JP2000227120A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing in which a cage made of a synthetic resin with improved rigidity at elevated temperatures and strength is installed without lowering workability and installability of the cage. SOLUTION: In this rolling bearing, a crown-shaped cage 7 made of a synthetic resin is installed. The cage 7 is composed of a synthetic resin composition of which bending modulus of elasticity is 4 GPa or more at 150 deg.C and deflection temperature under load is 200 deg.C or more. Rigidity and strength are thereby ensured at elevated temperatures to the same extent as those at ordinary temperature. Namely, the bearing is prevented from being under inoperative condition caused by the cage 7 by improving rigidity at elevated temperatures and strength of the cage 7 without lowering workability and installability even when the bearing is used under elevated temperature environment with high speed operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing used for high-temperature and high-speed rotation, and more particularly to a high-temperature and high-speed rolling bearing used for an alternator of an automobile, an electromagnetic clutch of a compressor for a car air conditioner, and a motor of a vacuum cleaner. The present invention relates to a rolling bearing suitable as a ball bearing used in a rotating environment.

[0002]

2. Description of the Related Art Rolling bearings used in alternators of automobiles, electromagnetic clutches of compressors for car air conditioners, and motors of vacuum cleaners are required to have high-temperature and high-speed performance.
Generally, deep groove ball bearings and double row angular contact ball bearings are used. The synthetic resin cage incorporated in such a ball bearing is processed into a crown shape as shown in FIG. 1 because of its good incorporation into the bearing. And in a single row deep groove ball bearing incorporating the crown type cage,
For example, as shown in FIG.
In the meantime, the retainer 7 is rotatably interposed, and the plurality of balls 6 (rolling elements) are guided and held by the retainer 7 in a rotatable state. Incorporation of the crown-shaped retainer 7 is performed by elastically deforming and expanding the claws 7a provided on the discontinuous sides of the respective pockets and inserting the respective balls 6, whereby the crowns 7a are incorporated between the inner and outer rings 5, 3. It is held in such a manner that it is guided by the ball 6.

Here, a lubricant such as grease is sealed in the bearing. In FIG. 2, reference numeral 8 indicates that the lubricant sealed in the bearing is prevented from leaking, and dust and the like are contained inside. Shows a seal to prevent entry. As a material for the synthetic resin retainer 7, conventionally, a polyamide
6,6 So-called engineering plastics such as resin, polyacetal resin, polybutylene terephthalate resin, polyphenylene sulfide resin, fluororesin, etc. are used alone, or composite materials reinforced by mixing short fibers such as glass fiber, carbon fiber, etc. Used in form. Among these materials, polyamide 6,6 resin is frequently used as a material for the synthetic resin retainer 7 because of a good balance between material cost and performance, and excellent performance has been confirmed under moderate environmental conditions. I have.

[0004] However, these synthetic resin materials are:
Due to the low rigidity at high temperatures, when the bearing is to be operated at high speed in a higher temperature environment, the claw 7a provided on the discontinuous side of the rolling element pocket of the cage 7 spreads to the outer diameter side due to centrifugal force. Interference with the raceway surface 2 of the outer race 3 or the entrance of the rolling element pocket becomes wider than the diameter of the rolling element (ball diameter), and the retainer 7 rattles without being restrained by the rolling element, generating heat and burning. There is a possibility that the bearings and noise may increase, and high-speed operation of the bearing in a high-temperature environment is limited.

[0005] On the other hand, conventionally, in order to increase the rigidity of the cage itself irrespective of room temperature or high temperature, the filling amount of the reinforcing fiber such as the glass fiber or the carbon fiber is increased,
Attempts have been made to increase the bottom thickness of the rolling element pocket of the cage 7.

[0006]

As described above, the conventional crown-shaped synthetic resin cage 7 for a ball bearing has a disadvantage that when the bearing is operated at a high speed under a higher temperature environment, the cage 7 is centrifugally driven. The pawl 7a provided on the discontinuous side spreads to the outer diameter side, causing interference with the raceway surface 2 of the outer race 3, or the entrance of the rolling element pocket becomes wider than the diameter of the rolling element, and is not restrained by the rolling element. There is a possibility that seizure, noise rise, etc. may occur, and there is a problem that high-speed operation of the bearing in a high-temperature environment is limited.

In the method of simply increasing the filling amount of reinforcing fibers such as glass fibers and carbon fibers in order to increase the rigidity of the cage 7, the rigidity at high temperatures is somewhat improved, but not sufficient. The deformability at room temperature decreases, and the moldability and the incorporation of the retainer 7 decrease. In addition, even if the bottom thickness of the rolling element pocket of the cage 7 is increased to increase the rigidity, the effect is not sufficient because there is naturally a limit depending on the width of the bearing.

The present invention has been made in view of the above-mentioned problems, and a synthetic resin cage having improved high-temperature rigidity and strength without deteriorating the workability and incorporation of the cage. It is an object to provide a rolling bearing incorporating the same.

[0009]

SUMMARY OF THE INVENTION The present invention reduces the workability and incorporation of a cage by employing a synthetic resin cage capable of securing the same rigidity and strength as room temperature in a high temperature environment. Without increasing the high temperature rigidity and strength of the cage,
Even if the bearing is used at a high speed in a high temperature environment, it prevents the bearing from being unable to operate due to the cage.

That is, in order to solve the above problems, the present invention provides a rolling bearing incorporating a crown-shaped cage made of a synthetic resin, wherein the cage has a flexural modulus at 150 ° C. of 4 GPa or more. And a load stress of 1.82 MPa
A rolling bearing characterized in that it is composed of a synthetic resin composition having a deflection temperature under load of 200 ° C. or more.

At this time, as a method for manufacturing the cage of the synthetic resin cage, particularly in the case of an odd pocket, an injection molding method using a disk gate is employed to enable continuous operation at high temperature and high speed. It is possible to provide sufficient strength. Here, the test conditions for the deflection temperature under load are as described in the examples below.

According to the present invention, a synthetic resin cage to be incorporated into a bearing has a flexural modulus at 150 ° C. of 4 GPa or more,
By manufacturing from a synthetic resin composition having a deflection temperature under load of 200 ° C. or higher, the cage has excellent high-temperature stiffness without excessively high stiffness at normal temperature (see Tables 1 and 2 below). 2). Here, the flexural modulus is 150
When the plastic crown type cage is used for high-speed rotating bearings, there is a critical region at about 130 ° C to 200 ° C, and the typical value is 150 ° C. is there.

The upper limits of the flexural modulus at 150 ° C. and the deflection temperature under load are not particularly limited.
No particular inconvenience occurs. As a result, even without special design changes, if the bearing rotates at high speed in a high temperature environment,
The claw provided on the discontinuous side of the cage due to centrifugal force spreads to the outer diameter side and causes interference with the inner diameter surface of the outer ring, or the entrance of the part holding the rolling element is wider than the rolling element diameter and is restrained by the rolling element. Problems such as disappearance are prevented, heat, seizure,
It is possible to prevent the bearing from becoming inoperable due to an increase in noise or the like.

Here, when the above-mentioned synthetic resin cage is injection-molded by a general tunnel gate or side gate,
Like a crown type cage having an odd number of pockets, a relatively weak weld may be formed at the bottom of a thin pocket, and when excessive force is applied to the cage, the cage may be damaged and the bearing may not be able to operate. is there. On the other hand, by adopting an injection molding method using a disk gate as a method of manufacturing the retainer, no weld is generated, so that there is no possibility that the retainer will be damaged even when an excessive force is applied.

Next, a description will be given of the synthetic resin constituting the retainer. The matrix resin of the resin composition used in the synthetic resin cage incorporated in the rolling bearing of the present invention is not particularly limited, and as the crystalline thermoplastic resin, modified polyamide 6T, polyamideimide ( PAI), thermoplastic polyimide, polyetheretherketone (PEEK), polyethernitrile (PEN), liquid crystal polyester, and the like. Examples of the amorphous thermoplastic resin include polyethersulfone having a glass transition temperature of 200 ° C. or higher ( Examples include so-called super-engineering plastic resins such as PES), polyarylsulfone, and polyetherimide (PEI), and these may be used alone or in combination. Further, even a resin having a low glass transition temperature such as a polyphenylene sulfide resin can be used as a so-called polymer alloy in combination with a resin having a high glass transition temperature.

That is, when a crystalline thermoplastic resin is used as the matrix resin of the resin composition, the glass transition temperature is 120 ° C. or higher, and when an amorphous thermoplastic resin is used, the glass transition temperature is 200 ° C. The above is a necessary condition for satisfying the requirements of the present invention. It goes without saying that the matrix resin has long-term thermal stability at high temperatures.

The fibrous filler is appropriately added as necessary to increase the rigidity of the cage to satisfy the requirements of the present invention and to improve dimensional accuracy. In order to make the resin composition constituting the synthetic resin cage satisfy the requirements of the present invention, the fibrous filler is added in an amount of 10 to 50% by weight in the total composition according to the purpose. It is preferred that More preferably, 15 to 4
0 wt% is preferably added.

[0018] The reason is that, even if the amount exceeds 50% by weight, not only the melt flowability of the resin composition is remarkably reduced but the moldability is deteriorated, but further improvement in mechanical properties and dimensional stability is expected. On the other hand, since the deformability of the material becomes extremely small (the tensile elongation at break at normal temperature decreases), the cage may be damaged at the time of forming the cage or assembling the bearing.

The tensile elongation at break of the resin composition containing the fibrous filler is not particularly limited, but the elongation at break is preferably 2% or more. Because if the elongation at break is 2% or more, when the rolling element is incorporated into the pocket of the cage, the claw of the cage may be broken and whitened without special treatment such as heating the cage. This is because there is no possibility of occurrence.

Conversely, if the amount of the fibrous filler is less than 10 wt%, the effect of reinforcing the mechanical properties is small, and the high-temperature rigidity is insufficient. However, for cages that require stronger mechanical strength and deformability, such as cages for crown type ball bearings, which cannot be forcibly removed when forming cages or forcibly inserted when incorporating rolling elements, fibrous fillers The addition amount is preferably 15 to 4
0 wt%.

The fibrous filler is not particularly limited, but may be glass fiber, carbon fiber, metal fiber, aramid fiber, or the like.
Aromatic polyimide fiber, liquid crystal polyester fiber, silicon carbide fiber, alumina fiber, boron fiber, silicon carbide whisker, silicon nitride whisker, alumina whisker,
Aluminum nitride whiskers, wollastonite, potassium titanate whiskers, aluminum borate whiskers, zinc oxide whiskers, magnesium oxide whiskers, mullite whiskers, calcium carbonate whiskers,
Examples thereof include graphite whiskers and magnesium oxysulfate whiskers. Among them, glass fibers and carbon fibers are preferable because of their good reinforcing properties.

As the form of the fiber, an aspect ratio of 3 to 200 is preferable. The reason is that if it is less than 3, the reinforcing effect of the cage will not be sufficiently exhibited, and it will be brittle, while if it exceeds about 200, uniform dispersion during mixing will be extremely difficult. Further, the fiber diameter is not particularly limited, but preferably has an average fiber diameter of 0.2 to 30 μm, more preferably 3 to 20 μm. The reason is that if the average fiber diameter is smaller than 0.2 μm, the fibers may agglomerate when mixed with the base material, and the dispersion of the fibers may be non-uniform. If the diameter is larger than this, not only may the smoothness of the surface be hindered, but also the mating surface that has slid may be damaged. Average fiber diameter is 3 ~
If it is 20 μm, such a tendency is completely eliminated and a favorable result can be obtained.

The resin composition for forming the synthetic resin cage to be incorporated in the rolling bearing of the present invention has an affinity between the matrix resin and the fibrous filler, and provides an adhesion between the fibrous filler and the matrix resin and a fibrous filler. In order to improve the dispersibility of the filler, the fibrous filler can be treated with a coupling agent such as a silane-based coupling agent or a titanate-based coupling agent, or a surface treatment method according to other purposes. It is not limited to these.

Incidentally, within a range not to impair the object of the present invention,
Various additives may be blended. For example, graphite, hexagonal boron nitride, fluorine mica, ethylene tetrafluoride resin powder, tungsten disulfide, solid lubricants such as molybdenum disulfide,
Inorganic powder, organic powder, lubricating oil, plasticizer, rubber, resin, antioxidant, heat stabilizer, ultraviolet absorber, light protectant, flame retardant, antistatic agent, release agent, flow improver, heat conduction Examples include a property improving agent, a non-tackifier, a crystallization accelerator, a nucleating agent, a pigment, a dye, and the like.

The method of mixing the matrix resin as the base material and various additives such as a fibrous filler is not particularly limited. For example, each can be melt-kneaded separately, or these materials can be preliminarily mixed by a mixer such as a Henschel mixer, a tumbler, a ribbon mixer, a ball mill, etc., and then supplied to the melt mixer. As the melt mixer, a known melt kneader such as a single-screw or twin-screw extruder, a kneading roll, a pressure kneader, a Banbury mixer, and a Brabender plastograph can be used. The temperature at the time of melt-kneading is not particularly limited, but may be appropriately selected within a temperature range in which the matrix resin serving as the base material sufficiently proceeds and does not deteriorate.

The method for manufacturing the synthetic resin cage incorporated in the bearing of the present invention is not particularly limited. For example, it can be molded by a usual method such as injection molding, compression molding, transfer molding and the like. In particular, the injection molding method is preferable because it is excellent in productivity and can provide an inexpensive cage. Further, even if the injection molding method is adopted, the gate position and the shape of the cage are not particularly limited. For example, known gate shapes such as a side gate, a tunnel gate, a fan gate, and a disk gate can be used. Among them, a disk gate is preferable because a low strength weld is not formed in a thin portion even in an odd-numbered pocket. Also in the side gate, the tunnel gate, and the like, it is preferable to provide the gate and the weld in the thick portion in order to improve the strength of the cage.

[0027]

Next, an embodiment of the present invention will be described. Parts and the like similar to those in the above-described conventional example will be described with the same reference numerals. The rolling bearing of this embodiment is a deep groove ball bearing, and its structure is the same as that of the conventional one as shown in FIG.

However, the cage 7 of the present embodiment is a crown-shaped cage made of a synthetic resin. The synthetic resin composition has a flexural modulus at 150 ° C. of 4 GPa or more and a deflection temperature under load. Is composed of a synthetic resin composition at 200 ° C. or higher. As described above, as a synthetic resin composition having a flexural modulus at 150 ° C. of 4 GPa or more and a deflection temperature under load of 200 ° C. or more, for example, as a matrix resin, a crystalline thermoplastic resin having a glass transition temperature of 120 ° C. or more By using polyetheretherketone as a resin and adding 30% of carbon fibers (CF) as a fibrous filler to be added in a blending ratio of the total composition, a synthetic resin composition having the above properties can be obtained. use.

Using this synthetic resin composition, it is molded into the form of a crown holder 7 as shown in FIG. 1 by, for example, injection molding. The cage 7 manufactured as described above is incorporated in a bearing to produce a rolling bearing, and is incorporated in a high-speed and high-speed rotating portion of a target device and used. By forming the cage 7 from the synthetic resin composition having the above-mentioned properties, the rigidity of the cage 7 at normal temperature does not become excessive, and the moldability and the incorporation of the cage 7 are reduced. There is no.

Further, the rigidity of the cage 7 at high temperature is substantially the same as that at normal temperature. Even if the bearing is used in a high-temperature and high-speed environment, when the bearing is operated at high speed, centrifugal force is applied. Claw 7a provided on the discontinuous side of the rolling element pocket of cage 7
Of the rolling element pocket is prevented from expanding beyond the diameter (ball diameter) of the rolling element 6 as well as the outside diameter of the rolling element is reduced. As a result, generation of heat, seizure, noise rise, etc. in the bearing is reduced.

The rolling bearing having the above-mentioned structure is, for example, the position of reference numerals 20 and 21 of the alternator of the automobile shown in FIG. 4, the position of reference numeral 22 of the electromagnetic clutch of the compressor for a car air conditioner shown in FIG. 5, and the cleaning shown in FIG. It can be incorporated and used at the position of reference numeral 23 of the motor of the machine. Since the shafts supported by the rolling bearings are all in a high-temperature atmosphere and rotate at a high speed, the use of the rolling bearings according to the present invention improves the life of the bearings supporting the shafts. This leads to an improvement in the life of the alternator of the automobile, the electromagnetic clutch of the compressor for the car air conditioner, and the motor of the vacuum cleaner, which incorporate the rolling bearing according to the present invention.

[0032]

EXAMPLES Examples and comparative examples for explaining the effects of the present invention will be shown below. However, the composition of the cage 7 of the present invention is as follows:
It is not limited to these. Using a synthetic resin composition in which a matrix and a fibrous filler were blended in the proportions shown in Tables 1 and 2, a test piece for measuring a flexural modulus, a test piece for measuring a deflection temperature under load, and a cage 7 for a deep groove ball bearing were prepared. Various tests were performed as described below. The examples shown in Table 1 satisfy the present invention, and the examples shown in Table 2 are comparative examples in which the present invention for comparison is not satisfied.

[0033]

[Table 1]

[0034]

[Table 2]

Here, the description of the raw materials of the cage 7 in the table indicates the following materials. (1) PA6 / polyamide 6 resin (Ube Industries: Ube nylon 1015U) (2) PA66 / polyamide 6,6 resin (Ube Industries:
Ube Nylon 2120U) (3) PA46 / Nylon 4,6 resin (DSM: Stanyl TW300) (4) Modified PA6T / Modified polyamide 6T resin (Mitsui Chemicals: Arlen A300) (5) PBT / polybutylene terretza (6) PPS / polyphenylene sulfide resin (Kureha Chemical Co., Ltd .: FORTRON KPS W-214) (7) PC / polycarbonate resin (Teijin Chemical: Panlite L-1250) (8) Amorphous polyarylate resin (U-Polymer U-100 manufactured by Unitika) (9) PES / polyether sulfone resin (VICTR)
EX: VICTREX PES 4100G) (10) PEEK / polyetheretherketone resin (VICTREX: VICTREX PEEK 4)
50G) (11) PEN / polyethernitrile (Idemitsu Materials: Idemitsu PEN RF) (12) TP1 / thermoplastic polyimide resin (Mitsui Chemicals: Aurum # 450) (13) PEI / polyetherimide resin (GE) Forest product:
(14) GF / glass fiber (FESS-015-0413, fiber diameter 10 μm, average fiber length 0.5 mm) (15) CF / carbon fiber (Vesfight HTA, manufactured by Toho Rayon Co., Ltd.) -CMF-500-E, fiber diameter 7 µm,
In addition, a twin screw extruder is used for the production of each composition, and fibrous fillers such as glass fiber and carbon fiber are added by a quantitative side feeder to prevent fiber breakage. Extruded and granulated. The obtained pellets were supplied to an in-line screw type injection molding machine and formed into a desired test piece (length 130 mm, width 13 mm, thickness 6.4 mm) and retainer shape (retainer for model No. 6303). .

The shape of the cage 7 was a crown type cage as shown in FIG. 1, and the shape of the gate was a one-point tunnel gate. The mixing ratios (wt%) of the various materials are shown in Tables 1 and 2. [Test Method for Flexural Modulus] First, in order to measure the flexural modulus at 150 ° C. of each of the obtained synthetic resin compositions, based on the ASTM D790I method “Plastic flexural property test method (three-point bending)”. Distance between supports 100m
The test was performed at a test speed of 2.8 mm / min.

The results are as shown in Tables 1 and 2 above. (Test method for deflection temperature under load) Next, in order to measure the deflection temperature under load of each of the obtained synthetic resin compositions,
The test was performed at a maximum bending stress of 1.82 MPa based on ASTM D648 "Method of measuring deformation temperature of plastic under bending load".

The results are as shown in Tables 1 and 2 above. [Performance of Cage 7 Installed in Bearing at High Temperature Rigidity] In order to confirm the performance of the synthetic resin cage 7 of the present invention in a high temperature environment, each of the obtained cages 7 was subjected to a bearing number 6303. A urea grease containing ether oil as the base oil is embedded in the seal, a seal is attached, and a rotation test is performed under the following high-temperature environment test conditions using a high-speed, high-speed bearing inner ring rotation tester manufactured by Meiko Seiko. 24 hours later, the amount of opening of the nail 7a in the diameter direction was examined.

The test conditions are as follows.・ Outer ring temperature: 180 ° C. ・ Rotation speed: 20000 rpm ・ Radial load: 150 kgf In this embodiment, an opening of 0.3 mm or less is accepted as 0.3 mm.
Those that exceeded were rejected. The results are as shown in Tables 1 and 2 above.

Next, in order to test the incorporation of the rolling elements into the plastic retainer of the present invention, an incorporation test was performed using an air-driven automatic ball incorporation device manufactured by Nippon Seiko Co., Ltd. As shown in FIGS. 7 (a) and 7 (b), the pneumatically-driven automatic ball assembling device used in the test has the balls 6 equally distributed on the pockets of the retainer 7, and then places the push plate 30 thereon. Is pressed by air pressure so that all the balls 6 can be instantaneously incorporated into the pocket portion of the retainer 7.
That is, in FIG.
2. The retainer support plate 33 is fixed, the retainer 7 in which the balls 6 are equally arranged on the pockets is placed on the retainer support plate 33, and the push plate 30 is applied thereto, and the air fixed to the frame 32 is pressed. A punch 35 provided at the tip of a cylinder rod 34a extending from the cylinder 34 is pressed against the pressing plate 30 by air pressure supplied to the cylinder 34, and all the balls 6 are instantaneously incorporated into the pocket portion of the retainer 7. In this case, the cylinder moving speed was 0.2 m / sec, the load was 15 kgf, and the ambient temperature was 20 ° C. Note that FIG.
In (a), the retainer 7 and the punch 35 are shown in a sectional view in the axial direction.

The test cage was manufactured in the same manner as in the above Examples and Comparative Examples, and the model number and the shape were 6303 equivalent crown type cages. Table 4 shows the mixing ratios (wt%) of various materials. Note that the test results of the incorporation property
In the case where no breakage or whitening was observed in the nails, the test was regarded as a success of the incorporation, and the success rate was determined and is shown in Table 3. In addition, the tensile elongation at break of various materials was measured and is shown in Table 3.

[0042]

[Table 3]

(Test Method for Tensile Elongation at Break) In order to measure the tensile elongation at break of each of the synthetic resin compositions shown in Table 3, a Type I test piece (thickness) was measured based on the ASTM D638 “Test Method for Tensile Properties of Plastics”. 3.2m
m), the distance between the gripping tools is 115 mm, and the test speed is 2
The test was performed at 0 mm / min.

As is apparent from Table 3, the cage 7 formed from the resin composition having a tensile elongation at break of 2% or more showed good incorporation without any breakage or whitening of the nail in the incorporation test. . As can be seen from Table 1 above, 15
All of the cages 7 manufactured from the synthetic resin composition according to the present invention having a flexural modulus at 0 ° C. of 4 GPa or more and a deflection temperature under load of 200 ° C. or more have a small opening of the claws 7 a and are excellent at high temperature and high speed. It has the performance which it did.

On the other hand, as in Comparative Example 14, 150
It can be seen that even if the flexural modulus at 4 ° C. is 4 GPa or more, if the deflection temperature under load is less than 200 ° C., the same high-temperature rigidity as at room temperature cannot be secured. Conversely, even when the deflection temperature under load is 200 ° C. or higher as in Comparative Example 7,
When the flexural modulus at 0 ° C. is less than 4 GPa, the same high-temperature rigidity as at room temperature cannot be ensured.

Next, a description will be given of the confirmation of the effect when the disk gate is employed when the cage 7 is injection-molded from the synthetic resin composition. 20 or 30 wt. Glass fiber is added to PES, which is generally said to have low weld strength.
Using the synthetic resin composition blended in%, a retainer 7 was produced by a disk gate and a one-point tunnel gate, and an annular tensile test was performed.

The test cage was a crown type cage (number of rolling elements: 7) corresponding to model No. 6303 similar to Examples 1 to 12 and Comparative Examples 1 to 22. The test method is such that the gate portion 11 is mounted on the annular tensile test jig 10 shown in FIG. 3 so that the gate portion 11 is located in the horizontal direction, and a tensile tester (Autograph AG-10KNG) manufactured by Shimadzu Corporation is used for 10 mm / min. An annular tensile test was performed at a tensile speed.

Table 4 shows the test results. As is clear from Table 4, the cage made by the disk gate is:
It showed better strength both at room temperature and at high temperature than the cage made by the one-point tunnel gate.

[0049]

[Table 4]

As described above, by employing the injection molding method using the disk gate, unlike the case of injection molding using a general tunnel gate or side gate, no weld is generated. There is no danger that the bearing will be damaged when it is applied and the bearing will not be able to operate.

[0051]

As described above, in the rolling bearing of the present invention, the workability of the synthetic resin cage at normal temperature and the assembling property of the cage at the room temperature are not reduced, and the cage is kept at room temperature. As a result of securing the same high-temperature rigidity, even if the bearing is used under high-temperature and high-speed rotation, the claw opening of the retainer is reduced.

Thus, even if the rolling bearing incorporating the synthetic resin cage is used at a high temperature and a high speed without deteriorating the assemblability of the cage and the like, the heat generation and the burning caused by the cage are caused. There is an effect that there is no danger that the bearing will not be able to operate due to the increase of the sound and the noise.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a retainer.

FIG. 2 is a cross-sectional view showing a rolling bearing.

FIG. 3 is a diagram illustrating a tensile test.

FIG. 4 is a diagram showing an alternator of a vehicle.

FIG. 5 is a view showing an electromagnetic clutch of a compressor for a car air conditioner.

FIG. 6 is a diagram showing a motor of the vacuum cleaner.

7A and 7B are views for explaining an automatic ball assembling device, and FIG.
Is a cross-sectional view, and (b) is a plan view showing a relationship between a retainer and a ball.

[Explanation of symbols]

 3 Outer ring 5 Inner ring 6 Ball (rolling element) 7 Cage 7a Claw

Claims (1)

[Claims] 1. A rolling bearing incorporating a crown-shaped cage made of a synthetic resin, wherein the cage has a temperature of 150 ° C.
Flexural modulus at 4 GPa or more and load stress 1.82
A rolling bearing comprising a synthetic resin composition having a deflection temperature under load of 200 ° C. or more in MPa.