JPS6019796B2 - Oil-impregnated resin bearing - Google Patents

Description

[Detailed description of the invention] This invention relates to oleoresin bearings.

Conventionally, synthetic resins known as so-called engineering plastics, such as polyethylene, polyacetal, polyamide, and polybutylene phthalate, have been widely used as super-moving members such as bearings.

The synthetic resins mentioned above have excellent friction and wear characteristics and can function satisfactorily even without lubrication, but these resins are limited to use under low load conditions and are difficult to use under high load conditions. It had some drawbacks.

For this reason, in order to improve the friction and wear characteristics of the above synthetic resins and make them able to withstand higher load operation, lubricating oils are mixed into these resins. As disclosed in Japanese Patent No. 48-22133, a resin that absorbs lubricating oil is mixed in, or a rubber-like substance that absorbs lubricating oil is mixed in as shown in Japanese Publication No. 49-4816 of Tsubaki. To make the lubricating oil absorbed by the contaminant, or to use the above-mentioned polymer compounds as the lubricating oil adsorbing substance,
As seen in the issue, it has been proposed to use graphite, but in the case of the former two types of polymer compounds that absorb lubricating oil, the lubricating oil absorption effect is due to the difference between the three-dimensional molecular structure of the polymer compound. This is due to the so-called swelling phenomenon that causes the lubricant to be absorbed, so once the lubricant is absorbed, it is difficult to leach out, and therefore it is difficult to leach out the lubricant to an extent that can contribute to improving the sliding properties. In addition, even if the polymer compound or graphite absorbs and carries lubricating oil, there is a limit to its absorption amount, and the amount of lubricating oil is usually about 3 volumes per 1 volume of lubricating oil absorbent. If you want to incorporate a large amount of lubricating oil into the bearing, you will naturally need a large amount of lubricating oil absorbent, which will impair the physical properties of the base range and cause a reduction in the mechanical strength, friction, and wear characteristics required for the bearing. There was a drawback.

Furthermore, the absorbents that function as lubricating oil carriers themselves have poor lubricity, so when they are exposed on the moving surface, they are forced to come into contact with the receiving shaft (rotating shaft), which results in low friction as a bearing. However, there were disadvantages in that the wear resistance and even the low abrasion properties were impaired.

Furthermore, the oil-free bearings made of synthetic resin have a high coefficient of thermal expansion and low thermal conductivity. Therefore, it is necessary to mold them to dimensions that take into account the coefficient of thermal expansion depending on the usage conditions, and there are drawbacks in dimensional stability. had.

Therefore, the application range of oil-impregnated resin bearings is as follows: bearings for office equipment, etc., where the PV value is 400k9' and w'min.
However, there was a problem in that the method was limited to those with a limit of In view of the above drawbacks, the present invention provides an oil-impregnated resin that can be impregnated with a sufficient amount of lubricating oil without impairing mechanical strength, thereby improving friction and wear characteristics, and having good dimensional accuracy and dimensional stability. As a result of intensive research aimed at obtaining bearings, we have found that rolls, gaskets,
It was discovered that polynorbornene-based synthetic elastomer, which is used as a low-hardness elastomer for packing etc., has extremely large oil absorption properties when left unvulcanized, and this work was made based on this knowledge. According to a first aspect of the present invention, an oil-impregnated oil-containing oil is characterized in that the oil-containing oil is composed of 1 to 4% by volume of lubricating oil, 0.1 to 2% by volume of polynorbornene-based synthetic elastomer, and the remainder by volume% of synthetic resin. The second invention is a resin bearing, in which lubricating oil 1-4% by volume, polynorbornene-based synthetic elastomer 0.1-2% by volume, metal powder 0.5-40% by volume and the remainder by volume. This is an oil-impregnated resin bearing characterized in that it is made of resin. In the above-mentioned first invention and second invention, the synthetic resin occupying the remaining volume % means the synthetic resin known as so-called engineering plastics such as the above-mentioned polyethylene, polyacetal, polyamide, polybutylene terephthalate, etc.

Next, this invention will be explained in more detail. The lubricating oil in this invention includes aromatic lubricating oil such as spindle oil, turbine oil, machine oil, dynamo oil, naphthenic lubricating oil, paraffinic lubricating oil, or synthetic oil such as hydrocarbon, ester, polyglycol, silicone, etc. Any commonly used lubricant may be used.

In addition, the polynorbornene-based synthetic elastomer is in the form of powder particles, and these particles can function as a lubricating oil absorbent, and polynorbornene-based resins or vulcanized compounds of polynorbornene-based resins are used.

Since this vorinorbonene synthetic elastomer is in the form of particles, it is extremely easy to mix with resins and fillers.
There is no need for crosstalk by rolls, bunburys, etc.

Since polynorbornene synthetic elastomer has an extremely porous structure, it can absorb a large amount of lubricating oil, and this absorption capacity reaches 1 volume per volume of polynorbornene synthetic elastomer. .

Moreover, as shown in the graph in the figure, the absorption amount increases as the temperature increases. Therefore, even when exposed to high temperatures during machining, the lubricating oil remains trapped and lubricates. It has the characteristics of preventing screw slippage due to oil leakage, and when the product temperature drops to room temperature after processing, lubricating oil leakage occurs due to a decrease in absorption capacity.
Therefore, when all the constituent pairs of an oleoresin bearing are assumed to be 100% by volume, for 1 to 4% by volume of lubricating oil, 0.1 to 20% by volume of polynorbornene synthetic elastomer and the remaining volume% are synthesized. By using resin, one having sufficient friction and wear characteristics can be obtained.

Further, in order to reduce the coefficient of thermal expansion and improve the thermal conductivity of the oleoresin bearing, metal powder such as copper thread metal powder such as bronze powder or Kelmet powder is added to the above structure. Next, the present invention will be explained using examples.

Example 1 Polynorbornene-based synthetic elastomer (product name: NOR
To 8% by volume (SOREX), 3% by volume of lubricating oil (trade name: Daphne Super Mechaniz Oil 100) was added, mixed with a Henschel mixer, and left at room temperature for several hours to combine with the lubricating oil. A homogeneous slurry with a polynorbornene-based synthetic elastomer was obtained, and polyacetal resin powder (trade name: Duracon M90) was added to the mixture as a synthetic resin.
-02) 62% by volume was added and mixed again in the Henschel mixer.

The obtained mixed powder was formed into a pellet by extrusion molding, and then a bearing body of a predetermined size was molded by injection molding. Example 2 Polynorbornene-based synthetic elastomer (product name: NOR
Add 3% by volume of lubricating oil (trade name: Daphne Super Mechanical Oil 100) to 8% by volume (SOREX), mix in the same manner as in Example 1 to obtain a slurry, and add polyacetal as a synthetic resin to the mixture. 42% by volume of resin powder (trade name: Duracon M90-02) and 2% by volume of Kagiri Kelmet powder (30% Pb) as metal powder were added and mixed again in the Henschel mixer.

A bearing body was formed using the obtained mixture in the same manner as in Example 1.
The bearing bodies molded in the above Examples 1 and 2 each have dimensions of 8 bars ◇ x 1 side ◇ x 15 ribs, and are made to receive a shaft of S4 $ unquenched and surface roughness $
Friction and wear tests were conducted under the following test conditions.

Test conditions 1 Axial load 5k9/ground 300pm 2 Ball load 2kg' ground 750pm Test results *Units
rThe comparative example in the above table is a subordinate example bearing,
It is made by mixing and molding polyacetal resin with lubricating oil.

As is clear from the table above, the products of the present invention are superior in wear resistance and friction properties compared to the conventional examples, and also have extremely excellent dimensional stability due to a small temperature rise.

As explained above, this invention uses a polynorbornene synthetic elastomer as a lubricant absorbent, which has an extremely porous structure and can absorb a large amount of lubricant. tA large amount of lubricating oil can be impregnated, making it possible to use resin bearings under high load conditions that were previously impossible, and
The above polynorbornene resin is 0.1 to 2% of the total amount.
Since it has sufficient lubricating oil absorption capacity even at 0 volume %, there is no need to mix in large amounts of activated carbon, synthetic rubber, etc. as in the past, so the physical properties of the base resin are less likely to deteriorate and the mechanical strength is excellent. be able to.

Furthermore, when metal powder is added, expansion due to heat can be prevented, so it has excellent dimensional stability, and there is no problem of determining molding dimensions by anticipating the coefficient of thermal expansion in advance, as was the case in the past. Because the metal powder is uniformly dispersed within the synthetic resin, and is also uniformly dispersed on the surface, this metal powder imparts lubricating oil spreadability to the synthetic resin, which originally has low lubricating oil spreadability. The lubricating oil film is formed and maintained, and the sliding properties of the bearing are also improved. As is clear from the above, the present invention exhibits superior sliding characteristics compared to conventional bearings, and therefore, for example, the pulsator of a washing machine has a PV value of 800 to 1000 k.
It can also be applied to high load bearings such as 9/flow and 2/min, increasing versatility.

[Brief explanation of the drawing]

The drawing shows the oil absorption temperature dependence curve of the polynorponene-based synthetic elastomer used in the present invention.

Claims (1)

[Scope of Claims] 1. An oil-impregnated resin bearing comprising 1 to 40% by volume of lubricating oil, 0.1 to 20% by volume of polynorbornene synthetic elastomer, and the remaining volume% of synthetic resin. 2 Lubricating oil 1-40% by volume, polynorbornene synthetic elastomer 0.1-20% by volume, metal powder 0.5-40%
An oil-impregnated resin bearing characterized in that the remaining volume is made of synthetic resin.