JP2008298105A - Bearing cage - Google Patents

Abstract

An object of the present invention is to provide a bearing cage with excellent durability that can be used continuously over a long period of time by maintaining and improving strength.
A bearing retainer that revolves along the inside of the bearing together with the plurality of rolling elements while holding the plurality of rolling elements rotatably inside the bearing, and is continuous in the circumferential direction along the inside of the bearing. And a pair of annular portions 2, 4 arranged opposite to each other in the axial direction, and a plurality extending between the pair of annular portions and arranged in the circumferential direction at predetermined intervals along the annular portion And a plurality of pockets 8 which are partitioned by a pair of annular portions and a plurality of pillar portions and rotatably hold a plurality of rolling elements one by one. The rigidity ratio between the rigidity and the rigidity of the other annular portion is set in the range of 0.7 to 1.5.
[Selection] Figure 1

Description

  The present invention relates to a bearing cage that is improved in strength.

  Conventionally, various types of cages that rotatably hold a plurality of rolling elements have been used for bearings that support the rotating portion of the apparatus, and the cages always receive a load from the rolling elements during bearing rotation. As an example, assuming a cage used in a railway vehicle axle bearing (double-row sealed tapered roller bearing), the cage has a plurality of pockets that rotatably hold a plurality of rolling elements (that is, rollers). Is provided. In this case, excessive stress concentration may occur at the four corners of each pocket by receiving a load from the “roller” during rotation of the bearing. Conventionally, as a measure for alleviating such stress concentration, generally, the radius of curvature of each corner of each pocket is set large.

  By the way, considering the interference with the chamfers (roller chamfering) provided at the four corners of each pocket, the curvature radii of the four corners of each pocket must be set to be equal to or less than the roller chamfer dimension. If the roller chamfer dimension is increased, it is possible to reduce the stress concentration at the four corners of the pockets by setting the radius of curvature at the four corners of the pockets to be large. However, since the load capacity of the bearing decreases as the chamfer dimension increases, there is a certain limit to increasing the radius of curvature of each corner of the pocket.

  In view of this, Patent Documents 1 to 4 propose techniques for reducing stress concentration at the four corners of the pockets without interfering with roller chamfering by forming reliefs at the four corners of the pockets. That is, Patent Document 1 discloses a roller bearing device in which arc-shaped notches are formed at the four corners of each pocket, and Patent Document 2 discloses a roller bearing retainer in which round portions are formed at the four corners of each pocket. Has been. Patent Documents 3 and 4 propose roller bearing retainers in which groove-shaped (concave) thin portions are formed at the four corners of each pocket.

However, when such a relief portion is formed, there is a problem that the thickness of the portion constituting each pocket is locally reduced, and as a result, the strength of the entire cage is reduced. . In particular, since a railway vehicle axle bearing is used at a high speed, the cage receives a large impact load from the rolling elements during the rotation of the bearing. Therefore, the conventional cage in which relief portions are formed at the four corners of each pocket is less durable against a large impact load, which may make it difficult to use continuously over a long period of time.
Japanese Utility Model Publication No. 61-168326 Japanese Patent Laid-Open No. 11-51060 JP-A-9-177793 JP 2002-242938 A

  The present invention has been made in order to solve such problems, and its purpose is to maintain a bearing with excellent durability that can be used continuously over a long period of time by maintaining and improving strength. Is to provide a vessel.

  In order to achieve such an object, the present invention provides a bearing retainer that revolves along the inside of a bearing together with the plurality of rolling elements while holding the plurality of rolling elements rotatably inside the bearing. A pair of annular portions that are continuous in the circumferential direction along the axial direction, and extend between the pair of annular portions, and are arranged at predetermined intervals in the circumferential direction along the annular portion. One annular ring is provided with a plurality of arranged pillars, a plurality of pockets that are partitioned by a pair of annular parts and a plurality of pillars, and that rotatably hold the rolling elements one by one. The rigidity ratio between the rigidity of the part and the rigidity of the other annular part is set in the range of 0.7 to 1.5.

In such an invention, the pair of annular portions have mutually different diameters and are disposed opposite to each other at a predetermined interval at the same center. In this case, the pair of circular ring portions, the small diameter annular portion of smaller diameter, the larger diameter than the small diameter annular portion is constituted by a large-diameter ring portion, the rigidity of the large diameter annular portion K _L and then, when the rigidity of the small-diameter annular portion and K _S, the stiffness ratio K of the pair of circular ring portions is set so as to satisfy _{0.7 <K = K L / K} S <1.5 the relationship Has been. In each pocket, a plurality of rollers are rotatably held as rolling elements one by one.

  According to the present invention, it is possible to realize a bearing cage having excellent durability that can be used continuously for a long period of time by maintaining and improving strength.

Hereinafter, a bearing cage according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 (a) shows a cage 1 used for a railway vehicle axle bearing (double-row sealed tapered roller bearing) as an example of a bearing cage of the present embodiment. The cage 1 is configured to revolve along the inside of the bearing together with the plurality of rolling elements while rotatably holding a plurality of rolling elements (that is, rollers) inside a bearing (not shown). The entire vessel 1 has an axially asymmetric shape.

  More specifically, the cage 1 includes a pair of annular portions 2 and 4 that are continuously disposed in the circumferential direction along the bearing interior and are opposed to each other in the axial direction, and between the pair of annular portions 2 and 4. And is divided by a plurality of pillar portions 6 arranged at predetermined intervals in the circumferential direction along the annular portions 2 and 4, and a pair of annular portions 2 and 4 and the plurality of pillar portions 6. And a plurality of pockets 8 for rotatably holding a plurality of rolling elements (rollers) one by one. In this case, the pair of circular ring portions 2 and 4 are different from each other in diameter, and include a small-diameter small-diameter ring portion 2 and a small-diameter circular ring portion 2 that are arranged opposite to each other at a predetermined interval at the same center. And a large-diameter annular portion 4 having a large diameter. The plurality of column portions 6 extend between the pair of annular portions 2 and 4, and both end portions 6 e are joined to the annular portions 2 and 4.

  The pair of ring portions 2, 4 and the plurality of column portions 6 may be integrally formed at the time of forming the cage, or the plurality of column portions 6 may be formed separately, and both end portions 6e thereof may be formed. It may be retrofitted to the pair of annular portions 2 and 4. In this case, as a method of retrofitting, various methods such as bonding, welding, fitting, and screwing the both end portions 6e of each column portion 6 to the pair of annular portions 2, 4 may be applied. Yes, but not specifically limited here. Moreover, as a material of the cage (ring portions 2, 4 and column portion 6), a resin material may be applied, or a metal material such as a steel plate or brass may be applied.

In the present embodiment, in the cage 1 described above, the rigidity ratio between the rigidity of one small-diameter annular portion 2 and the rigidity of the other large-diameter annular portion 4 is set in the range of 0.7 to 1.5. ing. Specifically, the rigidity of the large-diameter ring portion 4 and K _L, when the rigidity of the small-diameter annular portion 2 and K _S, the rigidity ratio K 2,4 between the pair of circular ring portions, 0.7 It is set so as to satisfy the relationship <K = K _L / K _S <1.5.

Here, the definition of the rigidity ratio K between the pair of annular portions 2 and 4 and the parameters associated therewith will be described with reference to FIGS. FIGS. 7B and 7C show the small-diameter annular portion 2 and the large-diameter annular portion 4 simplified as an annular model. FIG. 2C is a cross-sectional view taken along the line CC of FIG. In this case, when the load F is applied to the portions Pa and Pc facing each other across the center of gravity of the annular models 2 and 4, the relative displacement δac between the portions Pa and Pc is expressed as in equation (1). Can do.
δac = {(π / 4) − (2 / π)} Fr ³ / EI (1)

In the equation (1), r is the radius of the center of gravity position of the cross section of the annular models 2 and 4, E is the Young's modulus of the cage member, and I is parallel to the cage center axis Ax (FIG. 1 (d)). The cross-sectional second moment around the x-axis is shown. In this case, if the load F is constant (const.) And the Young's modulus E is also constant (const.),
δac≈r ³ / I (2)
To satisfy the relationship, the stiffness K _L and stiffness K _S of the small diameter annular portion 2 of the large diameter annular portion 4, (3), can be represented as (4).
K _L = r _L ³ / I _L (3)
K _S = r _S ³ / I _S (4)

In this embodiment, as shown in the equation (5), the rigidity ratio K between the pair of annular portions 2 and 4 is defined by taking the ratio of the stiffnesses K _L and K _{S in} the equations (3) and (4). is doing.
K = K _L / K _S (5)

  Next, as the cage 1 (FIG. 1A) of the present embodiment, for example, six types of cages 1 as shown in FIGS. 2A to 2F are prepared, and each cage 1 is incorporated. It is generated by a collision between the rolling element (roller) and the column portion 6 in a drop impact mode (vibration acceleration α = 15 to 41.25 G) with respect to a railway vehicle axle bearing (double-row sealed tapered roller bearing). The stresses at the four corners 8a and 8b (FIG. 1 (a)) of each pocket 8 were determined by a finite element method (FEM) analysis. In each cage 1 shown in FIGS. 2 (a) to 2 (f), the thickness of the large-diameter annular portion 4 is enlarged in a stepwise manner (six steps in the drawing) in the radial direction, As a result, the rigidity ratio K between the annular portions 2 and 4 in FIG. 10A is 0.1, the rigidity ratio K in FIG. 10B is 0.3, and the rigidity ratio K in FIG. 0.7, the rigidity ratio K of FIG. 10D is set to 1.1, the rigidity ratio K of FIG. 10E is set to 1.5, and the rigidity ratio K of FIG. .

  FIG. 3 shows an outline of the load application method in the FEM analysis. Here, 180 degrees of the cage 1 holding a plurality of rolling elements (rollers) 14 between the inner and outer ring raceway surfaces (between the inner ring raceway surface 10 and the outer ring raceway surface 12) is modeled. Then, the tangential direction (rolling body revolution direction) component of the load (α × rolling body weight) when each rolling element (roller) 14 is accelerated in the drop impact mode (vibration acceleration α = 15 to 41.25 G) is obtained. The cage 1 was loaded via rolling elements (rollers) 14. At this time, left-right symmetric restraints were applied to the 0 ° and 180 ° cross sections of the cage 1.

In this case, the main specifications of the model used for the FEM analysis are shown below.
Cage 1: Outer diameter φ = 210 mm of the large diameter annular part 4, Inner diameter φ = 168 mm of the small diameter annular part 2,
Width 68mm
Material of cage 1: Glass fiber 25% compounded polyamide 66 (PA66GF25)
Young's modulus E = 3450 MPa, Poisson's ratio ν = 0.35
Mass of rolling element 14: 220 g
Number of rolling elements (rollers) 14: 19 Material of rolling elements 14 (rollers): Rigid body

FIG 4 (a), (b) , in the case of the stress 1 of conventional (K = 0.1), and the rigidity ratio K relative to the stiffness K _S of the small diameter annular portion 2, each pocket 8 is a relationship between principal stress ratios generated at the corner 8b on the large-diameter annular portion 4 side (FIG. 1A) and the corner 8a on the small-diameter annular portion 2 side (FIG. 1A) (FEM). Analysis results) are shown. According to this, it can be seen that the principal stress ratio is minimized in the vicinity of K = 1.0. In this case, by setting K = 0.7 or more, the ratio of principal stresses generated at the four corners 8a and 8b of each pocket 8 can be significantly reduced as compared with the conventional product.

  In the region where K = 1.5 or more, the effect of reducing stress is reduced and the internal volume of the bearing is reduced. In particular, in the case of grease lubrication, the amount of enclosed grease is insufficient. Performance cannot be maintained. For this reason, by setting K = 0.7 to 1.5, the strength of the cage 1 and the lubrication performance of the bearing can be maintained and improved. If there is no restriction on the space inside the bearing, by setting K = 0.9 to 1.4, a further stress reduction effect can be obtained, and the main stress ratio can be reduced by 30% or more. .

As described above, according to the present embodiment, the rigidity ratio K between the pair of annular portions 2 and 4 of the cage 1 satisfies the relationship of 0.7 <K = K _L / K _S <1.5. By setting, the circumferential rigidity of each pillar portion 6 constituting each pocket 8 can be made uniform in the axial direction. In this case, the collision force generated between each column part 6 and the rolling elements (rollers) is uniformly distributed in the axial direction of each column part 6, so that the four corners (corner parts 8 a, 8 b) of each pocket 8 are formed. Stress concentration can be reduced. Thereby, it becomes possible to use the bearing in which the cage 1 is incorporated stably over a long period of time, and as a result, it is possible to extend the life of the bearing.

  Further, according to the cage 1 of the present embodiment, there is no need to form reliefs at the four corners of the pocket as in the prior art, so that the thickness of each column portion 6 constituting each pocket 8 is kept constant. Can do. Thereby, the intensity | strength of the whole holder | retainer can be maintained constant and can be improved rather than the past. As a result, it is possible to maintain and improve the durability of the cage 1 itself against a large impact load during high-speed rotation of the bearing.

Further, in the bearing cage 1 of the present invention, the shape of the annular portions 2, 4 satisfying the relationship that the rigidity ratio K is 0.7 <K = K _L / K _S <1.5 is as described above. The present invention is not limited to the form (FIGS. 2A to 2F), and may be configured as shown in FIGS. 5A to 5E, for example. Note that the cage 1 in FIGS. 4A to 4D can be injection molded by the axial draw method, and the cage 1 in FIG. 2E can be injection molded by the radial draw method. Is possible. Here, the thickness and shape of the large-diameter annular portion 4 are mainly changed, but in short, the rigidity ratio K between the pair of annular portions 2, 4 is set to 0.7 <K = K _L / If the relationship of K _S <1.5 can be satisfied, the shape of the annular portions 2 and 4 is not limited to the configuration examples of FIGS. 5A to 5E and is arbitrarily set. Therefore, there is no particular limitation here.

  Further, in the configuration examples of FIGS. 5A to 5E described above, as shown in FIGS. 6A to 6D, the small-diameter annular portion 2 and the large-diameter annular portion 4 are attached to one or both of them. The meat stealing portion 16 may be formed along the direction or the radial direction. In this case, the meat stealing portion 16 is formed by notching a part of the surfaces of the small-diameter annular portion 2 and the large-diameter annular portion 4 so as to be recessed into a concave shape, and is continuous along the axial direction or the radial direction. Or it can be configured intermittently. As an example, in FIG. 6 (a), a plurality of meat stealing portions 16 are formed along the axial direction or radial direction of the small-diameter annular portion 2, and FIGS. 6 (b) to (d) A plurality of meat stealing portions 16 are formed along the axial direction or radial direction of the large-diameter annular portion 4.

  Thus, by forming the meat stealing portion 16 in the small-diameter annular portion 2 and the large-diameter annular portion 4, the rigidity ratio K between the annular portions 2, 4 can be set to an optimum state. In addition, although the concave meat stealing part 16 is illustrated in drawing, it is not limited to this, For example, it can be set as arbitrary shapes, such as circular arc shape and a triangular shape. Further, the shape, size or depth of each meat stealing portion 16 is arbitrarily set according to the size and shape of the small diameter annular portion 2 and the large diameter annular portion 4, the rigidity ratio K to be set, etc. There is no particular limitation here.

  Moreover, in embodiment mentioned above, although demonstrated supposing the resin-made cage 1, it is not limited to this, For example, metal materials, such as a steel plate and brass, are good also as a material of the cage 1. FIG. As an example, FIGS. 7A to 7C show a configuration example of the cage 1 formed by pressing a steel plate. In this case, in the cage 1 shown in FIG. 5A, the small-diameter annular portion 2 extends in the inner diameter direction and the large-diameter annular portion 4 extends in the outer diameter direction. The retainer 1 in FIG. 5B has the large-diameter annular portion 4 bent and bent in the outer diameter direction, and the retainer 1 in FIG. It extends to. In addition, the shape of the small-diameter annular portion 2 of the cage 1 in FIGS. 5B and 5C is the same as that of the cage 1 in FIG.

If the rigidity ratio K of such a steel plate cage 1 can satisfy the relationship of 0.7 <K = K _L / K _S <1.5, the shape of the pair of annular portions 2, 4 Is not limited to the configuration examples of FIGS. 7A to 7C and can be arbitrarily set, and is not particularly limited here. In addition, as a kind of steel plate, although SPCC, SPB2, SPB1, SPHD etc. are mentioned, for example, since this is also arbitrarily selected according to the use purpose or use environment of the holder | retainer 1, it does not specifically limit here.

(a) is a perspective view showing a configuration of a bearing cage according to an embodiment of the present invention, (b) is an annular model in which a small-diameter annular part and a large-diameter annular part are simplified, (c ) Is a cross-sectional view taken along the line C-C in FIG. 4B, and FIG. 4D is a diagram showing a cross-sectional secondary moment in the small-diameter annular portion and the large-diameter annular portion. (a)-(f) is sectional drawing which shows the example of a structure of the holder | retainer for FEM analysis, respectively. The figure which shows the outline of the load loading method in FEM analysis. (a) is a figure which shows the relationship between the rigidity ratio on the basis of the rigidity of a small diameter annular part, and the principal stress ratio which arises in the corner by the side of a large diameter annular part, (b) is the rigidity of a small diameter annular part. The figure which shows the relationship between the rigidity ratio on the basis of and the principal stress ratio which arises in the corner by the side of a small diameter annular part. (a)-(e) is sectional drawing which respectively shows the structural example of the cage for bearings which concerns on the modification of this invention. (a) is sectional drawing which shows the structural example of the cage for bearings in which the meat stealing part was formed in the small diameter annular part, (b)-(d) has the meat stealing part formed in the large diameter annular part. Sectional drawing which shows the structural example of the retainer for bearings. (a)-(c) is sectional drawing which shows the structural example of the holder | retainer each formed by giving a press work to a steel plate.

Explanation of symbols

1 Cage 2 Small Diameter Ring 4 Large Diameter Ring 6 Column 8 Pocket

Claims (4)

A bearing retainer that revolves along the inside of the bearing together with the plurality of rolling elements while holding the plurality of rolling elements within the bearing rotatably,
A pair of annular portions that are continuous in the circumferential direction along the inside of the bearing and arranged opposite to each other in the axial direction;
A plurality of pillar portions extending between the pair of annular portions, and arranged at predetermined intervals in the circumferential direction along the annular portion,
A plurality of pockets that are partitioned by a pair of annular portions and a plurality of column portions and that rotatably hold the plurality of rolling elements one by one;
A bearing retainer characterized in that the rigidity ratio between the rigidity of one annular portion and the rigidity of the other annular portion is set in a range of 0.7 to 1.5.   The bearing retainer according to claim 1, wherein the pair of annular portions have different diameters and are opposed to each other at a predetermined interval at the same center. A pair of annular portion has a small diameter annular portion of smaller diameter, is composed of a large-diameter ring portion of larger diameter than the small-diameter annular portion, the rigidity of the large-diameter ring portion and K _L, diameter When the rigidity of the annular portion and K _S, the rigidity ratio K of the pair of circular ring portions,
0.7 <K = K _L / K _S <1.5
The bearing retainer according to claim 1 or 2, wherein the bearing retainer is set so as to satisfy the following relationship.   The bearing retainer according to any one of claims 1 to 3, wherein a plurality of rollers as rolling elements are rotatably held in each pocket one by one.

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