JPH1082424A - Cage for rolling bearing - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To easily take in lubricant into a gap 16 between an inner peripheral surface of a pocket 8 and a rolling surface of a ball 5, and suppress generation of retainer noise. SOLUTION: Opening edges 14 of a pocket 8 are provided with:
Chamfers 17 and 17 are formed by barrel processing or injection molding. Due to the presence of the chamfers 17, 17, the lubricant that tends to enter the gap 16 with the rolling of the ball 5 is less likely to be scraped off at the opening peripheral portions 14, 14. Then, a sufficient amount of lubricant can be taken into the gap 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage for a rolling bearing, which relates to an improvement of a cage constituting a rolling bearing used in various types of rotary machinery, and to lubricate a sliding contact portion between the cage and a rolling element. Sufficiently secured to reduce rolling bearing vibration and noise.

[0002]

2. Description of the Related Art A ball bearing as shown in FIG. 6, for example, is widely used as a rolling bearing for supporting various rotating parts such as a bearing part of various rotating machinery. This ball bearing comprises an inner race 2 having an inner race 1 on its outer peripheral surface and an outer race 3 on its inner peripheral surface.
And the outer ring 4 having a plurality of balls 5, 5 are provided concentrically with each other, and a plurality of balls 5, 5 are rotatably provided between the inner ring track 1 and the outer ring track 3. In the illustrated example, both the inner raceway 1 and the outer raceway 3 are of a deep groove type. The plurality of balls 5 are rollably held in pockets 8 provided in a holder 6.

[0003] The cage 6 constituting the ball bearing shown in FIG. 6 is called a corrugated press retainer. Each of the retainers 6 is formed by press-molding a metal plate material. It consists of a pair of elements 9,9. These two elements 9, 9 have recesses 8a, 8a for forming the pockets 8, 8 at a plurality of positions in the circumferential direction, respectively. Then, the pair of elements 9, 9 are butted at portions deviating from the concave portions 8 a, 8 a, and these portions are connected and fixed by a plurality of rivets 10, and the pockets 8 are formed at a plurality of positions in the annular direction in the circumferential direction. 8 as a retainer 6. The middle part of the inner surface of each of the recesses 8a, 8a
The holding concave surface 11 has a radius of curvature slightly larger than the radius of curvature of the outer surface of each of the balls 5, 5, and has a circular arc cross section. Therefore, when the pair of elements 9, 9 are abutted, the recesses 8 a, 8 a are combined to form pockets 8, 8.

A cage 6a called a crown-shaped cage shown in FIG. 7 is provided with balls 5, 5 (FIG. 6) at a plurality of circumferential positions of an annular main portion 7 made of synthetic resin or the like. ) Are provided so that they can roll freely. In the case of such a crown-shaped retainer 6a, each of the pockets 8, 8 is provided on the main portion 7 with a pair of elastic pieces 1 spaced from each other.
2 and 12 and a pair of elastic pieces 12, 1 in the axial direction (vertical direction in FIG. 7) of the main part 7 (upper surface in FIG. 7).
And a spherical concave portion 13 provided in a portion between the two. The radius of curvature of the concave portions 13, 13 is slightly larger than the radius of curvature of the outer surface of the ball 5. One side surface of these elastic pieces 12 and 12 and concave portions 13 and 13 constitute a holding concave surface.

When assembling the ball bearing, each of the balls 5,
5 is a pair of elastic pieces 1 forming each pocket 8, 8.
While elastically expanding the interval between the tip edges of 2, 12,
It is pushed between the pair of elastic pieces 12, 12. By holding the balls 5 and 5 in the pockets 8 and 8 in this manner, the retainer 6a connects the balls 5 and 5 to the inner raceway 1 and the outer raceway 3 (FIG. 6). In between, it is held so that it can roll freely.

The above-mentioned cage 6 or the above-mentioned cage 6a
When the ball bearing provided with is used, the relative rotation between the inner ring 2 and the outer ring 4 is made free with the rolling of the plurality of balls 5. At this time, the plurality of balls 5, 5 revolve around the inner ring 2 while rotating. The retainers 6 and 6a are
The balls 5 and 5 rotate around the inner ring 2 at the same speed as the revolution speed thereof.

A portion between the outer peripheral surface of the inner race 2 and the inner peripheral surface of the outer race 4 is filled or continuously supplied with a lubricant such as grease or other lubricating oil, so that the relative rotation is smoothly performed. Like In addition, vibration and noise are not generated in the ball bearing, and failures such as burn-in are prevented. still,
In some ball bearings, both ends of the space between the outer peripheral surface of the inner race 2 and the inner peripheral surface of the outer race 4 are closed by a sealing member such as a seal plate or a shield plate, and the lubricant leaks from this space. In some cases, foreign substances such as dust are prevented from entering this space. However, FIG. 6 shows a ball bearing without such a sealing member.

[0008] In the case of a ball bearing incorporating the retainers 6 and 6a as described above, even if a required amount of lubricant is filled or supplied, vibrations are induced in the retainers 6 and 6a, and the retainers 6 and 6a are vibrated. Noise or vibration called retainer sound may be generated in the ball bearing incorporating 6a. Such a cage 6, 6
The vibration of “a” is generated based on the sliding friction between the balls 5, 5 which are rolling elements and the cages 6, 6 a due to the large amount of movement of the cages 6, 6 a with respect to the balls 5, 5. I do. Conventionally, pocket 8,
The clearance between the inner surface of the ball 8 and the rolling surfaces of the balls 5 and 5 is reduced to reduce the amount of movement of the cages 6 and 6a with respect to the balls 5 and 5 and to suppress generation of cage noise. ing.

[0009]

However, simply reducing the amount of movement of the retainers 6, 6a with respect to the balls 5, 5 is due to the inner peripheral surface shape of the pockets 8, 8 of the retainers 6, 6a. Cage sound is generated. This reason will be described with reference to FIGS. As shown in FIGS. 8 to 9, sharp (greater curvature) corner portions 15, 15 are present at the opening peripheral portions 14, 14 of the pockets 8 of the retainers 6, 6 a. Resistance to lubricant flow. That is, the corrugated cage 6 made by press-molding a metal plate, or the crown-shaped cage 6a made by injection-molding a synthetic resin, also has Since there is a sharp edge due to burrs or the like, the curvature of each of the corners 15 is very large.

Therefore, the pocket 8 is required to suppress the retainer sound.
When the clearance between the inner surface of the ball 5 and the rolling surface of the ball 5 is reduced, the rolling surface of the ball 5 and the holding concave surface 11 (in the case of the cage 6 shown in FIG. 6; in the cage 6a shown in FIG. And elastic pieces 12, 1
2. One side and concave portion 13 portion. ) Becomes less likely to flow into the gap 16. That is, the lubricant that tries to enter the gap 16 from the surrounding space with the rolling of the ball 5 is scraped off by the corners 15, 15, and becomes difficult to enter the gap 16. For this reason, a sufficient amount of lubricant is not taken into the gap 16 between the holding concave surface 11 and the rolling surface of the ball 5, and the cages 6, 6a and the balls 5, 5
It is not possible to sufficiently suppress the frictional vibration of the sliding contact portion with the vehicle, which causes vibration and noise. The cage for a rolling bearing of the present invention has been made to solve such inconvenience.

[0011]

SUMMARY OF THE INVENTION A cage for a rolling bearing according to the present invention is similar to the conventional cage for a rolling bearing described above.
In order to hold the plurality of rolling elements rotatably, the whole is formed in an annular shape, and pockets are provided at a plurality of positions in the circumferential direction. In particular, in the rolling bearing retainer of the present invention, at least a part of the peripheral edge of the opening of each pocket is chamfered. Preferably, the rolling element is a ball, the chamfer is a curved surface having a circular cross section, and the radius of curvature of the cross section of the chamfer is 1 to 20% of the outer diameter of the ball.
More preferably, the radius of curvature of the cross section of the chamfer is 2 to 16% of the outer diameter of the ball, and more preferably, the radius of curvature of the cross section of the chamfer is 5 to 15% of the outer diameter of the ball.
And

[0012]

The operation of the rolling bearing retainer of the present invention configured as described above when the plurality of rolling elements are rotatably held is the same as that of the above-described conventional rolling bearing retainer. It is. In particular, in the case of the rolling bearing retainer of the present invention, the lubricant is easily taken into the gap between the inner surface of the pocket and the rolling surface of the rolling element, and the lubricating state of the sliding contact portion is improved. That is, based on the presence of the chamfer formed on the peripheral edge of the opening of each pocket, the lubricant can be easily introduced into the pocket without being prevented from flowing into the pocket. For this reason, vibration and noise called cage sound hardly occur.

[0013]

FIG. 1 shows a first embodiment of the present invention. In this embodiment, the present invention is applied to the crown type retainer shown in FIG. This retainer 18
Similarly to the above-described conventional cage 6a (FIG. 7), an annular main portion 7 made of synthetic resin and provided at a plurality of circumferential positions of the main portion 7, and a ball 5 serving as a rolling element is provided inside thereof. And a plurality of pockets 8 that hold each of them in a freely rolling manner.
Each pocket 8 has a pair of elastic pieces 12, 12 (see FIG. 7) arranged at intervals in the main part 7, and one side of the main part 7 in the axial direction (the upper surface in FIG. 1). Pair of elastic pieces 1
And a concave portion 13 provided in a portion between 2 and 12. One side of the concave portion 13 and the elastic piece 12 is in a spherical concave surface having a radius of curvature R ₁₃ is slightly larger than the radius of curvature r of the rolling surface of the ball 5 to be held the cage 18. These concave portions 13 and a pair of elastic pieces 12,
One side surface of 12 constitutes a holding concave surface for holding the ball 5 in a freely rolling manner. Further, in the case of the retainer 18 of the present invention, arc-shaped chamfers 17, 17 having an arc-shaped cross section are formed on the peripheral edges 14, 14 of the pockets 8 shown by dashed lines in FIG. , Are provided over the entire length of the opening peripheral portions 14, 14.

The operation itself of the rolling bearing retainer of the present invention configured as described above when the plurality of balls 5 are rollably held is the same as that of the above-described conventional rolling bearing retainer. It is. In particular, in the case of the cage for a rolling bearing of the present invention, the rolling surface of the ball 5 and the one side surface of the pair of elastic pieces 12,
The lubricant which is about to enter the gap 16 between the openings 16 and 16 is efficiently scraped into the gap 16 without being scraped off much at the opening peripheral portions 14 and 14. Therefore, one side surface of the pair of elastic pieces 12, 12, the concave portion 13 and the ball 5
A sufficient amount of lubricant is taken into the gap 16 between the rolling surface and the lubricant, and the lubricant can be held in the gap 16 for a long time. As a result, the frictional vibration of the sliding contact portion between the retainer 18 and the ball 5 can be sufficiently suppressed, and the possibility of inducing vibration or noise called retainer sound is reduced.

FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, in order to form the pocket 8 in the retainer 18a, the concave portion 1 provided in a portion between the pair of elastic pieces 12 and 12 arranged at an interval in the main portion 7 is provided.
Chamfers 17a, 17a are provided on both side portions (bottom portion of each pocket 8) of 3 respectively. Also in the case of this embodiment, since the lubricant is efficiently taken into the gap between the rolling surface of the ball and the concave portion 13 of the pocket 8 through the chamfers 17a, 17a, vibration called retainer sound is generated. And noise are less likely to be induced.

Next, FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, cylindrical portions 19, 19 are formed at both ends of the pocket 8, and these cylindrical portions 1 are formed.
9 and 19, and both end edges of the spherical concave portion 13 formed at the center of the pocket 8 are chamfered 1
7b and 17b are continuous. This chamfer 17
b, cage 18b having pocket 8 provided with 17b
Is formed by injection molding of a synthetic resin. The chamfers 17b, 17b are formed at the time of the injection molding. However, in some cases, the chamfers 17b, 17b may be formed by barrel processing after the injection molding. Further, the shapes of the chamfers 17b, 17b formed at the time of injection molding can be finished by barrel processing.

In any case, the chamfers 17b, 17b
Is a curved surface having a circular cross section. The radius of curvature of the cross-sectional shape of the chamfer is set to 1 to 20% of the outer diameter of the ball 5 held in the pocket 8. More preferably, the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is 2 to 16% of the outer diameter of the ball. More preferably, the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is the outer radius of the ball. 5 to 15% of the diameter. In the case of this embodiment as well, the lubricant is efficiently taken into the gap between the rolling surface of the ball 5 and the concave portion 13 of the pocket 8 through the chamfers 17b, 17b, and is therefore called retainer sound. Less likely to induce vibration and noise.

Next, FIG. 4 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, mortar-shaped inclined surfaces 20, 20 whose inner diameters increase toward the opening peripheral portion of the pocket 8 are formed at both end openings of the pocket 8,
The inner edge of each of these inclined surfaces 20, 20 and the pocket 8
And both end edges of the spherical concave portion 13 formed in the central portion of
Each is continuous by chamfers 17c, 17c.
The cage 18c having the pockets 8 provided with the chamfers 17c, 17c is formed by injection molding of a synthetic resin as in the case of the above-described third example. Each of the chamfers 17c,
17c is formed at the time of the injection molding. In some cases, after the injection molding, the chamfer 17 is formed by barrel processing.
c and 17c may be formed. Further, the shapes of the chamfers 17c formed at the time of injection molding can be finished by barrel processing.

In any case, each of the chamfers 17c, 17c
Is a curved surface having a circular cross section. The radius of curvature of the cross-sectional shape of the chamfer is set to 1 to 20% of the outer diameter of the ball 5 held in the pocket 8. More preferably, the radius of curvature of the cross-sectional shape of each of the chamfers 17c, 17c is 2 to 16% of the outer diameter of the ball 5, and more preferably, the radius of curvature of the cross-sectional shape of each of the chamfers 17c, 17c is 5 to 15% of the outer diameter of In the case of this embodiment as well, the lubricant is efficiently taken into the gap between the rolling surface of the ball 5 and the holding concave surface 13 of the pocket 8 through the chamfers 17c, 17c, and is therefore called retainer sound. Less likely to induce vibration and noise.

Each of the above-described embodiments has been described with respect to an example in which the present invention is applied to a crown-type cage constituting a ball bearing. However, the present invention is not limited to the above-mentioned crown type cage for ball bearings, but may be applied to a waveform cage, and further to a roller bearing cage, as long as it is a cage for rolling bearings. In addition, according to the present invention, in order to minimize the amount of displacement of the cage with respect to the rolling element, not only the structure in which the gap between the rolling surface and the inner surface of the pocket is made small, but also the structure in which this gap has a normal size. But you can get the effect.

[0021]

EXAMPLES Next, first and second experiments performed by the present inventors to confirm the effects of the present invention will be described. First,
In performing the first experiment, a crown-shaped retainer 6a as shown in FIG. 7 was injection-molded with polyamide 66, and one having a corner at the opening peripheral portion of the pocket 8 as it was injection-molded. (Comparative Example) and five types in which chamfers 17, 17 as shown in FIG.
5) and chamfering 17a as shown in FIG.
Seven kinds of samples were prepared, one of which formed 17a (Example 6). Each sample contains 10
Or 20 pieces were prepared, each was installed in a ball bearing and operated, and the occurrence of cage noise was observed. In the case where the chamfers 17a, 17a as in the sixth embodiment are formed industrially, they are formed at the time of injection molding without cutting.

The barrel processing conditions for Examples 1 to 5 and the operating conditions for all samples are as follows. Barrel processing conditions Common conditions Using 3 mm triangular alumina particles as abrasive grains, processed by rotary barrel or planetary barrel processing machine. Different conditions for each example Example 1: machining time = 1 hour Example 2: machining time = 5 hours Example 3: machining time = 12 hours Example 4: machining time = 48 hours Example 5: machining time = 72 Time Ball bearing operating conditions Lubrication conditions: Grease filling Rotational speed: 4000r. p. m. Radial load: 100kgf Ambient temperature: 0 ° C

When the presence or absence of cage sound was observed under the above-mentioned conditions, in the comparative example, cage sound was observed for all ten samples. Examples 1 to 5
With regard to all of the 20 samples,
No generation of cage sound was observed. Further, with respect to Example 6, no generation of cage sound was observed for all ten samples. These experiments confirmed that the present invention was effective in reducing cage noise.

Next, a description will be given of a second experiment conducted to find out the influence of the radius of curvature of chamfering on the generation of cage sound. In the second experiment, the ratio of the radius of curvature of the chamfers 17b to the outer diameter (diameter) of the ball 5 is variously changed using the retainer 18b as in the third example of the embodiment shown in FIG. The effect of this ratio on the cage noise generated during operation was measured. The test conditions are as follows. Bearing used: Deep groove type ball bearing with nominal number 6202 (outer diameter 35 mm, inner diameter 15 mm, width 11 mm) Cage used: outer diameter 25.5 mm, inner diameter 21.5 mm, width 5.80 mm, ball guided The central angle θ of the concave portion 13 (see FIG. 3): 46 degrees Operating conditions Lubrication conditions: 40% by volume of ether urea-based grease having a kinematic viscosity of 100 cst is filled into the space where it can be filled. : 4000 rpm Radial load: 100 kgf Thrust load: 50 kgf Ambient temperature and humidity: 0 ° C, 20%

Under the above-described conditions, each of the chamfers 17b, 1
When the relationship between the radius of curvature of 7b and the loudness of the cage sound generated during operation was determined, the result as shown in FIG. 5 was obtained. In FIG. 5, the abscissa indicates each of the chamfers 17b, 1
The vertical axis indicates the ratio between the radius of curvature of the cross-sectional shape of 7b and the outer diameter of the ball 5 held in the pocket 8, and the vertical axis indicates the noise generated by a ball bearing constructed using a conventional cage 6a as shown in FIG. The level is set to 0 dB, and the difference between the noise levels of the ball bearings when using the cage in which the radius of curvature of each of the chamfers 17b, 17b is changed is shown. As is clear from FIG. 5, when the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is set to 1% or more of the outer diameter of the ball 5 held in the pocket 8, the effect of temporarily reducing the cage sound is obtained. can get.
More preferably, if the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is 2 to 16% of the outer diameter of the ball 5,
The effect of reducing the retainer sound becomes significant. More preferably, if the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is set to 4 to 15% of the outer diameter of the ball 5, the effect of reducing the retainer sound becomes more remarkable.

The difference in the radius of curvature affects not only the loudness of the cage sound but also the workability. That is, the regulation on the lower limit side leads to easiness of mold processing, and the regulation on the upper limit side leads to a reduction in machining cost by saving barrel machining time. Further, as a processing method for setting the chamfers 17b, 17b to a desired radius of curvature, any conventionally known processing method may be employed. However, in the case of a synthetic resin cage, it is preferable to perform processing with a mold from the viewpoint of processing cost. Also, in the case of a metal cage, it is preferable to perform processing by barrel processing also from the viewpoint of processing cost. Note that the radius of curvature of the cross-sectional shape of each of the chamfers 17b, 17b is 20 times the outer diameter of the ball 5 held in the pocket 8.
%, The holding force of the ball 5 is weakened, and the amount of movement of the cage increases, and the ball 5 comes off the pocket 8. Therefore, the radius of curvature is equal to the ball 5
If the outer diameter exceeds 20% of the outer diameter of the roller, it is inappropriate as a retainer that enables normal operation of the bearing, and it is difficult to design a rolling bearing incorporating such a retainer. Therefore, the radius of curvature needs to be 20% or less of the outer diameter of the ball 5.

[0027]

The cage for a rolling bearing according to the present invention is constructed and operates as described above, so that the lubrication state of the sliding contact portion between the rolling surface of the rolling element and the inner peripheral surface of the pocket of the cage is ensured. Become good. As a result, in the rolling bearing formed by using the cage for a rolling bearing of the present invention, generation of cage noise is suppressed, and a low-vibration, low-noise rolling bearing can be obtained. Furthermore, in the case of the cage for a rolling bearing of the present invention, the friction of the sliding contact portion between the rolling surface of the rolling element and the inner peripheral surface of the pocket of the cage is reduced, so that the wear resistance of the cage can be improved. .

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a first example of an embodiment of the present invention and showing a part of a retainer with a ball held.

FIG. 2 is a partially enlarged perspective view of the retainer, showing the second example.

FIG. 3 is an enlarged cross-sectional view of the cage, showing the third example.

FIG. 4 is an enlarged sectional view of the retainer, showing the fourth example.

FIG. 5 is a diagram showing a relationship between a radius of curvature of chamfering and a loudness of a cage sound generated during operation.

FIG. 6 is a partially cutaway perspective view showing one example of a conventionally known ball bearing.

FIG. 7 is a perspective view showing another example of a conventionally known cage.

FIG. 8 is an enlarged cross-sectional view showing a state where a ball is held by the cage shown in FIG. 6;

FIG. 9 is an enlarged cross-sectional view showing a state where a ball is held in the cage shown in FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 inner ring track 2 inner ring 3 outer ring track 4 outer ring 5 ball 6, 6a retainer 7 main part 8 pocket 8a recess 9 element 10 rivet 11 holding concave surface 12 elastic piece 13 concave surface portion 14 opening peripheral edge 15 corner 16 gap 17, 17a, 17b, 17c Chamfer 18, 18a, 18b, 18c Cage 19 Cylindrical part 20 Inclined surface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Osumi 1-5-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd. No. Nippon Seiko Co., Ltd. (72) Inventor Hideki Koizumi 1-5-50 Kugenuma Shinmei 1-chome, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd. Inside Seiko Co., Ltd. (72) Inventor Toshihisa Ohata 1-5-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Prefecture Inside NSK Ltd. (72) Inventor Mando Noda 1-150 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Nihon Seiko Inside the corporation

Claims (2)

[Claims] In order to hold a plurality of rolling elements rotatably,
In a cage for a rolling bearing, which is entirely formed in an annular shape and has pockets at a plurality of positions in a circumferential direction, at least a part of an opening peripheral portion of each pocket is chamfered. And a cage for rolling bearings. 2. The rolling element is a ball, the chamfer is a curved surface having a circular cross section, and the radius of curvature of the cross section of the chamfer is 1 to 20% of the outer diameter of the ball. 2. The rolling bearing retainer according to 1.