WO1994015109A1

WO1994015109A1 - Roller bearing

Info

Publication number: WO1994015109A1
Application number: PCT/JP1993/001885
Authority: WO
Inventors: Yasushi Toyota; Kenji Yamamoto; Kazunori Hayashida
Original assignee: Koyo Seiko Co., Ltd.
Priority date: 1992-12-28
Filing date: 1993-12-27
Publication date: 1994-07-07
Also published as: JPH06280881A; JP2946272B2

Abstract

A roller bearing consisting of races (1, 2) consisting of a metal or ceramic material, rolling elements (3) provided rollably inside the races (1, 2) and consisting of a metal or ceramic material, and a lubricating film (5) provided so as to cover the rolling portions of the races (1, 2) and/or rolling elements (3) and obtained by disperse-mixing a synthetic fluoro-resin in a resin binder having imide bond or amide-imide bond, and removing hydrocarbon gas from the resultant mixture. Since a temperature for firing this lubricating film (5) is set to such a level that permits a hydrocarbon gas to be discharged completely from the lubricating film (5) during a firing treatment for the lubricating film (5), the discharge of a hydrocarbon gas from the lubricating film (5) in a high-temperature environment is prevented.

Description

Description Title of Invention

Rolling bearing technical field

The present invention relates to a rolling bearing, and particularly to a rolling bearing which is advantageous for use in a special environment such as a vacuum environment, a high-temperature environment, or a corrosive environment in which ordinary grease or oil cannot be used. Background art

The above-mentioned special environment includes, for example, a transfer system provided inside a semiconductor manufacturing apparatus. In such a special environment, if grease is used as a lubricant for a ball bearing, the Evaporation of the oil causes problems such as deterioration of the lubrication function and contamination of the use environment.

Conventionally, in such cases, soft metals such as gold, silver, lead, and copper, and solid lubricants such as carbon and molybdenum disulfide are mainly applied to the raceway surface of the bearing ring and the surface of the rolling elements. Coating is performed in the form of a film.

In the lubricating film made of the solid lubricant described above, the dusting condition is lower than when grease is used, such as when the lubricating film peels off little by little when it comes into contact with the rolling elements. appear .

Therefore, the present applicant is considering a method in which a lubricating film containing a fluorine-based resin is formed on a raceway or a retainer so that dust generation can be reduced by an order of magnitude compared to the conventional case. (See Japanese Patent Application Laid-Open No. 4-46219) . The lubricating film is formed by dispersing a fluororesin such as polytetrafluoroethylene (PTFE) in an organic solvent and a resin binder such as polyamide which has a rapid curing property, and spraying it onto the object to be formed. After coating, it is fixed by firing, but at present, the firing temperature is simply set at 180 ° C ± 10 in consideration of the transferability and fixability of the film. It is set relatively low. However, experiments have shown that such a lubricating film made of a fluororesin releases a large amount of hydrocarbon gas in an environment at a temperature higher than the firing temperature (Fig. 5). See graph.) This hydrocarbon-based gas has the potential to become an obstructive factor particularly when high-precision processing is required, such as in the semiconductor manufacturing process. However, and in earthenware pots by shown in the graph of FIG. 5, the above-mentioned hydrocarbon gas generator and a _{_{monitor, H 2, H 2 0,}} CO 'N 2 and, C 0 ₂ is also generated Suruga, these For example, even if high-precision processing is required as in the semiconductor manufacturing process, there is no problem because it does not become a hindrance element.

In view of such circumstances, an object of the present invention is to provide a structure that does not emit hydrocarbon-based gas in a high-temperature environment while suppressing dust generation due to peeling or chipping. Disclosure of the invention

[Constitution ]

The rolling bearing of the present invention includes: a raceway made of a metal or a ceramic material; a rolling element rolled and arranged on the raceway made of a metal or a ceramic material family; A fluorine-based synthetic resin is provided in a resin binder having an imido bond or an amide imide bond provided so as to cover the rolling portion of the rolling element. _U consisting of a lubricating film which has been subjected to the resin dispersion mixing and degassing of the hydrocarbon gas

Further, the rolling bearing of the present invention comprises: a raceway made of metal or ceramic material; a rolling body made of metal or ceramic material rolled on the raceway; A cage made of a metal or a synthetic resin material for holding the rolling element, and an imid provided to cover the rolling wheel and / or the rolling and sliding contact portions of the rolling element and / or the cage. It is composed of a lubricating film obtained by dispersing and mixing a fluorine-based synthetic resin in a resin binder having a bond or an amide-imide bond and performing a degassing treatment of a hydrocarbon gas.

Further, the rolling bearing of the present invention comprises a raceway made of metal or ceramic material, and a rolling rest made of metal or ceramic material rolled on the raceway. A cage made of a metal or a synthetic resin material for holding the rolling element, and an imid coupling or amidim provided to cover a sliding contact surface of the cage with the rolling element. And a lubricating membrane obtained by dispersing and mixing a fluorine-based synthetic resin in a resin binder having a metal bond and performing a degassing treatment of a hydrocarbon gas.

Further, in the rolling bearing of the present invention, in each of the above-mentioned inventions, the race and / or the rolling element are formed of silicon nitride-based ceramics.

As the metal constituting the bearing ring and rolling rest, especially in an environment where corrosion resistance is required, for example, martensitic stainless steel such as JIS standard SUS440C, for example, JIS standard SU

Precipitation hardening type stainless steel such as S630 can be used after appropriate hardening and aging treatment. For light load applications, it is also possible to use austenitic stainless steel such as JIS SUS304. Noh. Also, Ni—Cr—Mo alloys such as Hastelloy C122, Hastelloy C1-276, and Hastelloy C-14, manufactured by Mitsubishi Materials Corporation, are used as nickel-based alloys. It is also possible. In an environment where heat resistance is particularly required, JIS standard SKH4 steel, A1SI standard M-50 material, or the like is preferably used. Bearing steel such as JIS standard SUJ-2 commonly used.

Also, carburizing steel such as SAE standard 512 material can be used if heat treatment conditions such as quenching and tempering temperatures and times are appropriately adjusted. In addition, it is also possible to use a Ni_Cr-based alloy HAYNESSALLOY, for example, HA214, HA230, etc., manufactured by HaynesIntEternatelon, Inc.

Is a Sera mission-box material, as a sintering aid, Lee Tsu preparative rear (Y ₂ 03) and alumina (A 1 .0 α), other appropriate: nitride § Lumi (A 1 New), silicon nitride using titanium oxide emissions (T i 〇 ₂₎

(. S i 3 N ₄₎ others mainly composed of alumina (A 1 ₂ 0 a) and silicon carbide (S i C>, Jirukonia (Z r 0 _2), aluminum nitride

(A1) can be used.

As the metal forming the retainer, for example, JIS standard SUS304, brass, titanium material, or the like is suitably used. Examples of the synthetic resin material include fluororesins such as polytetrafluoroethylene (hereinafter abbreviated as PTFE), ethylenetetrafluoroethylene (ETFE), polyetheretherketone (PEEK), and polyphenylenesulfate. It is also possible to use engineering plastics such as sulfide (PPS), polyethersulfone (PES), and Nylon 46. Reinforcing fibers such as glass fiber are added to these resins. As the type of the retainer, a corrugated type, a crown type, a hollow type, or the like is suitably used. Examples of the resin binder having an imido bond or an amidomid bond include polyimide, polyimide, and the like. Examples of the fluorine-based synthetic resin include the same PTFE and ETFE as the fluorine-based resin used for the cage.

The lubricating oil of the present invention is characterized in that the resin binder having the above imido bond or amide imide bond is 10 to 50% by weight, and the fluorine-based synthetic resin is 1 to 20% by weight therein. Is formed by applying a solvent obtained by dispersing and mixing a solvent such as N-methyl-2-pyrrolidone to a coated surface by a bond film method or the like. Degassing of hydrocarbon power is 315. C-360. This is performed by firing at a temperature of C for a period of 30 minutes to 120 minutes.

[Action]

According to the above configuration, the lubricating film is subjected to the degassing treatment of the hydrocarbon-based gas. It is not required to be released, which is particularly advantageous in the use environment in which hydrocarbon-based gas may be an obstacle.

In addition, the baking in a high temperature range during the degassing process causes a resin binder having an imido bond or an amide bond to undergo a condensation reaction, thereby causing hardening and brittleness of the lubricating film surface due to oxidation and carbonization. And promotes transfer, as well as improving the lubricating performance with the increase in the adhesion of the oxidized component to the metal surface due to the polarity of the C 0 H group.

[Effect]

As described above, in the present invention, by setting the firing temperature at the time of firing and fixing the lubricating film to a temperature equal to or higher than the temperature at which the hydrocarbon-based gas is generated from the coating layer, the pocket of the cage can be improved. Coated on the inner surface The lubricating film is substantially free of hydrocarbon-based gas. However, even if the rolling bearing of the present invention is left in a high-temperature environment, no hydrocarbon-based gas is released from the lubricating film. Therefore, when high-precision processing is required, for example, in a semiconductor manufacturing process, the use of the rolling bearing of the present invention can contribute to an improvement in yield.

In addition, baking in a high temperature range during the degassing process causes a resin binder having an imido bond or an amide bond to undergo a condensation reaction, and is cured on the surface of the lubricating film by oxidation and carbonization. In addition, embrittlement occurs and transfer is promoted, and at the same time, the lubricating performance is improved with the increase in adhesion to the metal surface due to the polarity of the oxidized component (COH) group. At least one of the inner and outer races and rolling elements of the rolling bearing is made of silicon nitride ceramics, and at least the lubricating film on the pocket surface of the cage is treated as described above. If coated, the life will be significantly improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view of one embodiment of the rolling bearing of the present invention, FIG. 2 is a schematic diagram of an experimental apparatus used for measuring the amount of generated dust of the bearing, FIG. Is a graph showing the gas release status of this example, FIG. 5 is a graph showing the gas release status of Comparative Example 2, FIG. 6 is a graph showing the gas release status of Comparative Example 1, and FIG. 7 is an Example and Comparative Example 2. Fig. 8 is a graph showing the state of dust generation and hardness, Fig. 8 is a graph showing another heat pattern of the lubricating film baking process, and Fig. 9 is a graph showing the results of examining the properties of the lubricating film by infrared spectroscopy. , FIG. 10 is a diagram representing Table 1, FIG. 11 is a diagram representing Table 2, and FIG. 12 is a rolling shaft of the present invention. FIG. 3 is a longitudinal sectional view of a rolling bearing according to another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, details of the present invention will be described based on the embodiment shown in FIG. 1 or FIG. FIG. 1 shows an embodiment of the rolling bearing of the present invention. Here, a deep-clear type ball bearing is taken as an example. In the figure, 1 is an inner ring, 2 is an outer ring, 3 is a ball ', and 4 is a cage of a waveform. A lubricating film 5 in which a fluorine-based synthetic resin is dispersed and mixed in a resin binder having an imido bond or an amide imido bond is coated on the inner surface of each of the cages 4. The lubricating belly 5 is subjected to a degassing treatment of hydrocarbon gas.

More specifically, the inner and outer rings 1 and 2 and the ball 3 are made of JIS standard SUS440C, and the retainer 4 is made of JIS standard SUS304. The lubricating membrane 5 is composed of PTF E, which is the main component of lubrication, and polyimide, which is a thermosetting organic resin binder.

Next, an example of a method for forming the lubricating film 5 will be described.

(a) Degreasing the target cage 4 and covering a portion of the cage 4 except for the inner surface of the pocket with a mask (not shown), and then sandblasting the exposed portion. By this treatment, the adhesion of the lubricating film 5 is increased, and the pressure resistance is increased.

(b) A fluid obtained by dissolving PTFE powder and polyamide imide powder in N-methyl-12-pyrrolidone on the inner surface of the pocket not covered with the mask in the cage 4. Spray. This is a coating method called a so-called bond film method, in which each of the powders is almost uniformly diffused on the spray surface. Be in the state. The component ratio of the fluid is, for example, 5 PTFE powder, 25% polyamide powder, and 70% N-methyl-2-pyrrolidone.

(c) After removing the mask from the retainer 4, the sprayed film is heated and fired at a temperature as high as 315 to 360C for a predetermined time (about 30 minutes to 120 minutes). Then, the retainer 4 is fixed to the inner surface of the pocket. If the temperature in this firing step is as high as described above, the polyamide gas of the resin binder among the resins constituting the coating film will convert the hydrocarbon-based gas by a condensation reaction. It is released and there is almost no hydrocarbon gas.

Thereafter, (b) and (c) are repeated several times, and finally the thickness of the lubricating film 5 is set to, for example, 5 to 20 μm. You may do it.

When the sintering temperature of the lubricating film 5 is set to the high temperature as described above, the lubricating film 5 is oxidized and carbonized and hardened with the condensation reaction. (180 ° C ± 10 ° C) and the appearance color is different. This point has been confirmed by the pencil hardness measurement shown in FIG. 7 and the infrared spectroscopic measurement shown in FIG. First, as shown in the graph of FIG. 7, 180 ± 10. For 90 minutes at C and at 350 ° C ± 10 minutes for 30 minutes, 350. For C ± 1 0 in 3 0 minutes, 3 8 0 ^e C ± cited four examples of case 3 0 minutes at 1 0, but as a result raising the firing temperature of the lubricating film 5 The higher the hardness, the higher the hardness. On the other hand, as shown in the graph of FIG. 9, in the case of 180 minutes at ± 1ϋ for 90 minutes, 250. C + 10 ° C for 30 minutes, 300 ± 30 ° C for 30 minutes, 350 C for 10 minutes for 30 minutes However, as a result, the higher the firing temperature of the lubricating film 5, the higher the wave number 9 3 0 cm - ¹ (one CH ₂ - COO 15) a functional group has increased. Next, the dust generation from the lubricating film 5, the state of the released gas, and the life of dust generation in the rolling bearings are examined by experiments, and will be described.

(a) Dust generation

Figure 2 shows the equipment used for the experiment. In the figure, 50 is a rolling bearing, 51 is a rotating shaft, 52 is a casing, 53 is a magnetic fluid seal, 54 is a particle counting device (particle counter), and 55 is a particle counter. The measurement result recorder (Recorder), 56 is a bearing housing.

Bearing used: SEM L6O12 (06 x ^ 12 x 3) Rotation speed: 200 rpm

Load: Radial load (2N)

Atmosphere: Inside a clean bench of class 10 in the atmosphere, in the room Measurement conditions: Dust amount of 0.3 m or more in particle size

Experiment time: Continuous 20 hours

In the bearings used, the inner and outer rings and rolling elements are JIS S4S4400C, and the retainers are JIS S3S4. In Comparative Example 1, the lubricating film 5 was not formed on the inner surface of the pocket of the cage, and in Comparative Example 2, the greased lubricating film 5 composed of the above-described component was reduced on the inner surface of the pocket of the cage. In this embodiment, the lubricating film 5 is fired and fixed at a high temperature (± 10. C at 350). .

The result of this experiment is shown in Figure 3. That is, in the case of the working example, the amount of generated particles showed a tendency to be slightly larger than that of the comparative example 2, but was significantly smaller than that of the comparative example 1. This means that dust generation can be suppressed by the lubricating film 5. (b) Released gas

Figures 4 to 6 show the experimental results of the relationship between the ambient temperature and the released gas components, and Figure 7 shows the relationship between the firing temperature and the number of generated particles, and the relationship between the firing temperature and the hardness of the lubricating film. The experimental results are shown respectively. 4 is a graph relating to the example, FIG. 5 is a graph relating to Comparative Example 2 ′, FIG. 6 is a graph corresponding to Comparative Example 1, and FIG. 7 is a graph corresponding to Example and Comparative Example 2. A. on the vertical axis of the graph is an abbreviation of arbitrary unit, and indicates intensity.

In the case of Comparative Example 2, as shown in FIG. 5, when the ambient temperature exceeds 300 ° C., hydrocarbon-based (mass number 58, 71, 98) gas emission is remarkably generated. On the other hand, in the case of the embodiment, as shown in FIG. 4, even when the environmental temperature exceeds 400, no hydrocarbon gas is released. This is considered to be because the hydrocarbon-based gas is released from the lubricating film 5 during the firing because the firing temperature of the lubricating film 5 is increased, and the firing temperature of the lubricating film 5 is increased. Has proven its superiority.

As is clear from FIG. 7, the firing temperature was set at ³⁰⁰ eC ± 10 ° C. and 350 ° C. If we assume C ± 10, then 180. C ± 10. Although little comparable to the extent that dust amount is slightly more when used as compared with the case of the ratio Comparative Examples 2 to as C, when the firing temperature and ^{3 8 0 e C ± 1 0} tt C, during use The amount of dust generated is 300. C ± 10. C, 350. It is extremely high compared to the case of C ± 10 ° C. This means that if the firing temperature is too high, the lubricating film 5 will be oxidized and carbonized deep inside, and the entire film will become brittle, so that peeling and chipping will be constant in the depth direction. It is thought that there is a case, and the other is 300. In the case of C soil 10 at 350 and soil at 10 ° C, oxidation and carbonization will occur on the surface side of the synovial membrane 5, but less oxidation and carbonization inside. Therefore, it is considered that the peeling or lack of the film occurs from the surface side and the progress is relatively slow. This means that there is a desirable range for the firing temperature.

Furthermore, as compared with FIG. 6 relating to Comparative Example 1 in which the lubricating film 5 was not coated, Comparative Examples 2 and Examples in which the lubricating film 5 was coated show H ₂ , The amounts of H ₂ 0, C〇N ₂ and C 0 ₂ are increasing. Similarly, as is apparent from the difference between FIG. 4 and FIG. ho will in the case of high, but lower the case by Ri also H _2, H 7_Rei, CO. N ₂ and have summer many occurrence of C 〇 _2. These components can only be considered to have adhered to the surface of the lubricating film 5 in the atmosphere.Therefore, in the lubricating film 5 fired at high temperature, the surface became porous and the surface area increased, and the amount of adhesion increased. Therefore, it is considered that the amount of generation increased as described above. one

(c) Dust life

Regarding the dust generation life, in the experimental apparatus shown in Fig. 2, the axial load (20N) was applied to the rolling bearings 50, 50 (nominal number 608>). In this experiment, the rolling bearing 50 was continuously rotated until it reached the end of its service life, and the amount of dust generated was measured at intervals of 6 minutes using the particle counting device 54. The presence / absence of a dust generation abnormality was checked by determining whether the amount of dust was 100 000 particles / 0.1 cί, and this dust generation abnormality was confirmed 10 times in succession. The time required from the start to the point in time when the above was confirmed as the dust generation life is measured, and the results are shown in Table 1 shown in Fig. 10. The lubricating film 5 is used in any of the following cases. Also covers the pocket surface of the cage of the rolling bearing 50. (1) in Table 1 is for Comparative Example 2 described above, and (4) is for Not correspond to .

The “results” were (1), (5), (4), (2), (6), and (3) in descending order of dust generation life. (4) and (5) can be said to be practically preferable because of the assumption that they will not be released, because both the rolling elements, inner and outer rings, and the cage pocket surface showed wear after the experiment. However, at the point of dusting life, the lubricating film 5 almost disappears, and the lubrication state becomes non-lubricated, so that the sliding surface and the rolling surface of the bearing components are significantly worn, and this causes At the firing temperatures (2) and (3), the surface side of the lubricating film 5 is hardened and not too brittle at the baking temperatures (2) and (3), so that the lubrication film 5 does not become too brittle. It is probable that the loss was less likely to occur and the lubricity was reduced. On the other hand, in (4) and (5), oxidation of the surface side of It is considered that the carbonization became more advanced and the brittleness became moderately brittle, and the lubricating property was improved due to the easy separation and chipping on the surface side. Considering the lubrication performance of the film 5, it can be seen that a preferable firing temperature exists.

Based on the above experimental results, if the baking temperature of the lubricating film 5 is set in the range of 315 eC to 360, it is possible to completely eliminate the emission of hydrocarbon gases in a high temperature environment. In particular, lubricity can be extended as much as possible.

At this point, using the lubricating film 5 set at the above-mentioned preferred firing temperature, only the rolling elements of the rolling bearing 50, or the rolling elements and the inner and outer rings are made of silicon nitride (Si ₃ ,) series ceramics. For the case of mixing, the same dust generation life was examined as described above. The results are shown in Table 2 shown in Fig. 11.

Thus, (7) and (8) have a dusting life of (9) or (11) or the aforementioned ( 4) and (5) are much longer, so the inner and outer rings and rolling elements of rolling bearings are suitable! : If silicon nitride (S i ₃ ,) -based ceramics is used, it can be said that the dust generation life is significantly improved. In (7) and (8), the rolling elements, the outer ring, and the cage pocket surface were worn after the experiment.

Note that the present invention is not limited to only the above embodiment. For example, in the embodiment, the lubricant film is formed only on the surface of the cage that is in sliding contact with the ball, and then the hydrocarbon-based degassing process is performed. However, the degassing process may be performed on the entire surface of the cage. . In addition, as shown in HI 2, other than the cage 4, it may be formed on the raceway surfaces of the inner and outer rings 1 and 2, which are races, and on the surface of the ball 3 as shown in FIG. 13. In this case, it can be used as a full ball without cage. Further, the entire retainer may be formed of a resin having the above configuration. The bearing type refers to a deep groove ball bearing, but the present invention can be applied to other types of rolling bearings. A sealing plate may be attached to the end of the bearing.

Claims

The scope of the claims

1. A bearing ring made of metal or ceramic material;

A rolling element made of a metal or a ceramic material, which is rolled and arranged on the bearing ring;

A fluorocarbon synthetic resin is dispersed and mixed in a resin binder having an imido bond or an amidomid bond, which is provided so as to cover the rolling part of the orbiting wheel and / or the rolling element. And a lubricating bellow that has been degassed of hydrocarbon gas,

Rolling bearing consisting of.

2. A ring made of metal or ceramic material;

A cage made of metal or synthetic resin material for holding the rolling elements; and

A resin binder having an imido bond or an amide imide bond, which is provided so as to cover the rolling and sliding contact portions of the orbiting wheel and / or the rolling element and the Z or the cage, is provided. A lubricating film in which elementary synthetic resin is dispersed and mixed and a hydrocarbon gas is degassed;

Rolling bearing consisting of.

3. A raceway made of metal or ceramic material,

A rolling element made of metal or ceramic material, which is rolled and arranged on the bearing ring;

A resin binder having an imido-imido or amido-imido bond, which is provided so as to cover a sliding contact surface of the retainer with the rolling element. A rolling bearing comprising: a lubricating film obtained by dispersing and mixing a fluorine-based synthetic resin and degassing a hydrocarbon gas.

4. The rolling bearing according to any one of claims 1, 2 and 3, wherein the race and the rolling element or the rolling element are formed of silicon nitride-based ceramics.

5. The rolling bearing according to any one of claims 2 and 3, wherein the bearing ring and / or the rolling element is formed of stainless steel.

6. The rolling bearing according to any one of claims 1, 2 and 3, wherein the resin binder is a polyimide or a polyimide.