JPS5854320B2 - Method for manufacturing solid lubricant-embedded sliding parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a solid lubricant-embedded sliding member.

In general, in solid lubricant-embedded sliding parts, the solid lubricant is only useful if it is applied as a suitable coating on the friction sliding surface, and this coating is particularly important for its excellent durability against repeated friction. considered important.

Regarding the formation of a coating, the coating may be applied as a solid lubricant coating from the beginning by spraying or brushing on the friction sliding surface, or a solid lubricant may be applied to an appropriately shaped hole or groove drilled in the friction sliding surface. The embedded solid lubricant is automatically supplied to the sliding surface during frictional sliding to form a coating, or both may be used in combination.

Currently, in the case of such solid lubricant-embedded sliding components, especially bearings, a hole for embedding the solid lubricant is machined into the bearing base metal, the solid lubricant is press-fitted using adhesive, and then the solid lubricant is inserted. Machine finishing is performed along with the base metal.

Therefore, since the solid lubricant exposed surface forms the same surface as the inner surface of the bearing, the formation of a lubricating film on the contact interface by the solid lubricant during use requires wear of the base metal or an increase in the temperature of the friction sliding part. This is largely due to the expansion of the solid lubricant due to

For this reason, a lubricant film is not formed on the inner peripheral surface of the bearing until a certain period of time has elapsed during use, and the bearing surface and the mating material come into direct contact, increasing the coefficient of friction and causing problems.

Therefore, in order to overcome the above-mentioned drawbacks, it is necessary that a lubricant film be formed at the time the mating material is inserted into the bearing, and in order to form this lubricant film, a separate lubricant is applied to the inner circumferential surface of the bearing. It was troublesome as it had to be applied in advance.

In addition, in order for a lubricant film to be formed on the contact interface in a short time without the above-mentioned frictional sliding part wear or temperature rise, the embedded solid lubricant must protrude beyond the bearing surface. It is said that

However, it is practically impossible to make the solid lubricant protrude from the friction sliding surface by machining so as not to interfere with the fitting and insertion of the mating material.

The present invention relates to a method for manufacturing a solid lubricant-embedded sliding member that facilitates the formation of a lubricating film in order to suppress galling or rise in friction coefficient due to metal contact at the initial stage of operation.

That is, one end of the bearing base metal is opened to the friction sliding surface,
In a method for manufacturing a solid lubricant-embedded sliding member, which comprises drilling a buried hole with the other end closed and burying solid lubricant pellets in the buried hole, (1) graphite, molybdenum disulfide,
The main component is an interfold material selected from tungsten disulfide, and to this is added elasticity-imparting materials such as polytetrafluoroethylene, which has a low coefficient of friction, thermoplastic synthetic resin powder selected from polyolefins, wax, and higher fatty acid salts. (2) The solid lubricant pellets are made to protrude from the friction sliding surface of the bearing base metal and are press-fitted into the buried hole. (3) compressing the solid lubricant pellet into the buried hole by rolling the protruding frictional sliding surface of the solid lubricant pellet to impart elastic recovery force to the pellet; and (4) above (3). At the same time, a part of the solid lubricant pellets is transferred to the friction sliding surface to form a solid lubricant film on the friction sliding surface, and (1), (2), and (3) above.
The present invention provides a method for manufacturing a solid lubricant-embedded sliding member characterized by (4) and (4).

The method for manufacturing a solid lubricant-embedded sliding member of the present invention will be described below based on examples.

FIG. 1 is a longitudinal cross-sectional view of a solid lubricant-embedded bearing according to the present invention, in which numeral 1 indicates a cylindrical bearing base metal;
2 is a solid lubricant pellet embedding hole drilled in the bearing base metal by machining, and 3 is a solid lubricant pellet embedded in the embedding hole 2.

Further, 4 is a solid lubricant coating formed on the friction sliding surface of the bearing base metal 1, and 5 is a nozzle fitted to the outer peripheral surface of the bearing base metal 1.

The solid lubricant is, for example, 30% graphite by volume;
40% polytetrafluoroethylene, 20% wax,
This composition is made of 10% lithium stearate and is formed into pellets using a tablet machine or the like without heating.

Among the components of the above-mentioned solid lubricant, graphite is present on the friction sliding surface, filling minute irregularities on the friction sliding surface, smoothing it out, and having the effect of preventing seizure.

Further, examples of carbon having the same effect as graphite include interfold materials such as molybdenum disulfide and tungsten disulfide.

Polytetrafluoroethylene has the effect of lowering the coefficient of friction and preventing stick-slip, and when it is added and formed into pellets, it imparts elastic recovery force to the solid lubricant pellets obtained. The elastic recovery force can be adjusted as appropriate by adjusting the amount of polytetrafluoroethylene added.

Note that polyolefins such as polyethylene and polyfluoropylene can also be used in place of polytetrafluoroethylene or by partially blending it.

Petroleum-based waxes are used, and this wax not only acts as a binder to bind the powder components together, but also has a lubricating effect below the wax's melting point and its fluidity under pressure to form a solid lubricant film. It has a self-repairing effect.

Lithium stearate acts like the wax mentioned above, but also promotes the film-forming action as a solid lubricant.

This substance has strong polarity and orientation, but other higher fatty acid salts also work equally well.

Desirable component compositions of the solid lubricant used in the present invention are shown in the table below.

Next, a method for forming a solid lubricant film on a friction sliding surface, which is a feature of the present invention, will be described.

In FIG. 2, 6 is a compression roller, and as shown in the figure, solid lubricant pellets 3 are formed to be larger than the length in the longitudinal direction of the solid lubricant pellet embedding holes 2. is press-fitted.

A housing 5 is fitted onto the outer peripheral surface of the bearing base metal 1 to close one end of the buried hole 2 on the outer peripheral surface side, and the tip of the solid lubricant pellet 3 protrudes onto the friction sliding surface. ing.

While rotating and sliding the compression roller 6 over the entire surface of the friction sliding surface on which the solid lubricant pellets 3 protrude in the bearing base metal 1 configured as described above, the solid lubricant pellets 3 are placed on the same surface as the friction sliding surface. Compress until it forms a surface.

By rotating and sliding the compression roller 6 in this manner, elastic recovery force is imparted to the solid lubricant pellets 3, and a portion of the solid lubricant transfers to the friction sliding surface to provide lubrication. A coating 4 is formed.

Further, contrary to the above-described method, the base metal 1 may be rotated about its axis by appropriate means, and the compression roller 6 may be rotated and slid against the friction sliding surface.

The solid lubricant pellets 3 compressed by the compression roller 6 until they form the same surface as the friction sliding surface contain a thermoplastic resin such as polytetrafluoroethylene as described above. Due to its elastic recovery force, during use, it always slides into sliding contact with a mating material such as a shaft.

Therefore, the lubricant film 4 is constantly present on the friction sliding surface, and even if the lubricant film should break, it can be repaired within a very short time.

It is desirable that the solid lubricant-embedded bearing according to the present invention be used immediately after manufacture, but if it is left unused for a long period of time, the once compressed solid lubricant pellets will protrude from the friction sliding surface due to elastic recovery. , it may be possible to prevent the shaft from being inserted.

In such a case, the solid lubricant pellets may be compressed again using a compression roller.

As described above, in the solid lubricant-embedded bearing according to the present invention, a lubricating film is formed on the inner surface of the bearing, that is, on the friction sliding surface.
In addition, since the tip of the solid lubricant pellet is in sliding contact with the inserted shaft, metal contact between the bearing and the mating material at the initial stage of operation can be prevented, and the rise in the coefficient of friction can be suppressed.

Furthermore, in addition to the above-mentioned effects, the present invention has a number of other advantages, such as being able to omit the conventional running-in operation.

Although the present invention has been described using a cylindrical bearing as an example, the present invention is not limited to this, and the same effect can be obtained even if the present invention is applied to, for example, a plate-shaped sliding member.

[Brief explanation of the drawing]

1 and 2 are drawings showing an embodiment of the present invention. 1...Bearing base metal, 2...Solid lubricant buried hole, 3...Solid lubricant pellet, 4...
...Solid lubricant film, 5...Housing,
6... Compression roller.

Claims (1)

[Scope of Claims] 1. Solid lubricant embedding by drilling a buried hole in the bearing base metal with one end open to the friction sliding surface and the other end closed, and embedding solid lubricant pellets in the buried hole. In the method for manufacturing a molded sliding member, (1) the main component is an interosseous material selected from graphite, molybdenum disulfide, and tungsten disulfide, and polytetrafluoroethylene having a low coefficient of friction as an elasticity-imparting material; (2) Forming a solid lubricant containing thermoplastic synthetic resin powder selected from polyolefin, wax, and higher fatty acid salt into a pellet shape larger than the length in the longitudinal direction of the buried hole; (2) forming the solid lubricant pellet into a bearing; (3) rolling off the friction sliding surface from which solid lubricant pellets protrude and compressing the solid lubricant pellets into the buried hole; (4) imparting elastic recovery force to the pellet; (4) the above (3);
) At the same time, a portion of the solid lubricant pellets is transferred to the friction sliding surface to form a solid lubricant film on the friction sliding surface; (1), (2), (3) and (4) above; A method for manufacturing a solid lubricant-embedded sliding member, characterized by: