JP6480711B2 - Rolling device - Google Patents

Description

  The present invention relates to a rolling device such as a rolling bearing.

  When a rolling device such as a rolling bearing is used in an environment in which the rolling portion is poorly lubricated and the oil film is not sufficiently formed, surface damage such as peeling and seizure, and peeling starting from these damages occur. For example, according to Non-Patent Document 1, the life of a rolling bearing becomes longer when the oil film parameter Λ indicating the severity of the lubrication state is about 1.2 or more between the inner and outer rings of the rolling bearing. Under the condition of 1.2 or less, surface-origin type peeling occurs at the rolling part, and the rolling bearing life is reduced. Some rolling bearings used in an environment where oil film formation in the rolling part is actually insufficient are used in transmissions for automobiles and compressors for air conditioners.

  In a rolling bearing for a transmission, since a lubricating oil having a high operating temperature and a low viscosity is used, oil film formation is poor and surface damage is likely to occur. As a countermeasure for surface damage of a rolling bearing for a transmission, a method of forming a minute recess in a roller or inner and outer ring rolling portion of a needle roller bearing and coating the recess with a solid lubricant as described in Patent Document 1 It has been known.

  Inside the compressor of the air conditioner, lubricating oil is present in the refrigerant, and the refrigerant liquefies when the compressor is compressed. The mixing of the lubricating oil and the liquefied refrigerant deteriorates the oil film forming property of the rolling bearing, so that surface damage is likely to occur. As a countermeasure against surface damage of a rolling bearing for a compressor, there is known a method described in Patent Document 2 in which minute concave portions are randomly formed in a rolling portion to improve oil film formation.

  In addition, as a countermeasure against surface damage of a rolling bearing used in a state where the oil film formation is poor, the residual austenite structure of the surface layer is formed by carbonitriding one of the two surfaces in sliding contact described in Patent Document 3. A method of enriching and a method of improving oil film formation by applying a manganese phosphate salt coating treatment to the rolling part described in Patent Document 4 and the like are known.

JP 2006-161887 A Japanese Patent No. 2997074 JP 2004-144279 A Japanese Patent No. 3538519

Takada Hirotoshi, Suzuki Susumu, Maeda Yasuo, Lubrication, 26, 9 (1981) 645-650

  However, the processing for forming a recess in the rolling part in Patent Document 1 and Patent Document 2 and the carbonitriding process in Patent Document 3 have a complicated processing process and a long processing time. Become.

  In addition, in the case of the above-described manganese phosphate treatment in Patent Document 4, wastewater treatment costs after the treatment are expensive.

  The present invention has been made to cope with such problems, and can be manufactured without complicated processing, long-time processing, costly processing, etc. to prevent surface damage as described above, An object of the present invention is to provide a rolling device that realizes a long life without causing an early failure due to surface damage even when used in a state where the oil film forming property of the rolling portion is poor.

  The rolling device of the present invention is a rolling device including two components that are in rolling contact, and one of the two components is subjected to a coating treatment with a polyhydric alcohol compound on a steel member. The other component is made of a steel member, or the steel member is coated with a polyhydric alcohol compound, and the steel member of the one component and the other component There is a difference in hardness between the steel members of the parts.

  The polyhydric alcohol compound is chlorogenic acid or a derivative thereof.

  The coating treatment is characterized in that the treatment target is immersed in a treatment liquid in which the polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent.

  There is a hardness difference of 1 point or more in Rockwell hardness HRC between the steel member of the one component and the steel member of the other component.

  The lubricating oil film thickness ratio Λ between the two components in rolling contact is 1.2 or less.

  The rolling device includes an inner ring having an inner ring raceway surface on an outer periphery, an outer ring having an outer ring raceway surface on an inner periphery, and a plurality of rolling elements that roll between the inner ring raceway surface and the outer ring raceway surface. It is a rolling bearing, and the inner ring and the rolling elements are the two components, or the outer ring and the rolling elements are the two components, or both. It is characterized by.

  In the rolling device according to the present invention, one of the two components that are in rolling contact is one in which a steel member is coated with a polyhydric alcohol compound, and the other component is a steel member. Or a steel member subjected to a coating treatment with a polyhydric alcohol compound, and between the steel member of the one component and the steel member of the other component Since there is a difference in hardness, the surface roughness of the rolling part after a short time from the start of operation is small. That is, the rolling part is easy to adjust.

  Therefore, even if the rolling device of the present invention is used in a state where the oil film forming property of the rolling portion is poor, surface damage is unlikely to occur, premature failure due to surface damage is unlikely to occur, and long life can be achieved. The manufacture of the rolling device of the present invention does not require complicated processing as described above, long-time processing, and the like.

It is sectional drawing of the deep groove ball bearing which is an example of the rolling device of this invention. It is the schematic of the two cylinder test machine used for each test. It is a factor effect figure of quality engineering created based on the result of the rolling test to the specimen of L18 orthogonal table of Table 2. It is a rolling part microscope enlarged photograph after the test of the test piece of Table 7.

  In the rolling device such as a rolling bearing used in a state where the oil film forming property of the rolling part is poor, in order to prevent the occurrence of surface damage in the rolling part and realize a long life, It was considered to make the rolling part easy to adapt, that is, to reduce the surface roughness of the rolling part after a short time from the start of operation of the rolling device. Then, in the rolling device, the present inventors provide a hardness difference in the steel members of the two components that are in rolling contact, and at least one of the steel members is subjected to a coating treatment with a polyhydric alcohol compound, whereby the rolling is performed. I found that the moving part becomes easy to get used to. As a result, the occurrence of surface damage was prevented and a long life was realized. The present invention is based on such knowledge.

  In the present application, the rolling contact between the component parts includes a rolling contact accompanied by sliding between the component parts, and also includes a case where a film of a lubricant component or the like formed on the surface of the component part is interposed. Further, in the present application, the term “two components in rolling contact” refers to a rolling contact between the two components.

The rolling device of the present invention is defined as a rolling device that includes two components in rolling contact that satisfy the following two conditions:
(1) Of the two components, one component is a steel member that is coated with a polyhydric alcohol compound, and the other component is a steel member or a steel member. Is coated with a polyhydric alcohol compound.
(2) There is a difference in hardness between the steel member of the one component and the steel member of the other component.

  A rolling device capable of finding a plurality of two components that are in rolling contact with the above two conditions corresponds to the rolling device of the present invention.

  When the rolling device includes a plurality of two components that are in rolling contact with each other, if all or part of the rolling device satisfies the above two conditions, the rolling device corresponds to the rolling device of the present invention.

  The coating treatment with the polyhydric alcohol compound in the present invention is performed on the surface of the steel member. The coating treatment may be performed on the entire surface of the steel member, or may be performed on at least a surface of the steel member that is in rolling contact with other components of the rolling device. .

  As a coating treatment with a polyhydric alcohol compound in the present invention, for example, by immersing a steel member that is a coating formation target in a treatment liquid in which a polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent, The process which forms a film on the member surface is mentioned. This treatment is preferably performed while heating in order to accelerate the film formation. Also, as a coating treatment with a polyhydric alcohol compound in the present invention, a treatment liquid in which a polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent is applied to the surface of a steel member to be coated. A treatment for forming a film on the surface is also mentioned. The film formed by these treatments is considered to be an oxide film or an adsorption film of a polyhydric alcohol compound and / or a decomposition product thereof.

  In the case where both of the two components that make rolling contact in the rolling device of the present invention are subjected to a coating treatment with a polyhydric alcohol compound on a steel member, the polyvalent amount used for the steel member of one component The alcohol compound and the polyhydric alcohol compound used for the steel member of the other component may be the same or different.

  Examples of the polyhydric alcohol compound used in the present invention include plant-derived polyhydric alcohols. When a plant-derived polyhydric alcohol is used, a rolling device with a low environmental load can be obtained.

  Examples of the polyhydric alcohol compound 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, and catechin. Polyhydric alcohol compounds obtained from 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. They can also be derived from plants.

  Among these, gallic acid or its derivative, ellagic acid or its derivative, chlorogenic acid or its derivative, caffeic acid or its derivative, quinic acid, because it is easy to form a film on the surface of the steel member during the film treatment. Alternatively, it is preferable to use a derivative thereof, curcumin or a derivative thereof, quercetin or a derivative thereof.

  In the present invention, the steel member of one component part and the steel member of the other component part of the two component parts that are in rolling contact with each other need only have a hardness difference, and the metal materials constituting each of them are of the same type. It may be different or different. Specific examples include bearing steel (high carbon chromium bearing steel JIS G 4805), case hardening steel (JIS G4104, etc.), high speed steel (AMS 6490), stainless steel (JIS G4303), induction hardening steel (JIS G4051 etc.). ) And the like. The specific hardness difference is preferably 1 point or more in Rockwell hardness HRC (JIS Z2245).

  When the hardness of the two steel members is different in the surface roughness, it is preferable that the surface roughness is softer and the surface roughness is softer.

  The method for providing the difference in hardness between the two steel members is not particularly limited. For example, both of two steel members before quenching and tempering composed of SUJ2 (JIS G 4805) are quenched under the same conditions, and then tempered at a common tempering time with different tempering times. If it does, the one where tempering time is long will become soft, and the one where tempering time is short will become hard, and a hardness difference can be obtained.

  An example of the rolling device of the present invention is a rolling bearing. Specifically, radial rolling bearings such as deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, needle roller bearings, cylindrical roller bearings, self-aligning roller bearings, thrust ball bearings, thrust roller bearings, etc. Thrust type rolling bearings.

  A rolling bearing which is an example of a rolling device according to the present invention includes an inner ring having an inner ring raceway surface on the outer periphery, an outer ring having an outer ring raceway surface on the inner periphery, and a plurality of rolling between the inner ring raceway surface and the outer ring raceway surface. Or the inner ring and each rolling element are two components in rolling contact that satisfy the above conditions (1) and (2), or the outer ring and each rolling element are in the above condition (1). And two components in rolling contact that satisfy (2) and / or both.

  When the inner ring is formed by coating a steel member with a polyhydric alcohol compound, the coating may be applied to the entire surface of the steel member, or at least the inner ring raceway surface of the steel member. It may be applied to the surface. Further, when the outer ring is formed by coating a steel member with a polyhydric alcohol compound, the coating may be performed on the entire surface of the steel member, or at least the outer ring raceway on the surface of the steel member. It may be applied to the surface corresponding to the surface.

  Specific examples of the coating treatment include: (a) when all of the inner ring, the outer ring, and the plurality of rolling elements are subjected to the coating treatment on a steel member, and (b) all of the plurality of rolling elements. Is made of a steel member not subjected to the coating treatment, and both the inner ring and the outer ring are subjected to the coating treatment on the steel member, (c) all of the plurality of rolling elements are subjected to the coating treatment. When it is made of a steel member that has not been coated, and one of the inner ring and the outer ring has been subjected to the coating treatment on the steel member, and the other is made of a steel member that has not been coated with the coating, (D) When all of the plurality of rolling elements are subjected to the coating treatment on a steel member, and both the inner ring and the outer ring are made of a steel member not subjected to the coating treatment, (e) the All of the plurality of rolling elements are subjected to the above-mentioned coating treatment on a steel member, and And one of the outer ring is being subjected to the coating treatment on a steel member, when the other is made of a steel member that is not the coating process, and the like.

  Regarding the hardness difference, all of the steel members of the plurality of rolling elements are harder than the steel members of the inner ring and the outer ring, or all of the steel members of the plurality of rolling elements are the inner ring and the outer ring. In some cases, the steel member is softer than the steel member, or the steel members of the plurality of rolling elements are all harder than the steel member of the inner ring (outer ring) and softer than the steel member of the outer ring (inner ring). .

As an example of the case where the inner ring and each rolling element are two components that make rolling contact satisfying the above conditions (1) and (2),
All of the steel members of the plurality of rolling elements are harder than the steel member of the inner ring, and all of the plurality of rolling elements and / or the inner ring are coated with a polyhydric alcohol compound on the steel member. If
All of the steel members of the plurality of rolling elements are softer than the steel member of the inner ring, and all of the plurality of rolling elements and / or the inner ring are coated with a polyhydric alcohol compound on the steel member. There are cases.

In addition, as an example in the case where the outer ring and each rolling element are two components that are in rolling contact satisfying the above conditions (1) and (2),
All of the steel members of the plurality of rolling elements are harder than the steel member of the outer ring, and all of the plurality of rolling elements and / or the outer ring subject the steel member to a coating treatment with a polyhydric alcohol compound. If
All of the steel members of the plurality of rolling elements are softer than the steel member of the outer ring, and all of the plurality of rolling elements and / or the outer ring subject the steel member to a coating treatment with a polyhydric alcohol compound. There are some cases.

  A rolling bearing according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a deep groove ball bearing which is an example of a rolling bearing of the present invention. As shown in FIG. 1, a deep groove ball bearing (rolling bearing) 1 includes an inner ring 2 having an inner ring raceway surface 2a on the outer periphery, an outer ring 3 having an outer ring raceway surface 3a on the inner periphery, the inner ring raceway surface 2a and the outer ring raceway. A plurality of rolling elements 4 that roll between the surfaces 3 a and a cage 5 that holds the rolling elements 4 are provided. Seal members 6 fixed to the outer ring 3 and the like are respectively provided in the axially opposite end openings 8 a and 8 b of the inner ring 2 and the outer ring 3, and grease 7 is sealed around the rolling elements 4.

  Since the inner ring 2 and each rolling element 4 are in rolling contact, and the outer ring 2 and each rolling element 4 are also in rolling contact, the deep groove ball bearing 1 includes a plurality of two components that are in rolling contact. The inner ring 2 and the outer ring 3 are made by coating a steel member with polyhydric alcohol, each rolling element 4 is made of a steel member, and the steel member of the inner ring 2 and the steel member of each rolling element 4 There is a hardness difference of 1 point or more in Rockwell hardness HRC between the steel member of the outer ring 3 and the steel member of each rolling element 4.

As a preferable production condition of the two component parts that are in rolling contact with each other in the present invention, one of the above component parts is a steel member that is coated with a chlorogenic acid compound, and the steel member is a SUJ2 material. The quenching method is water-cooling, the tempering temperature is high (for example, 200 to 230 ° C.), the tempering time is long (for example, 5 to 10 hours), The other component part is made of a steel member, and the steel member is obtained by quenching and tempering SUJ2 material. The quenching method is water cooling, and the tempering temperature is high (for example, 200 to 230 ° C.). ), And tempering time is short (for example, 1 to 3 hours).
In addition, one of the above components is a steel member that is coated with a chlorogenic acid compound. The steel member is a SUJ2 material that has been quenched and tempered. The tempering temperature is high (eg, 200 to 230 ° C.), the tempering time is short (eg, 1 to 3 hours), and the other component is made of a steel member. The SUJ2 material is quenched and tempered, the quenching method is water cooling, the tempering temperature is high (eg, 200 to 230 ° C.), and the tempering time is long (eg, 5 to 10 hours). Is mentioned. These creation conditions are preferable from the comprehensive viewpoints such as compatibility of the rolling part and cost merit.

The rolling device of the present invention can be suitably used even under conditions where the oil film formation of the lubricating oil is insufficient at the rolling contact portion of the two components that are in rolling contact. For example, use under conditions where the contact portion is in a boundary lubrication state can be mentioned. In addition, for example, it is used under the condition that the parameter film thickness ratio Λ representing the degree of protrusion contact on the surface between two components that are in rolling contact is 1.2 or less. This film thickness ratio Λ is also called an oil film parameter, and is a ratio h ₀ / σ of the minimum film thickness h _{0 of the} lubricating oil film formed on the contact surface of the two objects in rolling contact and the combined root mean square roughness σ of the contact surface. is there. σ is represented by √ (σ ₁ ² + σ ₂ ² ), where the root mean square roughness of the two objects is σ ₁ and σ ₂ , respectively.

  Using the two-cylinder testing machine 11 shown in FIG. A rolling test was performed on 1 to 18 test pieces. Each experiment No. The test piece comprises a driving side (hereinafter referred to as D side) test piece 12 and a driven side (hereinafter referred to as F side) test piece 13. The D-side test piece 12 is rotated by a motor (not shown).

  Table 1 sets two or three levels for each of the eight control factors. Each experiment No. The test specimen preparation conditions are determined by selecting one level for each of the eight control factors. Experiment No. The preparation conditions of the test pieces 1 to 18 were determined according to the L18 orthogonal table (Table 2) of Quality Engineering (Taguchi Method).

  For the quenching of the steel materials on the D side and F side, soaking was performed at 850 ° C. for 45 minutes in an atmosphere furnace and cooled in a salt bath at 230 ° C. for 10 minutes. The sample was cooled by deep cooling, water cooling, or air cooling according to the test specimen preparation conditions.

  The tempering of the steel materials on the D side and the F side was performed in each experiment No. This was performed according to the temperature and time of the preparation conditions of the test piece (Table 2).

The chlorogenic acid treatment is not performed depending on the test piece preparation conditions, or after quenching and tempering, a coating treatment with a chlorogenic acid compound (chlorogenic acid hydrate) is applied to either the D side or the F side steel material. .
In this coating treatment, a treated test piece from which oil on the steel surface was removed by 10 wt% alkali cleaning was activated by immersing it in 18 wt% hydrochloric acid for 20 seconds, and then the treated test piece was treated with chlorogenic acid hydrate. The film is immersed in a 0.5 wt% aqueous solution at room temperature while stirring for a predetermined time.

  Each experiment No. Both the D-side test piece 12 and the F-side test piece 13 of this test piece have a cylindrical shape, and details of these test piece shapes and test conditions of the rolling test by the two-cylinder tester 11 are shown in Table 3. . In Table 3, Ra represents the arithmetic average roughness, and RΔq represents the root mean square slope (hereinafter, this symbol is used). In addition, the surface roughness of the D side and F side shown in Table 3 is the surface roughness before the said process about the test piece which performs a chlorogenic acid process.

  In the rolling test by the two-cylinder testing machine 11, a felt pad 14 impregnated with an additive-free poly-α-olefin oil (equivalent to VG5) is applied to the outer diameter surfaces of both the D-side and F-side cylinders 12 and 13. Lubricating oil was supplied by making it contact (FIG. 2).

  The surface roughness in the cylindrical axis direction is measured for all the test pieces after the test, and if the D-side and F-side cylinders 12 and 13 are created based on the data, the rolling part is We investigated whether it was easy to get familiar with using quality engineering.

  As an index of familiarity, an average value of the axial surface roughness (RΔq) of the D-side cylinder 12 and the axial surface roughness (RΔq) of the F-side cylinder 13 after the test is adopted, and this value is small. It was easy to get used to.

  This index of familiarity is a small desired characteristic. Using the rotational speed and load (Table 3) as error factors, the conditions under which the rolling part is easy to adjust regardless of the rotational speed and load were examined by analyzing the desired characteristics in quality engineering. FIG. 3 is a factor effect diagram obtained by this analysis. This factor-effect diagram shows that, for each control factor shown on the horizontal axis, the greater the level of the SN ratio on the vertical axis, the easier it is to become familiar with.

  In addition, the analysis of variance table in Table 4 shows the degree of influence of each control factor on the familiarity of the rolling section. The control factors listed in this analysis of variance table have a great influence on the familiarity, and other control factors are included in the error component. The superiority is estimated from the value of the dispersion ratio in the table, and it is shown that a control factor with a higher superiority is more likely to affect the familiarity. The contribution level indicates the magnitude of the influence on familiarity. From this analysis of variance table, it was found that the presence or absence of the chlorogenic acid treatment had the greatest influence on the familiarity, and then the D-side quenching method and the tempering temperatures on the D-side and F-side had the greatest influence on the familiarity.

  As a result of considering cost merit in addition to the above factor effect diagram and analysis of variance table, D side tempering is performed at high temperature for a long time and F side tempering is performed at a high temperature for a short time. It was found that the rolling part can be most easily adjusted by applying a chlorogenic acid treatment to either the D-side steel material or the F-side steel material with a hardness difference between them.

  Next, it was verified by a confirmation experiment whether or not the rolling part actually becomes easy to adjust according to such creation conditions.

  In the confirmation experiment, as shown in Table 5, a material close to general preparation conditions is set as a standard level, and from this standard level, D-side tempering is performed at a high temperature for a long time, F-side tempering is performed at a high temperature for a short time, and F A test piece with a standard level and a test piece with an optimal level were prepared according to these two preparation conditions, with the one that was changed so as to be subjected to chlorogenic acid treatment on the side. Table 5 is described using the level numbers set in Table 1.

  A rolling test was performed on the above-mentioned standard-level test piece and the optimal-level test piece using the two-cylinder tester shown in FIG. 2 under the conditions shown in Table 3 in the same manner as in the above-described experiment. The method for supplying the lubricating oil was the same as that used in the above-described experiment.

  The surface roughness (RΔq) in the cylindrical axis direction was measured for all test pieces after the test, and the compatibility of the standard level and the optimum level was compared. As described above, the average value of the axial surface roughness (RΔq) of the D-side cylinder 12 and the axial surface roughness (RΔq) of the F-side cylinder 13 after the test is adopted as an index of familiarity. The smaller the size, the easier it is to adapt.

  In the analysis, the SN ratio was calculated for the standard level and the optimal level (Table 5) using the rotation speed and load (Table 3) as error factors. The larger the S / N ratio, the more it is a creation condition that allows the rolling part to become familiar regardless of the rotational speed and load.

  The estimated gain and actual gain are also shown in Table 5. The gain is the difference between the S / N ratio between the standard level and the optimum level, the estimated gain is the gain estimated from the result of quality engineering, and the actual gain is the actual gain calculated from the result of the confirmation experiment.

  Generally, in quality engineering, if the difference between the estimated gain and the actual gain is within 30%, it is said that there is reproducibility. In this confirmation experiment, this difference is 22%. Therefore, it was judged that the rolling part was actually effective.

  Next, a test for confirming the effect on the surface damage was performed based on the knowledge of the preparation conditions that the rolling part obtained by the above was easy to adapt.

  The test was performed under the conditions shown in Table 6 using the two-cylinder tester 11 of FIG. In this experiment, the same lubricating oil supply method using the felt pad 14 as in the previous experiment was adopted.

  Table 7 shows the evaluated production conditions. The Rockwell hardness in Table 7 is C scale hardness (HRC) (JIS Z2245). FIG. 4 shows a microscope magnified photograph (magnification 200 times) of the outer diameter surface of the F-side cylinder 13 after the test of the standard product, Example 1 and Example 2. FIG. 4 shows that surface damage occurs in the standard product, but surface damage is prevented in Examples 1 and 2. From these results, it was confirmed that a Rockwell hardness HRC of 1 point or more was made between the D-side steel material and the F-side steel material, and at least one of the D-side steel material and the F-side steel material was subjected to chlorogenic acid treatment. It was found that the surface damage performance was improved.

  In the rolling device of the present invention, the surface roughness of the rolling part is small after a short time from the start of operation, i.e., the rolling part is easy to adapt, so that the occurrence of surface damage can be prevented and the oil film formation is insufficient. It can be suitably used in the environment.

1 Deep groove ball bearing (rolling bearing)
2 Inner ring 3 Outer ring 4 Rolling element 5 Cage 6 Seal member 7 Grease 8a Opening at both ends 8b Opening at both ends 11 Two-cylinder tester 12 Drive side (D side) test piece 13 Driven side (F side) test piece 14 For oil supply Felt pad

Claims (3)

A rolling device comprising two components in rolling contact,
It is used under the condition that the film thickness ratio Λ of the lubricating oil film between the two components in rolling contact is 1.2 or less,
Of the two components, one component is formed by coating a steel member with a polyhydric alcohol compound,
The other component consists of steel members,
The polyhydric alcohol compound is chlorogenic acid or a derivative thereof;
Said steel member of the one component of, between the steel member of the other components, Rockwell hardness HRC at Ri hardness difference there more than one points, the components of the one The rolling device according to claim 1, wherein the steel member has a larger Rockwell hardness HRC than the steel member of the other component .   The rolling device according to claim 1, wherein the coating treatment is a treatment of immersing the treatment target in a treatment liquid in which the polyhydric alcohol compound is dispersed or dissolved in water and / or an organic solvent. The rolling device includes an inner ring having an inner ring raceway surface on an outer periphery, an outer ring having an outer ring raceway surface on an inner periphery, and a plurality of rolling elements that roll between the inner ring raceway surface and the outer ring raceway surface. Rolling bearings,
Whether the inner ring and each rolling element are the two components;
Or said outer ring said each rolling element is the two component parts, or, the rolling device according to claim 1 or claim 2, wherein it is these both.