JP2003184889A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure excellent fluidity of a lubricant such as grease and to prevent early exfoliation caused by insufficient lubrication without degrading strength of a cage. <P>SOLUTION: In the rolling bearing, a notch 14 is formed to a thin part 13 formed on the rear face on the opposite side of each pocket 11 in the cage 10. Also, a volume rate of the notch 14 and the thin part 13 is made to be 0.1-40% of the whole of the cage 10. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grease-lubricated rolling bearing suitable for use in, for example, engine accessories (alternator, electromagnetic clutch, intermediate pulley, car air conditioner compressor, water pump, etc.). The present invention relates to a structure for ensuring good fluidity of grease and preventing early peeling due to poor lubrication.

[0002]

2. Description of the Related Art Generally, in order to support various rotating parts,
For example, as described in Japanese Utility Model Publication No. 6-53823, rolling bearings are frequently used. Rolling bearings
The inner ring having the inner ring raceway on the outer peripheral surface and the outer ring having the outer ring raceway on the inner peripheral surface are concentrically arranged, and a plurality of rolling elements held by the cage roll between the inner ring raceway and the outer ring raceway. Arranged freely.

Roller bearing cages are required to have adaptability to high-speed rotation, self-lubrication, low friction characteristics, light weight, corrosion resistance, low noise, and the like. Resin cages are preferred over cages. The resin cage is provided with a meat thin portion on the back surface. The thin meat portion makes it possible to make the cooling rate uniform at the time of molding the cage and improve the left-right mass balance.

However, the resin cage is disadvantageous in strength as compared with the metal machined cage and the press cage, so that it is inevitably large in size in order to secure the strength. Therefore, the amount of grease that can be filled is limited, and the oil film is liable to run out due to insufficient grease, which sometimes leads to peeling.

That is, for example, in the case of a rolling bearing for an electric accessory such as an alternator, since it rotates at a high speed,
When the grease viscosity increases due to the influence of the type of enclosed grease and the temperature of the operating environment, etc., the grease adheres to the meat hollow part of the cage and the inner wall surface of the seal part. Along with this, a shortage of grease occurs, and an oil film is cut off due to the lack of grease, which may lead to peeling.

The rolling bearing for an alternator will be described in detail. In the rolling bearing, high temperature, high vibration and high load (4G to 20G in gravitational acceleration) due to high speed rotation act simultaneously via the belt. For this reason, slippage between the rolling elements and the cage occurs, and poor lubrication easily occurs. If there is poor lubrication, there is a problem that premature peeling occurs in the load range of the fixed ring and the life of the rolling bearing is shortened.

[0007] As a measure for preventing such a premature detachment of the fixed ring, "SAE Technical Paper: SAE9509
No. 44 (Date held February 27-March 2, 1995) ", paragraphs 1-14 disclose a technique for clarifying the fatigue mechanism of the alternator bearing and preventing premature peeling. In other words, changing the bearing grease from E grease to M grease, which has a high damper effect, suppresses slippage between rolling elements and cages, and M grease absorbs high vibrations and loads and prevents metal contact. To do.

Since the alternator bearing is often used at high speed rotation (up to 20000 rpm), the cage rotates at high speed together with the grease existing between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. Therefore, the centrifugal force acts on the cage, the grease is stirred, and the grease stays in the meat-thinned portion and the seal portion of the cage. The grease once retained does not flow to the raceway surface and hardly contributes to the lubrication of the bearing.

Actually, the following experiment was attempted for the life of rolling bearings for electrical accessories such as alternators. That is, a conventional cage having a thin meat part is incorporated into a bearing (bearing name: 6303),
It was rotated at 000 rpm for 10 hours. After that, the grease retained in the slimy part and the seal part was colored and further rotated for 100 hours under the same conditions to confirm the behavior of the colored grease. As a result, it was confirmed that the grease retained in the slime-filled portion and the seal portion hardly flowed and did not contribute to lubrication.

Conventionally, as a structure for returning the grease accumulated in the meat-thinned portion of the cage to the raceway surface, FIG. 9 (a)
With reference to (b) and (b), in JP-A-8-177871, a ball having a plurality of projecting pieces 52 provided at equal intervals along the circumferential direction on a seal member 51 that rotates with the rotation of the ball bearing 50. Bearing 50 is described. The ball bearing 50 promotes the flow of grease to the raceway surface by each protruding piece 52 and avoids insufficient lubrication.

Further, referring to FIGS. 10A and 10B, in JP-A-8-177865, the width W in the circumferential direction from the end portion 61 facing the seal toward the pocket 62.
The rolling bearing cage 60 is described in which a plurality of grooves 63 each having a gradually enlarged shape are provided for each pocket 62. In the rolling bearing cage 60, each groove 63 promotes the flow of grease to the raceway surface, and avoids insufficient lubrication.

Further, referring to FIG. 11, Japanese Patent No. 303
Japanese Patent No. 5766 discloses a ball bearing cage 70 in which at least one pocket 71 has a projection 73 protruding inwardly of the pocket 71 at the edge of the pocket surface 72. The protrusion 73 of the pocket 71 improves the fluidity of the lubricant. As a result, the balls are retained in the ball bearing cage 70.
The resistance force at the time of sliding contact with the pocket surface 72 of the ball bearing is reduced, abnormal noise of the ball bearing is prevented, the torque of the ball bearing is reduced, and the life of the lubricant is extended.

[0013]

Among the above-mentioned conventional rolling bearings, in the ball bearing 50 shown in FIGS. 9 (a) and 9 (b) described in Japanese Patent Application Laid-Open No. 8-177871, each protruding piece 52 is provided. Since the provided seal member 51 rotates with the rotation of the ball bearing 50, there is a problem that each protruding piece 52 is easily broken when used under high speed rotation and high vibration.

Further, in the rolling bearing cage 60 shown in FIGS. 10 (a) and 10 (b) of JP-A-8-177865, the flowability of grease to the raceway surface is ensured and abnormal noise is generated. Is being prevented. That is, although there is a description of the effect on acoustics, nothing is described about white peeling, and no consideration is given to the grease retained in the meat thin section.

Further, in the ball bearing cage 70 shown in FIG. 11 of Japanese Patent No. 3035766, it is possible to prevent abnormal noise from being generated in the ball bearing, reduce the torque of the ball bearing and increase the length of the lubricant. The life can be extended. In other words, although there is a description of the effects on acoustics and low torque,
No mention is made of white peeling, and no consideration is given to the grease retained in the slime part and the seal part.

The present invention provides a rolling bearing capable of ensuring good fluidity of a lubricant such as grease without impairing the strength of a cage and preventing early peeling due to poor lubrication. The purpose is to do.

[0017]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rolling bearing in which a plurality of rolling elements respectively held in a plurality of pockets of a cage are incorporated between a pair of bearing rings. A notch is formed in the meat thin portion formed on the back surface on the opposite side to the back surface, and the volume ratio of the notch and the meat thin portion is 0.1 to 4 of the entire cage.
It can be achieved by rolling bearings characterized by 0%. Here, the volume ratios of the notch and the meat thin section are defined as follows. Volume ratio = ((normal retainer-retainer of the present invention) / normal retainer) × 100

The volume ratio of the notch and the meat thin portion is preferably 1 to 30% of the whole cage. If the volume ratio of the notch and the meat thin section is less than 0.1% of the entire cage, the effect of promoting the fluidity of the lubricant by the notch cannot be seen. Further, when the volume ratio of the notch and the meat thin portion exceeds 40% of the whole cage, the strength of the cage is lowered.

The above object of the present invention is to provide a rolling bearing in which a plurality of rolling elements respectively held in a plurality of pockets of a cage are incorporated between a pair of bearing rings, in the end face on the pocket side or the This can be achieved by a rolling bearing characterized in that a protrusion is provided on the back surface opposite to the pocket, and the volume ratio of the protrusion is 0.1 to 15% of the entire cage. Here, the volume ratio of the protrusion is defined as follows. Volume ratio = ((Cage of the present invention-ordinary cage) / Cage of the present invention) × 100

The volume ratio of the protrusions is preferably 1 to 10% of the whole cage. If the volume ratio of the protrusions is less than 0.1% of the entire cage, the protrusions may be damaged during high speed rotation. Further, when the volume ratio of the protrusions exceeds 15% of the entire cage, the space volume in the bearing decreases, so that the amount of lubricant enclosed is limited, and the possibility of oil film breakage or the like increases.

In the rolling bearing according to the present invention, for example, the lubricant such as grease staying in the meat-thickened portion of the cage during rotation is returned to the raceway surface through the notch formed in the meat-thickened portion. Therefore, good fluidity of the lubricant is ensured. Also, the volume ratio of the notch and the meat slime part,
Sufficient strength of the cage is ensured by being 0.1 to 40% of the entire cage.

In the rolling bearing according to the present invention, for example, the lubricant such as grease retained in the seal portion during rotation is provided with fluidity by the protruding portion protruding from the cage. Therefore, good fluidity of the lubricant is ensured. In addition, the volume ratio of the protrusion is 0.1 to 0.1
By being 15%, sufficient strength of the cage is secured.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The first of the rolling bearings of the present invention is described below.
The embodiment will be described in detail with reference to FIG. FIG. 1 is a perspective view of essential parts showing a cage for a rolling bearing according to a first embodiment of the present invention. As shown in FIG. 1, in the rolling bearing of the present embodiment, a plurality of rolling elements 12 respectively held in pockets 11 of a cage 10 are incorporated between a pair of inner and outer rings (not shown) each having a raceway surface. ing. The retainer 10 is provided with a meat thin portion 13 on the back surface opposite to each pocket 11. A notch 14 is formed in the meat-sunk portion 13. The volume ratio of the notch 14 and the meat thinned portion 13 is 0.1 to 4 of the entire cage 10.
It is 0%.

The operation of the rolling bearing of this embodiment will be described. With the high speed rotation of the rolling bearing and the cage 10, the grease that has adhered to and stayed in the meat-thickened portion 13 of the cage 10 is returned to the raceway surface again through the notch 14 of the meat-lubricated portion 13. This ensures good fluidity of the grease. In addition, the volume ratio of the notch 14 and the meat thinning portion 13 is 0.1 to 40% of the entire cage 10, so that the cage 10 has sufficient strength.

Next, a second embodiment of the rolling bearing of the present invention will be described in detail with reference to FIG. FIG. 2 is a perspective view of essential parts showing a cage for a rolling bearing according to a second embodiment of the present invention. As shown in FIG. 2, the rolling bearing according to the present embodiment has the protrusion 2 on the end surface of the cage 20 on the side of each pocket 21.
2 is projected. The volume ratio of the protruding portion 22 is 0.1 to 15% of the entire cage 20. Other configurations are the same as those in the first embodiment.

The operation of the rolling bearing of this embodiment will be described. With the high speed rotation of the rolling bearing and the retainer 20, the grease adhered to and retained in the seal portion is provided with fluidity by the protrusion 22 of the retainer 20. Therefore, good fluidity of the lubricant is ensured. Further, since the volume ratio of the protrusions 22 is 0.1 to 15% of the entire cage 20, sufficient strength of the cage 20 is secured.

Next, a third embodiment of the rolling bearing of the present invention will be described in detail with reference to FIG. FIG. 3 is a perspective view of an essential part showing a cage for a rolling bearing according to a third embodiment of the present invention. As shown in FIG. 3, in the rolling bearing of this embodiment, the protrusion 32 of the retainer 30 is provided on the back surface opposite to each pocket 31. Other configurations and operations are the same as those in the second embodiment.

As described above, according to the rolling bearing of the first embodiment, the notch 1 is formed in the meat fillet portion 13 formed on the back surface of the cage 10 on the side opposite to each pocket 11.
4 are formed. Further, according to the rolling bearings of the second and third embodiments, the end surface of the cage 20 on the side of each pocket 21 (second embodiment) or the back surface of the cage 30 on the side opposite to each pocket 31 (third embodiment). Embodiment),
Protrusions 22 and 32 are provided so as to project.

Therefore, even when the rolling bearing is applied to engine accessories, especially electrical accessories such as an alternator and used at high speed, the slime part 13 of the cage 10 (first embodiment). Alternatively, the seal portion (second and third
Good fluidity of the grease retained in the embodiment) can be secured. As a result, it is possible to reliably prevent early peeling due to poor lubrication.

Further, in the first embodiment, the volume ratio of the notch 14 and the meat fillet portion 13 is 0.1 in the entire cage 10.
-40%, preferably 1-30%. Also,
In the second and third embodiments, the volume ratio of the protrusions 22 and 32 is 0.1 to 15%, preferably 1 to 10% of the whole cage 20, 30. Therefore, the cage 10,
It is possible to secure sufficient strength of 20, 30, and it is possible to obtain a good balance between securing the fluidity of the grease and securing the strength of the cages 10, 20, 30.

[0031]

EXAMPLES Examples 1 to 1 of the rolling bearing according to the first embodiment
For 11, the peeling life test and the seizure test were performed together with Comparative Examples 1 to 7. The test conditions and test results are shown in FIGS. 4 and 5 and Table 1.

[0032]

[Table 1]

As the peeling life test, JP-A-9-897 is used.
The rapid acceleration / deceleration test disclosed in Japanese Patent No. 24, that is, the number of rotations of the bearing is 9000r at every predetermined time (for example, every 9 seconds).
A rapid acceleration / deceleration test was performed by switching between pm and 18000 rpm. Further, in the rapid acceleration / deceleration test disclosed in Japanese Patent Laid-Open No. 9-89724, since the calculated life of the bearing is 1350 hours, the test cutoff time was set to 1500 hours.
The test was performed 10 times, and when the vibration reached 5 times the initial vibration, the test was stopped and the presence or absence of peeling was confirmed.

As the seizure test, the rotation speed of the bearing was set to 20.
The rotation speed was kept constant at 000 rpm and the bearing temperature was continuously rotated at 140 ° C. The test number is 10 times, and the test termination time is 1
000 hours, seizure occurs and the bearing outer ring temperature is 150
If the temperature rises above 0 ° C, the test is terminated.

In both the present example and the comparative example, J was used as the test bearing.
Use the IS nominal number 6303 and set the bearing gap to 10-15μ.
m, and E grease was used as the enclosed grease. Also,
The load condition is P (load load) / C (dynamic load rating) = 0.
10. The test temperature was fixed at 80 ° C.

The test bearings were two kinds of bearing steel, the surface hardness of the inner and outer rings was HRC58 to 63, the amount of retained austenite was 0.05 to 15%, and the surface hardness of the rolling elements was HRC62.
Was set to 64. The surface roughness of the raceway is 0.015 μm
Ra and the surface roughness of the steel balls were 0.005 μmRa.

In Table 1, the volume ratios of the notch and the meat thin portion in the cage are 0.5%, 1% and 2%, respectively.
In Examples 1, 2 and 3 described above, although peeling and seizure are observed at a rate of 1 to 2 out of 10, the occurrence rate is low. Further, in Examples 4 to 11 in which the volume ratio of the notch and the meat thin portion in the cage was set to be 5 to 40%, neither peeling nor seizure was observed, and the notch was formed in the cage. It is understood that the effect of improving the fluidity of grease due to the above and the effect of greatly extending the bearing life associated therewith have been demonstrated.

On the other hand, in Comparative Example 1, the cage in which neither the meat thin section nor the notch was formed was used, but the evaluation time was 32.
White peeling occurred in all 10 out of 10 at 0 hours. In Comparative Example 2, the cage 40 having no notch as shown in FIG. 8 was used, but white peeling occurred in all 10 of the 10 cages in the evaluation time of 400 hours. Further, in Comparative Example 3, a cage having no notch and having fluidity of the grease retained in the meat-thinned portion by connecting the meat-thinned portion was used, but all 10 pieces out of 10 pieces in 320 hours of evaluation time were used. White peeling occurred.

Further, in Comparative Example 4, a cage in which the notch was formed in a portion other than the meat thin portion was used, and in Comparative Examples 5 to 7, the volume ratio of the notch and the meat thin portion was 45 to 60%. We used a cage with a notch, but 1 in 10
About 8 of them caused a decrease in strength and caused damage to the cage during the evaluation test.

Examples 1 to 11 and Comparative Examples 1 to 7 described above
From the results of the peeling life test and the seizure test, the volume ratio of the notch and the meat thin section in the cage is 0.1 to 0.1% for the entire cage from the balance of securing the fluidity of grease and securing the strength of the cage. It is understood that it is preferably 40%, more preferably 1 to 30%.

Next, Examples 12, 14, 15, 19, 20, 22 of the rolling bearing of the second embodiment and Examples 13, 16, 17, 17, 21 of the rolling bearing of the third embodiment.
The peeling life test and the seizure test were performed in the same manner as in the rolling bearing test of the first embodiment described above, together with Comparative Examples 8 to 13. Test conditions and test results
The results are shown in FIGS. 6 and 7 and Table 2.

[0042]

[Table 2]

In Table 2, in Example 12, Example 13 and Example 14 in which the volume ratios of the protrusions in the cage were 0.1%, 0.5% and 1%, respectively, 1 out of 10
It is understood that although peeling and seizure are observed at a rate of two, the occurrence rate is low.

Further, the volume ratio of the protrusions in the cage is 2
In Examples 15 to 19 set between 10% and 10%, neither peeling nor seizure was observed, and in Examples 20 to 22 in which the volume ratio of the protrusions was set to 12% and 15%, only seizure occurred. , Or peeling and seizure were slightly generated, it is understood that the effect of improving the fluidity of the grease by forming the protrusion on the cage and the effect of greatly extending the life of the bearing were proved.

Further, the protrusion is formed on the pocket side (Examples 12, 14, 15, 19, 20, 22) or on the non-pocket side (Examples 13, 16, 17, 1).
7, 21) or the like, there is no great difference in the molding position of the protrusion in the retainer, and it is understood that both are effective.

On the other hand, in Comparative Example 8, a retainer having no protrusion as shown in FIG. 8 was used, but white peeling occurred in all 10 of the 10 holders in the evaluation time of 320 hours. In Comparative Example 9, the protrusion was provided on the pocket side of the cage and the volume ratio of the protrusion was set to 0.05%. However, the strength of the protrusion itself was low, and the protrusion was damaged and no effect was obtained. It was

Further, in Comparative Examples 10 to 13, a protrusion is provided on the pocket side or the non-pocket side of the cage, and
The volume ratio of the protrusions was set to 18 to 30%, but 1 out of 10
At the rate of 5 pieces, peeling and seizure occurred, the volume ratio of the protrusions was large, and the strength of the cage itself decreased, so that the cage was broken at a rate of 1 to 8 out of 10.

Examples 12 to 22 and Comparative Example 8 described above
From the results of the peeling life test and the seizure test of No. 13, the volume ratio of the protrusions in the cage was 0.1 for the cage as a whole, from the balance of securing the fluidity of grease and the strength of the cage.
-15% is preferable, and more preferably 1-1.
It is understood that it is 0%.

[0049]

As described above, according to the rolling bearing of the present invention, the notch is formed in the meat fillet portion formed on the back surface of the cage on the side opposite to each pocket.
The volume ratio of the notch and the meat slime part is 0.1 to 40% of the whole cage. Therefore, good fluidity of the lubricant such as grease can be ensured without impairing the strength of the cage, and early peeling due to poor lubrication can be prevented.

Further, according to the rolling bearing of the present invention, a protrusion is provided on the end face of each cage side of the cage or on the back face opposite to each pocket, and the volume ratio of the protrusion is: It is 0.1 to 15% of the whole cage. Therefore, good fluidity of the lubricant such as grease can be ensured without impairing the strength of the cage, and early peeling due to poor lubrication can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing a cage of a rolling bearing according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part showing a cage for a rolling bearing according to a second embodiment of the present invention.

FIG. 3 is a perspective view of essential parts showing a cage for a rolling bearing according to a third embodiment of the present invention.

FIG. 4 is a graph showing a life test result of the cage in FIG.

5 is a graph showing the result of a seizure test of the cage in FIG.

FIG. 6 is a graph showing a life test result of the cage in FIGS. 2 and 3.

FIG. 7 is a graph showing a seizure test result of the cage in FIGS. 2 and 3.

FIG. 8 is a perspective view of a main part showing a cage of a conventional rolling bearing.

FIG. 9 is an enlarged sectional view and a partial perspective view of a main part of a rolling bearing in which a conventional sealing member for a rolling bearing is incorporated.

FIG. 10 is a main part plan view and a perspective view showing another cage of the conventional rolling bearing.

FIG. 11 is a perspective view of a main part showing still another cage of the conventional rolling bearing.

[Explanation of symbols]

10 cage 11 pockets 12 rolling elements 13 Meat slime part 14 notches 20, 30 cage 21,31 pockets 22, 32 protrusion

Claims (2)

[Claims] 1. A rolling bearing in which a plurality of rolling elements respectively held in a plurality of pockets of a cage are incorporated between a pair of bearing rings, wherein a meat sluice formed on a back surface opposite to the pockets, respectively. A notch is formed in the portion, and the volume ratio of the notch and the meat thin section is 0.1 to 40% of the whole cage.
Rolling bearing characterized in that 2. A rolling bearing in which a plurality of rolling elements respectively held in a plurality of pockets of a cage are incorporated between a pair of bearing rings, wherein an end surface on the pocket side or an opposite side to the pocket is provided. A rolling bearing, wherein a protrusion is provided on the back surface, and the volume ratio of the protrusion is 0.1 to 15% of the entire cage.