JP4059092B2 - Manufacturing method of rolling bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, deep groove ball bearings, a method of manufacturing a rolling bearings, such as self-aligning roller bearings.
[0002]
[Prior art]
In rolling bearings, lubricating oil and grease are generally used to improve the lubricity between the raceway surfaces of inner and outer rings (race rings) and the surfaces of balls or rollers (rolling elements). However, lubrication oil or grease may scatter to the outside of the bearing or foreign matter may enter from the outside of the bearing, resulting in poor contact between the raceway surface and the rolling element surface, and seizure may occur. is there. For this reason, a solid polymer lubricant in which a lubricating oil is dispersed in a resin is sealed in a space formed between the race and the rolling element, so that the rolling bearing having both lubricity and sealability is provided. Development is underway.
[0003]
Under such circumstances, for example, ultra high molecular weight polyethylene (number average molecular weight: 200,000 or more) and a lubricant are mixed, heated to the melting temperature of ultra high molecular weight polyethylene or higher (135 ° C. or higher), and then solidified by cooling to solid polymer lubrication. Techniques for encapsulating materials have been proposed. Specifically, (1) after injecting a mixture of ultrahigh molecular weight polyethylene and a lubricant dispersed in a solvent, the mixture is heated at a temperature equal to or higher than the melting temperature of the ultrahigh molecular weight polyethylene, and then cooled and solidified. Technology for encapsulating (for example, see Patent Document 1), and (2) Technology for injecting the same components into a gap in a molten state using an injection molding machine, and solidifying by cooling and solidifying (for example, see Patent Document 2) Has been proposed.
[0004]
[Patent Document 1]
JP-A-6-50330 (2nd page)
[Patent Document 2]
JP 2002-212581 A (second page)
[0005]
[Problems to be solved by the invention]
However, in the method (1), since it is necessary to heat and melt the ultrahigh molecular weight polyethylene at a high temperature in order to uniformly disperse the lubricant, the heating cost is high and it is difficult to provide an inexpensive product. was there. In the method (2), it is difficult to spread the molten resin to every corner of the space formed between the race and the rolling element, and a void is formed in the rolling bearing. was there. Furthermore, since any of the above methods (1) and (2) must be manufactured at a high temperature, there is a problem that it is difficult to apply to methods other than metal rolling bearings.
[0006]
The present invention has been made in view of such circumstances, and can ensure uniform dispersibility of the lubricant without heating at a high temperature, and there is no gap in the space formed between the race and the rolling element. rising rolling which had use a liquid polymeric lubricant capable of encapsulating the solid polymer lubricant to provide a manufacturing method of a bearing and an object.
[0007]
[Means for Solving the Problems]
A method of manufacturing a rolling bearing according to the present invention is formed between an inner ring, an outer ring, a plurality of rolling elements that are movably arranged between the inner ring and the outer ring, and the inner ring, the outer ring, and each rolling element. Is a method of manufacturing a rolling bearing having a solid polymer lubricant enclosed in a space to be manufactured.
[0008]
In the present method, include a lubricant, a resin and a volatile solvent for dispersing and dissolving the resin, the resin is liquid polymer lubricant has a number average molecular weight of 2,000 to 1 0,000 After injecting the agent into the space formed between the inner ring, the outer ring and the rolling elements, the volatile solvent is heated to a temperature higher than the volatile temperature of the volatile solvent in the liquid polymer lubricant. Is evaporated to form a solid polymer lubricant enclosed in the space.
[0009]
According to said structure, since the thing of the low molecular weight whose number average molecular weight is 2,000-10,000 was used as a resin component, this low molecular weight resin can be uniformly disperse | distributed in a solvent with a lubricant. . In addition, the liquid polymer lubricant uniformly dispersed in this way can be distributed to every corner of the space formed between the race and the rolling elements. Therefore, it becomes possible to enclose the solid polymer lubricant in which the lubricant is uniformly dispersed between the raceway and the rolling element without a gap. Further, since the solid polymer lubricant can be formed by volatilization of the solvent performed at a temperature lower than the melting temperature of the conventional ultrahigh molecular weight polyethylene, the heating cost can be suppressed, and therefore, an inexpensive rolling bearing can be provided. Furthermore, since high-temperature heating is unnecessary, there is an advantage that it can be applied to, for example, a rolling bearing composed of a resin ring or rolling element. Here, if the number average molecular weight of the resin is higher than 50,000, it cannot be uniformly dispersed in the solvent, and if it is less than 1,000, the strength of the solid polymer lubricant is insufficient. And preferably within the range of 2,000 to 10,000.
[0010]
According to the above configuration, the solid polymer lubricant is used as the solid polymer lubricant, which is obtained by removing the solvent in the liquid polymer lubricant by volatilization, so that the raceway surface and the rolling element surface are rotated during the rotation of the bearing. The lubricant can be stably supplied between them. Also, not only is the lubricant supplied due to wear of the solid polymer lubricant or the seepage of the lubricant during the rotation of the bearing, but also the solvent volatilization trails become a way to the contact area between the raceway surface and the rolling element surface. It becomes possible to supply a lubricant. In addition, the solid polymer lubricant can prevent foreign matters from entering the contact portion between the raceway surface and the rolling element surface. Therefore, it has good lubricity and sealing properties, and a long-life rolling bearing can be provided.
[0011]
Therefore, according to the configuration of the upper SL, it is possible to easily manufacture a rolling bearing having both good lubricity and sealability.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing a deep groove ball bearing according to an embodiment of the rolling bearing of the present invention. The deep groove ball bearing includes an outer ring 1, an inner ring 2, and a plurality of (for example, eight) balls 3 as a plurality of rolling elements between the inner and outer rings. A solid polymer lubricant 4 is enclosed in a space formed by the outer ring 1, the inner ring 2 and the balls 3.
[0013]
The solid polymer lubricant 4 can be formed using, for example, a liquid polymer lubricant containing low molecular weight polyethylene as a resin, toluene as a solvent, and polyalphaolefin (PAO) as a lubricant. Specifically, first, a low molecular weight polyethylene solution having a solid content of 20% by weight (polyethylene number average molecular weight: 5000, solvent: toluene) and PAO (30 cSt (40 ° C.)) are mixed at a weight ratio of 1: 1. To prepare a liquid polymer lubricant. Then, this liquid polymer lubricant is injected into the space formed by the outer ring 1, the inner ring 2 and each ball 3 (injected with a seal fitted on one side so as not to leak) to fill the space. The liquid polymer lubricant is heated to a temperature (60 to 80 ° C.) at which the solvent is easily volatilized. Thereby, toluene in the liquid polymer lubricant is removed by volatilization and solidifies. In addition, you may heat-process below this temperature. In this case, heating in a vacuum has an advantage that the volatilization of the solvent is promoted. In this way, the solid polymer lubricant 4 can be formed.
[0014]
The deep groove ball bearing according to this embodiment is formed by the outer ring 1, the inner ring 2, and the balls 3 because the solid polymer lubricant is formed using a liquid polymer lubricant containing low molecular weight polyethylene, toluene, and PAO. Solid polymer lubricant can be enclosed to every corner of the space. In addition, since low molecular weight polyethylene is used, PAO is uniformly distributed in the solid polymer lubricant. For this reason, PAO can be stably supplied from the solid polymer lubricant during rotation of the bearing. Therefore, the contact state between the raceway surfaces of the outer ring 1 and the inner ring 2 and the surface of each ball 3 becomes good over a long period of time, and a deep groove ball bearing having a long life is obtained. The inventor of the present invention uses a deep groove ball bearing (example product) in which a solid polymer lubricant obtained by removing and solidifying toluene by volatilization using the above-described low molecular weight polyethylene solution, and ultrahigh molecular weight polyethylene (number average molecular weight 200,000). As a result of a comparative test with a deep groove ball bearing (comparative example product) encapsulating a solid polymer lubricant that has been heated and melted and then cooled and solidified, the example product is longer than the comparative product. It has been confirmed that it was a lifetime.
[0015]
In the above, the case where low molecular weight polyethylene is used as the resin constituting the liquid polymer lubricant has been described. However, the number average molecular weight Mn should be in the range of 1,000 to 50,000, preferably 2,000 to 10,000. Various types of linear and branched resins can be used. Specifically, low molecular weight polypropylene, low molecular weight polyacetal, or the like can be used. These may be used alone or in combination of two or more.
Further, the solvent is not limited to toluene, and can be appropriately selected according to the type of resin to be dissolved. However, considering that the solvent is removed by volatilization, a highly volatile solvent is preferable. These may be used alone or in combination of two or more.
Furthermore, the lubricant is not limited to PAO, and a known lubricant such as mineral oil, synthetic lubricant, or grease may be used. However, those having low volatility are suitable so that they are not removed by volatilization with the solvent. These may be used alone or in combination of two or more.
The liquid polymer lubricant may be a dispersion of polytetrafluoroethylene (PTFE) powder, which is a solid lubricant. For example, PTFE powder may be dispersed in a solution in which low molecular weight polyethylene is dissolved in a solvent such as toluene. When such a liquid polymer lubricant is used, a solid polymer lubricant which is a eutectoid obtained by mixing PTFE into a precipitate of low molecular weight polyethylene is obtained by volatilizing a solvent such as toluene.
The present invention is not limited to deep groove ball bearings, and can be applied to various types of rolling bearings such as self-aligning roller bearings. Further, since the solid polymer lubricant can be formed at a temperature lower than the melting temperature of the resin, it can be applied to rolling bearings other than metal (for example, resin).
[0016]
【The invention's effect】
As described above , according to the above-described liquid polymer lubricant, a solid polymer lubricant in which the lubricant is uniformly dispersed can be produced, and a void is formed in the space formed between the race and the rolling element. Solid polymer lubricant can be encapsulated.
Then, according to the rolling bearing of the present invention prepared with the liquid polymeric lubricant, it is possible to supply the lubricant stable to the contact portion between the raceway surface and the rolling element surface during rotation of the bearing, the contact portion As a result, foreign matter can be prevented from being mixed into the product, resulting in a long life. Furthermore, according to the rolling bearing manufacturing method of the present invention, it is possible to easily manufacture a rolling bearing having both good lubricity and sealing properties.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a deep groove ball bearing according to an embodiment of a rolling bearing of the present invention.
[Explanation of symbols]
1 Inner ring 2 Outer ring 3 Ball (rolling element)
4 Solid polymer lubricant

Claims (1)

An inner ring, an outer ring, a plurality of rolling elements arranged to roll between the inner ring and the outer ring, and solid polymer lubrication enclosed in a space formed between the inner ring, the outer ring and each rolling element A method of manufacturing a rolling bearing comprising a material ,
A lubricant, a resin and, and a volatile solvent for dispersing and dissolving the resin, the resin is a liquid polymer lubricant has a number average molecular weight of 2,000 to 10,000, the inner ring, after injecting into the space formed between the outer ring and the rolling elements,
By volatilizing the volatile solvent is heated above the volatilization temperature in the volatile solvent of the liquid polymeric lubricant in, the rolling bearing and forming a solid polymeric lubricant sealed in said space Production method.

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