JP2001003941A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing capable of relaxing the stress concentration due to a contact of a chamfer part of a bearing and a bearing fitting surface at the time of fixing the rolling bearing to a housing or a shaft and capable of realizing the excellent bearing assembly and the application of the axial preload. SOLUTION: A crowning shape formed of a smooth continuous curved surface is formed between the inner diameter surface of an inner ring of a rolling bearing and at least one inner ring end surface and/or a flat part 10a as an outer diameter surface of an outer ring 10 and at least one outer ring end surface 10f. Since an edge is not formed in a chamfer part 10m at a starting part thereof, stress concentration due to a contact with the bearing fitting surface is relaxed, and generation of damage is previously prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing, and more particularly, to a fixed support of a rolling bearing unit on a housing or a shaft.

[0002]

2. Description of the Related Art Rolling bearings (hereinafter also simply referred to as bearings) according to the present invention are mainly used for home electric appliances, industrial motors, spindles, VTRs, HDDs, air conditioners, ventilation fans, cooling fans or belt transmissions for automobiles. Used for rotating parts, those with the inner ring supporting the rotating body and the outer ring fixed to the housing, and those with the outer ring supporting the rotating body and the inner ring fixed to the shaft. Is done.

[0003] Examples of use of the former method of rotating the inner ring and fixing the outer ring include general industrial motors and spindles for machine tools. The inner ring of the bearing unit is press-fitted to the rotating shaft.
The bearing unit is fitted tightly by means of shrink fit, bonding, or the like, and the outer ring of the bearing unit is often assembled into the housing with a loose fit thereafter. As the main dimensions of this type of rolling bearing, JIS B1512 stipulates dimensions indicating a contour defining a bearing boundary, such as a bearing inner diameter d, a bearing outer diameter D, a bearing width B, and a chamfer dimension r (FIG. 9).
Radial bearing example).

The chamfer dimension r is determined so that no burrs or burrs are generated when machining the outer ring outer surface, inner ring inner surface, outer ring end surface, and inner ring end surface of the bearing. It is standardized so as not to cause a problem in contact with the device. For example, deep groove ball bearing 600
In the case of 2, the bearing inner diameter d = 15 mm and the bearing outer diameter D = 32 m
m, bearing width B = 9 mm, and chamfer dimension r = 0.3 mm (minimum).

[0005]

[Problems to be Solved by the Invention] However, "Handbook of Rolling Bearings" (J. Blendline / P. Eschmann / L. Hasbergen / K. Weigand, co-authored, translated by Tatsuo Yoshitake, supervised by Junzo Okamoto, first edition, Industrial Research Committee, 1996
In the description of FIG. 1.100 (see FIG. 10) described on page 66, "The bevel of the bearing ring is not completely 1/4 of a circle for manufacturing reasons. In order to grind the bearing side surface and the inner and outer diameter surfaces, an edge (E) is formed at a portion where chamfering starts. ], A general rolling bearing actually distributed in the market may have an edge (E) at a portion where chamfering starts as shown in FIG.

This will be specifically described with reference to the drawings. FIG. 11 shows that the inner ring 1b of the bearing 1 is press-fitted and fixed to the rotating shaft 2 and the outer ring 1a of the bearing 1
FIG. 3 is an enlarged view showing a state where the rotary shaft 2 is inserted with a certain gap, and the center of the rotary shaft 2 and the center of the inner diameter surface 3a of the housing 3 are attached with a certain inclination θ. At this time, it is ideal that the flat portion 1c of the outer diameter surface of the bearing outer ring is mounted in a state parallel to the inner diameter surface 3a of the housing, but the processing accuracy and assembly of the housing 3 and the rotary shaft 2 as a single part. In accordance with the assembly accuracy and the like in the state, as shown in FIG.
a, the chamfered portion 1d of the bearing outer ring 1a may come into contact with the housing inner diameter surface 3a.

For example, the inner diameter is 15 mm and the outer diameter is 32 m as described above.
When the housing 3 is machined to the JIS standard H7 tolerance with respect to the deep groove ball bearing 6002 having a width of 9 mm and a width of 9 mm, the clearance when mounting this bearing is as follows. That is, the outer diameter tolerance of the bearing is the outer diameter D = 32 mm.
-11 to 0 μm, the housing inner diameter tolerance is 32 m in diameter
Since m is 0 to +25 μm, the minimum clearance is 0 and the maximum is 36 μm (radius clearance is 18 μm).

Now, assuming that the chamfer dimension r of the bearing is 0.3 mm, the bearing half width is 4.2 mm, and when the bearing is inserted into the housing, θ = the bearing outer diameter surface and the housing inner diameter surface.
When the inclination is 0.25 °, the outer diameter surface of the bearing contacts the inner diameter surface of the housing. This bearing is an example, and the bearing used in the technical field to which the present invention belongs is not allowed to have a large dimensional difference between the fitting of the bearing and the housing in order to secure rotational accuracy even if the bearing and the housing are different.
The range in which the inclination θ is allowed is within 1 ° when calculated by the above calculation method. The angle that can be inserted without contact in normal assembly is 3 ° or more, and it is extremely difficult to insert the outer ring into the housing without contact with such a small allowable angle difference.

At this time, if there is an edge E in a portion where chamfering as shown in FIG. 10 starts, as shown in FIG.
The edge E of the chamfered portion 1d of the bearing outer ring 1a comes into contact with the housing inner diameter surface 3a. Therefore, when a force is applied to move the housing 3 in the direction B and the bearing outer ring 1a relatively in the direction A, stress concentrates on a contact point between the edge E and the housing inner diameter surface 3a, The excessive force may damage the inner diameter surface 3a of the housing or the chamfered portion 1d, or may damage the inside of the bearing in some cases. Further, in a bearing device using a method of applying a preload by pressing the bearing outer ring in the axial direction using a spring,
Due to the contact between the edge E and the inner diameter surface 3a of the housing, the bearing outer ring 1a cannot move in the predetermined axial direction, and a state occurs in which an appropriate preload is not applied.

[0010] When the rotating device having such a problem is operated, the rotating device is developed into troubles such as abnormal vibration and abnormal sound of the bearing, and the performance of the rotating device is impaired. Therefore, the present invention has been made in view of such a conventional problem when the rolling bearing is fixed to the housing or the shaft, and reduces the stress concentration due to the contact between the chamfered portion of the rolling bearing and the bearing mounting surface. It is an object of the present invention to provide a rolling bearing that can relax and realize good incorporation of a bearing and secure addition of an axial preload.

[0011]

According to a first aspect of the present invention, there is provided a rolling bearing in which an inner ring and an outer ring rotate relative to each other through rolling of a rolling element. A crowning shape having a smoothly continuous curved surface between an inner diameter surface of the inner ring and at least one inner ring end surface and / or between an outer diameter surface of the outer ring and at least one outer ring end surface. I do.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, only the outer diameter surface of the bearing outer ring is shown in an enlarged manner, but the inner and outer rings, rolling elements, retainers, and seals that constitute the bearing (not shown) may have a conventionally known structure. FIG. 1 is a partial cross-sectional view of a bearing outer ring showing a first embodiment, in which a flat portion 10a is provided on the outer diameter surface of a bearing outer ring 10, and between the flat portion 10a and a side surface (end surface) 10f of the bearing outer ring. A crowning 10b having a radius of curvature Rb and a crowning 10c having a radius of curvature Rc are smoothly and continuously provided on the chamfered portion 10m). Here, the radius of curvature Rc of the crowning 10c in contact with the flat portion 10a is set to be larger than the radius of curvature Rb of the crowning 10b in contact with the bearing outer ring side surface portion 10f (R
c> Rb).

By providing such a shape, FIG.
Since there is no edge E at the portion where chamfering starts as shown in FIG. 0, even when a force is applied to move the housing and the bearing outer ring relatively (see FIG. 12), the chamfered portion and the inner diameter surface of the housing are not affected. Stress concentration at the contact point is reduced,
Damage to the inner diameter surface of the housing or the chamfer,
The risk of damaging the inside of the bearing can be avoided. Further, even in a bearing device using a method of applying a preload by pressing the bearing outer ring 10 in the axial direction using a spring, since the bearing outer ring 10 has no edge, the outer ring 10 moves in a predetermined axial direction. There is no hindrance, so that an appropriate preload can be applied.

Specifically, for example, in the case of FIG. 1, the radius of curvature Rb of the crowning 10b is 1 to 3 times the minimum value of the chamfer dimension r shown in FIG. 9, and the radius of curvature Rc of the crowning 10c is
Is about 2 to 10 times Rb, and the flat portion 10a is 50 to 90% of the bearing width B. The radius of curvature Rc of the crowning 10c is too small or the flat portion 10a is smaller than this value.
If the diameter is too large, an edge (E) is formed on the outer diameter of the bearing due to insufficient crowning effect, and the edge E hits the inner diameter (3a) of the housing as shown in FIG. Cannot be sufficiently prevented.

On the other hand, the radius of curvature Rc of the crowning 10c
Is too large or the flat portion 10a is too small, the contact area between the outer diameter of the bearing and the inner diameter of the housing becomes small, so that the bearing is insufficiently fixed to the housing, and unstable vibration caused by this during rotation. Is more likely to occur. FIG. 1 shows a case where the chamfered shapes and dimensions at both ends of the bearing outer ring are symmetrical. However, this is not necessarily required to be symmetrical. Set. For example, in the case where the action of the moment is not symmetrical, it is possible to design so that the contact area that exerts a large force becomes large.

In this embodiment, the case of a deep groove ball bearing is described. However, the present invention is not limited to this, and all rolling bearings used in a rotating device used in the technical field to which the invention pertains, that is, cylindrical roller bearings The same effect can be obtained for tapered roller bearings, angular ball bearings, self-aligning roller bearings, needle bearings, etc. by providing the outer ring with a crowning shape in the same manner. In this case, the performance of single bearings such as ordinary deep groove ball bearings, cylindrical roller bearings, and self-aligning roller bearings does not change when assembled and used from either direction. It is convenient when assembling.Bearings with a contact angle such as tapered roller bearings and angular contact ball bearings have a fixed mounting direction, so there is no need to make them symmetrical. There is also.

FIG. 2 is a partial sectional view of a bearing outer ring showing a second embodiment of the rolling bearing according to the present invention. In this case, a flat portion 10a is provided on the outer diameter surface of the bearing outer ring 10, and a crowning 10b having a radius of curvature Rb, a crowning 10c having a radius of curvature Rc, and a radius of curvature Rd are provided between the flat portion 10a and the side surface 10f of the bearing outer ring. The crowning 10d is provided smoothly and continuously. The radius of curvature Rd of the crowning 10d in contact with the flat portion 10a is
0c, larger than the radius of curvature Rc, and the crowning 10c
Is set to be larger than the radius of curvature Rb of the crowning 10b (Rd>Rc> Rb), and the same effect as in the first embodiment shown in FIG. 1 can be obtained.

In FIG. 2, as in FIG. 1, the radius of curvature Rb
Is 1 to 3 times the minimum value of the chamfer dimension r in FIG.
c and Rd are approximately 2 to 10 times the radius of curvature Rb,
The flat portion 10a has a value of 50 to 90% of the bearing width B. If the radius of curvature Rc or Rb is too small or if the flat portion 10a is too large, the crowning effect is insufficient, so that the edge E formed on the bearing outer diameter as shown in FIG. In some cases, a defect may occur. Conversely, if the radius of curvature Rc or Rd is too large or the flat portion 10a is small, the contact area between the bearing outer diameter and the housing inner diameter becomes smaller, so that the bearing is not sufficiently fixed to the housing, and during rotation, It may cause unstable vibration. FIG. 2 shows a case where the chamfered shapes and dimensions at both ends of the bearing outer ring are not bilaterally symmetric. However, this may or may not be bilaterally symmetric as in FIG. Crowning may be applied.

In the embodiment shown in FIGS. 1 and 2,
Although the example in which the plurality of arc-shaped crownings are provided continuously with the flat portion has been described, the present invention is characterized in that the edges generated on the flat portion and the side portions are eliminated, so that the arc-shaped crowning is provided. Not only that, it is also possible to apply an ellipse or an edgeless shape obtained by combining a plurality of curves (including straight lines), all of which are within the scope of the present invention.

As one example, a third embodiment of the present invention is shown in FIG. This is 8mm outside diameter, 4m inside diameter
A pseudo-arc crowning is formed by barrel processing on a bearing outer ring having a width of 2 mm and a width of 2 mm. The minimum value of the chamfer dimension r according to JIS of the bearing of this size is 0.1 mm. The flat portion 10a and the side surface 10 of the outer diameter surface of the outer race
The chamfered portion 10m is formed by chamfering a corner portion where f intersects at 5 ° to 45 °. Thereafter, the outer ring is subjected to barrel processing and rounded, so that the outer diameter surface 10a, the chamfered portion 10m, and the side surface 10f are connected by a smooth curved surface to eliminate edges, and the entire chamfered portion 10m can have a smooth curved surface shape. .

FIG. 3 shows that the chamfered portion 10 m
Is a quasi-arc crowning shape in which the length rx from the bearing end face 10f is 0.2 mm and the amount of fall ry from the outer diameter flat portion 10a is 0.13 mm. In this example, the radius of curvature of the arc of the pseudo crowning is approximately 0.65 at the center.
mm, the tangent R between the chamfered portion 10m and the outer diameter flat portion 10a is a compound arc having a diameter of about 0.15 mm. At this time, the number of pseudo-arc crowning need not be two, but may be one or two or more. In most cases, the radius of curvature can be set by changing the barrel conditions to be a combination in the range of 1 to 10 times the minimum value of the chamfer dimension.

When barrel processing is performed, as shown in FIG. 3, the edge of the joint between the outer diameter surface and the crowning becomes extremely smooth. Even if the radius of the arc increases by more than ten times the chamfer dimension, the individual tangent R
Even if a part of the diameter becomes smaller than the minimum value, if there is no joint edge due to the continuation of the tangent line R, as shown in FIG. 12, the edge E comes into contact with the housing inner diameter surface 3a during assembly, causing damage. Never.

FIG. 3 shows an example in which a barrel having an outer ring outer diameter of 8 mm and a width of 2 mm is subjected to barrel processing.
From smaller sized bearings, e.g., 3 mm outer diameter, 1 mm wide, to larger bearings, e.g., 200 mm outer diameter, 45 m wide
m. For a bearing having an outer diameter of more than 30 mm, a similar pseudo-crowning shape can be obtained by a process such as shot blasting or shot peening for an outer diameter of about 1000 mm.

Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, an inner diameter of 9 mm, an outer diameter of 24 mm, and a width of 7 m used for parts of home appliances, information and precision equipment are used.
m, so-called small diameter and miniature bearings
The outer diameter shape and roughness of the outer ring used in that case are specified. In the case of a small-diameter miniature bearing, the absolute value of the gap between the housing and the outer diameter of the outer ring becomes small because the bearing size is small. FIG. 4 shows a conventional inner diameter of 5 mm, outer diameter of 13 mm,
It is a measurement example of the outer diameter of the outer ring of a small-diameter miniature bearing having a width of 4 mm. In the grinding finish, the roughness is the center line average roughness Ra =
0.093 μm, and the skewness indicating the projection shape is R
sk = −0.01. When processed under these conditions, 1
For a lot of 00 pieces, the roughness Ra is 0.055 μm <R
a <0.2 μm range, skewness −0.3 <Rs
It is in the range of k <0.5. The shape of the outer surface of the outer ring outer diameter is almost flat and often convex, but there are also cases where the outer surface has a concave shape. The bearing of this lot has a 90% orthogonality ratio at the time of assembly, that is, a defect rate of 10%, and cannot be used for mass production of the bearing at this defect rate.

FIG. 5 shows a fourth embodiment of the present invention as a countermeasure.
(A) is an enlarged view showing the shape of the outer diameter surface of the outer race measured, and (b) is a diagram showing the roughness and skewness of the outer diameter surface. In this case, the bearing is super-finished and, if necessary, further barreled,
The roughness of the outer diameter surface of the bearing is set to be significantly smaller than that of the conventional bearing, the center line average roughness Ra is set to Ra ≦ 0.05 μm, and the skewness indicating the roughness projection shape is set to Rsk ≦ −0.5. To For example, the shape shown in FIG. 5 is a smooth crowning shape in which the center is convex at the center and both ends are several μm lower than the center. The roughness is Ra = 0.014 μm, R
sk = −0.11. When processed under these conditions, the roughness Ra is 0.005 μm <100 lots.
Ra <0.03 μm range, skewness −2.0 <
Rsk <−0.7. The shape is
All 100 are convex. In this case, the orthogonality ratio at the time of assembling the bearings of 100 pieces is 100%, which can be applied to the mass production process of the bearings. Given the roughness of the processing under these conditions,
It is more preferable that the center line average roughness Ra ≦ 0.03 μm and the skewness Rsk ≦ −0.7 indicating the roughness projection shape be satisfied.

Further, the hardness of the bearing outer diameter surface is made larger than the hardness of the housing inner diameter surface, and the roughness of the bearing outer diameter surface is made smaller than the roughness of the housing inner diameter surface. By combining the projections with the roughness of the housing surface along the outer diameter surface of the outer ring, the incorporation of the bearing can be improved.

FIG. 6 schematically shows the fitting of members having different roughness and hardness. In the present invention, a material having a small roughness is hard and a material having a large roughness is soft. As can be seen from this figure, if the roughness is smaller, the synergistic roughness is reduced by cutting the roughness of the soft surface when it comes into contact with the mating surface. On the other hand, if the higher the roughness, the harder the surface of the mating member is cut, and the higher the roughness, the greater the synergistic roughness. The relationship between the roughness and the hardness of the present invention is described in the third embodiment (FIG. 3) and the fourth embodiment (FIG. 5).
When applied to the case, the bearing material is a bearing steel SUJ2 or a material equivalent thereto, a case-hardened steel subjected to a surface treatment such as carburizing or carbonitriding, or a martensitic stainless steel having a Vickers hardness of Hv. ≧
700 or more, and the housing material may be any combination of aluminum alloy, stainless steel, steel plate, etc., having a Hv of 600 or less. Regarding the roughness, this combination can be achieved by setting the center line average roughness Ra ≦ 0.05 μm on the bearing outer diameter surface and the center line average roughness Ra> 0.05 μm on the housing inner diameter surface. .

(Examples) Comparative tests performed to confirm the effects of the present invention will be described below. A: Specimen As a specimen, a deep groove ball bearing 6002 (inner diameter 15 mm,
(Outer diameter 32 mm, width 9 mm).

Conventional example; JI as shown in FIG.
S-chamfered. Example: Pseudo-arc crowning by barreling the outer diameter surface of the outer ring. By using the same processing machine and barrel medium as in the third embodiment (FIG. 3) and increasing the processing time, the length rx of the ten bearings from the bearing end face is 0.9 to 1 The workpiece was machined so as to fall within the variation range of the pseudo-arc crowning shape of 0.5 mm and the fall amount ry from the outer diameter of the end face ry = 0.4 to 0.5 mm.
The radius of the arc of the chamfered portion 10m of the pseudo crowning is approximately 3 to 5 mm, the radius of curvature R of the curved surface of the connecting portion with the outer diameter surface flat portion 10a is approximately 0.7 mm, and the flat portion 10a has a bearing width B of 67 to 80 mm. % Range. B: Test Method Two test body bearings of the conventional example or the embodiment were separately incorporated into the motor shown in FIG. 7, and the vibration level of the motor housing 24 when the motor was operating was evaluated.

That is, 20a of the rotor shaft 21 of the motor
, And the test sample bearing of either the conventional example or the embodiment is press-fitted and fixed at positions 20b and 20b. This is inserted into the stator 22, and then the housing 24 is fixed to the stator 22 via the preload spring 23. The acceleration sensor 25 is mounted on the housing 24 and the motor is operated (rotation speed 1800 rpm).
The vibration of m) was sent to the FFT 27 via the amplifier 26, and the vibration frequency was analyzed. This test was performed by disassembling and assembling the motor 10 times each using the bearings of the example and the conventional example, and analyzing the vibration frequency each time. C: Test Result FIG. 8 shows an example of the vibration level of the motor housing 24 in the motor operating state. The abnormal level in FIG. 8 means that an appropriate preload is not applied to the test specimen bearing.
It is a typical vibration frequency characteristic of a motor. On the other hand, the normal level is a typical vibration frequency characteristic in a state where an appropriate preload is applied to the test bearing.

In the conventional bearing, three out of the ten bearings have frequency characteristics in which the peak of the vibration shown as an abnormal level in FIG. 8 appears at a frequency of about 1.5 to 2 kHz. The vibration level was higher than the normal level. This is because preload loss occurred because the bearing did not enter the housing smoothly.

On the other hand, in the bearing of the embodiment in which the pseudo crowning is performed, the abnormal vibration as described above does not appear.
All ten had normal levels of vibration values. FIG. 8 shows one of the data. From these results, it can be seen that in the bearing of the embodiment, good incorporation and reliable addition of the axial preload are realized. The above test results were obtained from 6002 (inner diameter 15 mm, outer diameter 32 m
m, width 9 mm) obtained for the bearing, but having an inner diameter of 5 mm and a diameter of 4 mm according to the fourth embodiment (FIG. 5) of the present invention.
A similar rotation test was performed on a bearing having an outer diameter of 13 mm and a width of 4 mm, and the conventional miniature bearing shown in FIG. 4. The difference due to the effect of the preload loss similar to the above was clearly recognized.

In the above description of the embodiment and the examples, it has been confirmed as described above that the effect is exhibited when the bearing unit, which is an assembly of the shaft is press-fitted into the inner ring, is assembled into the housing with a loose fit. However, the rolling bearing of the present invention is not limited to such an assembling method, and when the assembly with the housing is an interference fit such as press fitting or shrink fitting, the bearing alone is incorporated into the housing without mounting the shaft. In this case, the present invention can be applied to a case where a bearing such as a tapered roller bearing or a thrust bearing that can separate an inner ring and an outer ring is incorporated in a housing.

In the above description, the case where the outer ring is inserted into the housing has been described. However, when the outer ring is used by bonding, the present invention can be applied to not only the outer ring but also the inner ring. In this case, when the shaft outer diameter surface and the bearing inner diameter surface are inserted and mounted and the housing inner diameter surface and the bearing outer diameter surface are inserted and mounted, the edge of the bearing portion is smoothed by performing crowning, so that the adhesive is scraped off by the edge. Such a problem can be prevented. In addition, there is an advantage that a gap is formed between the shaft outer diameter surface and the bearing inner diameter surface and between the housing inner diameter surface and the bearing outer diameter surface by the crowning, and the adhesive penetrates therebetween, thereby increasing the adhesive force.

In the above embodiments and examples, the description has been given of the case where the bearing is used with the outer ring fixed and the inner ring rotated. However, the present invention can be applied to the case where the inner ring is fixed and the outer ring is rotated. For example, a bearing used for a spindle motor of a hard disk drive is used for outer ring rotation. In this case, there is a usual method of tightly fitting at least one of the inner and outer rings, and assembling the other with a clearance fit, but also a method of making the inner and outer rings a loose fit and bonding at least one or both. In many cases, in such a case, it is effective to provide crowning on the inner ring inner diameter surface or the outer ring outer diameter surface of the bearing raceway to be bonded. This is not limited to the bearing used for the spindle motor of the hard disk drive, but is also valid for all bearings for rotating devices in the field to which the inventions used for similar applications belong.

[0036]

As described above, according to the rolling bearing of the present invention, between the outer diameter surface of the outer ring and at least one side surface of the outer ring, and / or the inner diameter surface of the inner ring and at least one inner ring end surface. A crowning shape consisting of a smoothly continuous curved surface is provided between them, so that the edges existing in the chamfered portion can be eliminated to reduce stress concentration due to contact, and as a result, good bearing incorporation and reliable shaft There is an effect that the addition of the directional preload can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an outer race showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an outer race showing a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of an outer race showing a third embodiment of the present invention.

FIG. 4 is a diagram showing the roughness and skewness of the outer ring outer diameter surface of a conventional rolling bearing that has been ground and finished.

FIG. 5A is a diagram showing a shape of an outer diameter surface of an outer ring according to a fourth embodiment of the present invention, and FIG. 5B is a diagram showing roughness and skewness thereof.

FIG. 6 is a cross-sectional view illustrating a combination relationship between roughness and hardness of a fitting surface having roughness.

FIG. 7 is a sectional view of a rotation test device for evaluating the vibration level of a rolling bearing.

FIG. 8 is a diagram illustrating an example of a vibration level in a rotation test.

FIG. 9 is a longitudinal sectional view illustrating main dimensions of a radial bearing.

FIG. 10 is a cross-sectional view showing an edge formation by turning and grinding of a conventional rolling bearing outer ring.

FIG. 11 is a cross-sectional view showing a mounted state of a rolling bearing.

FIG. 12 is a sectional view showing an interference state between an edge of a rolling bearing outer ring and a housing inner diameter surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling bearing 1a Outer ring 1b Inner ring 1c Flat portion of outer ring outer diameter surface 1d Chamfered portion of outer ring outer diameter surface E Edge of chamfered portion of outer ring outer diameter surface 2 Rotation shaft 3 Housing 3a Housing inner diameter surface 10 Outer ring 10a Outer ring 10a Flat part 10b Crowning of outer ring 10c Crowning of outer ring 10d Crowning of outer ring

Claims (1)

[Claims] 1. A rolling bearing in which an inner ring and an outer ring rotate relative to each other through rolling of a rolling element, wherein between an inner diameter surface of the inner ring and at least one inner ring end surface and / or an outer diameter surface of the outer ring. A rolling bearing having a crowning shape formed of a smoothly continuous curved surface between at least one outer ring end face.