JP2001355638A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing using a retainer having an appropriate strength and being friendly to the living environment of the living thing. SOLUTION: This rolling bearing has the retainer composed of a material, which is formed by adding filler to biodegradable resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing, and more particularly, to a rolling bearing using a cage made of a biodegradable resin.

[0002]

2. Description of the Related Art The components of a rolling bearing include an inner ring,
Outer rings, rolling elements, cages, seals, lubricants, and the like. Among them, the inner ring, the outer ring and the rolling elements are generally made of bearing steel or ceramic, and the cage is made of iron-based material or resin. An iron-based material, rubber, or the like is used for the seal, and grease or oil is used for the lubricant.

[0003] Rolling bearings are generally used in various industrial machines as mechanical parts. Then, when the predetermined use period ends, the entire device is often disposed of as industrial waste without removing the rolling bearing. Most of the disposal methods include incineration, marine disposal, underground disposal, leaving in the mountains, and the like.

[0004]

In the case of such disposal, the iron-based material hardly emits harmful substances that affect the environment, and gradually loses its shape due to rust. On the other hand, resin and rubber are extremely stable, and remain in their original form with little decomposition even after long-term storage such as marine disposal, underground disposal, or standing in the mountains. There is.

For this reason, when the rolling bearing is left for a long period of time, the iron-based material does not retain its original shape, but the resin or rubber member retains its original shape. Further, when a fluid resin is used as the lubricant or the like, the resin may flow out of the rolling bearing and harm the biological environment. To solve this problem, Japanese Patent Application No. 11-305507 proposes that at least one of an inner ring, an outer ring, a rolling element, a retainer, and a seal constituting a rolling bearing is made of a biodegradable material. . However, in the case of a rolling bearing using a biodegradable resin for the retainer, the condition that can be used is limited because the cage is deformed due to insufficient strength of the biodegradable resin during high-speed rotation and high-temperature use.

Therefore, the present invention has an appropriate strength,
An object of the present invention is to provide a rolling bearing using a cage that is friendly to the living environment of living things.

[0007]

The present invention has solved the above-mentioned problems by using a retainer made of a material obtained by adding a filler to a biodegradable resin.

[0008] By using a material in which a filler is added to a biodegradable resin, functions such as strength as a retainer can be sufficiently exhibited, and after leaving for a long time, the member loses its shape, and the living environment of living organisms is reduced. Can be held.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A rolling bearing according to the present invention
This uses a retainer made of a material obtained by adding a filler to a biodegradable resin.

As shown in FIG. 1, the above-mentioned rolling bearing is formed of an outer ring 1, an inner ring 2, rollers 3, and a retainer 4, and the retainer 4 has a role of retaining the rollers 3.

Any of rolling bearings such as a bearing, a tapered roller bearing, a self-aligning roller bearing, and a needle roller bearing may be used.

The above-mentioned biodegradable resin refers to a resin which is decomposed by microorganisms in an environment, and a biodegradability test is specified in JIS K6950 or the like. Generally, a resin having a biodegradability of 60% or more according to the above test method is treated as a biodegradable resin.

[0013] The biodegradable resin used for the cage is not particularly limited. An example is poly (α-
(Hydroxy acid), poly (β-hydroxyalkanoate), poly (ω-hydroxyalkanoate), polyalkylenealkanoate and the like.

Examples of the poly (α-hydroxy acid) include polylactic acid and polyglycolic acid, and examples of the poly (β-hydroxyalkanoate) include copolymers of hydroxyvaleric acid and hydroxybutyric acid. can give. Also, as polyalkylene alkanoate,
Examples include a dehydration condensate of 1,4-butanediol and succinic acid (that is, polybutylene succinate) and a polyethylene terephthalate copolymer such as a polyethylene terephthalate-butylene adipate copolymer. From the viewpoint of heat resistance, the above polybutylene succinate, polyethylene terephthalate-polyethylene terephthalate copolymer such as butylene adipate copolymer, polyhydroxybutyric acid, or polylactic acid, or a mixture or copolymer thereof is more preferable. .

The filler can be used without any particular limitation as long as it is well dispersed in the biodegradable resin as a main component and imparts strength according to the purpose of use. Specific examples of the filler include glass fiber, metal fiber, polyvinyl alcohol fiber, carbon fiber, fibrous filler such as potassium titanate whisker, zinc oxide whisker, calcium sulfate whisker, aluminum borate whisker, mica, talc, etc. Is raised.

The amount of the filler to be filled in the biodegradable resin is preferably 5 to 40%, more preferably 10 to 40%. If the filling amount is less than 5%, the strength is not sufficient, and if the filling amount exceeds 40%, the biodegradability is impaired.

[0017]

Embodiments of the present invention will be described below. In addition,
The materials used in the examples and comparative examples are described below. PBS: 70% by weight of bionole (manufactured by Showa Kogyo Co., Ltd .: polybutylene succinate # 1020) + 30% by weight of glass fiber (manufactured by Asahi Glass Co., Ltd .: CS03JA429T) 100% by weight of polybutylene succinate # 1020 PA66 ··· A3HG2 (BASF: PA66)
90% by weight + glass fiber (same as above) 10% by weight) PLA: Lacia (manufactured by Mitsui Chemicals: polylactic acid, M-
151SQ52) 70% by weight + glass fiber (Asahi Glass Co., Ltd .: CS03JA429T) 30% by weight PLA: Lacia (Mitsui Chemicals: polylactic acid, M-)
151SQ52) 100% by weight ・ B-PET ... Biomax (DuPont WUH:
Mixture of polyethylene terephthalate copolymer and glass fiber)

(Examples 1 to 3) Of the above materials, PBS
Was mixed with a Henschel mixer, and molding pellets were produced using a kneading extruder. PLA is also PBS
A pellet for molding was produced in the same manner as described above. B-PE
T and the resulting pellets at 80 ° C. for 10
After drying for an hour, a test piece was formed by injection molding. Then, it was provided to the following tensile strength test, bearing test, and biodegradability test. Table 1 shows the results.

(Comparative Examples 1 to 3) The above PB
Example 1 except that S, PLA and PA66 were used.
A test piece was formed in the same manner as described above. Then, it was provided to the following tensile strength test, bearing test, and biodegradability test. Table 1 shows the results.

[Tensile strength test] A tensile strength test was performed according to JIS standards. That is, using a No. 1 dumbbell test piece, the strength at a tensile speed of 10 mm / min, at room temperature and at 80 ° C. was measured.

[Bearing test] The inner ring, outer ring and rolling elements
J2, 6 kinds of materials described above for the retainer, and biodegradable grease for the lubricant (Biotemp P, manufactured by Kyodo Yushi Co., Ltd.)
L) and a rolling bearing equivalent to 608 (outer diameter: 22m)
m, inner diameter: 8 mm, width: 7 mm).

The general conditions (F
a = 3 kgf, rotation speed = 10000 rpm, temperature = 80
° C). At this time, when the rotational torque of the bearing reached twice the initial value due to deterioration or deformation of the cage, the test was stopped because rotation was impossible. Table 1 also shows the time required until rotation becomes impossible.

[Biodegradability Test] The soil degradability of the cage of the above-mentioned rolling bearing was examined. According to the method, the cage is placed in soil at a temperature of 35 ° C. and a moisture of 30% (10 c from the surface).
m below ground) for 6 months. Then, the appearance change and the weight change after the elapse of the test period (the weight of the test specimen at the beginning of the test is
The resin residual ratio (% by weight) when the value was set to 00) was examined. The appearance was determined based on the following criteria. ：: easily disintegrates ×: no change and difficult to disintegrate

[0024]

[Table 1]

[Results] As is clear from Table 1, Examples 1 to 3 have excellent characteristics that the tensile strength is equivalent to that of PA66. Furthermore, the test piece after the biodegradation test was in a state where its shape collapsed due to a slight external force that could be touched by a finger, and when it was substantially removed from the soil, it was decomposed to such an extent that its shape could not be observed.

On the other hand, Comparative Example 1 shows excellent properties in strength and bearing tests, but has no biodegradability. In Comparative Examples 2 and 3, the biodegradability was sufficient, but the strength was low, and in the bearing test, the cage was deformed by high-speed rotation, and compared with Examples 1 to 3 and Comparative Example 1. It was short-lived.

[0027]

According to the present invention, a cage made of a material obtained by adding a filler to a biodegradable resin has sufficient strength due to the addition of the filler. Therefore, a rolling bearing using this cage can withstand long-term use. Further, when the rolling bearing is buried in the ground, the cage is excellent in biodegradability even if it is not a member formed of metal or ceramic, so that it is decomposed and returned to soil. Therefore, it does not adversely affect the environment. Therefore, the rolling bearing according to the present invention does not adversely affect the environment even when disposed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view showing an example of a rolling bearing.

[Explanation of symbols]

 1 outer ring 2 inner ring 3 roller 4 cage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J101 AA01 AA32 AA42 AA52 AA62 BA50 DA14 EA31 EA32 EA80 FA60 GA31 GA41 4F071 AA01 AA29 AA43 AA44 AA46 AB03 AB06 AB18 AB20 AB24 AB27 AB28 AB30 AD01 AE17 AH18 4CF01 DA01 CF01 DA066 DE106 DE186 DG056 DJ046 DJ056 DK006 DL006 FA042 FA046 FA066 GM05

Claims (2)

[Claims] 1. A rolling bearing using a cage made of a material obtained by adding a filler to a biodegradable resin. 2. The rolling bearing according to claim 1, wherein the biodegradable resin is polybutylene succinate, polyethylene terephthalate copolymer, polyhydroxybutyric acid, or polylactic acid, or a mixture or copolymer thereof.