JP3985393B2 - Method for producing lubricating film on bearing member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lubricating film on a bearing member such as a rolling bearing, a ball screw bearing, a ball spline bearing, and a linear motion bearing, and more specifically, a bearing used under high vacuum, high temperature, clean environment, and the like. The present invention relates to a method for producing a lubricating film on a member.
[0002]
[Prior art]
Generally, a lubricant is used for bearing members such as rolling bearings and ball screw bearings used in vacuum equipment, semiconductor and liquid crystal substrate manufacturing apparatuses, and as a solid lubricant with low dust generation, polytetrafluoro Ethylene (hereinafter referred to as PTFE) is used, which is dispersed in a binder such as polyamide or polyimide, applied to the rolling elements or raceways of the bearing member, and baked to form a lubricating film.
[0003]
[Problems to be solved by the invention]
The lubricating film used for the bearing member as described above is required to have excellent lubricity and excellent so-called cleanliness that does not generate dust due to peeling of the lubricating film at high temperatures.
[0004]
However, since the heat resistance temperature of the binder is lower than the heat resistance temperature of PTFE, the heat resistance temperature of the lubricant film formed by baking is determined by the heat resistance temperature of the binder, and the heat resistance temperature of PTFE (up to about 330 ° C) is improved. It cannot be used.
Further, since PTFE dispersed in the binder is a particle having a particle size of about 5 μm, it is difficult to form a thin film having a thickness of 1 μm or less by dispersing and applying PTFE particles in the binder.
[0005]
As described above, since the conventional lubricating film is thick and has insufficient heat resistance, it easily peels off when used at high temperatures, resulting in problems of dust generation and deterioration of lubricating performance.
The present invention aims to provide a method for producing a heat resistance and cleanness excellent lubricating film in the axial receiving member.
[0006]
[Means for Solving the Problems]
Method of manufacturing a lubricating film to the bearing member according to claim 1 for solving the above problems at least the rolling elements, the track portion of the bearing member having a raceway portion that guides the run rolling of the rolling elements, the average molecular weight of 25,000 or less of polytetrafluoroethylene particles dispersed in a solvent and coating the fabric, volatilize the solvent by heating and drying the bearing member, the axial load between the front Kiten body and said track portion multiplied wherein the polytetrafluoroethylene particles be familiar rotated Ru deposited in grain pressing the surface of the track section.
[0007]
Thus, if production of lubricating film to the bearing member by the method of the present invention, the average molecular weight of 25,000 composed only of the following fluororesin, yet be thinned below a thickness 1μm without a binder lubricating film since it is, superior in heat resistance and cleanliness, a bearing member that can effectively prevent a reduction in dust and the lubricating performance due to use at high temperatures is obtained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a rolling bearing in which a lubricating film is manufactured using the method of the present invention. In this rolling bearing, an inner ring 1 and an outer ring 2 are arranged concentrically. Between the inner ring 1 and the outer ring 2, a plurality of balls 3 as rolling elements and a cage 4 that holds the balls 3 are provided. It is intervened. Lubricating films 5 made of PTFE are formed on the balls 3, the pockets of the cage 4, and the raceways 11 and 21 of the inner ring 1 and the outer ring 2 on which the balls 3 roll.
[0012]
The inner ring 1, the outer ring 2, the plurality of balls 3 and the cage 4 are all made of bearing steel, stainless steel, ceramics, or the like.
The lubricating film 5 is manufactured by, for example, a method as shown in FIG. FIG. 2 shows an example in which the lubricating film 5 is formed on the track portion 11 of the inner ring 1. As shown in FIG. 2, first, PTFE particles are applied to at least the surface of the raceway portion 11 of the inner ring 1 as a base material. The PTFE particles have a particle size of about 5 μm and an average molecular weight of 25000 or less, preferably 8000 to 25000. This is dispersed in a solvent such as alternative chlorofluorocarbon such as CH ₃ CCl ₂ F and applied to the surface of the track portion 11. The application method is not particularly limited, and examples thereof include various methods such as dripping, dipping, and spraying. In this state, as shown in FIG. 2 (a), the film thickness (t1) is about 5 to 15 μm due to the overlap of the PTFE particles 6 or the like.
[0013]
In the state shown in FIG. 2 (a), the rolling bearing shown in FIG. 1 is assembled, and the ball 3 is loaded with a load on the raceway portion 11 to rotate it, and the PTFE particles 6 are crushed on the surface of the raceway portion 11 to obtain a film thickness of 1 μm. The following lubricating film 5 is adhered. The load is about 1 to 2 GPa and the familiar rotation is about 3 to 8 rotations. The film thickness of the lubricating film 5 is preferably about 1 to 0.1 μm.
[0014]
The load is performed so that the load is uniformly applied to the entire surface of the track portion 11 along at least one of the radial direction and the axial direction. It is particularly preferable to apply a load in the axial direction.
The solvent in which the PTFE particles 6 are dispersed is heated and volatilized either before or after the familiar rotation to dry the PTFE particles 6. Drying is performed by, for example, hot air drying at about 100 ° C.
[0015]
In this embodiment, since the lubricating film 5 is coated with PTFE particles 6 without using a binder, the PTFE particles 6 have excellent heat resistance, and the coated PTFE particles 6 are crushed to a thickness of 1 μm or less. Therefore, it has high lubrication characteristics. As a result, it can be used up to about 300 ° C. under high vacuum, and exhibits excellent clean performance with little dust generation.
[0016]
Thus, since the lubricating film 5 has good heat resistance, lubricity and low dust generation properties, the rolling bearing provided with this lubricating film 5 is in a special environment where cleanliness is required under high vacuum and high temperature. It can be used in
The lubricating film 5 may be attached to at least one of the ball 3, the pocket of the cage 4, the track portion 11, and the track portion 21. Moreover, although the rolling bearing shown in this embodiment includes the cage 4, it goes without saying that the rolling bearing can also be applied to a rolling bearing such as a full ball bearing without a cage.
[0017]
FIG. 3 is a cross-sectional view of a ball screw bearing in which a lubricating film is manufactured using the method of the present invention. This ball screw bearing is configured such that a reflux path 36 for the ball 34 is provided on the upper surface of the housing 35 and the ball 34 is guided by the screw groove 32 and the ball groove 33 of the screw 31. 34, a lubricant film is attached to at least one of the thread groove 32 and the ball groove 33. This lubricating film is formed in the same manner as the lubricating film in the rolling bearing .
This ball screw bearing can also be used in a special environment where cleanliness is required under high vacuum and high temperature, like the rolling bearing shown in FIG.
[0018]
FIG. 4 is a sectional view of a ball spline bearing in which a lubricating film is manufactured using the method of the present invention. In this ball spline bearing, an outer cylinder raceway portion 43 for guiding the ball 42 is provided on the inner wall of the outer cylinder 41, and a cage 44 and a spline shaft 45 for holding the ball 42 are inserted inside the ball spline bearing. A lubricating film is attached to at least one of the balls 42 and the outer cylindrical raceway portion 43 of the spline bearing. This lubricating film is formed in the same manner as the lubricating film in the rolling bearing .
This ball spline bearing can also be used in a special environment requiring cleanliness under high vacuum and high temperature, like the rolling bearing shown in FIG.
[0019]
FIG. 5 is a perspective view of a linear motion bearing in which a lubricating film is manufactured using the method of the present invention. In this linear motion bearing, track portions 52 for guiding the block 53 are provided on both sides of the linear rail 51, and rolling elements (not shown) that roll on both ends 54 of the block 53 while engaging the track portion 52. It is a linear motion bearing provided. A lubricating film is attached to at least one of the track portion 52 and the rolling elements. This lubricating film is formed in the same manner as the lubricating film in the rolling bearing .
As with the rolling bearing shown in FIG. 1, this linear motion bearing can also be used in a special environment that requires cleanliness under high vacuum and high temperature.
[0020]
【Example】
Hereinafter, the manufacturing method of the lubricating film on the bearing member of the present invention will be described with reference to examples and comparative examples.
Examples A dispersion liquid in which PTFE particles having an average molecular weight of 8000 to 25000, an average particle diameter of 5 μm, and a heat resistant temperature of 330 ° C. are dispersed in an alternative flon is applied to the raceway of the bearing, dried with hot air, and then axially 1 to 2 GPa. The PTFE particles were crushed by applying a load and running in conformity (5 rotations) to adhere a 1 μm thick lubricating film to the track.
[0021]
Comparative Example A lubricating film having a thickness of 5 to 15 μm was deposited in the same manner as in the example except that it did not rotate in conformity with the load.
[0022]
About each bearing of an Example and a comparative example, the amount of dust generation in the initial 10-hour operation under high vacuum and high temperature was investigated. The result is shown in FIG. As shown in the figure, it can be seen that the lubrication film (Example) subjected to the acclimation treatment has an extremely reduced dust generation amount compared to the lubrication film (comparative example) which has not been acclimated.
[0023]
On the other hand, in each bearing of the example and the comparative example, the rotational torque was compared. The result is shown in FIG. As shown in the figure, it can be seen that the lubrication film (Example) subjected to the acclimation treatment has a lower rotational torque and less variation in measurement than the lubrication film (comparative example) not subjected to the acclimation treatment.
[0024]
【The invention's effect】
By producing a lubricating film to the bearing member using the method of claim 1, superior in heat resistance and cleanness, the bearing can be effectively prevent a reduction in dust and the lubricating performance due to use at high temperatures A member is obtained.
[0026]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rolling bearing manufactured with a lubricating film using the method of the present invention.
FIG. 2 is an explanatory view showing a method for forming a lubricating film in the present invention.
FIG. 3 is a cross-sectional view of a ball screw bearing in which a lubricating film is manufactured using the method of the present invention.
4 is a cross-sectional view of a ball Lumpur spline bearings produced lubricating film using the method of the present invention.
FIG. 5 is a cross-sectional view of a linear motion bearing in which a lubricating film is manufactured using the method of the present invention.
FIG. 6 is a graph comparing the amount of dust generation between an example and a comparative example.
FIG. 7 is a graph comparing rotational torques of an example and a comparative example.

Claims (1)

Applying polytetrafluoroethylene particles having an average molecular weight of 25000 or less dispersed in a solvent to the raceway of the bearing member having at least a rolling element and a raceway for guiding rolling of the rolling element,
The bearing member is volatilized by heating and drying the bearing member,
Production of a lubricating film on a bearing member, characterized in that polytetrafluoroethylene particles are crushed and adhered to the surface of the raceway portion by applying an axial load between the rolling elements and the raceway portion, and rotating in accordance with the axial load. Method.

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