JP2000192979A - Rolling bearing - Google Patents

Abstract

(57) [Abstract] [Problem] To reduce noise and vibration of a preload applying type rolling bearing. An outer diameter surface of a bearing outer ring is covered with a cylindrical outer diameter member having a larger static friction coefficient than a kinetic friction coefficient. By joining the side member 7 having a large coefficient of static friction and having a sliding property in the axial direction and a function of suppressing rotation in the circumferential direction, the inner ring 2 can be incorporated into the housing 24 even after the inner ring 2 is pressed into the rotating shaft 23. It easily exerts a creep preventing function on the inner diameter of the housing 24 to be fitted into the gap, and realizes a vibration damping function and a reliable preload application.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing for supporting a rotating shaft of a home appliance, an industrial motor, a spindle, and the like, and more particularly to a rolling bearing which is used in a state where an outer ring is axially pressed by a spring member or the like and preloaded. It is suitable for a rolling bearing to be used.

[0002]

2. Description of the Related Art Generally, a rolling bearing used for a rotating device such as a motor or a spindle is used by tightly fitting an inner ring to a rotating shaft and fitting an outer ring to a housing with a gap, thereby increasing the rigidity of the rolling bearing. For this purpose, a preload is applied by pressing the side surface of the outer race in the axial direction by a spring member or the like via a spacer or the like (hereinafter also referred to as a constant pressure preload).

[0003] When the rolling bearing of such a rotating device is rotated, it receives a moment due to the bending behavior of the rotating shaft, vibration or impact due to eccentric motion, etc., which propagates to the housing and generates vibration and noise. In some cases, vibrations (e.g., rolling element passing vibrations) caused by the bearing itself also propagate to the housing, causing vibration and noise. As measures for reducing such vibration and noise, for example, Japanese Patent Application Laid-Open No. 9-6560
As described in Japanese Patent Application Laid-Open No. 4-8400, a bearing is supported by a plurality of O-rings, and sound transmission is absorbed by the O-rings to obtain a soundproofing effect. As described in Japanese Patent Application Laid-Open No. 7-67284, polyphenylene sulfide resin is injection-molded as an absorbing resin film covering an outer ring and a width surface of a bearing. In order to effectively absorb and attenuate vibration and noise, there is a type in which a fixed wheel is attached to a stator side of a motor via a vibration absorbing member made of synthetic resin or synthetic rubber. That is, there are many cases in which a vibration damping member for absorbing and attenuating vibration and noise is interposed between the bearing outer ring and the housing.

[0004]

However, when these rolling bearings are assembled by applying a preload in the axial direction, the problem is caused by the contact between the vibration damping member provided on the outer diameter of the outer ring and the housing. Is more likely to occur. For example, the accuracy of the vibration damping member made of rubber or resin, the dimension or shape accuracy when the vibration damping member is mounted on the outer diameter of the bearing outer ring is at least inferior to the accuracy of the bearing outer ring main body, and depending on the accuracy relationship with the housing, assembly may be performed. Sometimes the damping member mounted on the outer race may need to be pressed into the housing.

For example, when a rotary shaft is press-fitted into a bearing inner ring, and a vibration damping member attached to the bearing outer ring is pressed while pressing the rotary shaft, the vibration damping member is distorted in the axial direction due to friction with a housing. At the same time, as the coefficient of friction between the vibration damping member and the housing is larger, a greater force is required for press-fitting, and if it is severe, the press-fitting to a predetermined position cannot be performed. As a result, there is a possibility that an indentation due to the rolling element is generated on the bearing rolling surface. In addition, a shear force generated by friction between the damping member and the housing may cause a crack, peeling, falling off, or the like of the damping member.

In order to solve such a problem, there is a method of making the fitting gap between the vibration damping member and the housing sufficiently large so that the above-mentioned shearing force is hardly generated. In this case, the bearing outer ring and the damping member slide and rotate with respect to the housing with the rotation of the rotating shaft, so-called bearing creep is liable to occur. This creep also causes abnormal vibration and noise, There is a possibility that a serious obstacle may be caused to the entire rotating device, such as deterioration of rotation accuracy of the rotating shaft and wear of the housing.

As a countermeasure against such a bearing creep, for example, there is a method in which a groove formed in a circumferential direction of an outer ring outer diameter surface is filled with a synthetic resin so as to protrude from the outer ring outer diameter surface.
Also, as described in JP-A-10-37967, the outer diameter surface of a bearing outer ring is formed in a concave shape so that a creep preventing effect can be maintained against a temperature change.
As described in Japanese Patent Application Laid-Open No. 9-4643, a method has been proposed in which a recess is provided in a part of a bearing housing to fit a bearing, and an adhesive is injected into the recess.

However, in either method, since the bearing outer ring and the housing are in pressure contact or fixed state, there is a problem that a preload cannot be applied in the axial direction even if the outer ring is pressed by a spring member. The present invention has been developed in view of these problems, and does not require a drastic design review of the housing and the periphery of the shaft. It is another object of the present invention to provide a rolling bearing capable of reliably applying a preload.

[0009]

In order to achieve the above object, a rolling bearing according to the present invention is a rolling bearing which is used by rotating an inner ring while a preload is applied to an outer ring. The outer ring outer diameter surface member and the outer ring side surface member mainly composed of rubber or resin are attached to the surface and the side surface, and the coefficient of static friction of the outer ring outer diameter surface member is larger than the dynamic friction coefficient of the outer ring outer diameter surface member, and The coefficient of static friction of the outer ring side surface member is larger than or equal to the coefficient of static friction of the outer ring outer diameter surface member.

For example, "lubricity of plastic material"
(Written by Shozaburo Yamaguchi, 1st edition, Nikkan Kogyo Shimbun, Showa 56
As is clear from p) and p45, different values of the coefficient of friction are obtained depending on the test method and the combination of materials. As for the materials, the present invention can be applied to any combination of materials. For the housing, metal is used as a representative. Regarding the test method, even though the value of the coefficient of friction may differ depending on the test method, the tendency of the magnitude relationship hardly changes, and the values of the material having the small coefficient of friction are equal to those of the material having the large coefficient of friction. When converted by linear approximation, the values of the friction coefficients of other materials become almost equal.
Hereinafter, the value of the coefficient of friction is a measured value of the coefficient of friction obtained in each test, and the coefficient of static friction is such that the coefficient of static friction between aluminum alloys is μs = 0.55, tetrafluoroethylene PTF
The coefficients of static friction between F and F were used in linear approximation conversion so that μs = 0.134.
C) Linear approximation conversion is used so that the kinetic friction coefficient between them becomes μk = 0.468, and the kinetic friction coefficient between the tetrafluoroethylene PTFFs becomes μk = 0.083.

The outer ring outer diameter surface member is attached to the bearing outer ring outer ring surface, faces the inner diameter of the housing, and is fitted with a radial (radial) gap. For this reason, the outer ring vibrates very minutely with the movement of the rolling element due to the rotation of the bearing, and the axial movement for adjusting the preload change due to the temperature change or the like is caused by the outer ring outer diameter surface member. It is required that the dynamic friction coefficient μk be small together with the static friction coefficient μs, and that the static friction coefficient μs be larger than the dynamic friction coefficient μk. As described above, the static friction coefficient μs between the aluminum alloys as the material of the housing is 0.550, and the dynamic friction coefficient μk between the steels as the material of the bearing outer ring is 0.468. Satisfies the conditions. Also, the lower limit of the coefficient of friction is determined by the formability and workability of the material. If the coefficient of friction is smaller than a predetermined value, the material becomes too soft, making it difficult to ensure processing accuracy.
As shown in the figure, the static friction coefficient μs of the material of the outer ring outer diameter surface member
Is 0.2 to 0.55, and the dynamic friction coefficient μk is 0.1 to 0.4.
68. Materials for such outer ring outer diameter surface members include PPS (porophenylene sulfide) and linear P
Plastics such as SS, linear PPS + graphite, PPS + graphite + PTFE, nylon 6,6-6 nylon, polycarbonate, polyacetal, polyethylene, polyamide resin, thermoplastic polyimide resin, thermoplastic fluororesin, polyarylene sulfide, aromatic polyetherketone And acrylic rubber, nitrile rubber,
Synthetic rubbers such as acrylonitrile rubber, fluororubber, diene rubber, hydrogenated acrylontrilo rubber, silicone rubber, polyester elastomers, polyamide elastomers, and the like.

Further, the outer ring side member needs to generate a sufficient frictional force (for creep) so that the outer ring does not rotate with respect to the rotational force of the bearing. Is a standard (preferably, the coefficient of static friction μs between aluminum alloys is larger than 0.550 and the coefficient of kinetic friction between steels μk is greater than 0.468). In general, since the coefficient of kinetic friction is smaller than the coefficient of static friction, it is not easy to stop the movement of the outer ring that has once started to rotate with the outer ring side member, so it is important that the static coefficient of the outer ring side member is large. Depending on the conditions of use, the required conditions of rotation and creep in a rotating state are different, but at least when the coefficient of static friction of the outer ring outer diameter surface member is smaller, it becomes easier to rotate, so it is equal to or larger than this. There is a need to. Therefore, as a material of the outer ring side member, a material having a small friction coefficient, such as PTFE, which is not suitable as a detent member is removed from the material of the outer ring outer diameter surface member as shown in FIG. A coefficient μs = 0.3 to 0.8 is used. Note that the upper limit of the static friction coefficient μs is limited as having a certain elastic force and having a vibration damping effect, and those having a static friction coefficient μs exceeding 0.8 are too hard to have a vibration damping function. Will be gone.

When the coefficient of thermal expansion of the outer ring side member is larger than the coefficient of thermal expansion of the outer ring outer diameter member, a gap between the outer ring outer diameter member and the housing is reduced due to a rise in temperature during use. Therefore, it is desirable that the coefficient of thermal expansion of the outer ring side surface member is smaller than that of the outer ring outer diameter surface member. Therefore, as the material of the outer ring side member, PPS (porophenylene sulfide), linear PSS, linear PPS + graphite, PPS + graphite + PTFE, nylon 6,6-6 nylon, polycarbonate, polyacetal, polyethylene, polyamide resin, thermoplastic polyimide resin Plastics such as thermoplastic fluororesin, polyarylene sulfide, and aromatic polyether ketone; and synthetic rubbers such as acrylic rubber, nitrile rubber, acrylonitrile rubber, fluoro rubber, diene rubber, hydrogenated acrylon trilo rubber, silicon rubber, and the like. a polyester elastomer, polyamide elastomer, etc., so that a greater coefficient of friction is obtained, carbon fiber, mica, _{asbestos, SiO 2, Al 2 O 3} , fillers and additives such as carbon black Which was contained and the like.

These combinations are based on the assumption that the outer diameter of the bearing outer ring and the inner diameter of the housing are used with a normal fitting of JIS7 tolerance, and the bearing load, the rotation speed, and the rise in the temperature of the bearing cause the outer diameter of the bearing to increase. In consideration of the diameter, the thermal expansion of the vibration damping member, and the housing, the outer ring outer diameter surface member can be used as the outer ring side member. For example, PPS, polycarbonate, or the like is used as the outer ring outer diameter surface member, and acrylic rubber, fluorine rubber, or the like is used as the outer ring side member. In the case of PPS, the friction coefficient can be designed in a large range from 0.15 to 0.7 by blending glass fiber, graphite, carbon fiber, PTFE, and the like. The compounded material may be used as the outer ring outer diameter surface member, and the compounded material having a large friction coefficient may be used as the outer ring side member. When there is a difference between the coefficient of static friction and the coefficient of dynamic friction, and the coefficient of static friction is large and the coefficient of dynamic friction is small, the same material can be used for the outer ring outer diameter surface member and the outer ring side member.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a spindle in which two rolling bearings of the present invention are used to face each other, in which a preload is applied by a spring member 16 and the outer ring 1 is attached to a housing 24. In the figure, reference numeral 1 is an outer ring, 2 is an inner ring, 3 is a rolling element,
Reference numeral 4 denotes a holder, and reference numeral 5 denotes a seal. On the outer diameter surface 1a of the outer ring 1 of this rolling bearing, for example, the linear PPS +
The outer ring outer diameter surface member 6 which is formed in a cylindrical shape with 30% GF or the like is covered with an interference. Further, for example, the outer ring side member 7 formed in a ring shape with the acrylic rubber or the like,
The rolling bearing is attached to the side surface 1b of the outer ring 1 and the side surface of the outer ring outer diameter surface member 6 by bonding. The outer ring outer diameter surface member 6 attached to the bearing outer ring 1 includes a housing 2
4 is fitted with a clearance fit of JISH7.
At the time of assembly, the outer ring outer diameter member 6 faces the inner diameter surface of the housing 24 and the outer ring side member 7 is
By mounting so as to face the end face 4 and the spring member 16, vibration can be suppressed by the two members 6 and 7.

The spring member 16 applies a preload in the right direction in the figure to the left bearing outer ring 1 through the outer ring side member 7 through the outer ring side member 7, and this force is applied from the left bearing rolling element 3 in the figure. The bearing inner ring 2, the rotating shaft 23, and the right bearing inner ring 2 shown in the figure pass through the bearing rolling element 3 to the right bearing outer ring 1 shown in the figure, and are balanced with the reaction force in the housing 24 to the left generated in the housing 24. A preload corresponding to the spring constant acts on each rolling bearing.

At this time, for example, in the case where an O-ring is provided on the outer diameter of the outer ring, when the bearing outer ring is fixed to the housing by friction between the outer diameter surface of the bearing outer ring and the inner diameter surface of the housing, the leftward direction shown in the drawing occurs in the housing. The so-called preload loss occurs. In addition, when a member made of a material having both vibration damping properties and slidability, such as synthetic rubber, is attached to the outer ring outer diameter, it is necessary to reduce the influence of metal contact on the bearing end face. It is necessary to increase the contact area with the surface, and the gap between the bearing and the outer diameter of the bearing becomes smaller. Therefore, even if the vibration is small at first, the bearing (usually steel = SUJ2) will generate heat and change in the ambient temperature during use. The interference varies due to the difference in the coefficient of thermal expansion between bearing steel and carburized steel, carbonitrided steel, members (synthetic rubber and plastic), and housing (aluminum alloy, etc.) until they return to the proper preload state.
A stick-slip phenomenon may occur between the bearing outer ring and the housing, and the vibration level may increase irregularly. In order to avoid this, if the preload is made smaller and the effect of the contact between the bearing end face and the housing end face is reduced, vibration will be increased due to the small preload, and the friction between the bearing and the housing will be reduced. The rotation of the bearing causes a rotational motion between the outer diameter of the outer ring and the inner diameter of the housing, thereby causing creep.

On the other hand, in the present embodiment, the friction with the inner diameter surface of the housing 24 is reduced by mounting the outer ring outer diameter surface member 6, and the axial movement of the spring member 16 is improved due to its excellent sliding characteristics. The preload can be reliably applied by moving the outer ring in response to the preload in the direction, and the preload can be prevented from dropping out. Further, the outer race side member 7 includes an end surface of the housing 24 and the spring member 1.
6, the outer ring 1 is prevented from moving in the rotational direction by its high coefficient of friction, and the occurrence of creep between the outer diameter surface of the bearing outer ring and the inner diameter surface of the housing can be suppressed.
Note that, with respect to the constraint of the preload in the axial direction due to the large friction coefficient of the outer ring side member 7, the thickness of the outer ring side member 7 is set to be smaller than the width of the outer ring outer diameter surface member 6.
There are steps such as providing a step to reduce the outer diameter of the outer ring outer diameter surface member 6 and making the thermal expansion coefficient smaller than that of the outer ring outer diameter surface member 6. Furthermore, not only due to its sliding characteristics and anti-creep function, but also due to the excellent vibration damping characteristics of the material, the outer ring outer diameter surface member 6 suppresses the radial direction vibration, and the outer ring side surface member 7 suppresses the axial direction vibration, thereby reducing the vibration. Low noise rotation performance can be obtained.

The outer ring outer diameter surface member 6 only needs to have such an effect of absorbing and attenuating vibration and noise, and can slide in the axial direction with a load smaller than a predetermined axial preload. As described above, the static friction coefficient μs between aluminum alloys = 0.550 and the dynamic friction coefficient μk between steels = 0.46
It is a standard to use a material having a coefficient of friction smaller than that of No. 8, and in addition to the above, a fluororesin film bonded to the surface of a rubber-like elastic body as described in Japanese Patent Publication No. 46-23681, for example. Ya, Tokiko 57-3295
As described in Japanese Patent Publication No. 0, a resin obtained by heat-sealing an olefin-based resin may be used. Further, as a rubber elastic body having improved slidability, for example, JP-A-7-188469
JP-A-8-85758 discloses a mixture of acrylonitrile-butadiene rubber, a tetrafluoroethylene resin powder having carbon pierced on its surface and spherical graphite, or a polyphenylene sulfide resin as described in JP-A-8-85758. To which 5 to 40% by volume of a fluororesin, 3 to 25% by volume of an aromatic polyester resin, and 2 to 20% by volume of a para-aromatic polyamide fiber are added. The outer ring side member 7 is
Any material having a coefficient of friction equal to or greater than that of the outer ring outer diameter surface member 6 and generating a sufficient resistance to the creep force is desired, and further, a material having both absorption and damping effects on vibration and noise. By selecting, it is possible to further reduce vibration and noise.

In the first embodiment, the outer ring outer diameter surface member 6 is formed on the entire outer diameter surface 1a of the outer ring 1 in the axial direction, but may be a part thereof. Further, in the first embodiment, the outer ring side member 7 is formed in the entire radial direction of the side surface 1b of the outer ring 1, but may be a part thereof.
In the first embodiment, one side surface 1b of the outer race 1 is provided.
The outer ring side member 7 is attached only to the
It may be provided on the other side surface 1b.

The shape of the outer ring outer diameter surface member 6 and the outer ring side member 7 and the structure such as the ratio of the thickness to the outer ring 1 and the presence or absence of a mandrel are not limited at all. Also,
The mounting method or mounting structure between the outer ring outer diameter surface member 6 and the outer ring outer diameter surface 1a and the mounting method or mounting structure between the outer ring side surface member 7 and the outer ring side surface 1b are appropriately determined by bonding, injection molding, press-fitting, coating treatment, and the like. Can be adopted.

In the first embodiment, the preload is applied by pressing the bearing outer ring with a spring member. However, the present invention can also be applied to the case where the inner ring preload is applied. Further, in the first embodiment, the two bearings that support the rotating shaft are of the same type and have the same shape. However, the dimensions and model of the applied bearing may be different. For example, if the bearing has a contact angle, an angular bearing and a ball bearing may be used. Further, for example, one may be a rolling bearing and the other may be a sliding bearing, a dynamic pressure bearing, a magnetic bearing or the like other than the rolling bearing. However, the provisions of the present invention act only on rolling bearings.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, the outer ring outer diameter surface member 6 and the outer ring side surface member 7 of the first embodiment are integrally formed, and are simultaneously mounted on the outer diameter surface 1a and the side surface 1b of the outer ring 1. . This embodiment is possible by integrally forming the outer ring outer diameter surface member 6 and the outer ring side surface member 7 by so-called two-color molding or the like, and is suitable for mass production processing.
As described above, in the case of PPS, the friction coefficient can be largely changed from 0.15 to 0.7 by blending glass fiber, graphite, carbon fiber, PTFE, and the like. Can be used in combination with the outer ring outer diameter surface member 6 and the outer ring side member 7 having a large friction coefficient.
Such a material is suitable for integrally injection molding to obtain parts having different characteristics. Note that, similarly to the first embodiment, expansion of a part not shown is applied.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, the outer ring side member 7 of the first embodiment is formed integrally with the seal 5. In the present embodiment, the outer ring outer diameter surface member 6 is formed in a ring shape having a circular cross section. Note that, similarly to the first embodiment, expansion of a part not shown is applied. Further, in addition to the second embodiment, the outer ring outer diameter surface member 6, the outer ring side member 7, and the seal 5
May be integrally formed. The shape of the seal 5 is
Well-known things can be applied.

Next, a test was conducted to evaluate how the vibration and noise can be reduced by using the rolling bearing of the first embodiment shown in FIG. In the test, as shown in FIG. 5, the front bearing 10 and the rear bearing 11 that support the rotating shaft 23 of the motor at the front and rear ends, using the rolling bearings of the example and the comparative example of the embodiment, After they are press-fitted onto the rotating shaft 23, they are assembled into the motor housing 15, and further pre-loaded by the spring member 16 and covered with the rear housing 24.
The vibration detection sensor 18 is attached to the rear housing 24, and its output is converted to a fast Fourier transform device (FFT in the figure).
At 19, frequency analysis was performed. The specifications of the vibration damping members used as examples of the embodiment, that is, the outer ring outer diameter surface member 6 and the outer ring side member 7 are as follows, and the vibration level evaluation test conditions are as shown in Table 1 below. In addition, the code | symbol 12 in a figure is a rotor, 13 is a stator.

Outer ring outer diameter surface member 6: Linear PPS + 30%
The GF was formed into a cylindrical shape having a thickness of 1 mm and a width of 9 mm, and was press-fitted into the outer diameter surface of the bearing outer ring and attached. Outer ring side member 7: Acrylonitrile rubber is formed into a ring plate having a width of 1 mm, the outer diameter is the same as the outer ring outer diameter surface member, and the inner diameter is the same as the inner diameter of the bearing outer ring end surface. It was glued to the side and mounted.

[0027]

[Table 1]

FIG. 6 shows the vibration level subjected to frequency analysis by this test. As is clear from the drawing, the vibration level of the motor incorporating the rolling bearing of the embodiment is generally lower than the vibration level of the motor incorporating the rolling bearing of the conventional comparative example. In the embodiment, the frequency at which the maximum vibration level appears is shifted to the lower frequency side, and the maximum vibration level is also reduced by about 30% in the voltage output. This value is
This is a sound reduction effect of about 5 dB in noise level, and a clear noise reduction can be felt by hearing with the ear. For example, when applied to an air conditioner or the like, the conventional rolling bearing may be worried about the noise at night, but if the noise level can be reduced by 5 dB using the rolling bearing of the embodiment,
It becomes small enough to be hardly noticed. This is because, in the comparative example, the housing vibrated in the axial direction with the rotation of the bearing, so that resonance corresponding to the housing natural frequency of about 2500 Hz and about 3300 Hz appeared. However, the outer ring outer diameter surface member and the outer ring side surface By attaching the member,
This is because the vibration and noise are reduced by the vibration damping and absorbing effects.

Next, a test for examining the change over time of the vibration level was performed. [Rolling Bearing Used for Test] The specifications of the example and the comparative example are the same as those in Table 1 described above. Example 1 Same as the example in Table 1. Example 2 Outer ring outer diameter surface member 6: PPS + GF + PTF
E, Outer ring side member 7: PPS + GF Comparative Example 1 Same as Comparative Example in Table 1 (no vibration damping member).

Comparative Example 2 Only the outer ring surface member of the outer ring made of synthetic rubber was mounted (small gap with the housing). Comparative Example 3 Only the outer ring outer diameter surface member made of synthetic rubber was attached (small gap with the housing). [Test conditions] Vibration level was measured over time by assembling in the motor of FIG. It is assumed that the test time is 2000 hours.

[Test Results] The test results are shown in FIG. 7 (conventional example 1 is shown as a relative value as 1). In both Example 1 and Example 2, even after the test time of 2,000 hours,
% Vibration level. On the other hand, in Comparative Example 1, there is no change in the vibration level, but the vibration level is higher than in both examples. Further, in Comparative Example 2, the fluctuation in friction between the housing and the outer diameter portion of the outer ring outer diameter surface member resulted in a fluctuation in preload,
It appears as fluctuations in sound and vibration. This is because, in this test, synthetic rubber was attached to the outer diameter of the bearing outer ring in order to add a slidability and a detent function to Comparative Example 2. That is, it is difficult to control the outer diameter and the clearance of the entire bearing, and finally a clearance was selected so as to reduce the vibration at the beginning of the test. However, heat was generated during use (5 to 10 ° C. at the outer diameter of the bearing outer ring). ) And changes in ambient temperature (temperature change between minimum and maximum temperatures in a day, maximum 7 ° C)
Due to the difference in thermal expansion coefficient between UJ2), the outer ring outer diameter surface member (synthetic rubber), and the housing (aluminum alloy), instability called stick-slip caused by friction fluctuation at the contact portion between the housing and the outer ring outer diameter member. Vibration occurs, the interference fit occurs irregularly, preload loss occurs, and fluctuations in the sound and vibration values of the bearing appear for a short period until the preload is normally applied. In Comparative Example 3, the accuracy of the bearing outer ring gradually decreased due to the creep, and the vibration increased. This is because, in Comparative Example 2, preload loss occurred due to irregular interference fit, and in Comparative Example 3, the gap between the outer diameter surface of the outer ring outer diameter surface member and the inner diameter surface of the housing was increased to increase the preload. Although slippage was prevented, the frictional force between the outer ring outer diameter member and the housing became smaller, and a rotational motion occurred between the two, causing creep, and the outer ring outer diameter member was worn for a long period of time, The roundness deteriorated, and the sound and vibration values gradually increased.

In order to simultaneously provide the sliding characteristics in the radial direction and the anti-rotation characteristics in the circumferential direction, for example, a synthetic resin or the like is made of a single material that is stretched with the axial direction being the stretching direction and the circumferential direction being a direction perpendicular thereto. It is also possible. That is, as described in the above-mentioned "Lubricity of plastic material" p32 to p35, it has been clarified that the stretching of plastic greatly changes the friction coefficient between the stretching direction and the direction perpendicular to the stretching direction. You do it. For example,
When polyacetal, polyethylene terephthalate, or the like is molded to a state close to the outer diameter of the outer ring and stretched in the axial direction by 100 to 200%, a difference in friction coefficient of about 20% between the axial direction and the circumferential direction can be obtained. By utilizing this, when forming in the width direction at the time of forming and then stretching in the axial direction, the coefficient of friction in the axial direction is small and the coefficient of friction in the circumferential direction is large. By attaching this to the outer diameter portion of the bearing outer ring, it is possible to obtain a vibration damping member that is easy to move in the axial direction and has a large friction coefficient in the circumferential direction.

In the case of the plastic, the characteristics in the axial direction and the circumferential direction are the same in the material stage, and the change in characteristics due to stretching in the working stage is used. Has the same effect. In this case, the material is manufactured so that the friction coefficient is small in the axial direction and the friction coefficient is large in the circumferential direction, and it is attached to the outer diameter of the bearing outer ring to prevent sliding in the axial direction and prevent creep in the rotational direction. A rolling bearing having functions can be obtained.

[0034]

As is clear from the above description, according to the rolling bearing of the present invention, the static friction coefficient of the outer ring outer diameter member mounted on the outer diameter surface of the bearing outer ring is determined by the dynamic friction of the outer ring outer diameter member. Coefficient, and the coefficient of static friction of the outer ring side member mounted on the side surface of the bearing outer ring is greater than or equal to the coefficient of static friction of the outer ring outer diameter surface member, so that the slidability in the axial direction and the circumferential direction The rotation suppressing function can be obtained at the same time, and the improvement of the bearing assemblability and the reliable application of the preload can be realized while achieving both the vibration damping function and the creep preventing function.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram of a friction coefficient of a rolling bearing of the present invention.

FIG. 2 shows a first embodiment of the rolling bearing of the present invention, in which (a) is a longitudinal sectional view in an assembled state, and (b).
Is a longitudinal sectional view of a bearing alone.

FIG. 3 is a longitudinal sectional view of a bearing alone showing a second embodiment of the rolling bearing of the present invention.

FIG. 4 is a longitudinal sectional view of a bearing alone showing a third embodiment of the rolling bearing of the present invention.

FIG. 5 is an explanatory diagram of a tester for measuring a vibration level of a rolling bearing.

FIG. 6 is an explanatory diagram of frequency analysis of vibration levels of an example and a comparative example of the rolling bearing of the present invention.

FIG. 7 is an explanatory diagram of the change over time of the vibration level between the example of the rolling bearing of the present invention and the comparative example.

[Explanation of symbols]

 1 is outer ring 1a is outer ring outer diameter surface 1b is outer ring side surface 2 is inner ring 3 is rolling element 4 is retainer 5 is seal 6 is outer ring outer diameter surface member 7 is outer ring side member 16 is spring member 24 is housing

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J012 AB04 AB07 AB11 AB20 BB01 BB03 BB05 CB03 DB07 DB08 DB13 FB10 3J017 AA06 AA10 CA06 DA02 3J101 AA02 AA32 AA42 AA52 AA54 AA62 BA77 EA31 EA49 FA01 FA35 FA41 FA60 GA24

Claims (1)

[Claims] In a rolling bearing used by rotating an inner ring while a preload is applied to the outer ring, an outer ring outer diameter surface member and an outer ring side surface mainly composed of rubber or resin on an outer diameter surface and a side surface of the outer ring. A member is mounted, and the static friction coefficient of the outer ring outer diameter surface member is larger than the dynamic friction coefficient of the outer ring outer diameter surface member, and the static friction coefficient of the outer ring side surface member is larger than the static friction coefficient of the outer ring outer diameter surface member or A rolling bearing characterized by being equivalent thereto.