JP2008032078A - Grease-sealed rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grease-sealed rolling bearing which can sufficiently prevent the deterioration of its sealing performance and the increase of a torque loss, and also can effectively prevent the peeling of a rolling surface caused by hydrogen embrittlement. <P>SOLUTION: In the grease-sealed rolling bearing, a bearing space between an inner race 1 and an outer race 2 processed by heat treatment is sealed by a contact seal 5 for bringing a seal lip formed of an elastic member into contact with a seal sliding surface formed on the inner race 1 or the outer race 2, and grease is sealed as a lubricant which is produced by compounding base grease which is composed of base oil and a thickening agent, and an additive agent. The seal sliding surface formed on the inner race 1 or the outer race 2 is processed by a scale removing operation so as to remove scales generated in the heat treatment. Further, the additive agent of the grease contains aluminum powder and at least one aluminum base additive agent selected from aluminum compounds, and the ratio of the combination of the aluminum base additive agent is 0.05 to 10 pts.wt. to 100 pts.wt. of the base grease. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a grease-sealed rolling bearing, and in particular, a grease-sealed type for a rolling bearing for an automotive electrical component such as an alternator, an electromagnetic clutch for a car air conditioner, an intermediate pulley, and an electric fan motor, an auxiliary machine, and a rolling bearing for a motor. It relates to rolling bearings.

Prevents leakage of grease from the bearing space between the inner ring and outer ring, and entry of foreign matter such as water and dust from the outside, such as rolling bearings used for pulleys for automobile accessories and electromagnetic clutches for air conditioner compressors. Therefore, if the bearing space is required to be sealed with high sealing performance, the bearing space is sealed with a contact seal in which a seal lip formed of an elastic member is brought into contact with the seal sliding contact surface provided on the inner ring or the outer ring. A sealed type rolling bearing is used (see, for example, Patent Document 1). In addition, there is a type in which a slinger is attached to an inner ring or an outer ring and a seal sliding contact surface is provided on the slinger (for example, see Patent Document 2).
Conventionally, an inner ring and an outer ring raceway of a rolling bearing are manufactured in a manufacturing process as shown in FIG. 6, and a raceway surface to which a rolling element rolls is subjected to a grinding process or a superfinishing process after a heat treatment such as quenching. However, even if the seal sliding contact surface is provided, the sealing sliding contact surface is left in the turning process before the heat treatment.

As described above, even if the bearing ring of the conventional rolling bearing is provided with the seal sliding contact surface, the seal sliding contact surface is left in the turning process before the heat treatment. In a sealed rolling bearing provided with a contact surface, the surface roughness of the seal sliding contact surface becomes rough due to the scale generated during heat treatment. For this reason, there is a problem that the seal lip of the contact seal is worn at an early stage and the sealing performance is deteriorated, and the sliding contact resistance of the seal lip is increased to increase torque loss.
In order to prevent such deterioration in sealing performance and increase in torque loss, the present inventors first smoothed the surface roughness of the seal sliding contact surface of the bearing ring and slinger to 2.0 μm or less at R max. This is proposed (see Patent Document 5). However, in a sealed rolling bearing having a seal sliding contact surface on the race, the surface roughness of the seal sliding contact surface becomes rough due to the scale generated during heat treatment, as described above. There is a problem that the increase cannot be sufficiently prevented.

Further, grease is mainly used for lubrication of these rolling bearings. However, severe use conditions such as high-speed rotation at high temperatures cause a problem in that specific peeling accompanied by a change in white structure occurs at an early stage on the rolling surface of the rolling bearing.
This specific exfoliation is different from the exfoliation from the inside of the rolling contact surface caused by normal metal fatigue, and is a fracture phenomenon that occurs from a relatively shallow surface of the rolling contact surface. Yes. As a method for preventing such a specific peeling phenomenon accompanied by a white tissue change that occurs at an early stage, for example, a method of adding a passivating agent to grease is known (see Patent Document 3). A method of adding bismuth dithiocarbamate to a grease composition is known (see Patent Document 4).
However, in recent years, electrical components and accessories in automobiles, motors in industrial machines, etc., have increasingly used rolling bearings, such as frequent high-speed operation-sudden deceleration operation-rapid acceleration operation-sudden stop at high temperatures. However, the method of adding a passivating agent or bismuth dithiocarbamate has become insufficient as a measure for preventing the peeling phenomenon. In particular, as described above, in the case where the seal sliding contact surface remains in the turning process before the heat treatment, there is a problem that the grease leaks due to the deterioration of the sealing performance, and this peeling phenomenon is more likely to occur.
Japanese Utility Model Publication No. 7-10555 (Figs. 1 and 2) JP 2002-62305 A (FIG. 1) JP-A-3-210394 JP-A-2005-42102 JP 2005-155882 A

  The present invention has been made to cope with such a problem, and it is possible to sufficiently prevent a decrease in sealing performance and an increase in torque loss in a sealed rolling bearing in which a seal sliding contact surface is provided on a bearing ring, and An object of the present invention is to provide a grease-sealed rolling bearing capable of effectively preventing separation on a rolling surface due to hydrogen embrittlement in a grease-filled bearing.

  The grease-sealed rolling bearing of the present invention is a contact seal in which a bearing space between a heat-treated inner ring and an outer ring is brought into contact with a seal lip formed by an elastic member on a seal sliding contact surface provided on the inner ring or the outer ring. Sealed sliding contact surface provided on the inner ring or outer ring of a grease-sealed rolling bearing in which a base grease consisting of a base oil and a thickener is added to the lubricant, and a grease formed by adding an additive to the lubricant. In addition, the grease is subjected to a scale removal process for removing scales generated during the heat treatment, and the grease contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound, and the blending ratio of the aluminum-based additive Is characterized by 0.05 to 10 parts by weight per 100 parts by weight of the base grease.

The scale removal process is a shot blast process.
The scale removal process is a barrel polishing process.
The scale removing process is a cutting process for cutting hardened steel.

  The surface roughness of the seal sliding contact surface after the scale removal processing is 2.0 max or less in R max.

The aluminum compound is at least one compound selected from aluminum carbonate and aluminum nitrate.
The thickener is a urea-based thickener.
The base oil is at least one oil selected from alkyl diphenyl ether oil and poly-α-olefin oil.

  The grease-sealed rolling bearing according to the present invention has a smooth surface roughness on the seal sliding contact surface of the bearing ring in advance to prevent deterioration in sealing performance and increase in torque loss. Since the grease blended with is sealed, surface roughness on the seal sliding contact surface can be prevented, and the sealed grease can be contributed to the lubrication of the raceway ring without leaking. In addition, the aluminum compound blended with grease reacts on the frictional wear surface or the new metal surface exposed by wear, and an aluminum coating is formed on the bearing rolling surface along with iron oxide. Occurrence of peculiar peeling due to can be suppressed. As a result, it is possible to dramatically improve the life of the bearing. For this reason, for example, it can be suitably used as a rolling bearing for automobile electrical parts such as alternators, electromagnetic clutches for car air conditioners, intermediate pulleys, and electric fan motors, and auxiliary machines.

As a result of intensive studies to obtain a grease-sealed rolling bearing that can sufficiently prevent deterioration in sealing performance and increase in torque loss, and that can effectively prevent separation on the rolling surface due to hydrogen embrittlement in a grease-filled bearing. The seal sliding contact surface of the inner ring or the outer ring raceway is subjected to a scale removal process for removing scale generated during heat treatment, and at least a base grease composed of a base oil and a thickener is selected from aluminum powder and aluminum compound It was found that a grease-sealed rolling bearing with a sealing member attached after grease containing one aluminum-based additive dramatically improves the bearing life.
By sufficiently smoothing the surface roughness of the seal-sliding contact surface of the bearing ring by the scale removal process, the sealed grease can be brought into a state that contributes to the lubrication of the bearing ring without leaking. This prevents activation of the rolling contact surface due to wear caused by oil film breakage due to grease leakage due to grease leakage, or activation of the bearing rolling surface due to wear caused by early grease deterioration due to grease reduction. it can. Furthermore, even if the bearing rolling surface is activated, that is, when the bearing rolling surface is exposed to a frictional wear surface or a new metal surface exposed due to wear, the aluminum compound blended in the grease reacts, and the aluminum oxide is coated with the iron oxide. Can be generated on the rolling surface of the bearing, and the occurrence of specific delamination accompanied by white structure change can be suppressed.
As described above, in the present invention, the effect of contributing to the lubrication of the bearing ring without leaking the enclosed grease by the action of the improvement of the sealing performance and the like and the formation of the aluminum coating on the bearing rolling surface, and the rolling Rather than individually pulling out the effect of preventing specific exfoliation with white tissue changes that occur on the running surface, it is possible to perform specific exfoliation with white tissue changes that occur on the rolling surface by overlapping each action. It is considered that the effect to prevent can be exhibited synergistically and the bearing life is dramatically improved. The present invention is based on such knowledge.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a grease-sealed rolling bearing. As shown in FIG. 1, this grease-sealed rolling bearing has a contact seal 5 comprising a metal core 5a and an elastic member 5b in a bearing space in which a ball 3 is held by a cage 4 between an inner ring 1 and an outer ring 2. The contact seal 5 is fixed to a locking groove 2 a provided on the inner peripheral surface of the outer ring 2. Grease 8 is sealed at least around the rolling element 4.
FIG. 2 is an enlarged cross-sectional view showing a main part of FIG. As shown in FIG. 2, two inner and outer seal lips 6 a and 6 b are provided at the inner peripheral end of the contact seal 5, and the inner seal lip 6 a is a seal provided on the outer peripheral surface of the inner ring 1. The seal slidable contact surface 7a provided on the inner wall of the groove 1a is in contact, and the outer seal lip 6b is in contact with the seal slidable contact surface 7b provided on the outer edge of the seal groove 1a.

  In the embodiment described above, the sealed type rolling bearing is a deep groove ball bearing, but the sealed type rolling bearing according to the present invention can also be used for other types of rolling bearings such as other ball bearings and roller bearings. .

FIG. 3 is a process diagram showing a manufacturing process of the inner ring of FIG. 1, and FIG. 6 is a process chart showing a manufacturing process of a conventional bearing ring.
The inner ring 1 provided with the seal sliding contact surfaces 7a and 7b is manufactured by the manufacturing process shown in FIG. The material of the inner ring 1 is formed by forging and turning and then subjected to heat treatment such as quenching, and thereafter, the seal sliding contact surfaces 7a and 7b are subjected to scale removal processing for removing scale generated during the heat treatment. . The subsequent steps are the same as the manufacturing steps of the conventional bearing ring shown in FIG. 6, and width grinding, raceway surface grinding, inner diameter grinding, and raceway surface superfinishing are sequentially performed to obtain a finished product. Depending on the scale removal processing method, width grinding may be performed after the heat treatment and before the scale removal processing.

Examples of the scale removal process after the heat treatment in the present invention include a shot blast process, a barrel polishing process, or a cutting process for cutting hardened steel. In the case of adopting shot blasting and barrel polishing, the manufacturing process is as shown in FIG. 3, and in the case of adopting a cutting process for cutting hardened steel, width grinding is performed after heat treatment in the manufacturing process shown in FIG. Then, cutting is performed.
In the scale removal processing, it is preferable to perform a cutting process for cutting the hardened steel because it is an inexpensive means without increasing the processing steps.

The aluminum-based additive added to the grease is at least one selected from aluminum powder and aluminum compound. Aluminum compounds include aluminum carbonate, aluminum sulfide, aluminum chloride, aluminum nitrate and its hydrate, aluminum sulfate, aluminum fluoride, aluminum bromide, aluminum iodide, aluminum oxide and its hydrate, aluminum hydroxide, selenium Aluminum fluoride, aluminum telluride, aluminum phosphate, aluminum phosphide, lithium aluminate, magnesium aluminate, aluminum selenate, aluminum titanate, aluminum zirconate and other inorganic aluminum, aluminum benzoate, aluminum citrate and other organic aluminum Is mentioned. These aluminum-based additives may be added to the grease alone or in combination of two or more.
Particularly preferable in the present invention is an aluminum powder having a high extreme pressure effect because it is excellent in heat resistance and hardly decomposes thermally.

The mixing ratio of the aluminum-based additive is 0.05 to 10 parts by weight with respect to 100 parts by weight of the base grease. That is, (1) when the aluminum additive is only aluminum powder, 0.05 to 10 parts by weight of aluminum powder with respect to 100 parts by weight of the base grease, and (2) when the aluminum additive is only aluminum compound, 0.05 to 10 parts by weight of aluminum compound per 100 parts by weight of grease, and (3) when aluminum additive is aluminum powder and aluminum compound, aluminum powder and aluminum compound are added to 100 parts by weight of base grease. Combine 0.05 to 10 parts by weight.
If the blending ratio of the aluminum-based additive is less than this blending range, peeling on the rolling surface due to hydrogen embrittlement cannot be effectively prevented. Moreover, even if it exceeds the said range, the peeling prevention effect does not improve any more.

Base oils that can be used in the present invention include mineral oils such as spindle oil, refrigerator oil, turbine oil, machine oil, dynamo oil, highly refined mineral oil, liquid paraffin, polybutene, GTL oil synthesized by the Fischer-Tropsch method, poly- Hydrocarbon synthetic oil such as α-olefin oil, alkylnaphthalene, alicyclic compound, or natural oil, polyol ester oil, phosphate ester oil, polymer ester oil, aromatic ester oil, carbonate ester oil, diester oil, Non-hydrocarbon synthetic oils such as polyglycol oil, silicone oil, polyphenyl ether oil, alkyldiphenyl ether oil, alkylbenzene oil, and fluorinated oil can be used.
Among these, it is preferable to use alkyl diphenyl ether oil or poly-α-olefin oil excellent in heat resistance and lubricity.

Thickeners that can be used in the present invention include benton, silica gel, fluorine compounds, lithium soap, lithium complex soap, strong lucium soap, calcium complex soap, aluminum soap, aluminum complex soap, and other soaps, diurea compounds, polyurea compounds, etc. These urea compounds are mentioned.
Of these, urea compounds are desirable in view of heat resistance, cost, and the like.

  A urea compound is obtained by reacting an isocyanate compound and an amine compound. In order not to leave a reactive free radical, the isocyanate group of the isocyanate compound and the amino group of the amine compound are preferably blended so as to be approximately equivalent.

  A diurea compound is obtained by reaction of a diisocyanate and a monoamine, for example. Examples of the diisocyanate include phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, etc., and monoamines include octylamine, dodecylamine, hexadecylamine, stearylamine, Examples include oleylamine, aniline, p-toluidine, cyclohexylamine and the like. The polyurea compound can be obtained, for example, by reacting diisocyanate with a monoamine or diamine. Examples of the diisocyanate and monoamine include those similar to those used for the production of the diurea compound. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, xylenediamine, And diaminodiphenylmethane.

By adding a thickener such as a urea compound to the base oil, a base grease for blending the aluminum additive and the like can be obtained. A base grease using a urea compound as a thickener is prepared by reacting an isocyanate compound and an amine compound in a base oil.
The blending ratio of the thickener in 100 parts by weight of the base grease is 1 to 40 parts by weight, preferably 3 to 25 parts by weight. If the content of the thickener is less than 1 part by weight, the thickening effect will be reduced, making it difficult to make grease, and if it exceeds 40 parts by weight, the resulting base grease will be too hard and the desired effect will not be obtained. Become.

  In addition to the aluminum-based additive, a known grease additive may be included as necessary. Examples of the additives include antioxidants such as organic zinc compounds, amines, and phenolic compounds, metal deactivators such as benzotriazole, viscosity index improvers such as polymethacrylate and polystyrene, molybdenum disulfide, and graphite. Examples include solid lubricants, metal sulfonates, rust inhibitors such as polyhydric alcohol esters, friction reducers such as organic molybdenum, oil agents such as esters and alcohols, and antiwear agents such as phosphorus compounds. These can be added alone or in combination of two or more.

Reference example 1
Shot blasting is performed on the seal sliding contact surface of the rolling bearing as scale removal processing, the surface roughness of the seal sliding contact surface is measured, and the surface roughness of the seal sliding contact surface is shown in FIG. Table 1 shows the surface roughness R max.

Reference Comparative Example 1
The surface roughness of the seal sliding contact surface when the scale sliding processing after heat treatment was not performed on the seal sliding contact surface of the rolling bearing was measured, and the surface roughness of the seal sliding contact surface is shown in FIG. Table 1 shows the surface roughness R max of the sliding contact surface.

Reference example 2
Barrel polishing is performed as a scale removal process on the seal sliding contact surface of the rolling bearing, the surface roughness of the seal sliding contact surface is measured, and the surface roughness of the seal sliding contact surface is shown in FIG. Table 1 shows the surface roughness R max of each.

Reference example 3
Cutting is performed after quenching on the seal sliding contact surface of the rolling bearing, the surface roughness of the seal sliding contact surface is measured, and the surface roughness of the seal sliding contact surface is shown in FIG. R max is also shown in Table 1.

Moreover, the following foreign substance penetration | invasion test was done about the reference example 1 and the reference comparative example 1, and the foreign material penetration | invasion amount into the inside of a bearing after driving | running for the predetermined time was measured. The results are also shown in Table 1.
<Foreign matter penetration test>
Sealed type rolling bearings using the inner ring of Reference Example 1 and Reference Comparative Example 1 are mounted on a rotating test machine in an environment where water and mud foreign matter scatter, respectively, and foreign matter intrusion to investigate the amount of foreign matter entering the bearing space A test was conducted. The rotational speed of the bearing was 2000 rpm, the test time was 3 hours, and the amount of foreign matter intrusion was determined by measuring the weight increase W of the bearing before and after the test.

図４（ａ）、図４（ｂ）および表１から、参考比較例１のシール摺接面の表面粗さが R max で 2.6μm であるのに対して、ショットブラスト加工を行なった参考例１のシール摺接面の表面粗さは R max で 0.79μm と非常に滑らかになっている。また、参考比較例１のものは質量増加量Ｗが 0.46 g であったのに対して、参考例１のものは質量増加量Ｗが 0.02 g であった。したがって、参考例１のものは異物の侵入がほとんどなく、優れたシール性能を確保できることが確認された。
また、表１に示すとおり、参考例２および参考例３のシール摺接面の表面粗さは R max で、それぞれ 1.30μm および1.03μmであり、実施例１のものと同様に 2.0μm 以下の滑らかさになっている。

4 (a), 4 (b) and Table 1, the reference surface of the seal sliding contact surface of Reference Comparative Example 1 has a surface roughness R max of 2.6 μm, while the reference example was shot blasted. The surface roughness of the seal sliding contact surface of No. 1 is very smooth at 0.79μm in R max. Moreover, the mass increase W of the reference comparative example 1 was 0.46 g, whereas the mass increase W of the reference example 1 was 0.02 g. Therefore, it was confirmed that the thing of the reference example 1 has almost no foreign material invasion, and can secure an excellent sealing performance.
Moreover, as shown in Table 1, the surface roughness of the seal sliding contact surfaces of Reference Example 2 and Reference Example 3 is R max, which is 1.30 μm and 1.03 μm, respectively. It is smooth.

  In the above-described embodiment, the sealed type rolling bearing is a ball bearing, and the seal sliding contact surface is provided on the inner ring side. However, the sealed type rolling bearing according to the present invention includes other types of ball bearings, roller bearings, and the like. It can also be adopted for types of rolling bearings, and the seal sliding contact surface may be provided on the outer ring side.

Reference Example 4 to Reference Example 11
In half of the base oil shown in Table 2, 4,4-diphenylmethane diisocyanate (Millionate MT manufactured by Nippon Polyurethane Industry Co., Ltd., hereinafter referred to as MDI) is dissolved in the ratio shown in Table 2, and the remaining half of the base oil is dissolved. A monoamine that was twice the equivalent of MDI was dissolved. The blending ratio and type of each are shown in Table 2.
A solution in which monoamine was dissolved was added while stirring the solution in which MDI was dissolved, and then the reaction was continued for 30 minutes at 100 ° C. to 120 ° C. to produce a diurea compound in the base oil.
To this, an aluminum-based additive and an antioxidant were added at a blending ratio shown in Table 2, and the mixture was further stirred at 100 to 120 ° C. for 10 minutes. Thereafter, the mixture was cooled and homogenized with three rolls to obtain a grease.
In Table 2, the synthetic hydrocarbon oil used as the base oil is Shinflud 601 manufactured by Nippon Steel Chemical Co., Ltd. with a kinematic viscosity of 30 mm ² / sec at 40 ° C, and the alkyldiphenyl ether oil is Matsumura with a kinematic viscosity of 97 mm ² / sec at 40 ° C. Moresco High Lube LB100 manufactured by Petroleum Corporation was used. Moreover, the hindered phenol by Sumitomo Chemical Co., Ltd. was used for antioxidant.
The seal sliding contact surface provided on the inner ring or the outer ring was filled with the grease obtained from the rolling bearing not subjected to the scale removing process for removing the scale generated during the heat treatment, and a rapid acceleration / deceleration test was conducted. Test methods and test conditions are shown below. The results are shown in Table 2.

<Rapid acceleration / deceleration test>
An alternator, which is an example of an electrical accessory, was simulated, the above grease was enclosed in a rolling bearing, and a rapid acceleration / deceleration test was performed. The rapid acceleration / deceleration test conditions are as follows: the load load on the pulley attached to the tip of the rotating shaft is set to 1960 N, the operating speed is set to 0 rpm to 18000 rpm, and a current of 0.1 A flows through the test bearing. The test was conducted. Then, abnormal peeling occurred in the bearing, and the time when the vibration of the vibration detector exceeded the set value and the generator stopped (peeling life time, h) was measured. The test was terminated after 500 hours.

Examples 1 to 3
By a method according to Reference Example 4, a base grease was prepared by selecting a thickener and a base oil at a blending ratio shown in Table 2, and an additive was further blended to obtain a grease. Evaluation was made by enclosing the obtained grease in rolling bearings in which the scale removal processing of Reference Example 1 to Reference Example 3 was applied to the seal sliding contact surface provided on the inner ring or the outer ring, and performing the same test as in Reference Example 4. . The results are also shown in Table 2.

Reference Comparative Example 2 to Reference Comparative Example 4
By a method according to Reference Example 4, a base grease was prepared by selecting a thickener and a base oil at a blending ratio shown in Table 2, and an additive was further blended to obtain a grease. The seal sliding contact surface provided on the inner ring or the outer ring was sealed with the grease obtained from the rolling bearing not subjected to the scale removing process for removing the scale generated during the heat treatment, and evaluated by performing the same test as in Reference Example 4. . The results are also shown in Table 2.

表２に示すように、各参考例では、急加減速試験は全て 400 時間以上（剥離発生寿命時間）の優れた結果を示した。これは、アルミニウム系添加剤を所定割合で添加したことにより転走面で生じる白色組織変化を伴った特異的な剥離を効果的に防止できたためであると考えられる。
また、シール摺接面にスケール除去加工を施した各実施例では、急加減速試験は全て 500 時間以上（剥離発生寿命時間）であり、各参考例よりも白色組織変化を伴った特異的な剥離を効果的に防止できた。これは、アルミニウム系添加剤の効果にくわえて、スケール除去加工によりシール性能の低下によるグリース漏れを防止できたためであると考えられる。

As shown in Table 2, in each reference example, all the rapid acceleration / deceleration tests showed excellent results of 400 hours or longer (peeling life time). This is considered to be because the specific exfoliation accompanied by the white texture change that occurs on the rolling surface can be effectively prevented by adding the aluminum-based additive at a predetermined ratio.
In each example where the seal sliding contact surface was scale-removed, the rapid acceleration / deceleration tests were all 500 hours or longer (exfoliation occurrence life time). Separation was effectively prevented. This is considered to be because grease leakage due to a decrease in seal performance was prevented by scale removal processing in addition to the effect of the aluminum-based additive.

  The grease-sealed rolling bearing of the present invention has a white structure produced on the rolling surface due to the overlap of the respective actions, such as improvement in sealing performance and specific peeling prevention accompanied with a white structure change occurring on the rolling surface. The life of the bearing can be dramatically extended by synergistically extracting the effect of preventing specific separation accompanied by changes. For this reason, it can be suitably used as an alternator, an electromagnetic clutch for a car air conditioner, an intermediate pulley, an automobile electrical component such as an electric fan motor, a rolling bearing for an auxiliary machine, and a motor bearing.

It is a longitudinal section showing an embodiment of a grease seal type rolling bearing. It is sectional drawing which expands and shows the principal part of FIG. It is process drawing which shows the manufacturing process of the inner ring | wheel of FIG. (A), (b) is a graph which shows the surface roughness of the seal sliding contact surface of the reference example 1 and the reference comparative example 1, respectively. (A), (b) is a graph which shows the surface roughness of the seal slidable contact surface of the reference example 2 and the reference example 3, respectively. It is process drawing which shows the manufacturing process of the conventional bearing ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 1a Seal groove 2 Outer ring 2a Locking groove 3 Ball 4 Cage 5 Contact seal 5a Core 5b Elastic member 6a, 6b Seal lip 7a, 7b Seal sliding contact surface 8 Grease

Claims (8)

The bearing space between the inner ring and the outer ring subjected to the heat treatment is sealed with a contact seal in which a seal lip formed of an elastic member is brought into contact with a seal sliding contact surface provided on the inner ring or the outer ring. In a grease-sealed rolling bearing in which a grease made by adding an additive to a base grease consisting of a thickener is enclosed,
The seal sliding contact surface provided on the inner ring or the outer ring is subjected to a scale removal process for removing the scale generated during the heat treatment,
The grease contains at least one aluminum-based additive selected from aluminum powder and aluminum compound, and the mixing ratio of the aluminum-based additive is 0.05 to 10 parts by weight with respect to 100 parts by weight of the base grease. A grease-sealed rolling bearing.   2. The grease-sealed rolling bearing according to claim 1, wherein the scale removing process is a shot blast process.   2. The grease-sealed rolling bearing according to claim 1, wherein the scale removing process is a barrel polishing process.   2. The grease-sealed rolling bearing according to claim 1, wherein the scale removing process is a cutting process for cutting hardened steel.   5. The grease-sealed rolling according to claim 1, wherein a surface roughness of the seal sliding contact surface after the scale removal processing is 2.0 μm or less at R max. bearing.   6. The grease-sealed rolling bearing according to any one of claims 1 to 5, wherein the aluminum compound is at least one compound selected from aluminum carbonate and aluminum nitrate.   The grease-sealed rolling bearing according to any one of claims 1 to 6, wherein the thickener is a urea-based thickener.   The grease-sealed rolling bearing according to any one of claims 1 to 7, wherein the base oil is at least one oil selected from alkyl diphenyl ether oil and poly-α-olefin oil.

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