Holder for radial roller bearing, and radial roller bearing

Abstract

To provide a good-quality holder for a radial roller bearing capable of improving lubricity, and a radial roller bearing.SOLUTION: A holder 10 for a radial roller bearing comprises: a pair of annular rim parts 11 provided parallel to each other at both axial end parts; a plurality of pillar parts 12 spanning between the rim parts 11, and provided at predetermined intervals along a circumferential direction; a plurality of pockets 13 that houses rollers 16 between adjacent pillar parts 12; and a plurality of notch parts 15 provided at predetermined intervals along the circumferential direction in a rim inner diameter part 11a of at least one of the rim parts 11, with notch tips 15a extending outward beyond a PCD of the plurality of rollers 16.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, among the rotational support parts of automotive transmissions and various mechanical devices, radial roller bearings are incorporated in parts where large radial loads are applied. The cage for a radial roller bearing (hereinafter simply referred to as a cage) that constitutes this radial roller bearing includes a pair of annular rim parts provided in parallel with each other at both axial ends, and a plurality of column parts spanned between these two rim parts and provided at predetermined intervals in the circumferential direction, and a plurality of pockets in which rollers, which are rolling elements, are accommodated between adjacent column parts.

[0003] By the way, radial roller bearings (especially needle roller bearings) used in environments where large loads are applied require high lubricity. However, the oil permeability of lubricating oil decreases as the number of needles accommodated is increased to increase the load capacity.

[0004] Therefore, in the radial needle bearing described in Patent Document 1, a meat theft part is provided at the non-contact part (the rim inner diameter part corresponding to the column part) between the needle tip part and the rim inner diameter part of both rim parts. Further, in the cage for a roller bearing of Patent Document 2, an oil groove is provided on the outer peripheral side of the annular body (corresponding to the above-mentioned rim part), and a protrusion is provided at a position corresponding to the oil groove on the outer surface of the support column. Furthermore, in the needle roller bearing of Patent Document 3, a cage having a notch penetrating in the axial direction is provided at a position corresponding to the pocket of the ring part (corresponding to the above-mentioned rim part).

[0005] By providing these meat theft parts, oil grooves or notches in the cage, it is possible to increase the lubricating oil flowing into the bearing from the outside or enhance the fluidity of the lubricating oil between adjacent pockets.

Prior Art Documents

Patent Documents

[0006] Patent Document 1 Japanese Patent Application Laid-Open No. 2010-270884 Patent Document 2 Japanese Patent Application Laid-Open No. 2001-304270 Patent Document 3 Japanese Patent Application Laid-Open No. 2007-078090 Summary of the Invention Problems to be Solved by the Invention

[0007] However, in the radial roller bearings provided with cages described in Patent Documents 1 to 3 above, since the formation positions and sizes of these meat theft portions, oil grooves, and notch portions are limited, the inflow property of lubricating oil is not sufficient, and further improvement in lubricity is desired.

[0008] The present invention has been made in view of the above-described problems, and an object thereof is to provide a good cage for a radial roller bearing and a radial roller bearing capable of improving lubricity. Means for Solving the Problems

[0009] In order to achieve the above-described object, the cage for a radial roller bearing and the radial roller bearing according to the present invention are characterized as follows. (1) A pair of annular rim portions provided in parallel to each other at both axial ends, a plurality of column portions spanned between these two rim portions and provided at predetermined intervals in the circumferential direction, a plurality of pockets for accommodating rollers between adjacent said column portions, a plurality of notch portions provided at predetermined intervals in the circumferential direction on the inner diameter portion of the rim of at least one of said rim portions, and having notch tips extending to the outer diameter side from the PCD (pitch circle diameter) of the plurality of said rollers, A cage for a radial roller bearing, characterized by comprising:

[0010] A radial roller bearing, characterized in that the cage for the radial roller bearing described in (1) above is incorporated.

Advantages of the Invention

[0011] According to the cage for a radial roller bearing and the radial roller bearing of the present invention, by improving the lubricity of the radial roller bearing, the life of the bearing can be improved.

[0012] The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through the embodiments for carrying out the invention described below (hereinafter referred to as "embodiments") with reference to the accompanying drawings.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0014] Specific embodiments of the present invention will be described below with reference to the respective drawings.

[0015] (First Embodiment) First, the cage 10 for a radial roller bearing according to the first embodiment of the present invention will be described. FIG. 1 is an overall perspective view of a radial roller bearing 1 provided with a cage 10 for a radial roller bearing according to the first embodiment of the present invention, and FIG. 2 is a perspective view of the cage 10 for a radial roller bearing shown in FIG. 1.

[0016] As shown in FIGS. 1 to 2, the cage 10 for a radial roller bearing of the present first embodiment (hereinafter, may be simply referred to as a cage) includes a pair of annular (cylindrical or ring-shaped) rim portions 11 arranged in parallel with a space therebetween at both axial ends, and a plurality of column portions 12. These column portions 12 are arranged at predetermined intervals in the circumferential direction, and both ends of each are connected to the outer diameter ends of the opposing inner surfaces of the pair of rim portions 11. And the space surrounded by the circumferential-direction both side edges of these adjacent column portions 12 in the circumferential direction and the opposing inner surfaces of the both rim portions 11 is a pocket 13 for rotatably holding a cylindrical roller 16 as a rolling element, respectively.

[0017] Retention portions 12a that slightly extend in the circumferential direction from both circumferential-direction side edges are provided at both axial ends of the column portion 12, preventing the roller 16 inserted into each pocket 13 from the inner diameter side of the cage 10 from coming out to the outer diameter side.

[0018] FIG. 3 is a front view of the radial roller bearing 1 shown in FIG. 1. In the rim inner diameter portion 11a of the rim portion 11, a plurality (four in the present first embodiment) of notch portions 15 notched in a substantially trapezoidal shape are arranged at predetermined intervals in the circumferential direction. Note that the number of notch portions 15 is not limited to four, and may be five or more.

[0019] As shown in FIG. 3, this notch portion 15 has an arcuate notch tip 15a with a radius R2 located on the outer diameter side of the PCD (Pitch Circle Diameter) of a plurality (16 in this first embodiment) of rollers 16, and has a predetermined width (width corresponding to approximately three rollers 16) in the circumferential direction. That is, the depth of the notch portion 15 (the difference L between the radius R1 of the rim inner diameter portion 11a of the rim portion 11 and the radius R2 of the notch tip 15a) is set to the depth at which the end face on the central axis X of the roller 16 is exposed from the notch portion 15 of the rim portion 11 (see FIG. 4).

[0020] The radial roller bearing cage 10 configured as described above constitutes a radial roller bearing 1 by rotatably holding the rollers 16 in their respective pockets 13. FIG. 4 is a schematic longitudinal sectional view showing a state in which the radial roller bearing 1 shown in FIG. 1 is assembled to a support shaft 25 as a support bearing for a planetary gear 20 in a planetary gear mechanism, and FIG. 5 is a front view of the radial roller bearing 1 shown in FIG. 4 as viewed from the direction of arrow A.

[0021] As shown in FIG. 4, the radial roller bearing 1 of this first embodiment is disposed, for example, on the outer peripheral surface 25a of a support shaft (pinion shaft) 25 in a planetary gear mechanism that constitutes an automatic transmission of an automobile, and rotatably supports the planetary gear 20. More specifically, the radial roller bearing 1 uses the outer peripheral surface 25a of the support shaft 25 as an inner ring raceway and the inner peripheral surface 20a of the planetary gear 20 as an outer ring raceway, so that the rolling surfaces of the respective rollers 16 are in rolling contact with these inner and outer ring raceways. It goes without saying that the radial roller bearing 1 of this first embodiment can be used not only for a planetary gear mechanism that constitutes an automatic transmission but also for support bearings of rotating members in a transmission, support bearings of connecting rods in an engine, etc., for the rotational support portions of various mechanical devices.

[0022] Since the cage 10 for the radial roller bearing is used for outer diameter guidance, it is pressed against the inner peripheral surface 20a of the planetary gear 20, and sliding will occur between the inner peripheral surface 20a and the outer peripheral surface of the cage 10. At this time, the gap between the outer peripheral surface 25a of the support shaft 25 and the notch tip 15a at the portion where the notch 15 is provided is larger than the gap between the outer peripheral surface 25a of the support shaft 25 where the notch 15 is not provided and the rim inner diameter portion 11a.

[0023] As described above, according to the radial roller bearing 1 of the first embodiment, as shown in FIG. 5, a plurality of notches 15 with large openings are provided in the rim portion 11 of the cage 10 for the radial roller bearing without restricting the formation positions.

[0024] Thereby, the gap between the rim portion 11 and the outer peripheral surface 25a of the support shaft 25 is enlarged to secure a lubricating oil flow path (diagonal hatching portion in FIG. 5), and it is possible to easily allow a highly viscous lubricating oil to flow into the cage 10. In addition, a space for retaining the lubricating oil in the radial roller bearing 1 can be secured, and the lubricity of the rollers 16 can be improved. As a result, the life of the radial roller bearing 1 can be improved.

[0025] FIG. 7 is a front view showing a state in which a conventional radial roller bearing 101 is assembled to a support shaft 25 as a support bearing for a planetary gear 20 in a planetary gear mechanism. As is clear from the conventional radial roller bearing 101 shown in FIG. 7, compared with the cage 10 for the radial roller bearing shown in FIG. 5, the cage 110 for the radial roller bearing has a smaller gap between the rim portion 11 and the outer peripheral surface 25a of the support shaft 25, and the lubricating oil flow path (diagonal hatching portion in FIG. 7) is narrow. Therefore, it is difficult for lubricating oil to flow into the cage 110 for the radial roller bearing, and once the oil has flowed in, it is difficult to be discharged to the outside. As a result, the fluidity of the oil in the cage decreases, and there is a risk of retention of deteriorated oil and contaminants.

[0026] Also, according to the radial roller bearing 1 of the first embodiment, by providing the large notch portion 15 in the opening portion on the rim portion 11, the cage 10 can be lightened and the weight of the radial roller bearing 1 can be reduced. Therefore, the torque resistance during operation can be reduced, and the transmission efficiency of the radial roller bearing 1 can be improved.

[0027] (Second Embodiment) Next, the cage 10A for a radial roller bearing according to the second embodiment of the present invention will be described. Note that the cage 10A for a radial roller bearing according to the second embodiment has the same basic configuration as the first embodiment, so the same reference numerals are given to the same or corresponding parts, and the description thereof is omitted or simplified. FIG. 6 is an overall perspective view of a radial roller bearing 1A provided with a cage 10A for a radial roller bearing according to the second embodiment of the present invention.

[0028] As shown in FIG. 6, the cage 10A for a radial roller bearing according to the second embodiment (hereinafter sometimes simply referred to as a cage) includes a pair of annular (cylindrical or ring-shaped) rim portions 11 arranged in parallel with a space therebetween at both axial ends, and a plurality of column portions 12. The cage 10A for a radial roller bearing configured as described above constitutes a radial roller bearing 1 by rotatably holding the rollers 16 in their respective pockets 13.

[0029] A plurality of (eight in the second embodiment) notch portions 15A notched in a substantially semicircular shape are arranged at predetermined intervals in the circumferential direction on the rim inner diameter portion 11a of the rim portion 11. As shown in FIG. 6, this notch portion 15A is located on the outer diameter side of the PCD of a plurality of (sixteen in the second embodiment) rollers 16, and the notch tip 15a, which is the apex of the arc, is positioned, and has a predetermined width (the width of approximately one roller 16) in the circumferential direction. That is, the depth of the notch portion 15A (the difference L between the radius R1 of the rim inner diameter portion 11a of the rim portion 11 and the radius R2 of the notch tip 15a) is set to the depth at which the end face on the central axis X of the roller 16 is exposed from the notch portion 15 of the rim portion 11.

[0030] As described above, in the radial roller bearing 1A of the second embodiment, a large number of notches 15A with large openings are provided in the rim portion 11 of the cage 10A for the radial roller bearing without restricting the formation positions. Accordingly, according to the radial roller bearing 1A of the second embodiment, the same operational effects as those of the radial roller bearing 1 of the first embodiment can be obtained.

[0031] Note that the present invention is not limited to the above-described embodiments, and can be modified, improved, etc. as appropriate. In addition, the material, shape, dimensions, number, arrangement position, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

[0032] For example, in each of the above-described embodiments, the notch 15 cut in a substantially trapezoidal shape and the notch 15A cut in a substantially semicircular shape have been described as examples. However, the shape of the notch of the present invention is not limited to these, and it goes without saying that the notch can take various shapes as long as the notch tip 15a can be located on the outer diameter side of the PCD of the plurality of rollers 16.

[0033] Further, in each of the above-described embodiments, the case where the notches 15 (15A) are provided in the rim inner diameter portions 11a of the pair of rim portions 11 has been described. However, for the cage for the radial roller bearing of the present invention, it is sufficient that a plurality of notches are provided in the rim inner diameter portion 11a of at least one of the rim portions 11.

[0034] Here, the features of the embodiments of the cage for the radial roller bearing and the radial roller bearing according to the present invention described above are briefly summarized and listed in [1] to [2] below, respectively.

[0035] [1] A pair of annular rim portions (11) provided in parallel with each other at both axial ends, A plurality of column portions (12) spanned between these two rim portions (11) and provided at predetermined intervals in the circumferential direction, A plurality of pockets (13) for accommodating rollers (16) between the adjacent column portions (12), A plurality of notches (15, 15A) provided at predetermined intervals in the circumferential direction on the inner diameter portion (11a) of the rim portion (11) of at least one of the rim portions, and having notch tips (15a) extending to the outer diameter side of the PCD (pitch circle diameter) of the plurality of rollers (16). A radial roller bearing cage (10, 10A), characterized by comprising the above.

[0036] According to the radial roller bearing cage (10, 10A) having the configuration of [1] above, a plurality of notches (15, 15A) with large opening portions are provided in the rim portion (11) of the radial roller bearing cage (10, 10A) without restricting the formation positions. As a result, the gap between the rim portion (11) and the outer peripheral surface of the rotating shaft can be enlarged to secure a lubricating oil flow path, and it is possible to easily allow a highly viscous lubricating oil to flow into the cage (10, 10A). Further, a space for retaining the lubricating oil in the radial roller bearing (1, 1A) can be secured, and the lubricity of the rollers (16) can be improved.

[0037] [2] A radial roller bearing (1, 1A), characterized in that the radial roller bearing cage (10, 10A) described in [1] above is incorporated.

[0038] According to the radial roller bearing (1, 1A) having the configuration of [2] above, the life of the radial roller bearing (1, 1A) can be improved.

Explanation of reference numerals

[0039] 1 Radial roller bearing 10 Radial roller bearing cage 11 Rim portion 12 Column portion 13 Pocket 15 Notch 15a Notch tip 16 Roller

Claims

1. A pair of annular rim portions provided parallel to each other at both axial ends; A plurality of column portions spanned between these two rim portions and provided at predetermined intervals in the circumferential direction; A plurality of pockets for accommodating rollers between adjacent said column portions; A plurality of notch portions provided at predetermined intervals in the circumferential direction on the inner diameter portion of the rim of at least one of said rim portions, and having notch tips extending to the outer diameter side of the PCD (pitch circle diameter) of the plurality of said rollers; A radial roller bearing retainer characterized by comprising the above.

2. A radial roller bearing characterized in that the radial roller bearing retainer according to Claim 1 is incorporated.

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