occur, thereby improving the rigidity of the cage.

[0034] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0035] This application is based on a Japanese patent application (Patent Application No. 2025-039384) filed on March 12, 2025, the contents of which are incorporated herein by reference.

[0036] 10 Cage and roller (radial roller bearing) 13 Cylindrical roller 14 Cage 15 Rim 16 Column 16A Column center 16B Column end 16C Column connection 17 Pocket 19 Flange 20 Chamfered section 30 Chamfer punch 31 Inclined surface

Claims

1. A cage for a radial roller bearing comprising: a pair of annular rim portions; a plurality of column portions connected between the pair of rim portions and provided at predetermined intervals in the circumferential direction; and a plurality of pockets formed by adjacent column portions and the pair of rim portions for holding rollers so as to roll freely, wherein each column portion has a column central portion located radially inward relative to the axial central portion region, a column end portion located radially outward relative to the axial end portion region, and a column connecting portion located between the column central portion and each of the column end portions, and a chamfered portion is formed on the inner circumferential edge portion between the circumferential side surface and the inner circumferential surface of the column end portion.

2. The chamfered portion is formed by pressing, the cage for a radial roller bearing according to claim 1.

3. The column end is wider in the circumferential direction than the central part of the column, and the column end is connected to the rim while gradually widening in the circumferential direction, as described in claim 1.

4. A welded cage, a cage for a radial roller bearing according to any one of claims 1 to 3.

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