JP2003013973A - Heat-resistant, high speed, and high-loaded rolling bearing and grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant, high speed, and high-loaded rolling bearing, which is used for accessory units or electrically-powered components, having non abnormal flaking phenomena, sufficiently long life, and superior durability under high temperature, high speed, and high loading operating conditions. SOLUTION: Grease composition, in which diurea compound showed in the following chemical expression 5 is combined as a thickener and a passive agent such as sodium nitrite is also added at 0.1 to 5 wt.% in base oil mixed alkyl diphenyl ether oil and aromatic ether oil with 20 to 150 mm<2> /s of dynamic viscosity at 40 deg.C in a range from 50:50 to 80:20 (weight ratio) and is filled in the heat-resistant, high speed, and high-loaded rolling bearing. (where, R2 shows an aromatic hydrocarbon group having 6 to 15C, R1 and R3 show an aromatic hydrocarbon group having 6 to 12C, or an cycloalkane family hydrocarbon group having 6 to 20C, a rate of aromatic hydrocarbon of R1 and R3 occupied in a full amount are 1/2 or more in a mole ratio, and R1 and R3 may be the same or different.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant, high-speed, high-load rolling bearing for use in automobile auxiliary machinery or electrical components, and a grease composition for rolling bearings supporting the rotary shaft of automobile auxiliary machinery or electrical components. Regarding things.

[0002]

2. Description of the Related Art With the demand for smaller and lighter automobiles and improved quietness, air conditioners, electric fans, and other electrical components and auxiliary components (hereinafter simply referred to as electrical components and auxiliary machinery) are made smaller and lighter. Although the inside of the engine room is hermetically sealed, there is an increasing demand for higher output and higher efficiency in the performance of the equipment itself, and the reduction in output that accompanies the miniaturization of electrical equipment accessories should be rotated at high speed. The method of supplement is taken.

However, when the conventional rolling bearings for electric auxiliary equipment using grease are used under high-speed and high-load conditions, separation (flaking) occurs on the rolling surfaces, and these bearings reach the end of their service life early. Cases leading to were seen.

The peeling phenomenon that causes this early life is different from the usual peeling of the surface of the rolling surface and the surface layer, which is caused by metal fatigue, and a peculiar fracture phenomenon (hereinafter referred to as abnormal peeling phenomenon) that suddenly occurs from a deep portion inside. It was).

As a solution to the above-mentioned abnormal peeling phenomenon, Japanese Unexamined Patent Publication No. 1-259097 discloses a grease which uses an alkyldiphenyl ether as a base oil and a diurea compound whose end is mainly an aromatic hydrocarbon group as a thickener. Is disclosed.

[0006]

However, the above-mentioned conventional grease does not cause abnormal peeling phenomenon under high speed and high load conditions, but has inferior flow characteristics, and the grease does not sufficiently adhere to the bearing rolling surface. It is hard to be supplied. Therefore, the rolling bearing in which it is enclosed may not have sufficient durability when used under conditions of high speed and high load.

As a technique for solving the above problems, Japanese Patent No. 2
557597 discloses alkyl diphenyl ether oil and poly alpha olefin oil from 20:80 to 80:20.
Blended in the range of (weight ratio), the kinematic viscosity at 40 ° C is 51 to 7
An aromatic diurea compound or an aromatic urea-urethane compound as a thickener is added to a base oil of 3 cSt in an amount of 5 to 4
It is described that a grease composition containing 0% by weight and further containing a passivating oxidant and an organic sulfonate is enclosed in a rolling bearing.

[0008] However, the above-mentioned grease-filled rolling bearings have insufficient high temperature durability for use in the application of electrical components and auxiliary equipment, which have become smaller in size.
1000 in an atmosphere of 150 ° C, as in high-speed experimental conditions
It could not be continuously used for more than 2000 hours at a rotation speed of 0 rpm.

Further, in Japanese Patent Laid-Open No. 9-3466, a dialkyldiphenyl ether oil is used as a grease composition used for rolling bearings of automobile electric parts and auxiliaries.
A grease composition is described in which an aliphatic ester synthetic oil or a poly-α-olefin oil is mixed to form a base oil, and a diurea compound having an aromatic hydrocarbon group at the end is used as a thickener.

However, the above grease composition is
In some cases, durability was not sufficient under high speed conditions.

Therefore, a first object of the present invention is to solve the above-mentioned problems and to provide a heat-resistant, high-speed, high-load rolling bearing used for an auxiliary machine of an automobile or an electric component,
Under high-temperature, high-speed and high-load use conditions, abnormal peeling does not occur, the life is sufficiently long, and heat resistance is excellent.
High-speed, high-load rolling bearings.

A second object of the present invention is to provide a grease composition for rolling bearings which supports a rotating shaft of an auxiliary machine of an automobile or an electric component, does not cause abnormal peeling, and has a sufficiently long life and high temperature. -To provide a grease composition with excellent durability at high speed and high load.

[0013]

In order to solve the above-mentioned first problem, in the present invention, an alkyl diphenyl ether oil and an aromatic ester oil are added from 50:50 to 80: 2.
A grease composition in which 0.15% by weight of a passivating agent is added to a base oil mixed in the range of 0 (weight ratio) and a diurea compound represented by the following formula 2 as a thickener is added. It is a heat-resistant, high-speed, high-load rolling bearing that is filled with objects.

[0014]

[Chemical 2] (In the formula, R ₂ is an aromatic hydrocarbon group having 6 to 15 carbon atoms,
R ₁ and R ₃ represent an aromatic hydrocarbon group having 6 to 12 carbon atoms or an alicyclic hydrocarbon group having 6 to 20 carbon atoms, and the aromatic hydrocarbon group in the total amount of R ₁ and R ₃ The ratio is 1/2 or more in terms of molar ratio, and R ₁ and R ₃ may be the same or different. )

The lubricating grease having the above composition uses an alkyl diphenyl ether oil which is excellent in heat resistance and hardly causes abnormal peeling, and is used by mixing with an aromatic ester oil which is excellent in heat resistance and has good fluidity. As a result, the supply of lubricating oil to the friction surface is extremely excellent, and sufficient durability can be obtained even under high-speed, high-load bearing usage conditions accompanying the downsizing of electrical accessories.

Further, by adding a passivating agent to an aromatic ester oil having excellent heat resistance and good fluidity, a passivation film is formed under the use conditions of high temperature, high speed and high load. It is possible to prevent abnormal peeling (premature peeling) and to prevent oxidative deterioration of grease or lubricating oil during high temperature use, which is another function of the passivating agent. Dramatically improve the durability of group ester oils.

This "prevention of oxidative deterioration of grease or lubricating oil when used at high temperature" has a great effect when added to a lubricating oil having an aromatic ring having excellent heat resistance. Therefore, a rolling bearing containing a grease composition is Abnormal peeling does not occur under high speed and high load conditions, life is extended under high speed and high load conditions, and durability is excellent under high temperature conditions.

In the above heat-resistant, high-speed, high-load rolling bearing, the aromatic ester oil has a kinematic viscosity of 20 to 40 ° C.
An aromatic ester oil of 150 mm ² / s is a more preferable condition for producing a heat-resistant, high-speed, high-load rolling bearing excellent in durability without abnormal peeling phenomenon.

Further, in order to solve the above-mentioned second problem, a grease composition for rolling bearings of automobile auxiliary machines or electric components is formed from the above grease composition.

Since the above-mentioned grease composition is blended with the predetermined base oil and the predetermined thickener as described above, it is used as an auxiliary machine for automobiles such as an alternator, an electromagnetic clutch, a tension pulley or a one-way clutch. Lubricating oil with good heat resistance is sufficiently supplied to the friction surface even under conditions of high temperature, high speed and high load when using electrical components, and the life is sufficiently long. Further, since the grease having such characteristics is blended with a predetermined amount of the passivating agent, the abnormal peeling phenomenon does not occur under the above-mentioned use conditions, and the grease composition has excellent durability.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The alkyl diphenyl ether oil used in the present invention is obtained by an addition reaction of 1 mol of diphenyl ether and 1 to 3 mol of an α-olefin having 10 to 22 carbon atoms.

The aromatic ester oil used in the present invention is an alkyl ester of trimellitic acid or pyromellitic acid. The alkyl group is an alkyl group having 4 to 18 carbon atoms, specifically, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group. , Hexadecyl group, heptadecyl group, octadecyl group and the like. These alkyl groups may be linear or branched. In the alkyl ester, all the alkyl groups may be the same or different.

The above aromatic ester oil is superior in heat resistance to ester oils such as poly-α-olefin oil, polyol ester oil, and diester oil, has less evaporation and oxidative deterioration at high temperatures, and is used at high temperatures. It can be used for a long time in.

The mixing ratio of the alkyl diphenyl ether oil and the aromatic ester oil used as the base oil of the present invention is 5
It is from 0:50 to 80:20. This is because if the amount of the aromatic ester oil in the base oil is less than 20%, the flow characteristics will be poor and the supply to the rolling surface of the bearing will be poor, so that sufficient durability will not be obtained under high speed and high load conditions. . If the amount of the aromatic ester oil in the base oil exceeds 50%, abnormal peeling is likely to occur under high speed and high load conditions.

Next, the thickener used in the present invention is
As described above, the diurea compound represented by the following chemical formula 3 is used.

[0026]

[Chemical 3] (In the formula, R ₂ is an aromatic hydrocarbon group having 6 to 15 carbon atoms,
R ₁ and R ₃ represent an aromatic hydrocarbon group having 6 to 12 carbon atoms or an alicyclic hydrocarbon group having 6 to 20 carbon atoms, and the aromatic hydrocarbon group in the total amount of R ₁ and R ₃ The ratio is 1/2 or more in terms of molar ratio, and R ₁ and R ₃ may be the same or different. )

Examples of the alicyclic hydrocarbon group having 6 to 20 carbon atoms include cyclohexyl group and cyclohexyl derivative.

Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms include phenyl group, toluyl group, xylyl group and t-
Examples thereof include a butylphenyl group and a benzyl group. A monovalent aromatic hydrocarbon group is particularly suitable.

A specific example of R ₂ shown in the chemical formula 3 is a compound shown in the chemical formula 4 below, which is an aromatic hydrocarbon having a chemical structure having excellent thermal stability and oxidation stability. The group is not particularly limited as long as it is a group.

[0030]

[Chemical 4]

The proportion of aromatic hydrocarbon groups in the total amount of R ₁ and R _{3 in} such a diurea compound is 50 to 10
It is 0 mol%. If the proportion of aromatic hydrocarbon groups in the total amount of R ₁ and R ₃ is less than 50% by weight, sufficient abnormal peeling resistance cannot be obtained.

The amount of the thickener for the diurea compound in the present invention is preferably 5 to 30% by weight. Because
If the amount of the diurea compound is less than 5% by weight, abnormal peeling resistance may not be sufficiently obtained, and grease leakage from the bearing may increase. On the other hand, if the amount is more than 30% by weight, the durability of the bearing at high temperature and high speed will be significantly deteriorated, and abnormal rotation noise may occur at low temperature.

Next, the passivating agent used in the present invention is an oxidizing agent that causes passivation to the metal surface such as steel constituting the rolling bearing for electrical equipment accessories, such as nitrite, nitrate, Chromate, phosphate, molybdate,
Use a cathodic depolarization type inorganic corrosion inhibitor such as tungstate. Of these, sodium nitrite is preferable.

These passivating agents cause passivation to the metal surface and improve the peeling resistance and rust preventive ability.
In addition, these passivating agents are advantageous in that they have an effect of preventing the oxidative deterioration of grease during use at high temperatures, and have been newly found to dramatically improve the durability of grease under high temperature conditions. .

This effect is particularly effective when added to a lubricating oil having an aromatic ring having excellent heat resistance. Addition to an aromatic ester oil or alkyl diphenyl ether oil makes the grease durable under high temperature and high speed conditions. It dramatically improves the sex.

The amount of these passivating agents added is suitably 0.1 to 5% by weight. If the addition amount is 0.1 wt% or less, the effect is small, and if it is 5 wt% or more, the acoustic characteristics of the bearing may be adversely affected.

In order to further enhance the excellent performance of the grease composition of the present invention, known additives can be used, if necessary. Examples of the additive include other thickeners such as metallic soap, benton, and silica gel, and amine-based, phenol-based, sulfur-based, zinc dithiophosphate, and other antioxidants, and zinc dithiophosphate, Extreme pressure agents such as organic molybdenum, fatty acids, oily agents such as vegetable oils, metal sulfonates, dinonylnaphthalene sulfonates, rust inhibitors such as sorbitan esters, metal deactivators such as benzotriazole, Viscosity index improvers such as polymethacrylate, polyisobutylene, polystyrene and the like can be added alone or in combination of two or more kinds.

[0038]

[Examples and Comparative Examples] [Examples 1 to 5] A base oil composed of a mixed oil of an alkyl diphenyl ether oil and an aromatic ester oil was prepared at a compounding ratio shown in Table 1, and 1 mol of 4, 4 4'-diphenylmethane diisocyanate (MDI) was dissolved, 2 mol of monoamine was dissolved in the remaining half amount of the base oil, and the mixture was added to the half amount of the base oil while stirring, and then the stirring was continued at 100 to 120 ° C for 30 minutes. After the reaction, the diurea compound was deposited on the base oil. To this, 2.0% by weight of the antioxidant shown in Table 1 was added, and further 100-
The mixture was stirred at 120 ° C for 10 minutes. After cooling, the passivating oxidizer was added and mixed in the proportions shown in Table 1, and homogenized with a three-roll mill to obtain a grease composition.

While measuring the consistency of this grease composition, the grease composition was sealed in a rolling bearing and subjected to a high-temperature high-speed durability test, a rapid acceleration / deceleration test, and a high-speed high-load durability test by the test methods described below. Is also shown in Table 1. Workability: Measured according to JIS K2220 5.3. High temperature and high speed durability test: Rolling bearing (6204) was filled with 0.7 g of each test grease, and the bearing outer ring outer diameter temperature was 150.
C., a radial load of 67 N, and an axial load of 67 N were rotated at a rotation speed of 10,000 rpm, and the time until seizure was measured. Rapid acceleration / deceleration test: A rapid acceleration / deceleration test was performed on a rolling bearing in which an inner ring supports a rotating shaft that supports a pulley around which a rotating belt of an alternator, which is an example of an electrical accessory, is wound. As the rapid acceleration / deceleration test conditions, the operating conditions were set under the conditions that the load applied to the pulley was 3234 N and the rotation speed was 0 to 18000 rpm. The durable time (life time) was evaluated as the time until abnormal separation occurred in the bearing, the vibration of the vibration detector exceeded the set value, and the generator stopped. High-speed and high-load durability test: Rolling bearing (6204) was filled with 1.8 g of each test grease, and radial load was 3234.
The outer ring was rotated at a rotation speed of 10,000 rpm under N, and the time until seizure was measured.

[0040]

[Table 1]

Comparative Examples 1 to 6 The base oils shown in Table 1 were prepared, 1 mol of 4,4'-diphenylmethane diisocyanate was dissolved in half of the base oil, and 2 mol of monoamine was dissolved in the remaining half of the base oil. Then, the mixture was added to the above-mentioned half amount of the base oil while stirring, and then the mixture was continuously stirred at 100 to 120 ° C. for 30 minutes to react to dilute the diurea compound into the base oil. The antioxidant shown in Table 1 is added to this, and the amount of 100 to 12 is further added.
It was stirred at 0 ° C. for 10 minutes. Then, the mixture was cooled, the passivating oxidant shown in Table 1 was added, and the mixture was homogenized with a triple neck to obtain a grease composition.

While measuring the consistency of this grease composition, the grease composition was sealed in a rolling bearing and subjected to a high-temperature high-speed durability test, a rapid acceleration / deceleration test, and a high-temperature high-load durability test as follows.
The results are also shown in Table 1.

As is clear from the test results shown in Table 1, Comparative Example 1 in which the passivating agent was not added was any of the high temperature high speed durability test, the rapid acceleration / deceleration test, and the high speed high load capacity durability test. But it was inferior.

Further, in Comparative Example 2 in which the aromatic ester was used alone, early abnormal peeling occurred in the rapid acceleration / deceleration test. Comparative Example 3 using the alkyl diphenyl ether oil alone,
It seized early in a high-speed, high-load durability test. Comparative Example 4 using a diurea compound having no aromatic hydrocarbon group (alicyclic diurea compound) because it was not compounded within a predetermined range as a thickener, abnormal peeling occurred early in a rapid acceleration / deceleration test. It was Comparative Example 5, which used alkyl diphenyl ether oil and pentaerythritol ester as the base oil, was inferior in all of the high temperature high speed durability test, the rapid acceleration / deceleration test, and the high speed high load durability test. Further, Comparative Example 6 using an alkyl diphenyl ether oil as a base oil and a poly α-olefin was inferior in the high temperature high speed durability test.

On the other hand, an alkyl diphenyl ether oil as a base oil and an aromatic ester oil are blended within the above predetermined range, and an aromatic diurea compound and an alicyclic diurea compound as a thickener are within the above predetermined range. Examples 1 to 5 in which the grease containing the passivating agent was used in addition to the above compound were excellent results in any of the high temperature high speed durability test, the rapid acceleration / deceleration test, and the high speed high load durability test.

[0046]

EFFECTS OF THE INVENTION The heat-resistant, high-speed, high-load rolling bearing of the present invention comprises a diurea thickener and a passivating agent mixed with a base oil in which an alkyl diphenyl ether oil and an aromatic ester oil are mixed in a predetermined ratio. By using a rolling bearing that contains a grease composition with added grease, the supply of lubricating oil to the friction surface and the prevention of oxidative deterioration of grease are extremely excellent.・ In high-speed and high-load rolling bearings, abnormal peeling phenomenon does not occur, and the life is sufficiently long.
It has the advantage of being a heat-resistant, high-speed, high-load rolling bearing with excellent durability.

Further, in the above heat-resistant, high-speed, high-load rolling bearing, if an aromatic ester oil having a predetermined kinematic viscosity is adopted, abnormal peeling phenomenon is unlikely to occur and the durability is excellent in heat-resistant, high-speed, high load. It becomes a rolling bearing.

Further, since the rolling bearing grease composition of the present invention contains the predetermined base oil and the predetermined thickener as described above, it can be used in an automobile such as an alternator, an electromagnetic clutch, a tension pulley or a one-way clutch. The lubricating composition having sufficient heat resistance is sufficiently supplied to the friction surface even under the conditions of high temperature, high speed and high load when using the auxiliary machinery or the electric component, and the grease composition has a sufficiently long life. Further, since a predetermined amount of the passivating agent is added to the grease having the above characteristics, the grease composition has excellent durability without causing abnormal peeling phenomenon even under use conditions of high temperature, high speed and high load.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10M 125/20 C10M 125/20 125/24 125/24 169/00 169/00 // C10N 10:02 C10N 10:02 10:12 10:12 30:00 30:00 Z 30:06 30:06 30:08 30:08 40:02 40:02 50:10 50:10 (72) Inventor Mitsunari Aso Mie Prefecture Kuwana-shi large-scale Touhou character Oyumi 3066 F term in NTT Corporation (reference) 3J101 AA01 CA32 EA63 FA06 FA32 GA16 GA24 4H104 AA11C AA17C AA20C BB08A BB23A BE13B FA01 FA06 LA03 LA04 LA20 PA01 QA18

Claims (4)

[Claims] 1. A base oil prepared by mixing an alkyl diphenyl ether oil and an aromatic ester oil in a range of 50:50 to 80:20 (weight ratio), and a diurea compound represented by the following chemical formula 1 as a thickener. A heat-resistant, high-speed, high-load rolling bearing that contains a grease composition containing 0.1 to 5% by weight of a passivating agent while being blended. [Chemical 1] (In the formula, R ₂ is an aromatic hydrocarbon group having 6 to 15 carbon atoms,
R ₁ and R ₃ represent an aromatic hydrocarbon group having 6 to 12 carbon atoms or an alicyclic hydrocarbon group having 6 to 20 carbon atoms, and the aromatic hydrocarbon group in the total amount of R ₁ and R ₃ The ratio is 1/2 or more in terms of molar ratio, and R ₁ and R ₃ may be the same or different. ) 2. An aromatic ester oil having a kinematic viscosity at 40 ° C.
Is 20-150 mm ²/ S is an aromatic ester oil
A heat-resistant, high-speed, high-load rolling bearing according to claim 1. 3. A grease composition for a rolling bearing of an auxiliary machine or an electric component of an automobile, which comprises the grease composition according to claim 1 or 2. 4. An auxiliary machine or an electrical component is an alternator,
The rolling bearing grease composition according to claim 3, wherein the grease composition is an electromagnetic clutch, a tension pulley, or a one-way clutch.