JP2005233239A - Rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling device assuring a low dust emission and low out-gas. <P>SOLUTION: A lubricating oil containing sila-hydrocarbon oil as the base oil is uniformly applied in thin film form on the surfaces of an inner ring 1, an outer ring 2, rolling elements 3, and a retainer 4 of a rolling bearing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rolling device such as a rolling bearing, a ball screw, a linear guide device, and a linear motion bearing.

  Many rolling devices are lubricated with a lubricant such as lubricating oil and grease so as to operate under severe conditions such as high-speed rotation and high load. However, the rolling device in which the lubricant is used causes the lubricant to scatter (dust generation) during operation, or the base oil of the lubricant to vaporize (outgas) due to the temperature rise, and pollutes the surrounding environment. In some cases, there is a problem that it cannot be used for a device that requires a clean environment, such as a clean room, a semiconductor manufacturing device, and a liquid crystal panel manufacturing device. For the same reason, there is a problem that it cannot be used in a vacuum environment.

  In particular, various electronic devices such as semiconductor devices and drive circuits for liquid crystal panels have been increasingly miniaturized and highly integrated in recent years. The impact on the environment is growing. For this reason, there is a growing demand for low dust generation properties for rolling devices used in semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, and the like that require a clean environment.

  For these reasons, devices that require a clean environment as described above and rolling devices that can be applied in a vacuum environment have been proposed. For example, a rolling device in which a solid lubricating film is formed on a raceway surface or the surface of a rolling element, or a rolling device using a lubricant that has low dust generation and low base oil evaporation (see Patent Document 1). Proposed. Moreover, what is provided with the retainer made from a fluororesin is proposed about the rolling bearing among rolling devices.

  As the solid lubricant film, a soft metal (gold, silver, lead, etc.), a layered compound (molybdenum disulfide, tungsten disulfide, etc.), a fluororesin, etc. are generally used. In the case of soft metals and fluororesins, the frictional force generated by the operation of the rolling device causes the lubricant particles to be gradually scraped from the surface of the solid lubricating film, and the wear particles are transferred to the mating surface and become thin. Lubrication is performed by forming a coating. In the case of a layered compound, since it has a cleavage property, the cleavage surface is worn away little by little, thereby exhibiting lubricity.

Furthermore, in the case of a cage made of fluororesin, wear particles of fluororesin are generated due to sliding contact between the cage and the rolling element as the rolling bearing rotates, and the raceway surface of the bearing ring and the rolling surface of the rolling element Lubrication is performed by forming a lubricating film by transferring to.
JP 2001-72987 A

However, since all the solid lubricant films have a self-sacrificial lubrication mechanism, the generation of wear particles is inevitable, and an excellent low dust generation property cannot be expected.
In the case of a cage made of fluororesin, the frictional wear characteristics of the material constituting the cage affect the transferability of the wear particles. That is, in the case of a material that easily wears, not only the wear particles are excessively transferred to cause dust generation, but also the rotation of the rolling bearing may be stopped due to the biting of the wear particles. On the other hand, in the case of a material that is difficult to wear, there is little transfer of wear particles and insufficient lubrication. Furthermore, since fluororesin has low moldability, the cage must be manufactured by shaving, which increases the cost.

Furthermore, although the rolling device described in Patent Document 1 has low dust generation and low outgas, further improvement is necessary to meet the demand for low dust generation and low outgas, which has been increasing in recent years. It is.
Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a rolling device with low dust generation and low outgas.

  In order to solve the above problems, the present invention has the following configuration. That is, the rolling device according to claim 1 of the present invention has an inner member having a raceway surface on the outer surface, and a raceway surface facing the raceway surface of the inner member, and is disposed outside the inner member. A rolling device comprising: an outer member that is formed, and a plurality of rolling elements that are arranged to freely roll between the both raceway surfaces. The contact surface of the inner member with the rolling element, the outer member At least one of the contact surface with the rolling element and the rolling surface of the rolling element is covered with a lubricating oil based on a silahydrocarbon oil represented by the following chemical formula (I). And

In the chemical formula (I), R ₁ , R ₂ , and R ₃ are the same or different hydrocarbon groups, and n is an integer of 0-2.
According to a second aspect of the present invention, the rolling device includes an inner member having a raceway surface on the outer surface, and a raceway surface facing the raceway surface of the inner member, and is disposed outside the inner member. An outer member, a plurality of rolling elements arranged between the both raceway surfaces so as to be freely rollable, and a cage for holding the rolling element between the inner member and the outer member. In the rolling device, at least one of a contact surface of the inner member with the rolling element, a contact surface of the outer member with the rolling element, a rolling surface of the rolling element, and a surface of the cage is provided. It is characterized by being covered with a lubricating oil based on a silahydrocarbon oil represented by the following chemical formula (I).

In the chemical formula (I), R ₁ , R ₂ , and R ₃ are the same or different hydrocarbon groups, and n is an integer of 0-2.
Furthermore, the rolling device of claim 3 according to the present invention is the rolling device of claim 1 or 2, wherein the silahydrocarbon oil has a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 250 mm ² / s or less.

The rolling device of the present invention is characterized in that a sliding surface of a member constituting the rolling device is covered with a lubricating oil based on silahydrocarbon oil. Since the silahydrocarbon oil does not easily scatter and has a low vapor pressure, the rolling device of the present invention has low dust generation and low outgas.
When the kinematic viscosity at 40 ° C. of the silahydrocarbon oil is less than 30 mm ² / s, the lubricity of the lubricating oil becomes insufficient, and the above-mentioned parts constituting the rolling device are abraded and wear powder is generated. There is a fear. On the other hand, if it exceeds 250 mm ² / s, evaporation of the lubricating oil may be promoted by heat generated by the stirring resistance.

  The present invention can be applied to various rolling devices. For example, a rolling bearing, a ball screw, a linear guide device, a linear motion bearing, and the like. In the present invention, the inner member includes an inner ring when the rolling device is a rolling bearing, a screw shaft when the ball screw is also used, a guide rail when the linear guide device is used, and a linear bearing. In the case, each means an axis. The outer member is an outer ring when the rolling device is a rolling bearing, a nut when it is a ball screw, a slider when it is a linear guide device, and an outer cylinder when it is also a linear bearing. Means each.

  Since the rolling device of the present invention is lubricated with a lubricating oil based on silahydrocarbon oil, it has low dust generation and low outgas.

An embodiment of a rolling device 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 a rolling bearing which is an embodiment of a rolling device according to the present invention. This rolling bearing (deep groove ball bearing) includes an inner ring 1 having a raceway surface 1a on the outer peripheral surface, an outer ring 2 having a raceway surface 2a opposite to the raceway surface 1a on the inner peripheral surface, and a raceway between both raceway surfaces 1a and 2a. A plurality of rolling elements (balls) 3 that are movably arranged, and a cage 4 that holds the plurality of rolling elements 3 between an inner ring 1 and an outer ring 2 are provided. In addition, the holder | retainer 4 does not need to be provided.

  The inner ring 1 and the outer ring 2 are made of a metal material such as bearing steel or stainless steel, but the entire surface thereof may be covered with a ceramic coating if desired. The type of ceramic is preferably titanium nitride, titanium carbonitride, chromium nitride or the like because of its excellent adhesion to the metal material (base material) constituting the inner ring 1 and the outer ring 2. When the rolling bearing is used in a particularly corrosive environment, the entire inner ring 1 and outer ring 2 may be made of ceramics such as silicon nitride, silicon carbide, partially stabilized zirconia, and alumina.

The rolling element 3 is also made of a metal material such as bearing steel or stainless steel, but may be made of ceramics such as silicon nitride, silicon carbide, partially stabilized zirconia, or alumina.
If the inner ring 1, outer ring 2, and rolling element 3 are made of ceramics (or if they are made of a metal material and a ceramic coating is provided on the surface), the corrosion resistance is excellent, so even in highly corrosive environments Excellent dust generation. If the ceramics constituting the rolling element 3 and the ceramics constituting the inner ring 1 and the outer ring 2 are of different types (or the ceramics constituting the rolling element 3 and the coating provided on the surfaces of the inner ring 1 and the outer ring 2). If the ceramics to be formed are of a different type), adhesive wear is less likely to occur compared to the case of the same type of ceramics, so that the generation of dust can be suppressed.

  Lubricating oil based on silahydrocarbon oil is uniformly applied as a thin film on the surfaces of the inner ring 1, outer ring 2, rolling element 3, and cage 4 of such a rolling bearing (not shown). The rolling bearing is lubricated. It is most preferable to apply the lubricant to the surfaces of all of the inner ring 1, the outer ring 2, the rolling elements 3, and the cage 4. However, the lubricant should be applied to at least one surface of the bearing parts. Thus, the rolling bearing can be lubricated. Lubricating oil may be applied to the entire surface of the inner ring 1, outer ring 2, rolling element 3, and cage 4, but the contact surface (track surface) of the inner ring 1 with the rolling element 3, the outer ring 2 on the contact surface (track surface) with the rolling element 3, the rolling surface (ball surface) of the rolling element 3, and the sliding surface of the cage 4 (contact surface with the inner ring 1, outer ring 2 and rolling element 3). If the lubricating oil is applied, the rolling bearing can be lubricated.

  In such a rolling bearing of this embodiment, a lubricating oil based on a silahydrocarbon oil is used as a lubricant, but the silahydrocarbon oil is difficult to scatter and has a low vapor pressure. The form of rolling bearing is low dusting and low outgassing. In the rolling bearing of this embodiment, the inner ring 1, the outer ring 2, the rolling elements 3, and the cage 4 are less likely to be worn over a long period of time, so that dust generation due to generation of wear powder is less likely to occur.

The kind of silahydrocarbon oil will not be specifically limited if it is the silahydrocarbon oil represented by the above-mentioned chemical formula (I). For example, R ₁ , R ₂ , and R ₃ in the chemical formula (I) may be any hydrocarbon group such as an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. And 1 type of silahydrocarbon oil may be used and 2 or more types may be mixed and used. Also, other types of base oils may be mixed with the silahydrocarbon oil as long as the object of the present invention is not impaired.

In addition, various additives may be added to the lubricating oil based on the silahydrocarbon oil as desired in order to further improve various performances. Examples of the additive used include an antioxidant, a rust inhibitor, an extreme pressure agent, an oily agent, and a metal deactivator. These may be used alone or in combination of two or more. it can.
In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, a deep groove ball bearing has been described as an example of the rolling device, but the present invention can be applied to various types of other rolling bearings. For example, radial rolling bearings such as angular contact 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. The present invention can be applied not only to rolling bearings but also to various other types of rolling devices. For example, a ball screw, a linear guide device, a linear motion bearing, or the like.

〔Example〕
Hereinafter, the present invention will be described more specifically with reference to examples. In the rolling bearing (nominal number 608) having substantially the same configuration as the rolling bearing of FIG. 1, the material of each bearing component (inner ring, outer ring, rolling element, cage), presence / absence and type of coating, and type of lubricating oil and Various kinematic viscosities at 40 ° C. were prepared as shown in Tables 1 to 3.
Each rolling bearing is manufactured by completely degreasing the inner ring, the outer ring, the rolling elements, and the cage, and applying the lubricating oil to assemble. The lubricating oil was applied as follows. After applying 0.03 ml of lubricating oil to the raceway surface of the inner ring, the raceway surface of the outer ring, the rolling surface of the rolling element, and the sliding surface of the cage, it is mounted on the centrifuge and a centrifugal force of 500 G acts. To remove excess lubricating oil (5 minutes).

Among the lubricating oils listed in Tables 1 to 3, “SHC1” is a silahydrocarbon oil having a chemical structure of Si (C ₃ H ₆ Si (n—C ₆ H ₁₃ ) ₃ ) ₄ , and its vapor pressure is 9.00 × 10 ⁻⁹ Pa. “SHC2” is a silahydrocarbon oil having a chemical structure of CH ₃ Si (CH ₂ CH ₂ Si— (C ₁₀ H ₂₁ ) ₃ ) ₃ . “SHC3” is a silahydrocarbon oil having a chemical structure of nC ₈ H ₁₇ Si (C ₃ H ₆ Si (n—C ₁₂ H ₂₅ ) ₃ ) ₃ , and its vapor pressure is 9.00 × 10 6. ^-7 Pa. The "SHC4", an _{(n-C 12 H 25)} 2 Si (C 8 H 16 Si (n-C 12 H 25) 3) 2 consisting Sila hydrocarbon oil chemical structure, its vapor pressure is 4. 00 × 10 ⁻⁷ Pa. Further, the vapor pressure of tri (2-octyldodecyl) cyclopentane in Table 3 is 1.33 × 10 ⁻⁶ Pa.

The dust generation properties of the 16 types of rolling bearings thus obtained were evaluated using a bearing dust generation test apparatus 20 as shown in FIG. Two sets of rolling bearings 10 and 10 are attached between the shaft 11 of the bearing dust generation test apparatus 20 and the housing 12, and an axial load is applied to the rolling bearings 10 and 10 by a coil spring 13. ing. The rolling bearings 10 and 10 are rotationally driven by the power of the motor 14 transmitted through the rotation introducing machine 17 with a magnetic fluid seal including the belt 15 and the pulley 16.
When the rolling bearings 10 and 10 are rotated, dust is generated, and the dust particles are scattered outside the rolling bearings 10 and 10 and collected in a funnel 18 provided at a lower portion of the bearing dust generation test apparatus 20. The dust particles are sent to a light scattering type particle counter 19 and the number thereof is measured.

Test conditions are shown below, and the test results are also shown in Tables 1 to 3.
Rotation speed: 300rpm
Axial load: 9.8N
As can be seen from Tables 1 to 3, the rolling bearings of Examples 1 to 9 had a small amount of dust generation regardless of the material of each bearing part and the presence or absence of a ceramic coating. However, in Example 8 where the kinematic viscosity of the lubricating oil (silahydrocarbon oil) was relatively low and Example 9 where the viscosity was relatively high, the amount of dust generation was slightly higher than in the other examples. When the viscosity is low, the lubricity is slightly low, so it is considered that the bearing parts are worn and wear powder is generated. In the case of a high viscosity, it is considered that the evaporation of the lubricating oil is accelerated by the heat generated by the stirring resistance, and the vapor of the lubricating oil discharged from the rolling bearing is aggregated into particles.

On the other hand, Comparative Examples 1, 2, and 7 having different types of lubricating oil, Comparative Example 3 in which the cage is made of fluororesin (PTFE), and Comparative Examples 4 to 6 having a solid lubricating film are implemented. Compared with Examples 1-9, the amount of dust generation was large, and it was about 10 times or more of Examples 1-9 except for Comparative Example 7.
Next, the relationship between the kinematic viscosity of the lubricating oil and dust generation was investigated. Two types of silahydrocarbon oils having different kinematic viscosities at 40 ° C. were mixed at various ratios to prepare nine types of lubricating oils having different kinematic viscosities. Sila hydrocarbon oil used is a _{CH 3 Si (CH 2 CH 2} Si- (C 6 H 13) 3) 3, Si (C 3 H 6 Si (n-C 12 H 25) 3) _4. The kinematic viscosity at former 40 ° C. is 57 mm ² / s, the latter is 206 mm ² / s.
In the same manner as described above, a rolling bearing coated with lubricating oil was obtained, and the dust generation property was evaluated using the bearing dust generation test apparatus 20. The results are shown in Table 4.

From this result, kinematic viscosity at 40 ° C. of the lubricating oil, 70 mm ² / s or more 206mm is preferably from ² / s, more preferably not more than 80 mm ² / s or more ^{180mm 2 / s, 90mm 2 /} s or more 120 mm ² / s It can be said that the following is more preferable.

  The rolling device of the present invention is suitable for applications that require high cleanliness. For example, it can be suitably used for a semiconductor manufacturing apparatus, a liquid crystal panel manufacturing apparatus, and the like.

It is a fragmentary longitudinal cross-section which shows the structure of the rolling bearing which is one Embodiment of the rolling device which concerns on this invention. It is the schematic of the bearing dust generation test apparatus which measures the dust generation amount of a rolling bearing.

Explanation of symbols

Reference Signs List 1 inner ring 1a raceway surface 2 outer ring 2a raceway surface 3 rolling element 4 cage 10 rolling bearing

Claims (3)

An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member and disposed outside the inner member, and rolling between the raceway surfaces In a rolling device comprising a plurality of freely arranged rolling elements,
At least one of the contact surface of the inner member with the rolling element, the contact surface of the outer member with the rolling element, and the rolling surface of the rolling element is represented by the following chemical formula (I). A rolling device characterized by being covered with a lubricating oil based on silahydrocarbon oil.

In the chemical formula (I), R ₁ , R ₂ , and R ₃ are the same or different hydrocarbon groups, and n is an integer of 0-2. An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member and disposed outside the inner member, and rolling between the raceway surfaces In a rolling device comprising a plurality of freely arranged rolling elements, and a cage for holding the rolling elements between the inner member and the outer member,
At least one of the contact surface of the inner member with the rolling element, the contact surface of the outer member with the rolling element, the rolling surface of the rolling element, and the surface of the cage is represented by the following chemical formula ( A rolling device characterized in that it is covered with a lubricating oil based on a silahydrocarbon oil represented by I).

In the chemical formula (I), R ₁ , R ₂ , and R ₃ are the same or different hydrocarbon groups, and n is an integer of 0-2. The rolling device according to claim 1, wherein the silahydrocarbon oil has a kinematic viscosity at 40 ° C. of 30 mm ² / s to 250 mm ² / s.

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