JP2005214255A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing for hardly generating heat caused by friction by hardly generating abnormal noise by self-excited vibration of a retainer. <P>SOLUTION: An angular ball bearing is equipped with an inner ring 1, an outer ring 2, a plurality of rolling elements 3 rotatably arranged between the inner ring 1 and the outer ring 2, and a retainer 4 for retaining a plurality of rolling elements 3 between the inner ring 1 and the outer ring 2. The retainer 4 is made of a resin material such as phenolic resin. The resin material includes a microcapsule containing at least one of oil, grease and an additive for a lubricant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rolling bearing.

Conventional rolling bearings have a problem that if the grease is insufficient during high-speed rotation, self-excited vibration is generated in the cage and abnormal noise is generated. In particular, in an angular contact ball bearing, the inner peripheral surface of the outer ring and the outer peripheral surface of the cage are in contact with each other in the guide gap, so that the amount of heat generated by friction increases as the rotational speed increases, and the temperature rises. Had.
As a method for solving these problems, it is conceivable to use a rolling element guide type crown cage used in a deep groove ball bearing. Further, as described in Patent Document 1, a method of increasing the amount of grease supplied to the raceway surface by providing a radial groove penetrating from the inner diameter surface to the outer diameter surface of the cage on the inner surface of the cage pocket. Can be considered.
JP 2001-280347 A

However, the rolling element guide type crown cage used in the deep groove ball bearing can prevent friction between the cage and the inner and outer rings, but the cage strength is insufficient, so the number of balls is large. It is difficult to apply to angular contact ball bearings.
Moreover, since the shape of the cage described in Patent Document 1 is limited and the shape is different from that of a conventional cage, it cannot be manufactured using a conventional mold. Therefore, there is a problem that the manufacturing cost is improved.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a rolling bearing that solves the above-described problems of the prior art and is unlikely to generate abnormal noise due to self-excited vibration of a cage, and that does not easily generate heat due to friction.

  In order to solve the above problems, the present invention has the following configuration. That is, the rolling bearing according to claim 1 according to the present invention includes an inner ring, an outer ring, a plurality of rolling elements that are freely rollable between the inner ring and the outer ring, and the inner ring and the outer ring. A rolling bearing comprising a cage for holding a rolling element, wherein the cage is made of a material containing a microcapsule containing at least one of oil, grease, and a lubricant additive. It is characterized by.

When a load is applied to the cage or wear occurs, the microcapsule is broken, and at least one of the contained oil, grease, and lubricant additive is in sliding contact between the cage and the inner and outer rings. The lubricity of this sliding contact portion is maintained well over a long period of time. Therefore, abnormal noise due to self-excited vibration of the cage and heat generation due to friction are suppressed.
In addition, it is preferable that content of the microcapsule in the said material which comprises a holder | retainer shall be 3 mass% or more and 50 mass% or less. If it is less than 3% by mass, the lubricity imparted to the cage may be insufficient, and if it exceeds 50% by mass, the strength of the material will be reduced and the strength of the cage will be insufficient. There is a fear. In order to make such inconvenience less likely to occur, the content of the microcapsules in the material is more preferably 3% by mass or more and 35% by mass or less.

  Since the rolling bearing of the present invention includes a cage made of a material containing a microcapsule containing at least one of oil, grease, and a lubricant additive, the cage and the inner and outer rings The lubricity of the sliding contact portion is well maintained over a long period. Therefore, the rolling bearing of the present invention hardly generates abnormal noise due to the self-excited vibration of the cage, and hardly generates heat due to friction.

Embodiments of a rolling bearing according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial longitudinal sectional view showing a structure of an angular ball bearing which is an embodiment of a rolling bearing according to the present invention.
The angular groove ball bearing of FIG. 1 is disposed between an inner ring 1 having a raceway surface 1a on an outer peripheral surface, an outer ring 2 having a raceway surface 2a on an inner peripheral surface, and both raceway surfaces 1a and 2a. A plurality of rolling elements (for example, steel balls) 3 and an annular cage 4 disposed between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2 to hold the plurality of rolling elements 3 in a freely rollable manner; It is equipped with.

The cage 4 is formed with cylindrical pockets 4a for holding the rolling elements 3 at equal intervals in the circumferential direction. The pocket 4 a has an inner diameter slightly larger than the diameter of the rolling element 3.
Further, non-contact type seals 5 and 5 are attached to both ends of the inner peripheral surface of the outer ring 2. The lip portion, which is the inner peripheral edge of the seals 5 and 5, is close to the outer peripheral surface of the inner ring 1, and the seals 5 and 5 almost cover the opening between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2. ing. A space surrounded by the inner ring 1, the outer ring 2 and the seals 5, 5 is filled with a lubricant such as grease (not shown) and sealed inside the angular ball bearing by the seals 5, 5.

  Further, a shoulder 11 is formed on the outer peripheral surface of the inner ring 1 on one side of the raceway surface 1a (left side in FIG. 1), and the inner ring 1 of the raceway surface 2a is defined on the inner peripheral surface of the outer ring 2. A shoulder 12 is formed on the opposite side. As described above, by forming the shoulders 11 and 12 on the inner ring 1 and the outer ring 2, respectively, a radial load and an axial load can be applied to the angular ball bearing.

The inner diameter of the cage 4 is formed larger than the outer diameter of the shoulder 11 of the inner ring 1, the outer diameter of the cage 4 is formed slightly smaller than the inner diameter of the shoulder 12 of the outer ring 2, and A guide gap 15 is formed between the outer peripheral surface and the inner peripheral surface of the shoulder 12 of the outer ring 2. The above-described lubricant is supplied to the guide gap 15 and the sliding contact portion between the outer ring 2 and the cage 4 is lubricated.
Furthermore, the cage 4 is made of a resin material such as phenol resin, and the resin material contains 3 to 50% by mass of microcapsules containing at least one of oil, grease, and lubricant additive. Contains. An example of a suitable microcapsule is a microcapsule manufactured by Nippon Capsule Products Co., Ltd. The company's microcapsules are made of melamine resin and have a diameter of about 5 μm to 10 μm and contain mineral oil.

  When the angular ball bearing rotates and the outer peripheral surface of the retainer 4 and the inner peripheral surface of the shoulder 12 of the outer ring 2 facing each other with the guide gap 15 interposed therebetween, the retainer 4 is slightly worn. Then, the microcapsule contained in the resin material constituting the cage 4 is broken, and the inclusion of the microcapsule is a sliding contact portion between the outer circumferential surface of the cage 4 and the inner circumferential surface of the shoulder 12 of the outer ring 2. To be supplied. When the inclusions of the microcapsules are supplied to the sliding contact portion, the lubricity of the sliding contact portion is improved, so that the self-excited vibration and abnormal noise of the cage 4 are suppressed. Moreover, since the wear of the sliding contact portion of the cage 4 is suppressed, an increase in the amount of heat generated and an increase in temperature due to an increase in rotational speed are suppressed.

Below, a microcapsule and a resin material are demonstrated in detail.
[About microcapsules]
The type of material constituting the microcapsule is not particularly limited, but considering the pressure and temperature when the cage is manufactured by the injection molding method, thermosetting resin, inorganic such as metal, metal oxide, etc. Compounds are preferred.
Specific examples of the thermosetting resin include phenol resin, urea resin, unsaturated polyester resin, vinyl ester resin (for example, epoxy acrylate resin), diallyl phthalate resin, epoxy resin, wholly aromatic polyimide resin (for example, manufactured by Du Pont). Polypyromellitimide), bismaleimide-based polyimide resin, nadic acid-terminated polyimide resin, acetylene-terminated polyimide resin, triazine-based resin, styrylpyridine-based resin, melamine resin and the like. A fibrous reinforcing material such as glass fiber, carbon fiber, or aramid fiber may be added to these thermosetting resins.

The method for producing the microcapsules is not particularly limited, and is selected in consideration of the properties of the inclusions and the properties of the materials constituting the microcapsules. Specific examples include an interfacial polymerization method, an in situ polymerization method, a phase separation method, a liquid drying method, an orifice method, a spray drying method, an air suspension coating method, a hybridizer method, and the like.
In order to produce a microcapsule having a uniform particle size, it is preferable to appropriately adjust the production conditions of the microcapsule, but the microcapsule having a particle size distribution has a uniform particle size by a centrifugal separation method or a filter method. Microcapsules may be separated.

[About oil contained in microcapsules]
The type of oil contained in the microcapsule is not particularly limited, and any oil that is generally used as a base oil for grease or lubricating oil can be used without any problem.
Specific examples of the oil include mineral oil, synthetic oil, and animal and vegetable oils. Examples of mineral oils include paraffinic mineral oils, naphthenic mineral oils, and mixed oils of these, but vacuum distillation, solvent removal, solvent extraction, hydrocracking, solvent dewaxing, sulfuric acid washing, clay refining, and hydrogenation refining. A mineral oil refined to have a viscosity index of 100 or more by at least one of the above is preferred. And what is called highly refined mineral oil refine | purified so that a viscosity index may be 120 or more is more preferable.

Synthetic oils include synthetic hydrocarbon oils, ester oils, ether oils, silicone oils, fluorine oils and the like.
Among these, synthetic hydrocarbon oils include normal α-olefins such as normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, 1-decene and ethylene co-oligomer, and hydrides thereof. Further, alkylbenzenes such as monoalkylbenzene, dialkylbenzene, and polyalkylbenzene, and alkylnaphthalenes such as monoalkylnaphthalene, dialkylnaphthalene, and polyalkylnaphthalene are also included.

  In addition, as ester oil, diester oil such as dibutyl sebacate, di (2-ethylhexyl) sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl glutarate, methylacetyl ricinolate, trioctyl trimellitate, Aromatic ester oils such as tridecyl trimellitate and tetraoctyl pyromellitate are listed. In addition, polyol ester oils such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, monobasic acid and dibasic acid mixed fatty acid and polyhydric alcohol And complex ester oils which are oligoesters.

  In addition, ether oils include polyglycols such as polyethylene glycol, polypropylene glycol, polyethylene glycol monoether, polypropylene glycol monoether, monoalkyl triphenyl ether, alkyl diphenyl ether, dialkyl diphenyl ether, tetraphenyl ether, pentaphenyl ether, monoalkyl. Examples thereof include phenyl ether oils such as tetraphenyl ether and dialkyl tetraphenyl ether.

Synthetic oils other than the above include tricresyl phosphate, silicone oil, perfluoroalkyl ether oil and the like.
Examples of animal and vegetable oils include beef tallow, pork tallow, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, and other oils or hydrides thereof.
These oils can be used alone or in combination of two or more.
Of the oils shown here, di (2-ethylhexyl) sebacate (DOS) is most preferred from the viewpoint of lubricity. When this DOS is directly mixed with the resin material, the resin material becomes too soft or DOS bleeds, so it cannot be contained in a large amount. However, if it is encapsulated in a microcapsule, the upper limit of the content can be increased.

[Grease contained in microcapsule]
The type of grease contained in the microcapsule is not particularly limited, and any grease that is generally used as a lubricant can be used without any problem. For example, the thickener is lithium soap and the base oil is one of mineral oil, diester oil, polyvalent ester oil, or silicone oil, or the thickener is sodium soap and the base oil is mineral oil. Some sodium soap grease. In addition, the thickener is calcium soap, the base oil is mineral soap calcium soap, the thickener is a mixture of sodium soap and calcium soap, the base oil is mineral oil, the thickener is calcium complex soap. , Aluminum composite soap, composite base grease which is one of lithium composite soap, thickener is one of urea, bentonite, carbon black, fluorine compound, heat-resistant organic compound, base oil is synthetic oil ( Non-soap base greases which are diester oils, polyester oils, synthetic hydrocarbon oils, silicone oils and fluorine oils.

[About the additive for lubricant contained in the microcapsule]
The type of additive for lubricant contained in the microcapsule is not particularly limited, and there is no problem as long as it is generally used as an additive added to lubricants such as lubricating oil and grease. Can be used. For example, an antioxidant, a rust inhibitor, an extreme pressure agent, an oily agent, a metal deactivator, and the like can be used, and these can be used alone or in combination of two or more.

As the antioxidant, known ones commonly used in conventional greases can be used without problems. For example, amine antioxidant, phenol antioxidant, sulfur antioxidant, zinc dithiophosphate and the like.
Among these, specific examples of amine-based antioxidants include phenyl-1-naphthylamine, phenyl-2-naphthylamine, diphenylamine, phenylenediamine, oleylamidoamine, phenothiazine and the like.

  Specific examples of the phenolic antioxidant include pt-butyl-phenyl salicylate, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-phenylphenol, 2,2 '-Methylenebis (4-methyl-6-t-octylphenol), 4,4'-butylidenebis-6-t-butyl-m-cresol, tetrakis [methylene-3- (3', 5'-di-t-butyl) -4′-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, 2-n-octyl-thio-4,6-di (4′-hydroxy-3 ′, 5′-di-t- Til) phenoxy-1,3,5-triazine, 4,4′-thiobis (6-tert-butyl-m-cresol), 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) ) Hindered phenols such as -5-chlorobenzotriazole.

Examples of the rust preventive include sulfonic acid metal salts (metals are alkali metals, alkaline earth metals, etc.) and esters. Also, alkyl succinic acid derivatives and alkenyl succinic acid derivatives such as alkyl succinic acid esters and alkenyl succinic acid esters can be preferably used as rust preventives.
Specific examples of the sulfonic acid metal salt include metal salts of dinonylnaphthalene sulfonic acid and heavy alkylbenzene sulfonic acid (calcium sulfonate, barium sulfonate, sodium sulfonate, etc.).

  Specific examples of the esters include sorbitan esters such as sorbitan monolaurate, sorbitan tristearate, sorbitan monooleate, and sorbitan trioleate, which are partial esters of polybasic carboxylic acids and polyhydric alcohols, and polyoxy Examples thereof include alkyl esters such as ethylene laurate, polyoxyethylene oleate, and polyoxyethylene stearate.

  Furthermore, examples of extreme pressure agents include phosphorus extreme pressure agents, zinc dithiophosphate, and organic molybdenum. Examples of the oily agent include fatty acids such as oleic acid and stearic acid, alcohols such as lauryl alcohol and oleyl alcohol, amines such as stearylamine and cetylamine, phosphate esters such as tricresyl phosphate, and animal and vegetable oils. Furthermore, examples of the metal deactivator include benzotriazole and sodium nitrite. In addition, gelling agents such as Benton and silica gel, viscosity index improvers such as polymethacrylate, polyisobutene, and polystyrene can be used.

[Resin material constituting the cage]
The type of resin material constituting the cage is not particularly limited, but is mainly composed of polyamide resin (for example, polyamide 66, polyamide 46), polyphenylene sulfide resin, thermoplastic polyimide resin, polyether ether ketone resin, or the like. A resin composition is preferred.
A fibrous reinforcing material such as carbon fiber or aramid fiber may be added to the resin composition for the purpose of improving the strength of the cage. In the case of carbon fibers and aramid fibers, the amount added is preferably 10% by mass or more and 30% by mass or less of the entire resin composition. If it is less than 10% by mass, the strength may be insufficient, and if it exceeds 30% by mass, the moldability may be deteriorated and the appearance of the molded product may be deteriorated. In order to make it difficult for such inconvenience to occur, the addition amount is more preferably 20% by mass or more and 30% by mass or less of the entire resin composition.

When the rolling bearing is used under high-speed rotation conditions, it is preferable to use carbon fibers or aramid fibers as the fibrous reinforcing material, but glass fibers can also be used depending on the use conditions. The addition amount in the case of glass fiber is preferably 10% by mass or more and 40% by mass or less of the entire resin composition. The reason is the same as in the case of carbon fiber or aramid fiber.
In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, the rolling bearing of the present embodiment includes a non-contact type seal, but may be a contact type seal or may not include a seal.

The type of the cage is not particularly limited, and examples thereof include a crown-shaped cage, a cage-shaped cage, and a single shape cage.
Furthermore, in the present embodiment, the angular ball bearing has been described as an example of the rolling bearing, but the present invention can be applied to various types of rolling bearings. For example, radial rolling bearings such as deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, and self-aligning roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.

〔Example〕
Hereinafter, the present invention will be described more specifically with reference to examples.
First, regarding the resin material constituting the cage, the relationship between the content of the microcapsules in the resin material and the strength of the resin material was evaluated. A cage for an angular ball bearing having a nominal number of 7008CTYDB was manufactured using a resin material in which the above-mentioned microcapsules manufactured by Nippon Capsule Products Co., Ltd. were contained in a phenol resin. As shown in Table 1, the content of the microcapsules was 0, 3, 20, 35, 50, and 70% by mass. And the annular tensile test was implemented about these cages and the annular tensile breaking strength was measured.

  The results are shown in Table 1 and the graph of FIG. In addition, the annular tensile breaking strength shown in the graphs of Table 1 and FIG. 2 is a relative value when the annular tensile breaking strength of a cage made of a resin material having a microcapsule content of 0% by mass is defined as 100. It is shown by. As can be seen from the graph of FIG. 2, when the content of the microcapsules in the resin material exceeds 50% by mass, the annular tensile breaking strength of the cage is greatly reduced. It can be seen that the content of the microcapsules is preferably 50% by mass or less and more preferably 35% by mass or less in order to make the annular tensile breaking strength of the cage sufficient.

Next, among the above cages, a cage having a microcapsule content of 3 mass% (Example 1), a cage of 50 mass% (Example 2), and a cage of 0 mass% (Comparative Example) Was assembled into an angular ball bearing having a nominal number of 7008CTYDB to produce an angular ball bearing (test bearing) having substantially the same configuration as the angular ball bearing shown in FIG. Note that the guide type of the cage is an outer ring guide type. The lubricant enclosed in the test bearing is grease (Isoflex NBU15) manufactured by NOK CRUBA CORPORATION, and the amount enclosed is 15% by volume of the space surrounded by the inner ring, the outer ring and the seal. It is.
These test bearings were rotated at various rotational speeds of 2000 to 20000 rpm, and the amount of increase in bearing temperature was measured. The results are shown in Table 2 and the graph of FIG.

  As can be seen from the graph in FIG. 3, the test bearings of Examples 1 and 2 had a smaller temperature rise than the test bearing of the comparative example.

  The rolling bearing of the present invention is suitable for use under high temperature, high speed and high load conditions. For example, the rolling bearing of the present invention includes automobile electrical components, automobile engine accessories (alternators, intermediate pulleys, car air conditioner electromagnetic clutches, water pumps, hub units, etc.), gas heat pump electromagnetic clutches, compressors, machine tools. It is suitable as a rolling bearing used for machines and the like.

It is a fragmentary longitudinal cross-section which shows the structure of the angular ball bearing which is one Embodiment of the rolling bearing which concerns on this invention. It is a graph which shows the correlation with content of a microcapsule, and an annular tensile breaking strength. It is a graph which shows the correlation with content of a microcapsule, and the temperature rise of an angular contact ball bearing.

Explanation of symbols

1 Inner ring 2 Outer ring 3 Rolling element 4 Cage

Claims (1)

  In a rolling bearing comprising an inner ring, an outer ring, a plurality of rolling elements that are arranged to freely roll between the inner ring and the outer ring, and a cage that holds the rolling element between the inner ring and the outer ring. The rolling bearing is made of a material containing microcapsules containing at least one of oil, grease, and a lubricant additive.

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