JP2010196879A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of reducing an environmental load and having excellent high-temperature/high-speed durability. <P>SOLUTION: This rolling bearing 1 includes: an inner ring 2 having a rolling surface in the outer peripheral surface thereof; an outer ring 3 having a rolling surface in the inner peripheral surface thereof; a plurality of rolling elements 4 interposed 5 holding the rolling elements 4. The inner ring 2, the outer ring 3, the rolling elements 4 or the holder 5 is a metal bearing member, and a sliding surface or a rolling surface of at least one member of the metal bearing members is coated with a film of a polyhydric alcohol compound originating in a plant such as curcumin, quercetin and chlorogenic acid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing used at high temperature and high speed for home appliances and industrial equipment.

  Rolling bearings incorporated in various industrial machines and vehicles are encapsulated with a lubricating composition in order to impart lubricity. This lubricating composition is obtained by kneading a base oil and a thickener and, if necessary, an additive. As the base oil, synthetic lubricating oil such as mineral oil, ester oil, silicone oil, ether oil, etc. As the thickener, a metal soap such as lithium soap or a urea compound is generally used. Moreover, as an additive, various additives, such as antioxidant, a rust inhibitor, a metal deactivator, a viscosity index improver, are mix | blended as needed. As the antioxidant, an organic zinc compound such as zinc alkyldithiophosphate, an amine compound such as alkylated diphenylamine, or the like is used alone or in combination.

  In recent years, rolling bearings used for home appliances and industrial equipment are used at high temperature and high speed rotation. In addition, it is required to be excellent in quietness and high temperature and high speed durability. Conventionally, as a lubricating composition such as grease that has excellent durability at high temperature, suppresses abnormal noise during cold, and has excellent releasability under high temperature and high load, it has been added to a base oil consisting of synthetic hydrocarbon oil and ester oil. Lubricating compositions containing a funnel or the like are known (see Patent Document 1 and Patent Document 2).

  Further, as a lubricating composition having a long seizure life under high-temperature and high-speed rotation conditions, a grease composition containing 3 to 30% by weight of a thickener containing an ester oil as a base oil and an aliphatic diurea compound as an essential component is known. (See Patent Document 3).

  Also, a sliding or rolling member having a compound reaction film layer having a thickness of 0.05 to 0.5 μm formed by a chemical bond reaction with at least one of an organophosphorus compound, an organosulfur compound, an organochlorine compound, and an organometallic compound. Is known (see Patent Document 4). Further, a bearing metal material formed by forming a thiophosphate metal salt coating is known (see Patent Document 5).

JP-A-9-208982 (Claims) Japanese Patent Laid-Open No. 11-270566 (Claims) JP 2001-107073 A (Claims) Japanese Patent Laid-Open No. 02-256920 (Claims) Japanese Patent Laid-Open No. 11-030236 (Claims)

  However, even when using a lubricating (grease) composition as described in Patent Documents 1 to 3 or when adding a combination of conventional antioxidants to these, high-temperature, high-speed rotation of recent home appliances and industrial equipment, etc. When encapsulated in a bearing used in the above, there may be a case where the performance cannot be satisfied with respect to high temperature and high speed durability.

  In Patent Document 4 and Patent Document 5, the purpose is to improve the wear resistance, and the effect of preventing seizure at high temperature and high speed is not sufficient. Further, when disposing of used rolling bearings as industrial waste, it is desired not to use organophosphorus compounds or the like in order to avoid adverse effects on the biological environment.

  The present invention has been made to cope with such problems, and an object of the present invention is to provide a rolling bearing having a low environmental load and excellent high temperature and high speed durability.

  The rolling bearing according to the present invention includes, as a metal bearing member, an inner ring, an outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a cage that holds the rolling elements. At least one member of the bearing member is a member obtained by coating a sliding surface or rolling surface of the member with a plant-derived polyhydric alcohol compound. In particular, the film-treated member is the cage.

  The member subjected to the coating treatment has an iron oxide coating on the sliding surface or rolling surface of the member. The coating treatment is a treatment of immersing a metal bearing member to be coated in a treatment liquid in which the plant-derived polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent. And

  The plant-derived polyhydric alcohol compound is curcumin or a derivative thereof. The plant-derived polyhydric alcohol compound is quercetin or a derivative thereof.

  The plant-derived polyhydric alcohol compound is chlorogenic acid or a derivative thereof. The plant-derived polyhydric alcohol compound is caffeic acid or a derivative thereof. The plant-derived polyhydric alcohol compound is quinic acid or a derivative thereof.

  The plant-derived polyhydric alcohol compound is gallic acid or a derivative thereof. The plant-derived polyhydric alcohol compound is ellagic acid or a derivative thereof.

  Since the rolling bearing of the present invention is coated with a plant-derived polyhydric alcohol compound on the sliding surface or rolling surface of at least one member of the metal bearing member constituting the bearing, Excellent high-speed durability and can prevent seizure at high temperature and high speed. Moreover, because of the coating treatment using a plant-derived polyhydric alcohol compound, the rolling bearing has a low environmental load.

It is sectional drawing of a deep groove ball bearing. It is a figure which shows a sliding test machine. It is a figure which shows a specific wear amount and a friction coefficient measurement result.

  As for the rolling bearing, when the bearing member surface was treated with a plant-derived polyhydric alcohol compound and subjected to a high temperature durability test, it was found that the bearing life could be extended. This is because the action of the polyhydric alcohol compound derived from the plant causes an iron oxide film to be formed on the surface of the metal (bearing steel) bearing member, the surface is inactivated, and the grease and lubricating oil sealed in the bearing This is considered to be because the oxidative deterioration can be suppressed. The present invention is based on this finding.

  A rolling bearing according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a deep groove ball bearing which is an embodiment of the rolling bearing of the present invention. As shown in FIG. 1, a deep groove ball bearing 1 includes an inner ring 2 having a rolling surface 2a on the outer peripheral surface, an outer ring 3 having a rolling surface 3a on the inner peripheral surface, and the both rolling surfaces 2a, 3a. A plurality of rolling elements 4 and a cage 5 that holds the rolling elements 4. Seal members 6 fixed to the outer ring 3 and the like are provided in the axial end openings 8a and 8b of the inner ring 2 and the outer ring 3, respectively. The inner ring 2, the outer ring 3, the rolling element 4, or the cage 5 is a metal bearing member, and a plant-derived polyhydric alcohol described later is provided on the sliding surface or rolling surface of at least one member of the metal bearing member. The film is treated with a compound.

  Bearing members used in the rolling bearing of the present invention, such as the inner ring 2, the outer ring 3, the rolling element 4, and the cage 5, are made of a well-known bearing metal material. In the present invention, at least one of the metal bearing members needs to be made of a metal material that can be coated with a plant-derived polyhydric alcohol compound. Specific examples of the bearing ring material include bearing steel (high carbon chromium bearing steel JIS G 4805), case-hardened steel (JIS G4104, etc.), high-speed steel (AMS 6490), stainless steel (JIS G4303), induction-hardened steel. Steel entering (JIS G4051 etc.) etc. are mentioned. Examples of cage materials include cold rolled steel plates for punching cages (JIS G 3141, etc.), carbon steel for machined cages (JIS G4051), high strength brass castings for machined cages (JIS H 5102, etc.) and the like. It is done. Other bearing alloys can also be employed.

  The seal member 6 may be made of a metal or a rubber molded body alone, or may be a composite of a rubber molded body and a metal plate, a plastic plate, a ceramic plate, or the like. From the viewpoint of durability and ease of fixing, a composite of a rubber molded body and a metal plate is preferable.

  The rolling bearing of the present invention is a rolling bearing in which a lubricant such as lubricating oil or grease is applied or filled in the bearing, and the type of a radial ball bearing, a thrust ball bearing, or the like is not particularly limited. The lubricant is not particularly limited as long as it is a lubricant generally used for bearings. In the deep groove ball bearing 1 shown in FIG. 1, grease 7 is sealed around the rolling elements 4.

  In the rolling bearing of the present invention, the coating treatment applied to the sliding surface or rolling surface of the metal bearing member may be a treatment in which an iron oxide coating is formed on the surface by the action of a plant-derived polyhydric alcohol compound. The film processing method is not particularly limited. As a coating treatment method, for example, a metal bearing member to be coated is immersed in a treatment liquid in which a plant-derived polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent, and iron oxide is formed on the member surface. A method of forming a film can be employed. In this method, it is preferable to carry out heating while accelerating the film formation.

  Further, by applying a treatment liquid in which a plant-derived polyhydric alcohol compound is dispersed or dissolved in water or an organic solvent to a sliding surface of a metal bearing member to be coated, an iron oxide coating is applied to the surface. Can also be formed.

  The polyhydric alcohol compound that can be used in the present invention is derived from a plant described later. By subjecting the bearing member to a coating treatment using these compounds, in addition to improving the high temperature and high speed durability of the bearing by forming the iron oxide coating, a rolling bearing with a low environmental load is obtained.

  Examples of plant-derived polyhydric alcohol compounds that can be used in the present invention include gallic acid, ellagic acid, chlorogenic acid, caffeic acid, quinic acid, curcumin, quercetin, pyrogallol, theaflavin, anthocyanin, rutin, lignan, catechin and the like. It is done. Polyhydric alcohol compounds obtained from plant-derived sesamin, isoflavones, coumarins and the like can also be used. Such polyhydric alcohol compounds may be used alone or in combination of two or more.

  Among these, gallic acid or its derivatives, ellagic acid or its derivatives, chlorogenic acid or its derivatives, caffeic acid or its derivatives, because it is easy to form an iron oxide film on the surface of the metal bearing member during the coating treatment. It is preferable to use quinic acid or its derivative, curcumin or its derivative, quercetin or its derivative. In addition, curcumin, quercetin, or chlorogenic acid is particularly preferable because the high temperature durability of the bearing after coating treatment is excellent.

Gallic acid used in the present invention is a polyhydric alcohol compound contained in fusinoki, tea leaves, etc., and has a structure represented by the following formula (1). Moreover, the ellagic acid used for this invention is a polyhydric alcohol compound contained in a red raspberry etc., and has a structure shown to following formula (2).

  Derivatives of gallic acid used in the present invention include gallic acid esters such as methyl gallate, ethyl gallate, propyl gallate, butyl gallate, pentyl gallate, hexyl gallate, heptyl gallate, and octyl gallate. Examples thereof include gallates such as bismuth. Moreover, the same derivative can be used also about ellagic acid.

Chlorogenic acid used in the present invention is a polyhydric alcohol compound contained in coffee beans and the like, and has a structure represented by the following formula (3).

Caffeic acid and quinic acid used in the present invention are polyhydric alcohol compounds obtained by hydrolysis of chlorogenic acid. Caffeic acid has a structure represented by the following formula (4), and quinic acid has a structure represented by the following formula (5). .

Curcumin used in the present invention is a polyhydric alcohol compound contained in turmeric and the like, and has a structure represented by the following formula (6).

Quercetin used in the present invention is a polyhydric alcohol compound contained in citrus fruits and has a structure represented by the following formula (7).

  All the polyhydric alcohol compounds used in the following examples used reagents manufactured by Tokyo Chemical Industry Co., Ltd.

Examples 1 to 7
A treatment solution was prepared by adding 0.5 g of the polyhydric alcohol compound shown in Table 1 to 99.5 g of the solvent shown in Table 1. A 6204 bearing (bearing dimensions: inner diameter 20 mm, outer diameter 47 mm, width 14 mm, material: SUJ2) is immersed in the treatment solution for 4 hours, and the entire surface of the metal bearing member of the rolling bearing is iron oxide. A film was formed. 0.7 g of grease (Maltemp SRL manufactured by Kyodo Yushi Co., Ltd.) was sealed in this bearing to obtain a rolling bearing test piece. The obtained rolling bearing test piece was subjected to the high temperature durability test described below, and the bearing life time was measured. The results are also shown in Table 1.

<High temperature durability test>
Rotate the bearing outer ring outer diameter of the rolling bearing test piece at 150 ° C, radial load 67 N, axial load 67 N at a rotational speed of 10,000 rpm, and measure the time until seizure as the bearing life time.

Example 8 to Example 10
A treatment solution was prepared by adding 0.5 g of the polyhydric alcohol compound shown in Table 1 to 99.5 g of the solvent shown in Table 1. A cage (material: SPCC) of a 6204 bearing (bearing dimensions: inner diameter 20 mm, outer diameter 47 mm, width 14 mm) was immersed in the treatment solution for 4 hours to form an iron oxide coating on the cage surface. . A bearing was manufactured using this cage, and 0.7 g of grease (Multemp SRL manufactured by Kyodo Yushi Co., Ltd.) was sealed therein to obtain a rolling bearing test piece. The obtained rolling bearing test piece was subjected to the above high temperature durability test, and the bearing life time was measured. The results are also shown in Table 1.

Comparative Example 1
Rolling bearing test piece with 6204 bearing (bearing dimensions: inner diameter 20 mm, outer diameter 47 mm, width 14 mm), 0.7 g of grease (Kyodo Yushi Co., Ltd. Martemp SRL) sealed without metal surface treatment Got. The obtained rolling bearing test piece was subjected to the above high temperature durability test, and the bearing life time was measured. The results are also shown in Table 1.

  As shown in Table 1, Examples 1 to 10 exhibited excellent high temperature durability with a lifetime of 120 hours or more in the high temperature durability test. This is considered to be because the iron oxide film formed of a specific polyhydric alcohol compound was able to suppress the oxidative deterioration of the grease. On the other hand, in Comparative Example 1, the life was shorter than in Examples 1 to 10.

Example 11
In the treatment liquid of Example 3 (containing chlorogenic acid), rotate the SUJ2 ring-shaped substrate having dimensions of 40 mm outer diameter x 20 mm inner diameter x t10 mm (sub curvature R 60 mm) for 4 hours while immersed. Then, an iron oxide film was formed on the entire surface of the substrate to obtain a ring-shaped test piece. The obtained ring-shaped test piece was subjected to the sliding test shown below, and the specific wear amount and the coefficient of friction at the end of the test were measured twice. The results are shown in Table 2 and FIG. The specific wear amount in Table 2 is an average value of specific wear amounts measured three times. In FIG. 3, the bar graph is individual data obtained by measuring the specific wear amount three times, and the circle indicates the friction coefficient at the end of each measurement.

<Sliding test>
The sliding tester shown in FIG. 2 was used. 2A shows a front view, and FIG. 2B shows a side view. A ring-shaped test piece 12 is attached to the rotating shaft 11, and a steel plate 14 is fixed to an air slider 13 of the arm portion. The ring-shaped test piece 12 is rotationally brought into contact with the steel plate 14 while applying a predetermined load 15 from above in the drawing, and the lubricating oil is supplied to the outer peripheral surface of the ring-shaped test piece 12 from the felt pad 16 impregnated with the lubricating oil. The frictional force generated when the ring-shaped test piece 12 is rotated is detected by the load cell 17. The steel plate 14 was an SCM415 carburizing and quenching tempered product (Hv 700), and the lubricating oil was Mobil Velocity Oil No. 3 (Exxon Mobil: VG2). The load is 9.7 N, the sliding speed is 0.05 m / sec, and the test time is 1 minute.

Comparative Example 2
A SUJ2 ring-shaped base material having the same dimensions as in Example 11 was subjected to black dyeing treatment at 140 ° C. for 30 minutes using BK-3901 manufactured by Nippon Parkerizing Co., Ltd. to obtain a ring-shaped test piece. The obtained ring-shaped test piece was subjected to the above sliding test, and the specific wear amount and the coefficient of friction at the end of the test were measured twice. The results are shown in Table 2 and FIG. The specific wear amount in Table 2 is an average value of the specific wear amount measured twice. In FIG. 3, the bar graph is individual data obtained by measuring the specific wear amount twice, and the circle indicates the friction coefficient at the end of each measurement.

Comparative Example 3
The SUJ2 ring-shaped substrate having the same dimensions as in Example 11 was subjected to the sliding test as a ring-shaped test piece without being subjected to surface treatment, and the specific wear amount and the coefficient of friction at the end of the test were measured three times each. did. The results are shown in Table 2 and FIG. The specific wear amount in Table 2 is an average value of specific wear amounts measured three times. In FIG. 3, the bar graph is individual data obtained by measuring the specific wear amount three times, and the circle indicates the friction coefficient at the end of each measurement.

  As shown in Table 2 and FIG. 3, Example 11 having an iron oxide film formed of a specific polyhydric alcohol compound has a smaller coefficient of friction and specific wear than Comparative Example 2 subjected to blackening treatment. It can be seen that the sliding characteristics are excellent.

  The rolling bearing of the present invention has a long life even at high temperatures and high speeds because the sliding surface or rolling surface of the metal bearing member is coated with a plant-derived polyhydric alcohol compound. For this reason, it can be suitably used as a rolling bearing used under high-temperature and high-speed rotation conditions such as home appliances, automobile electrical equipment / auxiliary equipment, and industrial equipment.

DESCRIPTION OF SYMBOLS 1 Deep groove ball bearing 2 Inner ring 3 Outer ring 4 Rolling body 5 Cage 6 Seal member 7 Grease 8a Both-end opening 8b Both-end opening 11 Rotating shaft 12 Ring-shaped test piece 13 Air slider 14 Steel plate 15 Load 16 Felt pad 17 Load cell

Claims (11)

As a metal bearing member, in a rolling bearing comprising an inner ring, an outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a cage for holding the rolling elements,
A rolling bearing, wherein at least one member of the metal bearing member is a member in which a sliding surface or a rolling surface of the member is coated with a plant-derived polyhydric alcohol compound.   The rolling bearing according to claim 1, wherein the film-treated member is the cage.   The rolling bearing according to claim 1, wherein the member subjected to the coating treatment has an iron oxide coating on a sliding surface or a rolling surface of the member.   The coating treatment is a treatment of immersing the metal bearing member to be coated in a treatment liquid in which the plant-derived polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent. The rolling bearing according to claim 1, claim 2 or claim 3.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is curcumin or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is quercetin or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is chlorogenic acid or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is caffeic acid or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is quinic acid or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is gallic acid or a derivative thereof.   The rolling bearing according to any one of claims 1 to 4, wherein the plant-derived polyhydric alcohol compound is ellagic acid or a derivative thereof.

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