JP2000081044A - Contact member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability in conditions as easily causing seizure and abrasion by covering the surface with a substance formed by combining an organic sulfur compound or an organic metal compound with a solid lubricant. SOLUTION: The outer diameter face of a roller of the bore 20 mm, the outer diameter 50 mm, and the width 15 mm is crowned by a curvature radius of 100 mm and the outer diameter face 1a is coated with coating of the width 12.3 μm after machining so that a specimen 1 is formed. The compositions of the coating are molybdenum disulfide as solid lubricant, 2-(4' morpholinodithio) benzothiazole as the organic sulfur compound, and polyamidimide used as binder. It is coated with a substance formed by dispersing and solving the polyamidimide and the molybdenum disulfide with N-methyl-2 pyrolidone set to solvent and burned at the temperature 200 deg.C so as to form a coating layer 1b on the outer diameter face 1a. This constitution can improve the durability even in conditions as easily causing the seizure and the abrasion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant composition applied to a contact member used for various industrial machines and vehicles, for example, a bearing, etc., which is accompanied by slip with a load, and easily causes seizure and wear. The present invention relates to a surface treatment technique that can improve durability under conditions.

[0002]

2. Description of the Related Art Oil lubrication is generally used for lubrication of bearings and the like.
The following are examples of conventional oil lubrication technologies:
Is mentioned. (B) Under conditions where seizure and wear are likely to occur,
MoS as an additive _TwoSolid lubricants such as dialkyl
Molybdenum dithiophosphate (MoDTP), dialkyldi
Molybdenum thiocarbamate (MoDTC), dialky
Effect of using zinc rudithiophosphate (ZnDTP)
It is known that there is. (B) Under operating conditions where oil cannot be supplied sufficiently, the shaft
MoS on the sliding contact part of the receiver_TwoAnd fluorine resin compounds
Coated with a solid lubricant, which allows
Prevent galling at the beginning and improve seizure resistance
Known techniques are known. (C) As shown in JP-A-6-313185,
Powdered organic molybdenum with known solid lubricant as resin binder
Lubricating compositions containing butane compounds are used to reduce friction and
It is known to improve wear characteristics.

[0003]

However, in the above (a), the supply of oil is temporarily stopped due to insufficient supply of oil to the lubricating portion, especially at the start of operation, or a condition of acceleration. Due to exposure to the situation, there is a disadvantage that seizure resistance and wear resistance cannot be sufficiently ensured.

In the above (b), the coating of the solid lubricant is effective for seizure resistance in the initial non-lubrication condition where the oil supply is insufficient, but the coating is peeled off as the operating time elapses, and However, there is an inconvenience that the durability performance of the bearing and the like is remarkably reduced.

Further, in the above (c), the sliding agent composition in which a powdered organic molybdenum compound is blended with a known solid lubricant generates MoS ₂ by the heat of sliding to form a contact portion and a surface of a mating material. Although this is a technique for reducing friction to adhere to the surface, there is a disadvantage that the durability performance of the bearings and the like is deteriorated as in (b) because the adhesion and the durability with the metal surface are lacking.

[0006] The present invention has been made in order to solve such a disadvantage, and an object of the present invention is to provide a contact member capable of improving durability under conditions in which seizure and wear are likely to occur.

[0007]

In order to achieve the above object, a contact member according to the present invention is a metal contact member having rolling and / or sliding contact, wherein the surface of the contact member is made of an organic sulfur compound or an organometallic compound. And a combination of a solid lubricant and a solid lubricant.

Examples of the contact member include an inner and outer ring, a rolling element and a cage constituting a rolling bearing, a sliding member having sliding contact, and the like, and at least one contact of a component constituting the rolling bearing or the sliding member. The surface is coated with a combination of an organic sulfur compound or an organometallic compound and a solid lubricant.

As the solid lubricant, known compounds, for example, at least one of molybdenum disulfide, fluororesin, tungsten disulfide, boron nitride, graphite and the like can be used. A compound or an organometallic compound is added.

The organic sulfur compounds include thiol compounds, thiazole compounds, sulfanamide compounds, sulfonamide compounds, mercapto compounds, mercaptobenzimidazole compounds,
Thiourea, thiourea, thiuram (thiocarbamoyl), dithiocarbamic acid, thiophthalimide, thiopropionic acid, thiadiazole, sulfide, polysulfide, thiophthalimide, thiophosphoric, dithiophosphoric, dithiophosphoric, thio Aldehyde-based, thioketone-based, thioacetal-based, thiocarboxylic acid-based, and xanthate-based organic sulfur-based compounds can be mentioned. Seizure and durability against galling and the like can be improved.

Also, organic sulfur compounds added to solid lubricants, particularly, structural formulas (1), (2),
Benzothiazoles shown in (3), (4) and (5),
Thiuram, dithiocarbamic, xanthate, and thiourea compounds are effective in improving durability, and these compounds are N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone. And those which can be dissolved or dispersed in an organic solvent such as Cellsolve acetate, toluene, xylene and acetate.

[0012]

Embedded image

The function and effect of the contact member whose surface is coated with the above-mentioned organic sulfur compound blended with a solid lubricant are as follows. When these organic sulfur compounds are present on the surface of the metal contact member, the temperature of the metal surface locally rises due to the amount of heat generated by rolling contact or sliding contact on the surface, and in the process, the organic sulfur compound is removed. It melts and decomposes and reacts with iron on the metal surface to form a sulfur compound film on the metal surface. This reaction film becomes a protective film on the metal surface,
Even under poor lubrication operating conditions, direct contact between metals is avoided to ensure seizure resistance and to prevent galling and the like. In this case, the organic sulfur compound desirably has a melting point of 250 ° C. or less, and preferably has a thermal decomposition temperature of 300 ° C. or less.

In addition, the above-mentioned organic sulfur compound is represented by a metal species M in the structural formulas (3) and (4) shown in Chemical Formula 1.
An organometallic compound containing (K, Zn) is also effective in forming a sulfur compound reaction film on the metal surface. Examples of the organometallic compound containing the metal species M include nickel, tellurium, selenium, antimony, bismuth, and copper-substituted dialkyldithiocarbamic acid compounds, dithiophosphate compounds, thiazole compounds, thiourea compounds, and thiocarbamoyl compounds (thiuram compounds). Etc. can be used.

In order to coat the surface of the contact member with a coating material in which the above-mentioned organic sulfur compound is blended with the solid lubricant, for example, the coating material is fixed to the surface of the contact member using a thermosetting resin as a binder. be able to. Examples of the binder for the thermosetting resin include an epoxy resin, a polyamideimide resin, a polyimide resin, and a furan resin. The compound of the structural formulas (1) to (5) shown in Chemical Formula 1 is 0.1 to 50 wt%.
A solution added to a binder and dispersed in an organic solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, cellosolve acetate, toluene, xylene, and acetate. be able to.

It is effective to increase the surface area of the metal surface of the contact member, which is the coated surface, by shot-pinning, barrel treatment, chemical conversion treatment or the like in advance to fix the coating agent.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an explanatory sectional view for explaining a first embodiment of the present invention, FIG. 2 is an explanatory sectional view for explaining a second embodiment of the present invention, and FIG. Four
FIG. 4 is a graph showing the relationship between the blending ratio of 'morpholinodithio) benzothiazole and the durability time, and FIG. 4 is a graph showing the relationship between the blending ratio of zinc butylxanthogenate and the durability time.

First, the first embodiment will be described. In this embodiment, as shown in FIG.
100R on the outer surface of roller with 50mm outer diameter and 15mm width
, And coating the outer diameter surface 1a with the coating with a thickness of 12.3 μm on the outer diameter surface 1a after the processing.
It was created. The composition of the coating agent is as follows: molybdenum disulfide (10% by weight) as a solid lubricant, and an organic sulfur compound.
2- (4'morpholinodithio) benzothiazole, a polyamideimide as a binder (binder). In addition,
The amount of 2- (4'morpholinodithio) benzothiazole and polyamideimide was varied by weight ratio, and various (2- (4'morpholinodithio) benzothiazole: 0.01 to 70 w
Specimen 1 was prepared.

The coating method of the coating agent on the outer diameter surface 1a is as follows. Polyamide imide, molybdenum disulfide, 2- (4'morpholinodithio) benzothiazole is used as a solvent in N-methyl-2-pyrrolidone to a weight ratio of 50 wt%. The dispersed solution is coated using a spray, and then
By baking at 00 ° C., a coating layer 1b having a thickness of 12.3 μm was formed on the outer diameter surface 1a. The average value of the thickness of the coating layer 1b was determined by measuring four points with an electromagnetic film thickness meter.

Then, for each of the specimens 1 to which 2- (4'morpholinodithio) benzothiazole was added, the flat plate 2 was pressed horizontally against the outer peripheral surface under the conditions of a rotation speed of 2000 rpm and a load of 20 kgf. Oil (VG
32) was applied to the outer peripheral surface of the test piece 1 at 0.1 cc, and the test piece 1 was rotated by a motor to perform a durability test. In the durability evaluation, the load current of the motor was measured with a meter ammeter, and the point at which the current increased to 150% after the start of the test was defined as the durability time.

FIG. 3 shows the relationship between the blending ratio of 2- (4'morpholinodithio) benzothiazole and the durability time. As is clear from the figure, the durability is improved when the blending ratio of 2- (4′morpholinodithio) benzothiazole is 1 to 60 wt%, and the durability is further improved when the blending ratio is 8 to 40 wt%. If 2- (4'morpholinodithio) benzothiazole is 1 wt% or more in weight ratio to the coating agent, it melts and decomposes on the metal surface by frictional heat and reacts with iron to form a protective film of a sulfur compound on the metal surface. As a result, direct contact between metals is avoided, and the endurance time to burn-in is extended. 2- (4
If the amount of benzothiazole is less than 1% by weight, the amount of the decomposition reaction caused by surface contact is small, while if it exceeds 60% by weight, the bonding strength is weakened and drops off from the metal surface, so the decomposition reaction on the metal surface is sufficient. Is not done.

Next, a second embodiment will be described. In this embodiment, as shown in FIG. 2, each rolling surface 3 of the upper and lower races 3, 4 of a thrust bearing (without a retainer) of a total ball including only the upper race 3, the lower race 4, and the rolling elements 5.
Specimens 7 were prepared by coating the coating materials a and 4a with a thickness of 9.0 μm.

The composition of the coating agent is molybdenum disulfide as a solid lubricant, zinc butylxanthate as an organometallic compound, and polyamideimide (40 wt%) as a binder (binder). By changing the mixing ratio with zinc acid and diluting it with an equal amount with acetylacetamide on the rolling surfaces 3a and 4a, various types (zinc butylxanthogenate: 0.0
(1 to 70 wt%).

The method of coating the rolling surfaces 3a, 4a with the coating agent is as follows: the upper and lower races 3, 4 having the rolling surfaces 3a, 4a
Warm to 0 ° C. and immerse in coating, then 100
After drying at 200 ° C for 2 hours, firing at 200 ° C
A coating layer 6 having a thickness of 9.0 μm was formed on a and 4a.

Then, for each specimen 7 having a different mixing ratio of molybdenum disulfide and zinc butylxanthogenate,
Supply 50μg of turbine oil, load 300kgf,
At 8000 rpm, seizure resistance was evaluated by a rolling test. In the evaluation of seizure resistance, a thermocouple was inserted into the specimen 7, and a point at which a rapid temperature rise (exceeding 200 ° C.) from a steady state occurred was defined as a durability time.

FIG. 4 shows the relationship between the mixing ratio of zinc butylxanthogenate and the durability time. As is apparent from the figure, the durability is improved when the content of zinc butylxanthogenate is 1 wt% or more, and the durability is further improved when the content is 8 to 40 wt%. In a rolling bearing using a thrust bearing as in this embodiment, 8000 rpm
Rolling surface 3a, 4 with spin slip, etc.
a and the rolling elements slip. For such a rolling slip, zinc butylxanthogenate is applied to the rolling surfaces 3a, 4
In the case of the element a, the time until a temperature rise of 200 ° C. is extended. This is because the decomposition temperature of zinc butylxanthogenate is 150 ° C or less, and a local temperature rise due to surface contact causes a decomposition reaction with the metal surface, forming a protective film of a sulfur compound with iron on the surface. That's because. The compounding ratio of zinc butyl xanthate necessary for forming the protective film may be 1 wt% or more, and the upper limit of the compounding ratio is not particularly limited. However, even if it is more than 60 wt%, the performance is not improved. Therefore, the mixing ratio of zinc butylxanthogenate is preferably set to 1 to 60% by weight, more preferably 8 to 40% by weight.

[0027]

As is clear from the above description, according to the present invention, it is possible to provide a contact member capable of improving durability under conditions in which seizure and wear easily occur.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view for explaining a first embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view for explaining a second embodiment of the present invention.

FIG. 3 is a graph showing the relationship between the blending ratio of 2- (4′morpholinodithio) benzothiazole and the durability time.

FIG. 4 is a graph showing the relationship between the mixing ratio of zinc butylxanthogenate and the durability time.

Claims (1)

[Claims] 1. A contact member made of metal with rolling and / or sliding contact, wherein the surface is coated with a combination of an organic sulfur compound or an organometallic compound and a solid lubricant. .