JPH11193477A - Rolling member or sliding member and rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the seizing life by chemically treating the surface with tannic acid, thereby forming a coating film excellent in lubricity on the surface. SOLUTION: The chemical treatment using tannic acid is performed by dipping a rolling member or a sliding member in an aq. soln. of tannic acid or applying the soln. on the whole or a part of the member. In this case, at least one among the plurality of rolling members or sliding members in contact with one another should be treated. Further, when a soft metal element is finely dispersed in the chemically treated layer, the seizing life of the members is further improved. Au, Ag, Pb, etc., are exemplified as the soft metal element. The metal element is dispersed by dispersing the metal element in an aq. soln. of tannic acid and dipping the members in the dispersion. the raceway, rolling element, holders, etc., of a rolling bearing are exemplified as the rolling member and a mechanical seal, etc., as the sliding member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling member or a sliding member having an improved seizure life, and a rolling bearing using the rolling member.

[0002]

2. Description of the Related Art A member of a mechanical part which supports a load and brings a relatively moving part into contact with each other by a rolling movement,
A member that is generally called a rolling member and that comes into contact with and rubs against a constantly moving member or the like of a rotating shaft is generally called a sliding member. These are widely used as members of automobile parts, starting machine parts, precision machine parts and the like.

The rolling members include, for example, track members such as inner and outer rings of rolling bearings, rolling elements, cages, and the like, and the sliding members include, for example, bearing seals and mechanical seals. In these rolling members or sliding members, a material excellent in lubricating performance is used in order to minimize friction due to rolling motion and rubbing.

[0004] Among the rolling members or sliding members, the rolling members are used for rolling bearings as described above. FIG.
FIG. 1 is a schematic view showing a single-row deep groove ball bearing which is a kind of such a rolling bearing, in which the upper part is a perspective view and the lower part is a sectional view. This single row deep groove ball bearing 10 has a groove 11a
Are formed, an outer ring 12 having a groove 12a formed in the center on the inside, a ball 13 of a rolling element sandwiched between the inner ring 11 and the outer ring 12, and a retainer 14 holding the ball 13. It is mainly used for general machinery, automobiles and the like.

[0005] In such a rolling bearing, grease or the like is used as a lubricant in order to smoothly perform the rolling motion. At this time, the friction state between the two contacting metal surfaces changes depending on the viscosity of the grease or the like used, the bearing load, the number of rotations, and the like. In a completely lubricated state in which an oil film is formed between the friction surfaces, contact between the metal surfaces hardly occurs, and the friction coefficient is extremely small.

However, if the lubrication surface is in an incomplete lubrication state in which at least a part of the lubrication is caused to cause metal-metal contact, a so-called splashing phenomenon occurs, and there is a possibility that damage such as seizure may occur on the lubrication surface. Therefore, in order to prevent such a phenomenon, an extreme pressure additive, an anti-wear agent and the like are added to the lubricating oil, and the addition of the extreme pressure additive and the like can prevent the seizure phenomenon to some extent. it can.

However, in such a member using a lubricant, there is a possibility that grease or the like may be powdered and scattered around during use, so that an electronic device such as a semiconductor device which is susceptible to dust is manufactured. In places where
There is a need for a rolling bearing that uses as little lubricant as possible or that does not use any lubricant.

Therefore, even when the lubricant is reduced or no lubricant is present, the surface of the rolling member is conventionally coated with an organic molybdenum compound, an organic zinc compound, or the like so that the rolling members have sufficient lubricity. (Japanese Patent Publication No. 8-23371).
No.). However, when processing with a mixed solution containing an organic molybdenum compound or the like, the temperature of the processing liquid is 170 to 220 ° C.
Temperature, the tempering phenomenon occurs, and the life of the rolling member is shortened.

[0009] Further, the rolling bearings are plated with gold, silver, copper or the like. However, in this case, a special apparatus for plating is required, and the processing cost is high. However, a rolling bearing having sufficient lubrication performance has not always been obtained.

Furthermore, a method of forming an oxide film on the surface of a rolling bearing or the like by treating the rolling bearing with a solution containing an organic phosphorus compound or the like is disclosed.
A rolling bearing having sufficient lubrication performance has not always been obtained.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a rolling member or a sliding member having an improved seizure life by forming a film having excellent lubrication performance on the surface thereof. It is another object of the present invention to provide a rolling bearing using the rolling member.

[0012]

The present invention is a rolling member or a sliding member whose surface is chemically treated with tannic acid. Hereinafter, the present invention will be described in detail.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The tannic acid used in the present invention is not particularly limited, and any tannic acid that is usually used as tannic acid can be used. The chemical treatment method using tannic acid is not particularly limited, but usually, the chemical treatment is performed by dissolving in a solvent such as water to form a solution, and immersing a rolling member or a sliding member in this solution. . Further, the liquid material may be applied to all or a part of the rolling member or the sliding member by using an application member or the like.

When the chemical treatment is performed using a tannic acid solution, the concentration of tannic acid in the solution is preferably 0.1% by weight or more. The temperature of the solution is not particularly limited, and may be a room temperature condition in which heat treatment is not particularly performed. Further, the time of the chemical treatment is not particularly limited, and even if the chemical treatment is performed for about several minutes, the lubrication performance of the treated member is sufficiently improved.

By the above-mentioned chemical treatment, a film having excellent lubricating performance is formed on the surface of the rolling member or the sliding member, and since this film has excellent durability, the seizure of a machine component using the rolling member or the sliding member is performed. The life is greatly improved.

The above chemical treatment may be performed on at least one of a plurality of rolling members or sliding members that come into contact with each other. When both the rolling member and the sliding member that come into contact with each other are subjected to the above-described chemical treatment, the lubricating performance of a mechanical component such as a rolling bearing using the same is, of course, further improved.

In the case of a rolling bearing, it is sufficient that at least one of the inner ring, the outer ring, and the rolling element has been subjected to the chemical treatment. In the case of the inner ring and the outer ring, at least a portion in contact with the rolling element has the chemical treatment. It suffices if the processing has been performed. Further, when the chemical treatment is applied to both the cage and the rolling members that come into contact with each other, the lubrication performance of the rolling bearing using the same is further improved.

Further, when a lubricant such as grease is used in a mechanical component using a rolling member or a sliding member, if the above-mentioned tannic acid is contained in the lubricant, the mechanical component can be used during use. , Chemical treatment with tannic acid,
Since a film having excellent lubricating performance is regenerated, the seizure life of the mechanical component can be further improved.

According to a second aspect of the present invention, there is provided a rolling member or a sliding member characterized in that the surface is chemically treated with tannic acid, and further the soft metal element is finely dispersed in the chemically treated layer. It is. The soft metal element may be finely dispersed inside and / or on the surface of the chemically treated layer. Examples of the soft metal element include Au, Ag, Pb, Zn, Al, Sn, and Ga.

As a method for dispersing the soft metal element in a fine state, first, when performing the chemical treatment with tannic acid, the soft metal element is dispersed in a solution containing tannic acid, and the rolling member is added to the solution. Alternatively, a method in which the chemical treatment and the dispersion of the soft metal element are simultaneously performed by immersing the sliding member or the like may be used.

Further, a method of immersing a rolling member or a sliding member in a solution containing the soft metal element after the completion of the chemical treatment with the tannic acid may be used. When dispersing the soft metal element, the soft metal element is added so that the amount of the soft metal element in the treatment liquid is 0.5 to 10% by weight, and the immersion treatment or the like is performed.

By performing immersion treatment or the like with a solution containing the soft metal element, the soft metal element is further finely dispersed inside and / or on the surface of the film formed on the rolling member or the sliding member. Therefore, the lubricating state is stably maintained by the soft metal element, and the seizure life of the mechanical component using the rolling member or the sliding member is further improved.

In the above-mentioned rolling bearing, a coating excellent in lubrication performance and the like is formed on at least one of the rolling members constituting the rolling bearing, and the coating is formed on the inside and / or the surface of the coating. Since the soft metal element is finely dispersed, the lubrication state of the rolling bearing is stably maintained, and the seizure life is further improved.

A mechanical part such as a rolling bearing using the rolling member or the sliding member subjected to the chemical treatment, or a rolling member or a slide in which the soft metal element is finely dispersed after the chemical treatment. Machine parts using moving members do not use lubricants, or they can be used for a long period of time even with a small amount of lubricant, so they can be suitably used in places such as clean rooms where dust is not available. it can.

Although the rolling member is not particularly limited, for example, radial bearings such as deep groove ball bearings, angular ball bearings, cylindrical roller bearings, tapered roller bearings, thrust angular ball bearings, thrust needle roller bearings And rolling members, rolling elements, cages, etc., which constitute rolling bearings such as thrust bearings such as thrust tapered roller bearings.

The sliding member is not particularly limited, and examples thereof include components such as a bearing seal for sealing a rotating shaft and the like, a mechanical seal, and the like.
A rolling bearing using a rolling member such as the above-mentioned track member, rolling element, and cage is also one of the present invention. In addition, the material of these rolling members, sliding members, or rolling bearings is not particularly limited, and may be metal, plastic, rubber, or the like.

[0027]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A bearing steel ball as a ball 13 of a single-row deep groove ball bearing 10 made of a material of JIS SUJ2 shown in FIG. 1 was immersed in a 3% tannic acid aqueous solution at 25 to 35 ° C. for 4 hours. Chemical treatment with tannic acid was performed.

The tannic acid used in the chemical treatment was 210-06332 manufactured by Wako Pure Chemical Industries. Single-row deep groove ball bearing 1 using bearing steel balls subjected to the above chemical treatment
No. 0 was assembled, and a four-ball friction test according to JIS K 2519 was performed under the condition without a lubricant, and the lubrication performance was investigated.

In the four-ball friction test, the applied load was 32 N
(2445 MPa) and the number of rotations is 10 r / m (115.2
mm / min), the ambient temperature was set to room temperature, and the atmosphere was not cooled during the test. The four-ball friction test was performed on six samples. The results are shown in Table 1.

Example 2 The same bearing steel balls as those used in Example 1 were added to a 3% aqueous solution of tannic acid, and 25 to 35 to which 5% of copper was added.
After immersion in a solution at 4 ° C. for 4 hours, a four-ball friction test was performed in the same manner as in Example 1 to investigate the lubrication performance.

The copper used in the above treatment was special grade copper (purity: 99.99%) manufactured by Mitsuwa Pure Chemical Industries.
The results are shown in Table 1.

Comparative Example 1 Single-row deep groove ball bearing 1 not subjected to any of the above chemical treatments
For 0, a four-ball friction test was performed in the same manner as in Example 1,
The lubrication performance was investigated. The results are shown in Table 1.

[0034]

[Table 1]

As is clear from the results of the Examples and Comparative Examples shown in Table 1, the single-row deep groove ball bearings of Comparative Example 1 which had not been subjected to any chemical treatment had an initial torque of 400 gf ·
cm and the torque rise time up to 500 gf · cm is as short as 123 seconds, whereas the single-row deep groove ball bearing of Example 1 that has been chemically treated with tannic acid has a reduced initial torque of 350 gf · cm. And 500gf ・ c
The time required for increasing the torque up to m was twice as long as 275 seconds, and the lubrication performance was greatly improved.

Further, in the single-row deep groove ball bearing of Example 2 in which a chemical treatment was performed with tannic acid and fine powder of copper as a soft metal element was dispersed, the initial torque was 22%.
The torque was further reduced to 5 gf · cm, and the torque rise time to 500 gf · cm was 480 seconds, which is about four times longer than that of Comparative Example 1, and the lubricating performance was further improved.

[0037]

The rolling member or sliding member according to the first aspect of the present invention is chemically treated with tannic acid, and a coating having excellent lubrication performance is formed on the surface of the rolling member or sliding member. The seizure life of the machine component using the member is greatly improved.

In the rolling member or sliding member according to the second aspect of the present invention, the soft metal element is finely dispersed inside and / or on the surface of the coating having excellent lubricating performance formed on the surface. By this soft metal element, the lubricating state is stably maintained, and the seizure life of the machine component using the rolling member or the sliding member is further improved.

The rolling bearing of the present invention uses the above-mentioned rolling member having excellent lubricating performance, so that the seizure life is further improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a single-row deep groove ball bearing which is a kind of a rolling member, in which the upper part is a perspective view and the lower part is a cross-sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Single row deep groove ball bearing 11 Inner ring 11a, 12a Groove 12 Outer ring 13 Ball 14 Cage

Claims (3)

[Claims] 1. A rolling member or a sliding member whose surface is chemically treated with tannic acid. 2. A rolling member or a sliding member, the surface of which is chemically treated with tannic acid, and further the soft metal element is finely dispersed in the chemically treated layer. 3. A rolling bearing comprising the rolling member according to claim 1 or 2.