JP2003262228A - Rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling device having a superior lubricating property and a long life under high temperature. <P>SOLUTION: Grease compound G, which contains synthetic oil and perfluoropolyether oil as base oil and contains N-substitution terephthalic amide acid metallic salt and fluoroplastic as thickener, is filled up inside an open space of a ball bearing 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling device having excellent lubricity and having a long life even at high temperatures, and more particularly to automobile electrical components such as an alternator and an electromagnetic clutch, and an automobile engine auxiliary such as an idler pulley. The present invention relates to a rolling device that can be suitably used for a rotating portion or a sliding portion of equipment used under high temperature and high speed conditions such as office machines such as copying machines, copying machines, and printers.

[0002]

2. Description of the Related Art Since automobiles (passenger cars) are required to be smaller and lighter and to have a larger living space, it is inevitable to reduce the engine room space. Therefore, electric components and engine accessories are more compact and lighter. It is being advanced further. In addition to this, since the quietness is desired to be improved and the engine room is being hermetically sealed, the temperature rise in the engine room is promoted. Therefore, each of the above parts is also required to have a property of withstanding high temperatures. For example, a bearing for an electric fan motor has been conventionally used at a bearing temperature of 130 to 150 ° C, but in recent years, it has been required to endure a high temperature of 180 to 200 ° C.

For bearings used in a high temperature environment of 150 ° C. or higher, conventionally, for example, as shown in Japanese Patent No. 2977624, a synthetic oil type lubricating oil is mixed with a lithium type soap and a urea compound. This has been dealt with by filling the grease inside the bearing. However, even with such a grease, seizure occurs early at a high temperature of 160 ° C. or higher, so that a grease having higher heat resistance is required.

On the other hand, in OA equipment, especially in copying machines, colored fine powder (toner) consisting of a thermoplastic resin and a colorant is heated and melted and fixed on the paper surface by pressure,
A heater is inserted in the shaft center of the roller, and the temperature of the rolling bearing of the bearing part is 140 ℃ to 200 ℃ depending on the model.
It may reach back and forth. Therefore, it is necessary to use grease having excellent heat resistance for such rolling bearings.

[0005]

For example, a fluorine-based grease containing polytetrafluoroethylene (PTFE) as a thickener and perfluoropolyether oil (PFPE oil) as a base oil has excellent heat resistance. The rolling bearing filled with the system grease can be used even in a high temperature environment of 160 ° C. or higher.

However, it is difficult to add an additive compounded to a general grease to the above-mentioned fluorine-based grease, and there is a tendency that it is inferior in lubricity, rust prevention, and performance of preventing metal corrosion. Furthermore, fluorinated grease
There is also a problem that it is about 5 to 20 times more expensive than synthetic oil type grease. In addition, JP-A-11-1814
Japanese Patent Laid-Open No. 65 discloses a grease composition in which fluorine oil is mixed with urea grease to improve heat resistance. However, since mineral oil or synthetic oil, which is the base oil of urea-based grease, has a poor affinity with fluorine oil, the grease composition has a large oil separation and is not suitable for bearings for parts that rotate at high speed. There was a problem.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems of the prior art and to provide a rolling device having excellent lubricity and long life even at high temperatures.

[0008]

In order to solve the above-mentioned problems, the present invention has the following constitution. That is, the rolling device of the present invention has an inner member having a raceway surface on the outer surface and an outer member having a raceway surface facing the raceway surface of the inner member and arranged outside the inner member. And a plurality of rolling elements rotatably disposed between the two raceway surfaces, and a space formed between the inner member and the outer member in which the rolling elements are disposed. And a grease composition, wherein the grease composition contains at least one of mineral oil and synthetic oil and perfluoropolyether oil as a base oil, and contains an N-substituted terephthalamic acid metal salt and fluorine. It is characterized in that it contains a resin as a thickener.

Since the perfluoropolyether oil is contained as the base oil and the fluororesin is contained as the thickener, the grease composition has excellent heat resistance. Therefore, the rolling device of the present invention has a long life even at high temperatures. In addition, since the viscosity of the base oil of the grease composition can be suppressed low, the low temperature fluidity is also excellent. Further, since it contains at least one of mineral oil and synthetic oil as the base oil, various additives can be added. Therefore, the grease composition has lubricity, rust prevention,
It also has excellent performance to prevent metal corrosion.

Further, since the base oil contains at least one of mineral oil and synthetic oil and the thickener contains N-substituted terephthalamic acid metal salt, the grease composition is compared with the fluorine-based grease. It is inexpensive.
In the grease composition, 20 to 60% by mass of N-substituted terephthalamic acid metal salt and 80 to 40% of fluororesin are used.
It is preferable to form a thickener together with mass%. Moreover, in the grease composition, it is preferable that the base oil is composed of 10 to 90% by mass of at least one of mineral oil and synthetic oil and 90 to 10% by mass of perfluoropolyether oil.

The N-substituted terephthalamic acid metal salt is 20
If it is less than mass%, the fluororesin will exceed 80 mass%, and the grease composition will be expensive. On the other hand, when the N-substituted terephthalamic acid metal salt is more than 60% by mass and the fluororesin is less than 40% by mass, the heat resistance of the grease composition becomes insufficient. In order to make such a problem less likely to occur, N-substituted terephthalamic acid metal salt 30 to
It is preferable that the thickener is composed of 50% by mass and 70 to 50% by mass of the fluororesin.

Further, if at least one of the mineral oil and the synthetic oil is less than 10% by mass, the effect of addition cannot be sufficiently obtained when the additive is added to the grease composition. When the content of at least one of the mineral oil and the synthetic oil is less than 10% by mass, the perfluoropolyether oil exceeds 90% by mass, so that the grease composition becomes expensive. On the other hand, if at least one of the mineral oil and the synthetic oil exceeds 90% by mass and the perfluoropolyether oil is less than 10% by mass, the heat resistance of the grease composition becomes insufficient.

Further, in the grease composition,
The content of the thickener is preferably 5 to 40% by mass based on the whole grease composition. If it is less than 5% by mass, it will be difficult to maintain the grease state, and if it exceeds 40% by mass, the grease composition will be excessively hardened and it will be difficult to exhibit sufficient lubricity.

Further, in the grease composition,
The kinematic viscosity of at least one of mineral oil and synthetic oil at 40 ° C. is ²⁰ to 400 mm ² / s, and the kinematic viscosity of perfluoropolyether oil at 40 ° C. is ²⁰ to 400 mm ²
/ S is preferable. If the kinematic viscosity of both of them exceeds 400 mm ² / s at 40 ° C., the oil film becomes relatively thick and the electric resistance value becomes large. Further, the fluidity at low temperature becomes insufficient, and there is a possibility that abnormal noise may occur when the rolling device is started at low temperature.

However, if the kinematic viscosity is less than 20 mm ² / s, it is not suitable because of problems of evaporation loss and lubricity. That is, if the viscosity of the base oil is too low, it becomes difficult to form a lubricating oil film sufficient to avoid metal contact between the raceway surface and the rolling elements at high temperatures, for example, during rotation of the bearing. In order to make such a problem less likely to occur, the kinematic viscosity of both at 40 ° C. is more preferably 30 to 200 mm ² / s.

The components constituting the grease composition will be described in detail below. [Thickener] As the thickener of this grease composition, it is necessary to use both an N-substituted terephthalamic acid metal salt and a fluororesin. It should be noted that other types of thickeners may be used in combination as long as the amounts do not impair the object of the present invention.

The N-substituted terephthalamic acid metal salt used as a thickener in the present invention is represented by the following general formula (I).

[0018]

[Chemical 1]

The substituent R ₁ bonded to the nitrogen atom in the formula (I) is a linear, branched or cyclic saturated or unsaturated monovalent hydrocarbon group, and M is It is a metal and n is a number equal to the valence of the metal. When the substituent R ₁ is a linear or branched hydrocarbon group, the hydrocarbon group has 10 to 32 carbon atoms, preferably 12 to 22 carbon atoms, and when the substituent R ₁ is a cyclic hydrocarbon group. , The carbon number of the hydrocarbon group is 6 to
28, preferably 7 to 22. When the number of carbon atoms of the hydrocarbon group is smaller than the lower limit value, the thickener is difficult to disperse in the base oil, and the thickener and the base oil are easily separated. On the other hand, a thickener in which the carbon number of the hydrocarbon group is larger than the above upper limit is industrially impractical.

Examples of the substituent R ₁ include decyl group, tetradecyl group, hexadecyl group, octadecyl group, cyclohexyl group, benzyl group, phenyl group, tolyl group and butylphenyl group. Further, as the metal M,
Metals of groups 1, 2, 12 and 13 such as lithium,
Examples include potassium, sodium, magnesium, calcium, barium, zinc and aluminum. Particularly, sodium, barium, lithium and potassium are preferable,
Sodium is the most realistic.

Such N-substituted terephthalamic acid metal salt may be separately synthesized and dispersed in the base oil, or may be synthesized in the base oil and dispersed in the base oil. However, the latter method is more advantageous for industrial production because the thickener can be easily dispersed in the base oil. On the other hand, the type of fluororesin, which is another thickener, is not particularly limited, but polytetrafluoroethylene (PTFE) or tetrafluoroethylene and other ethylene-based non-fluorinated ethylene compounds which are wholly or partially fluorinated. A copolymer with a saturated hydrocarbon monomer (hereinafter referred to as a tetrafluoroethylene copolymer) and the like are preferable.

Examples of the tetrafluoroethylene copolymer include those shown in the following (1) to (3). One or more comonomers of perfluoroalkylethylenes such as vinylidene fluoride, hexafluoroisobutene, chlorotrifluoroethylene and perfluoropropene are added to PTFE in an amount of 0.01 to 3 mol%, preferably 0.05 to 0. Modified polytetrafluoroethylene copolymerized with 0.5 mol%.

Tetrafluoroethylene (TFE) thermoplastic copolymerized with 0.5 to 8 mol% of at least one perfluoroalkyl vinyl ether (where the perfluoroalkyl group has 1 to 6 carbons). Copolymer.
Examples include perfluoropropyl vinyl ether and T
Examples thereof include a copolymer with FE, a copolymer with perfluoromethyl vinyl ether and TFE, and a copolymer with perfluoroethyl vinyl ether and TFE.

A TFE thermoplastic copolymer prepared by copolymerizing 2 to 20 mol% of a perfluoroolefin having 3 to 8 carbons. Examples include hexafluoropropene and TF
Examples thereof include copolymers with E. The copolymer may be copolymerized with another comonomer having a perfluorovinyl ether structure as long as it is less than 5 mol%.

Perfluoromethyl vinyl ether (0.5 to 13 mol%) and the following formulas (II) to (IV)
One or more of the fluorine compound monomers (0.05 to 5
Mol%) and a TFE thermoplastic copolymer.

[0026]

[Chemical 2]

[0027]

[Chemical 3]

[0028]

[Chemical 4]

However, R ₃ in the formula (IV) is a perfluoroalkyl group having 1 to 5 carbon atoms, and CF ₃ is preferable. X ₁ and X ₂ are each independently a perfluoroalkyl group having 1 to 3 carbons or F, and CF
₃ is preferred. In addition, R _F in the formulas (II) and (III)
Is at least one of the following (i) to (iii).

(I) Perfluoroalkyl group having 2 to 12 carbons (ii) A chemical structure represented by the following formula (V). However, r in the formula (V) is an integer of 1 to 4, and r ′ is 0.
Is an integer of ˜3.

[0031]

[Chemical 5]

(Iii) A compound having a chemical structure represented by the following formula (VI). However, the structural unit (OCF in formula (VI)
X) and (OCF ₂ CFY) are statistically distributed along the chain. Further, T is a perfluoroalkyl group having 1 to 3 carbons, and optionally has 1 H or Cl.
Further, X and Y are F or CF ₃ . Further, Z is -CFX- or -CF ₂ CFY-, q and q 'are the same or different numbers to each other an integer of 0.

[0033]

[Chemical 6]

Further, the number average molecular weight of the fluorine compound monomer of formula (II) and formula (III) is 200 to 2000. It should be noted that although a suitable numerical value range for the numerical value in the molecular formula, the copolymerization ratio, and the average molecular weight is defined for, if these numerical values are less than the lower limit of the above range, a grease-like composition is obtained. Sufficient thickening property is not imparted to the tetrafluoroethylene copolymer. On the other hand, when the content exceeds the upper limit of the above range, the grease composition is hardened and it becomes difficult to exhibit sufficient lubricity.

[Base oil] As the base oil of this grease composition, it is necessary to use at least one of mineral oil and synthetic oil and perfluoropolyether oil. However, other types of base oils may be used in combination as long as they do not impair the object of the present invention. The type of mineral oil used in the grease composition is not particularly limited, but paraffin-based mineral oil, naphthene-based mineral oil, and mixed oils thereof are preferably used. Further, the type of synthetic oil is not particularly limited, and synthetic hydrocarbon oil, ether oil, ester oil, fluorine oil and the like are preferably used.

More specifically, examples of the base oil will be shown. Poly α-olefin oil or the like is used as the synthetic hydrocarbon oil, dialkyl diphenyl ether oil, alkyl triphenyl ether oil, alkyl tetraphenyl ether oil or the like is used as the ether oil, and diester oil, neopentyl type polyol ester oil or the like is used as the ester oil. These complex ester oils, aromatic ester oils, carbonate ester oils, etc. can be used as the fluorine oils, and perfluoroether oils, fluorosilicone oils, chlorotrifluoroethylene oils, fluorophosphazene oils, etc. can be used. . In addition, these can be used individually or in mixture of 2 or more types.

Of these, considering the lubricating performance and life under high temperature and high speed conditions, it is preferable that the base oil contains at least a synthetic oil, and particularly ester oil, ether oil and fluorine oil are preferable. On the other hand, the type of perfluoropolyether oil used in the grease composition is not particularly limited, and one composed of at least one selected from the following fluorooxyalkylene structural units is preferable. . Note that X _{3 in} the formula
It is CF ₃ (CF _{2) n} - and is, n is an integer from 0-4.

[0038]

[Chemical 7]

When the perfluoropolyether oil is composed of two or more of the above fluorooxyalkylene structural units, each structural unit is statistically distributed along the chain. The terminal groups are CF ₃ −, C ₂ F ₅ −,
_{C 3 F 7 -, CF 2} Cl (CF 3) CF-, CF 3 CF
_{ClCF 2 -, CF 2 ClCF 2} -, CF 2 Cl-, C
HF ₂ -, CF ₃ CHF- such as, one H and /
Alternatively, it is a fluoroalkyl group optionally containing Cl.

[Regarding Additives] If desired, various additives may be added to the grease composition in order to further improve various performances. Examples of the additives used include antioxidants, rust preventives, extreme pressure agents, oiliness agents, and metal deactivators. These may be used alone or in combination of two or more. it can.

As the antioxidant, known antioxidants commonly used in conventional greases can be used without any problem.
For example, phenol-based antioxidants such as 2,6-di-t-butylphenol, amine-based antioxidants such as phenyl-1-naphthylamine, sulfur-based antioxidants, zinc dithiophosphate, etc. Examples of the rust preventive agent include organic sulfonates of alkali metals and alkaline earth metals, succinic acid derivatives such as alkyl succinic acid esters and alkenyl succinic acid esters, and partial esters of polyhydric alcohols such as sorbitan monooleate. can give.

Further, as the extreme pressure agent, a phosphorus-based extreme pressure agent,
Examples include zinc dithiophosphate and organic molybdenum. Further, examples of the oiliness agent include oiliness improvers such as fatty acids and animal and vegetable oils. Furthermore, examples of the metal deactivator include benzotriazole and the like. The content of such an additive is preferably 20% by mass or less based on the entire grease composition. Even if added in an amount of more than 20% by mass, improvement of the effect of addition cannot be expected, and since the amount of the base oil becomes relatively small, the lubricity may decrease, which is not preferable.

The method for producing the grease composition is not particularly limited. For example, at least one of mineral oil and synthetic oil is used as a base oil, N-substituted terephthalamic acid metal salt grease having an N-substituted terephthalamic acid metal salt as a thickener, and perfluoropolyether oil as a base oil are used. It may be produced by separately producing a fluorine grease using a resin as a thickening agent and mixing them. Alternatively, a base oil obtained by mixing at least one of a mineral oil and a synthetic oil with a perfluoropolyether oil is added with N-
It may be produced by adding a substituted metal salt of terephthalamic acid and a fluororesin as a thickener.

A rolling device provided with such a grease composition has excellent lubricity and has a long life even at high temperatures. Therefore, automotive electrical components such as an alternator and an electromagnetic clutch, an automobile engine such as an idler pulley, etc. Auxiliary machine, copy machine,
It can be suitably used for rotating parts and sliding parts of equipment used under high temperature and high speed conditions such as office equipment such as printers.

The present invention can be applied to various rolling devices, and examples thereof include rolling bearings, ball screws, linear guide devices, linear motion bearings and the like. The inner member in the present invention refers to an inner ring when the rolling device is a rolling bearing, a screw shaft when the ball screw is the same, a guide rail when the linear guide device is the same, and a linear motion bearing when the linear guide device is the same. Means each axis. Further, the outer member means an outer ring when the rolling device is a rolling bearing, a nut when the ball screw is the same, a slider when the linear guide device is the same, and an outer cylinder when the rolling device is the linear motion bearing. Mean respectively.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rolling device according to the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional view showing a structure of a ball bearing 1 which is an embodiment of a rolling device according to the present invention. The ball bearing 1 includes an inner ring 10 and an outer ring 11
And a plurality of balls 13 rotatably arranged between the inner ring 10 and the outer ring 11, and a cage 12 for holding the plurality of balls 13.
And contact-type seals 14 and 1 attached to the outer ring 11.
4 and. In addition, the grease composition G is filled in the bearing space surrounded by the inner ring 10, the outer ring 11 and the seals 14 and 14 and is sealed in the ball bearing 1 by the seal 14. The grease composition G lubricates the contact surfaces between the raceways of both wheels 10 and 11 and the balls 13.

This grease composition G is composed of 20% by mass of a thickening agent and 80% by mass of a base oil. The thickener is composed of 50 mass% N-substituted terephthalamic acid metal salt and 50 mass% PTFE, and the base oil is 50 mass% polyol ester oil and 50 mass% perfluoropolyether. It is composed of ether oil (PFPE oil). This grease composition G consists of PTFE and P
Since it contains FPE oil, it has excellent heat resistance.

The present embodiment shows an example of the present invention, and the present invention is not limited to this embodiment. For example, the types of base oil and thickener are not limited to those described above, and the grease composition G
Various additives may be added to. Further, in the present embodiment, the 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, angular ball bearings,
They are radial type rolling bearings such as self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings and self-aligning roller bearings, and thrust type rolling bearings such as thrust ball bearings and thrust roller bearings.

The present invention can be applied not only to rolling bearings but also to various types of other rolling devices. For example, a ball screw, a linear guide device, a linear motion bearing, or the like. Next, 18 types of compositions (Examples 1 to 12 and Comparative Examples 1 to 1) having substantially the same structure as the grease composition G described above were used.
The grease composition of 6) was subjected to consistency measurement, rust resistance test, copper plate corrosion test, seizure test, and grease leak test.

The compositions of the grease compositions of Examples 1 to 12 and Comparative Examples 1 to 6 are as shown in Tables 1 to 3, and N-octadecyl terephthalamic acid metal salt (sodium salt or barium salt) and fluororesin ( (PTFE or copolymer) and a base oil composed of synthetic oil and PFPE oil (excluding Comparative Examples 1 and 2).
Then, as additives, 1.0% by weight of the grease composition as a whole, an amine-based antioxidant, 0.5% by weight of a calcium sulfonate-based rust inhibitor, and 0.05% by weight of a benzotriazole-based metal. And an inactivating agent.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

The contents of the base oil and the thickener shown in Tables 1 to 3 are 100% based on the total amount of the base oil and the thickener.
And the above additives are not taken into consideration. Further, the numerical values described in the columns of the type of thickener and the type of base oil indicate the amount ratio (% by mass) of each component in the whole thickener and the whole base oil. less than,
Each component of the grease composition will be described.

Copolymer: Copolymer of vinylidene fluoride and hexafluoroisobutylene (molar ratio is 1: 1) Polyol ester oil: Kinematic viscosity 70 m at 40 ° C.
m ² / s Alkyl diphenyl ether oil: Kinematic viscosity at 40 ° C. 100 mm ² / s PFPE oil: Kinematic viscosity at 40 ° C. 190 mm ² / s Next, each test method and test results will be described.

[Measurement Consistency] JIS K22
According to No. 20, the measurement of the mixing consistency was performed. The results are also shown in Tables 1 to 3. The grease compositions of Examples 1 to 12 had a good consistency, whereas Comparative Example 6 had a small consistency because the content of the thickener was too large.
Further, in Comparative Example 3, the thickener content was too small, so that it did not become a grease.

[Regarding Anticorrosion Test] A deep groove ball bearing with a rubber seal having an inner diameter of 17 mm, an outer diameter of 47 mm, and a width of 14 mm (having the same configuration as that in FIG. 1) was used in Examples 1 to 12 and Comparative Examples 1 to 6. The grease composition was filled so as to occupy 50% of the bearing space volume. 3 at a rotation speed of 1800 min ^-1
After running-in (rotating) for 0 seconds, 0.5 ml of 0.5 mass% salt water was injected into the bearing, and the rotation speed was 1800 again.
A break-in operation was performed for 30 seconds at min ^-1 . Next, 80 ° C
Install this ball bearing in a constant temperature and humidity tank adjusted to 100% RH.
After standing for 8 hours, the ball bearing was disassembled and the state of rust generated on the raceway surface was visually observed. Then, the following ranks were evaluated.

# 7: No rust generation # 6: Stain-like microscopic rusting # 5: Dotted rust having a diameter of 0.3 mm or less # 4: Rust having a diameter of 1.0 mm or less # 3: Diameter 5 Rust of 0.0 mm or less # 2: Rust of 10.0 mm or less in diameter # 1: Rust occurs on almost the entire raceway surface. Note that # 7 to # 5 are considered to have good rust prevention and # 4 to # 1 are protected. It was considered to be rusty.

The results are also shown in Tables 1 to 3. Example 1
The grease composition of No. 12 showed good rust prevention. Therefore, the grease compositions of Examples 1 to 12 can be suitably used for bearings used in a harsh environment where they are likely to come into contact with rainwater or the like and rust easily occurs. On the other hand, Comparative Example 1 did not contain mineral oil or synthetic oil (that is, because it was a normal fluorine grease), and therefore the rust preventive property was poor.

[Copper plate corrosion test] JIS K22
It carried out based on the copper plate corrosion test method of the grease of 20.
The test temperature was 100 ° C., and the discolored state of the copper plate after 24 hours was visually observed. And, according to the standard of discoloration of copper plate,
Evaluation was made on the basis of 4 grades of 4 and 1 was regarded as good. The results are shown in Tables 1 to 3.
Are also shown. The grease compositions of Examples 1 to 12 showed almost no discoloration of the copper plate, whereas Comparative Example 1 contained no mineral oil or synthetic oil (that is, because it was a normal fluorine grease), and the discoloration of the copper plate was observed. Was observed.

[Regarding the seizure test] Examples 1 to 12 and Comparative Examples 1 to 1 were applied to deep groove ball bearings with an iron shield having an inner diameter of 8 mm, an outer diameter of 22 mm, and a width of 7 mm (having a structure similar to that of FIG. 1). The grease composition of 6 was added to the bearing space volume of 50
Filled so as to occupy%, ASTM as shown in FIG.
It was mounted on a tester similar to the bearing life tester of D1741.

The bearing temperature is 180 ° C. and the axial load is
3000 min under heavy load of 59N ^-1Rotation speed of
(Other conditions are in accordance with ASTM D 1741
Due to seizure, the outer ring temperature rises above 190 ° C.
The time until it was taken was the life. And 1000 hours
Pass if the temperature does not rise above 190 ° C even after turning
The test was terminated as. The rotation test is for one type of bearing
4 times, and the average value was used as the test result.

The results are also shown in Tables 1 to 3. Example 1
The grease composition of No. 12 showed a good life, while Comparative Example 2 did not contain the fluororesin and the PFPE oil (that is, it was a normal N-substituted terephthalamic acid metal salt grease). The seizure resistance at high temperature was poor. Further, in Comparative Examples 4 and 5, since the contents of the fluororesin and the PFPE oil were small, the seizure resistance at high temperature was insufficient.

[Grease Leakage Test] Inner Diameter 17
mm, outer diameter 40 mm, width 12 mm with rubber seal deep groove ball bearing (having the same configuration as in FIG. 1)
The grease compositions of No. 2 and Comparative Examples 1 to 6 were filled so as to occupy 35% of the bearing space volume. And the outer ring temperature 18
The inner ring is 145 under the condition of 0 ℃ and 200N axial load.
The grease composition was rotated at a rotation speed of 00 min ⁻¹ for 20 hours, and the mass of the grease composition leaked from the bearing during rotation was measured.

The case where the amount of leakage of the grease composition was 10% by mass or less of the amount of the filled grease composition was regarded as acceptable. The test was performed four times for each bearing, and the average value was used as the test result. The test results are also shown in Tables 1 to 3. The grease compositions of Examples 1 to 12 had a small amount of leakage, and all passed.

Examples 7-12 and Comparative Examples 1, 2,
Anticorrosion test, seizure test, and grease composition of 4, 5
And a graph of the results of the grease leakage test,
This is shown in FIGS. 3 and 4. The horizontal axis of each graph shows the proportion of fluororesin (PTFE or copolymer) in the thickener. As can be seen from these graphs, when the proportion of the fluororesin in the thickener is 40 to 80 mass% (that is, the proportion of the N-substituted terephthalamic acid metal salt is 60 to 20 mass%), Both rust and seizure life were excellent, and the amount of grease leakage was small.

[0067]

As described above, the rolling device of the present invention has excellent lubricity and has a long life even at high temperatures.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a structure of a ball bearing which is an embodiment of a rolling device according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a bearing life tester for evaluating the seizure property of a grease composition.

FIG. 3 is a graph showing the correlation between the proportion of fluororesin in the thickener, the seizure life of the ball bearing, and the antirust property of the grease composition.

FIG. 4 is a graph showing the correlation between the proportion of fluororesin in the thickener, the seizure life of the ball bearing, and the amount of grease leakage.

[Explanation of symbols]

1 ball bearing 10 inner ring 11 outer ring 13 balls G grease composition

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10M 115/08 C10M 115/08 119/22 119/22 169/02 169/02 F16C 19/02 F16C 19 / 02 // C10N 10:02 C10N 10:02 10:04 10:04 20:02 20:02 40:02 40:02 50:10 50:10 F Term (Reference) 3J101 AA01 AA32 AA51 AA62 CA12 CA32 EA64 FA06 FA32 GA01 GA24 GA29 GA53 4H104 BB33A BB34A BE11B CD01B CD04A CD04B DA02A EA02A FA01 FA02 PA01 QA18

Claims (7)

[Claims] 1. An inner member having a raceway surface on the outer surface, an outer member having a raceway surface facing the raceway surface of the inner member and arranged outside of the inner member, and the both raceways. A plurality of rolling elements that are rotatably disposed between the surfaces, and a grease composition that is filled between the inner member and the outer member and that is filled in a space in which the rolling elements are disposed. In the rolling device, the grease composition contains at least one of mineral oil and synthetic oil and perfluoropolyether oil as a base oil, and contains an N-substituted terephthalamic acid metal salt and a fluororesin as a thickener. A rolling device characterized by being contained as. 2. The thickening agent is composed of 20 to 60% by mass of the N-substituted terephthalamic acid metal salt and 80 to 40% by mass of the fluororesin. Rolling device. 3. The base oil is composed of 10 to 90% by mass of at least one of the mineral oil and synthetic oil, and 90 to 10% by mass of the perfluoropolyether oil. The rolling device according to claim 2. 4. The rolling device according to claim 1, wherein the content of the thickener is 5 to 40% by mass of the entire grease composition. 5. The kinematic viscosity of at least one of the mineral oil and the synthetic oil at 40 ° C. is ²⁰ to 400 mm ² / s,
The rolling device according to claim 1, wherein the perfluoropolyether oil has a kinematic viscosity at 40 ° C. of ²⁰ to 400 mm ² / s. 6. The rolling agent according to claim 1, further comprising an additive, and the content of the additive is set to 20% by mass or less based on the total amount of the grease composition. apparatus. 7. A rolling bearing for use in automobile electrical components, automobile engine accessories, or office equipment that is used in a high-speed environment and / or a high-temperature environment. The rolling device according to claim 1.