JP3761727B2 - Metal lubrication film and rolling bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal lubricating film and a rolling bearing. This rolling bearing is mainly used in a vacuum environment or a high temperature environment where lubricating oil or grease cannot be used, such as an X-ray tube or a vacuum vapor deposition apparatus.
[0002]
[Prior art]
Conventionally, a rolling bearing used in a special environment as described above has a film of soft metal such as silver or lead, graphite, molybdenum disulfide, etc. on at least one of the raceway surface and rolling element surface of the bearing ring. It is known to coat.
[0003]
By the way, especially in a situation where reduction of vibration and noise is required, soft lead is suitable as a lubricating film used for a rolling bearing.
[0004]
When lead is coated with a metal material, the lead has poor adhesion when coated to the metal material. Therefore, by providing a base film such as tin (Sn), the lead adhesion can be improved. is there.
[0005]
[Problems to be solved by the invention]
As described above, in the metal lubricating film in which lead is coated with tin as a base, the melting point of lead is 327 ° C., but the melting point of tin is 231.84 ° C. Therefore, when the environmental temperature exceeds the melting point of tin, this tin Since the material melts and becomes fluid, the film becomes unstable due to peeling of lead that is not in a molten state, and the temperature further rises. As a result, tin and lead are partially alloyed, but since the melting point is low, the entire film evaporates and scatters, and the lifetime is rapidly shortened. That is, in such a rolling bearing using the conventional metal lubricating film, the operation duration time is remarkably shortened when the operating environment temperature exceeds the melting point of tin described above.
[0006]
In view of such circumstances, an object of the present invention is to provide a metal lubricating film and a rolling bearing that exhibit excellent quietness and lubricity in a wide temperature range from low temperature to high temperature.
[0007]
[Means for Solving the Problems]
Metal lubricating film according to claim 1 is a metal lubricating film to be coated with respect to at least one of the two members at least roll is used in an environment that can not use lubricating oil or grease, to lead Antimony is blended at a rate of 10 mass%.
[0008]
The rolling bearing according to claim 2 is a rolling bearing used in an environment in which lubricating oil or grease cannot be used , and at least one of the raceway surface of the bearing ring and the outer surface of the rolling element has antimony against lead. Is coated with a metal lubricating film made of an alloy containing 10 mass% .
[0009]
A rolling bearing according to a third aspect of the present invention is a rolling bearing used in an environment where lubricating oil or grease cannot be used , and at least one of the raceway surface of the bearing ring and the outer surface of the rolling element has antimony against lead. Is coated with an undercoat film made of tin. The metal lubricant film made of an alloy containing 10 mass% is coated with tin.
[0010]
The rolling bearing according to claim 4 is the rolling bearing according to claim 2 or 3, wherein the bearing ring or rolling element covered with the metal lubricating film is JIS standard SKH4, JIS standard SUS440C, JIS standard SUS630, JIS standard SUS304, It consists of any one selected from AISI standard M50 or JIS standard SUS2 to which an energization corrosion-resistant film is applied.
[0011]
In short, in the present invention, since the proportion of antimony is set so as to maintain the softness based on soft lead compared to silver or the like, the transfer of two members compared to a metal lubricating film such as silver or the like is set. The movement and sliding operation are quiet, and the lubrication action is good as in the case of using lead alone.
[0012]
Further, when the metal lubricating film is made of an alloy of lead and antimony as in claim 2, the melting point thereof becomes higher than that of lead alone, so that it can be used in a higher temperature range than the conventional example. .
[0013]
Further, if tin is used as the base film as in the fourth aspect, the adhesion of the metal lubricating film made of lead and antimony is improved, so that it is difficult to peel off even at the initial stage of operation.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on embodiments shown in the drawings.
[0015]
FIG. 1 is a longitudinal sectional view of an upper half of a rolling bearing according to Embodiment 1 of the present invention. In the figure, 1 is an inner ring, 2 is an outer ring, 3 is a rolling element made of balls, and 4 is a metal lubricating film. The inner / outer rings 1 and 2 and the rolling element 3 are made of a metal material such as JIS standard SKH4.
[0016]
In the illustrated example, the metal lubricant film 4 is coated only on the outer surface of the rolling element 3, but at least one of the outer surface of the rolling element 3 or the raceway surfaces of the inner and outer rings 1 and 2 is coated. That's fine.
[0017]
The metal lubricating film 4 in this embodiment is an alloy in which antimony (Sb) is blended at a ratio of 10 mass% with respect to lead (Pb).
[0018]
The metal lubricating film 4 is formed with a film thickness of 0.2 to 0.8 μm, for example. As a method for coating the metal lubricating film 4, for example, a known vapor deposition method such as sputtering or ion plating is employed.
[0019]
The melting point of lead serving as the base of the metal lubricating film 4 is 327 ° C. and the melting point of antimony is 630.5 ° C., but the melting point in the alloyed state at the above-mentioned ratio is 361 ° C. Further, the hardness of lead is 5 in terms of Brinell hardness, and the hardness of antimony is in the range of 30 to 58 in terms of Brinell hardness, but the hardness in the alloyed state at the above-mentioned ratio is 7 in terms of Brinell hardness.
[0020]
In such a metal lubricating film 4, the metal lubricating film 4 maintains a solid state for a period until the environmental temperature reaches a required temperature (361 ° C.) or higher. The metal lubricating film 4 is peeled off minutely and transferred to the rolling elements 3 to perform a lubricating action. However, when the required temperature (361 ° C.) or higher is reached, the metal lubricating film 4 melts and becomes a fluid state. The rolling and sliding parts between the rolling element 3 and the inner / outer rings 1 and 2 are lubricated better. Moreover, even if the metal lubricating film 4 is in a solid state, it is almost as soft as lead, so that quietness can be ensured.
[0021]
As described above, the metal lubricating film 4 in the present embodiment can exhibit good lubricity while maintaining quietness up to a high temperature range as compared with the conventional example having a two-layer structure of lead and tin. Therefore, the rolling bearing in this embodiment can be suitably used for supporting the rotating shaft of an X-ray tube, for example.
[0022]
Incidentally, the relationship between the blending ratio of lead and antimony constituting the metal lubricating film 4 and the rotational operation sound of the rolling bearing is examined using an X-ray tube bearing simulated tester as shown in FIG.
[0023]
In the X-ray tube bearing simulated tester shown in FIG. 2, 10 is a wall of the vacuum chamber, 11 is a support attached to the vacuum chamber 10 in a cantilever shape, 12 is a case surrounding the support 11, and 13 is a support. A rotating shaft that is rotatably supported by the body 11 via two test bearings 20, 20, 14 is a rotor fixed to the rotating shaft 13, 15 is a stator that gives a rotational driving force to the rotor 14, and 16 is a case in the case A halogen lamp for adjusting the ambient temperature, 17 is a thermocouple for measuring the temperature of the test bearings 20 and 20, 18 is a rotation sensor for measuring the rotation speed of the rotor 14, and 19 is a vibration pickup for measuring vibration.
[0024]
As test conditions, the pressure in the case 12 is 10 ⁻⁴ Pa or less (turbo molecular pump), the temperature of the outer ring of the test bearing 20 is 150 ° C., the rotational speed of the rotor 14 is 3000 r / min, and the test bearing is driven by its own weight. The moment load acting on 20 is 11 N · m. And the rotational operation sound of the test bearing 20 is recognized according to the measurement result by the vibration pickup 19.
[0025]
The test was performed by coating the metal lubricating film 4 only on the outer surface of the rolling element of the test bearing 20, and changing the blending ratio of lead and antimony constituting the metal lubricating film 4 as described below.
[0026]
That is, the metal lubricant film 4 in the embodiment has a composition in which the blending ratio of antimony (Sb) to lead (Pb) is set to 10 mass% as described above, and the metal lubricant film 4 in Comparative Example 1 is made of antimony. It is set as the composition which set lead to 100mass% without mix | blending, the metal lubricating film 4 in the comparative example 2 is set to the composition which set the compounding ratio of the antimony with respect to lead to 5mass%, and the metallic lubricating film 4 in the comparative example 3 is The composition ratio of antimony to lead is set to 20 mass%.
[0027]
As a result, the rotational noise of the test bearing 20 was 67 dB in the embodiment, 70 dB in the comparative example 1, 69 dB in the comparative example 2, and 70 dB in the comparative example 3. Thus, even if the blending ratio of antimony is less than 10 mass% or 10 mass% or more, the rotational operation sound of the bearing is increased, so that the blending ratio of antimony to lead is set to 10 mass% as described above. It can be said that it is preferable to specify.
[0028]
FIG. 3 is a longitudinal sectional view of the upper half of the rolling bearing according to the second embodiment of the present invention. The difference between the second embodiment and the first embodiment is that the outer surface of the rolling element 3 is coated with tin (Sn) as a base film 5 and then the surface of the metal lubricant film made of an alloy of lead and antimony. 4 is covered.
[0029]
In this case, the film thickness of the base film 5 made of tin may be as thin as 0.01 to 0.05 μm, for example. With such a structure, the adhesion of the metal lubricating film 4 to the metal rolling element 3 is improved, and therefore it is difficult to peel off even at the initial stage of operation. Even if the temperature exceeds the tin melting point, alloying lead and antimony raises the melting point, so that the entire film does not evaporate up to 361 ° C.
[0030]
In addition, this invention is not limited only to the said embodiment, Various application and deformation | transformation can be considered.
[0031]
(1) In the above embodiment, an example in which the metal lubricating film 4 is an alloy of lead and antimony is given. However, the present invention includes a two-layer structure in which antimony is a lower layer and lead is an upper layer. . Again, the ratio of antimony and lead is set to 1: 9.
[0032]
(2) In the above embodiment, a deep groove type ball bearing is used as an example, but other ball bearings (angular type ball bearings, three-point contact type ball bearings, etc.), roller bearings, and the like can be used.
[0033]
(3) In the above embodiment, the member to be coated with the metal lubricant film 4 is JIS standard SKH4. However, the member can be used up to the heat resistant temperature of the member other than JIS standard SUS440C, SUS630, SUS304 or AISI standard M50. Further, a JIS standard SUJ2 may be provided with a conductive corrosion resistant coating. Further, the rolling element 3 and any of the inner and outer rings 1 and 2 are made of a ceramic material such as silicon nitride, alumina, silicon carbide, etc., and this lubricating film is applied to the metal member to be contacted so that the metals can be in contact with each other. Compared to longer life.
[0034]
(4) In the above embodiment, a full ball bearing without a cage is used, but a cage, corrugated or crown type cage may be used. These cages include the above JIS standard SUS304 material, copper or copper alloy, polyamide resin, polyether ether ketone resin (PEEK), polyether sulfone resin (PES), polytetrafluoroethylene resin (PTFE), polyphenylene sulfide. It is formed of a synthetic resin material such as resin (PPS), phenol resin, polyimide resin, or polyamideimide resin. The metal lubricating film 4 of the present invention may be coated on the pocket surfaces of these cages. It is also possible to arrange a shield plate or an oil seal on the end faces of the inner / outer rings 1 and 2.
[0035]
【The invention's effect】
Since the metal lubricating film of the present invention has a structure in which lead and antimony are combined, a temperature range higher than that of the conventional example is ensured while ensuring quietness as in the conventional example of a structure in which lead and tin are combined. Can be suitable for use in
[0036]
Further, in the rolling bearing of the present invention, the metal lubricating film is interposed between the rolling and sliding parts, so that the quietness and lubricity can be improved over a wide range from low temperature to high temperature. It can be expanded.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an upper half of a rolling bearing according to a first embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a configuration of an X-ray tube bearing simulated tester used in an experiment of the rolling bearing according to the present invention. FIG. 3 is a longitudinal sectional view showing the upper half of a rolling bearing according to a second embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Rolling element 4 Metal lubricating film 5 Base film

Claims (4)

A metal lubricating film coated on at least one of at least two rolling members used in an environment where lubricating oil or grease cannot be used ,
A metal lubricating film comprising an alloy in which antimony is blended at a ratio of 10 mass% with respect to lead. A rolling bearing used in an environment where lubricating oil or grease cannot be used.
A rolling material characterized in that at least one of the raceway surface of the raceway and the outer surface of the rolling element is coated with a metal lubricating film made of an alloy in which antimony is mixed at a ratio of 10 mass% with respect to lead. bearing. A rolling bearing used in an environment where lubricating oil or grease cannot be used.
At least one of the raceway surface of the raceway and the outer surface of the rolling element is coated with a metal lubricating film made of an alloy in which antimony is blended at a ratio of 10 mass% with respect to lead via a base film made of tin. A rolling bearing characterized by that.   The raceway or rolling element on which the metal lubricating film is coated is composed of any one selected from JIS standard SKH4, JIS standard SUS440C, JIS standard SUS630, JIS standard SUS304, AISI standard M50, or JIS standard SUS2 with an anti-corrosion coating. The rolling bearing according to claim 2 or 3, characterized by the above-mentioned.

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