JP3121702B2 - Rolling bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing using fluorine grease as a lubricant.

[0002]

2. Description of the Related Art In some cases, fluorine grease is used as a lubricant for rolling bearings. Grease is generally a mixture of a base oil that acts as a lubricant, a thickener to keep it semi-solid, and an additive to improve the properties of the oil. Is, for example, a fluorine-based oil as a base oil, to which a fluorine-based compound PT
It is obtained by mixing FE (polytetrafluoroethylene) as a thickener.

[0003] Since fluorine-based grease has poor adhesion to the surface of the base material (meaning that "glue" and "fitting" to the surface of the base material are not good), it is necessary to improve this property in advance. A pretreatment film is formed on the surface of the base material. If the adhesion is not good, sufficient lubricity and durability cannot be obtained. The pre-treatment film is formed by immersing a finished bearing product or a bearing component in a treatment liquid obtained by dispersing and diluting (about 5%) fluorine-based grease in Freon, followed by drying. Since the pretreatment film formed in this manner has the same components as the fluorine-based grease to be sealed, the adhesion of the fluorine-based grease is improved by the affinity between the two.

[0004]

Recently, destruction of the ozone layer by freon has been regarded as a problem, and the use of freon has been regulated on a worldwide scale. As described above, conventional bearings using fluorine-based grease use chlorofluorocarbon in the coating process of the pre-treatment film. May be impossible.

Accordingly, an object of the present invention is to provide a rolling bearing in which fluorine-based grease is sealed, so that the use of chlorofluorocarbon in the manufacturing process is unnecessary in preparation for the future ban on chlorofluorocarbon.
Moreover, the object is to ensure the same good durability as the conventional one.

[0006]

According to the present invention, there is provided a rolling bearing comprising:
In a bearing in which a fluorine-based grease is sealed in a bearing, a coating made of polytetrafluoroethylene is formed on at least a surface of the components constituting the bearing that generates rolling friction or sliding friction.

[0007]

The good affinity between the PTFE coating and the fluorine-based grease ensures that the adhesion of the fluorine-based grease to the surface of the base material is almost the same as before. Moreover, it is not necessary to use Freon in the coating treatment step.

[0008]

Embodiments of the present invention will be described below.

FIG. 1 shows an embodiment in which the present invention is applied to a sealed deep groove ball bearing. This bearing is mounted on the inner ring 1, the outer ring 2, the plurality of balls 3 interposed between the inner and outer rings 1, 2, the retainer 4 for holding the balls 3 at equal circumferential intervals, and the inner diameter portions at both ends of the outer ring 2. And a bearing component such as a shield plate 5. Then, coatings 1a, 2a, 3a made of PTFE (polytetrafluoroethylene) are formed on the rolling surfaces of the inner and outer rings 1, 2 and the surface of the ball 3, and a fluorine-based grease 6 is sealed in the bearing. ing.

The coatings 1a, 2a, and 3a are formed by immersing a bearing component or a finished bearing product (without the shield plate 5) for about 10 seconds in a processing solution in which PTFE is dispersed in an organic solvent, and then immersing the bearing component in the air. And dried. P
As TFE, for example, Vidax AR, Vidax 1000 (both manufactured by DuPont), MP120
0, MP1300 (all manufactured by Mitsui Fluorochemicals), Lubron D-1 (manufactured by Daikin Industries, Ltd.) and the like can be used. When Vydax AR is used as PTFE, for example, toluene, benzene, or the like can be used as the organic solvent. In addition, in FIG.
Coatings 1a and 2a are not formed on the fitting surfaces and the like of the outer surface of No. 2 but are not subjected to coating treatment by masking or removed before the final product. After the coatings 1a, 2a, and 3a are formed on the rolling surfaces of the inner and outer rings 1 and 2 and the surface of the ball 3 in advance, the fluorine-based grease 6 is sealed in the bearing.

FIG. 2 schematically shows the rolling surface of the inner ring 1 as an example (the same applies to the rolling surface of the outer ring 2 and the surface of the ball 3). In this embodiment, the coating 1a is uniformly distributed on the rolling surface of the inner ring 1. The fluorinated grease 6 is obtained by mixing a fluorinated oil as a base oil 6a with PTFE (having an average molecular weight larger than that of PTFE exemplified above as a coating material) as a thickener 6b.
Examples of the fluorine-based grease 6 include Krytox 240AC (manufactured by DuPont) and Varielta L-55 / 2
(Made by Kluber).

In the bearing of this embodiment, since the coating 1a and the fluorine-based grease 6 are of the same kind as the fluorine-based compound, the adhesion of the fluorine-based grease 6 to the rolling surface (due to the affinity between the two). "Glue" and "Familiarity" on the raceway are ensured. In particular, PTFE as the material for forming the coating 1a and PTFE as the thickener 6b for the fluorine-based grease 6 are the same or the same type (in the case of the present embodiment, they are the same type because the average molecular weight is different). With good affinity, good adhesion similar to that of the prior art can be expected.

The coatings 1a, 2a and 3a are not limited to a uniform distribution, but may be island-like distributions (where islands are discontinuous) or continuous island-like distributions (where islands and islands are thin coatings). May be continuous in some parts). Further, the bearing type is not limited to the deep groove ball bearing illustrated in FIG. 1 and can be widely applied to rolling bearings in general.

[0014]

As described above, in the rolling bearing of the present invention, in a rolling bearing in which a fluorine-based grease is sealed in a bearing, at least a surface of the bearing constituting the bearing that generates rolling friction or sliding friction has PTFE. Because of the good affinity between the PTFE coating and the fluorine-based grease, the adhesion of the fluorine-based grease to the base material surface is ensured, and the same level of durability as conventional products can be secured. it can. Moreover, since it is not necessary to use chlorofluorocarbon in the film forming process, this is an effective means as a measure against the chlorofluorocarbon use restriction.

Incidentally, as a result of a durability test by the present applicant, it has been confirmed that the rolling bearing of the present invention has the same level of durability as a conventional product.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sealed deep groove ball bearing according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view schematically showing a rolling surface portion of an inner race in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 1a coating 2 Outer ring 2a coating 3 Ball 3a coating 6 Fluorine grease

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 107: 38 119: 22) C10N 40:02 50:08 50:10

Claims (1)

(57) [Claims] 1. A bearing in which a fluorine-based grease is sealed in a bearing, wherein a film made of polytetrafluoroethylene is formed on at least a surface of the parts constituting the bearing that generates rolling friction or sliding friction. Rolling bearing.