JP2008256197A - Rolling bearing and manufacturing method thereof - Google Patents

Abstract

A rolling bearing and a method of manufacturing the same are provided.
A deep groove ball bearing includes an inner ring, an outer ring, a plurality of rolling elements, a non-contact type sealing device, and a lubricant. An inner end portion 5 b of the sealing device 5 is opposed to the outer peripheral surface of the inner ring 1 with a gap, and an inner end portion 5 b of the sealing device 5 that faces the inner ring 1 and a surface of the inner ring 1 of the sealing device 5. Minute irregularities are formed on at least one of the opposed surface 1b facing the inner end 5b. An oil repellent film made of an oil repellent is coated on the portion where minute irregularities are formed.
[Selection] Figure 2

Description

  The present invention relates to a rolling bearing and a manufacturing method thereof.

In rolling bearings, low torque may be required depending on the application. In such a case, the torque can be reduced by using a non-contact type sealing device (seal, shield, etc.) that does not come into sliding contact with the race, or by using lubricating oil without using grease as a lubricant. Figured.
However, when a non-contact type sealing device is used, there is a problem that the lubricant is likely to leak from there because there is a gap between the race and the sealing device. In particular, when lubricating oil is used as the lubricant, leakage is likely to occur due to low viscosity.
Patent Document 1 discloses a rolling bearing in which an oil repellent film that repels a lubricant is formed on a facing portion of a raceway ring and a sealing device that face each other across the gap. In such a rolling bearing, since the lubricant is repelled by the oil repellent film, the lubricant is hardly leaked from the gap.
JP 2006-226659 A

However, there is a case where leakage of the lubricant from the gap cannot be sufficiently suppressed only by forming the oil repellent film, and particularly when lubricating oil is used as the lubricant, the tendency is strong, and further improvement is desired. It was.
In addition, since the cylindrical roller bearing is often used in an oil tank, there is a problem that a space for providing the oil tank is required and that it is expensive to use the cylindrical roller bearing.
Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a rolling bearing that hardly causes the lubricant to leak and a manufacturing method thereof.

  In order to solve the above problems, the present invention has the following configuration. That is, the rolling bearing according to claim 1 of the present invention includes an inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the inner ring. A non-contact type sealing device that is attached to one of the race rings and faces the other race ring with a gap, and in a bearing internal space surrounded by the inner ring, the outer ring, and the seal device A rolling bearing provided with a lubricant that lubricates between both the raceway surfaces and the rolling surfaces of the rolling elements, and a facing portion that faces the other raceway of the sealing device; At least one of the surfaces of the other bearing ring facing the facing portion of the sealing device is formed with minute irregularities and covered with an oil repellent coating made of an oil repellent. Features.

When at least one of the facing portion of the sealing device and the facing surface of the other raceway ring has minute irregularities, which increases the surface area, so that no minute irregularities are formed Compared with, the oil repellency of the oil-repellent coating coated thereon is higher (the larger the surface area, the higher the oil repellency). Therefore, the leakage of the lubricant is less likely to occur from the gap between the sealing device and the other raceway ring, and the leakage is sufficiently suppressed even if the lubricant is a lubricating oil having a low viscosity. Moreover, since the oil-repellent coating also has the property of repelling water, the entry of water from the gap is also suppressed.
Furthermore, as described above, the cylindrical roller bearing is often used in an oil tank, but since it is difficult for the lubricant to leak out, it is not necessary to use the cylindrical roller bearing in the oil tank. Therefore, a space for providing the oil tank is unnecessary, and the cost required for using the cylindrical roller bearing can be reduced.

  A rolling bearing according to a second aspect of the present invention includes an inner ring, an outer ring, a plurality of rolling elements arranged to freely roll between a raceway surface of the inner ring and a raceway surface of the outer ring, and the inner ring. A non-contact type sealing device that is attached to one of the race rings and faces the other race ring with a gap, and in a bearing internal space surrounded by the inner ring, the outer ring, and the seal device A rolling bearing comprising a lubricant that lubricates between both raceway surfaces and the rolling surfaces of the rolling elements, at least one of the entire surface of the sealing device and the entire surface of the other raceway Is characterized in that fine irregularities are formed and an oil-repellent film made of an oil-repellent is coated.

Such a rolling bearing has a process for forming minute irregularities and an oil repellency, in addition to the fact that the lubricant is unlikely to leak from the gap between the sealing device and the other raceway ring for the same reason as described above. Since the coating process is performed on the entire surface of the member (sealing device, the other race ring), it can be manufactured at low cost and easily.
In addition, when the entire surface of the sealing device is covered with an oil repellent coating, the lubricant in the bearing inner space is repelled on the inner surface of the sealing device and supplied to the sliding portion between the raceway surface and the rolling element. Therefore, the lubricity of the rolling bearing is excellent. Further, when the entire surface of the other raceway is covered with an oil repellent coating, rust is unlikely to occur on the raceway.

  Furthermore, a rolling bearing according to a third aspect of the present invention includes an inner ring, an outer ring, a plurality of rolling elements arranged to freely roll between a raceway surface of the inner ring and a raceway surface of the outer ring, and the inner ring. A non-contact type sealing device that is attached to one of the race rings and faces the other race ring with a gap, and in a bearing internal space surrounded by the inner ring, the outer ring, and the seal device A rolling bearing provided with a lubricant that lubricates between both of the raceway surfaces and the rolling surface of the rolling element, the entire raceway of the sealing device and the raceway among the surfaces of the other raceway ring. At least one of the entire surface excluding the surface is formed with minute irregularities and an oil repellent film made of an oil repellent is coated.

  Such a rolling bearing has a process for forming minute irregularities and an oil repellency, in addition to the fact that the lubricant is unlikely to leak from the gap between the sealing device and the other raceway ring for the same reason as described above. Since the coating process is performed on almost the entire surface of the member (sealing device, the other raceway ring), it can be manufactured at low cost and easily. Further, since the oil repellent coating is not coated on the raceway surface of the other raceway, formation of the lubricating oil film at the sliding portion between the raceway surface and the rolling element is not hindered.

Further, when the entire surface of the sealing device is covered with an oil repellent coating, the lubricant in the bearing inner space is repelled on the inner surface of the sealing device and supplied to the sliding portion between the raceway surface and the rolling element. Therefore, the lubricity of the rolling bearing is excellent. Further, when the oil repellent coating is coated on the entire surface except the raceway surface of the other raceway ring, the raceway is unlikely to rust.
Furthermore, the rolling bearing of Claim 4 which concerns on this invention is a rolling bearing as described in any one of Claims 1-3, The part to which the said sealing device was attached among the said one bearing rings, and its peripheral part And an oil-repellent film made of an oil-repellent agent.

  Lubricant may leak from the part to which the sealing device is attached. However, if the oil-repellent coating is coated on the part to which the sealing device is attached and its peripheral part, the lubricant will be repelled. The leakage of the lubricant can be almost suppressed. Further, when an oil repellent coating is coated on the entire surface of the one raceway ring or on the entire surface except the raceway surface of the one raceway ring, rust is hardly generated on the raceway ring.

Furthermore, the rolling bearing of Claim 5 which concerns on this invention is a rolling bearing as described in any one of Claims 1-4, The said micro unevenness | corrugation is formed by spraying of the projection material, It is characterized by the above-mentioned. And
According to the spraying of the projecting material, minute irregularities can be easily formed at low cost, and such a rolling bearing is inexpensive.

Furthermore, the rolling bearing according to a sixth aspect of the present invention is the rolling bearing according to the fifth aspect, wherein the projection material is silicon carbide fine particles.
Furthermore, the rolling bearing of Claim 7 which concerns on this invention is a rolling bearing as described in any one of Claims 1-6. WHEREIN: While the said oil-repellent film has fluorocarbon silane as a main component, fluorocarbon silane and alkoxy It contains a copolycondensate with silane.

Furthermore, the rolling bearing according to claim 8 of the present invention is the rolling bearing according to any one of claims 1 to 7, wherein the oil repellent coating comprises fluorocarbon silane, alkoxysilane, a surfactant, and a catalyst. It is obtained by placing the aqueous emulsion contained in a film on the surface to be treated and heating.
Such an oil-repellent coating has high adhesion to the base and is not easily damaged. Therefore, the rolling bearing has a long life with little lubricant leaking over a long period of time.

Furthermore, the manufacturing method of the rolling bearing of claim 9 according to the present invention includes an inner ring, an outer ring, and a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring. A non-contact type sealing device that is attached to one of the inner ring and the outer ring and faces the other bearing ring with a gap, and a bearing surrounded by the inner ring, the outer ring, and the sealing device A rolling bearing comprising an inner space and a lubricant that lubricates between both of the raceway surfaces and the rolling surface of the rolling element, over the entire surface of the other raceway ring. A projecting step of spraying a projecting material to form minute irregularities, and a finishing step of polishing only the raceway surface of the entire surface of the other race ring on which the minute irregularities are formed by the projecting step; Before the raceway surface is finished by the finishing process And oil-repellent treatment step of coating the other consisting of oil-repellent agent on the entire surface of the bearing ring oil-repellent coating, in that it comprises the features.
According to such a method, since the process of forming minute irregularities and the process of covering the oil repellent film are performed on the entire surface of the member (sealing device, the other raceway ring), the rolling of the lubricant is less likely to occur. The bearing can be easily manufactured at low cost.

  Furthermore, the rolling bearing manufacturing method according to claim 10 of the present invention includes an inner ring, an outer ring, and a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring. A non-contact type sealing device that is attached to one of the inner ring and the outer ring and faces the other bearing ring with a gap, and a bearing surrounded by the inner ring, the outer ring, and the sealing device A rolling bearing comprising an inner space and a lubricant that lubricates between both of the raceway surfaces and the rolling surface of the rolling element, over the entire surface of the other raceway ring. A projection step of spraying a projection material to form minute irregularities, and an oil-repellent treatment step of covering an entire surface of the other race ring on which the minute irregularities are formed by the projection step with an oil-repellent coating made of an oil-repellent agent And the oil repellent coating is coated by the oil repellent treatment step. Characterized in that it and a finishing step of the polishing process is performed only on the raceway surface of the entire surface of the other race.

  According to such a method, the process of forming minute irregularities and the process of coating the oil-repellent coating are performed on the entire surface of the member (sealing device, the other raceway ring), and then the polishing process is performed only on the raceway surface. As a result, the oil-repellent coating formed on the raceway surface is removed at this time, so that it is possible to easily produce a rolling bearing that is unlikely to cause leakage of the lubricant. Further, since the oil repellent coating is not coated on the raceway surface of the other raceway, formation of the lubricating oil film at the sliding portion between the raceway surface and the rolling element is not hindered.

Furthermore, the rolling bearing manufacturing method according to claim 11 of the present invention is the rolling bearing manufacturing method according to claim 9 or 10, wherein a projection material is sprayed on the entire surface of the sealing device to form minute irregularities. And a step of coating an oil-repellent film made of an oil-repellent agent.
According to the spraying of the projection material, minute irregularities can be easily formed at low cost. Therefore, the rolling bearing can be easily manufactured at low cost.
Furthermore, the manufacturing method of the rolling bearing of Claim 12 which concerns on this invention is a manufacturing method of the rolling bearing as described in any one of Claims 9-11. WHEREIN: The said projection material is a silicon carbide microparticle, It is characterized by the above-mentioned. To do.

Furthermore, the manufacturing method of the rolling bearing of Claim 13 which concerns on this invention is a manufacturing method of the rolling bearing as described in any one of Claims 9-12. WHEREIN: The said oil-repellent film has fluorocarbon silane as a main component. In addition, a copolycondensation product of fluorocarbon silane and alkoxysilane is contained.
Furthermore, the manufacturing method of the rolling bearing of Claim 14 which concerns on this invention is a manufacturing method of the rolling bearing as described in any one of Claims 9-13 WHEREIN: The said oil-repellent film is fluorocarbon silane, alkoxysilane, interface. An aqueous emulsion containing an activator and a catalyst is arranged in a film form on the surface to be treated, and is obtained by heating.

  In the rolling bearing of the present invention, the leakage of the lubricant is difficult to occur. Moreover, the manufacturing method of the rolling bearing of this invention can manufacture the rolling bearing which is hard to produce a lubricant leak at low cost and easily.

Embodiments of a rolling bearing according to the present invention will be described in detail with reference to the drawings.
[First embodiment]
FIG. 1 is a partial longitudinal sectional view showing a structure of a deep groove ball bearing which is an embodiment of a rolling bearing according to the present invention.
The deep groove ball bearing shown in FIG. 1 includes an inner ring 1 having a raceway surface 1a, an outer ring 2 having a raceway surface 2a opposite to the raceway surface 1a, and a plurality of rolling elements disposed between the raceway surfaces 1a and 2a. A moving body (ball) 3, a cage 4 that holds the rolling element 3 between the inner ring 1 and the outer ring 2, and non-contact type sealing devices 5 and 5 (for example, a seal and a shield) are provided. In the bearing inner space surrounded by the inner ring 1, the outer ring 2, and the sealing devices 5, 5, the lubricant 6 that lubricates between the raceway surfaces 1 a and 2 a and the rolling surface 3 a of the rolling element 3. (For example, lubricating oil, grease) is arranged.

  The sealing device 5 is a substantially annular member, and an outer end portion 5 a thereof is attached to both axial end portions of the inner peripheral surface of the outer ring 2. In FIG. 1, the outer end portion 5 a of the sealing device 5 is caulked and inserted into grooves formed at both axial end portions of the inner peripheral surface of the outer ring 2. The inner end 5 b of the sealing device 5 is opposed to the outer peripheral surface of the inner ring 1 with a gap. The outer ring 2 corresponds to “one race ring (a race ring to which a sealing device is attached)” which is a constituent requirement of the present invention, and the inner ring 1 corresponds to “the other race ring (sealing device) which is a constituent requirement of the present invention. Corresponds to an orbiting ring facing with a gap). The inner end 5b of the sealing device 5 may be attached to the inner ring 1 and the outer end 5a may be opposed to the inner peripheral surface of the outer ring 2 with a gap.

At least one of the facing portion 5b (inner end portion 5b) facing the inner ring 1 of the sealing device 5 and the facing surface 1b facing the inner end portion 5b of the sealing device 5 among the surfaces of the inner ring 1 is minute. Irregularities (not shown) are formed. Then, an oil repellent film (not shown) made of an oil repellent is coated on the portion where the minute irregularities are formed (see FIG. 2).
Since such a deep groove ball bearing has a large surface area due to the formation of minute irregularities, the oil-repellent film coated thereon is compared to a case where minute irregularities are not formed. The oil repellency is high.

  Therefore, it is difficult for the lubricant to leak out from the gap between the sealing device 5 and the inner ring 1 (labyrinth gap), and the leakage is sufficiently suppressed even if the lubricant is a lubricating oil having a low viscosity. The contact angle between the oil repellent coating and the lubricant is preferably 90 ° or more and 160 ° or less. By doing so, leakage of the lubricant is less likely to occur. Further, since the sealing device 5 is a non-contact type, the deep groove ball bearing has a low torque, and if the lubricant is a lubricating oil having a low viscosity, the deep groove ball bearing has a lower torque. And since the leakage of the lubricant hardly occurs, the deep groove ball bearing has excellent lubricity and a long life. Furthermore, since the oil-repellent coating also has a property of repelling water, entry of water from the gap is also suppressed.

  As shown in FIG. 2, the facing surface 1 b of the inner ring 1 is a portion that forms a labyrinth by facing the facing portion 5 b of the sealing device 5 through a gap, and a minute unevenness and oil repellent coating are formed on the facing surface 1 b. If it is formed, leakage of the lubricant from the gap between the sealing device 5 and the inner ring 1 can be sufficiently suppressed. However, the surface of the outer ring of the inner ring 1 is wider than the portion forming the labyrinth (wide in the axial direction) rather than forming the minute irregularities and the oil-repellent coating only on the portion forming the labyrinth (opposing surface 1b). Leakage of the lubricant can be further suppressed by forming fine irregularities and an oil repellent coating on the surface of the range. The minute irregularities are preferably such that the surface on which the minute irregularities are formed has a surface roughness of 0.1 μmRa to 1 μmRa.

  Here, a process for forming minute irregularities will be described. The method is not particularly limited as long as minute irregularities are formed and the surface area is increased. For example, a method of spraying a projection material (shot blasting, etc.), a method of irradiating laser light, or a method of etching Can be given. In particular, the method of spraying the projection material is preferable because the processing can be easily performed at low cost. In addition, the minute unevenness formed by spraying the projection material has no directionality to the roughness compared to the unevenness formed by ordinary grinding (the unevenness formed by grinding is the direction of processing during processing ( Depending on the grinding direction), the roughness differs between the circumferential direction and the axial direction, and the axial direction is usually rougher), and the oil repellency of the coated oil repellent film becomes higher. The type of the projection material is not particularly limited, but for example, ceramic fine particles such as silicon carbide fine particles are preferable.

Next, an oil repellent film made of an oil repellent will be described. The type of oil repellent coating is not particularly limited as long as it has sufficient oil repellency to repel the lubricant, but contains fluorocarbon silane as a main component and a copolycondensate of fluorocarbon silane and alkoxysilane. Those that do are preferred.
As the fluorocarbon silane, for example, perfluoroalkyl represented by the following chemical formula 1 is preferable. In particular, those in which k in Chemical Formula 1 is 6 are 1 to 2% by mass, those in which k is 8 are 62 to 64% by mass, those in which k is 10 are 23 to 30% by mass, and k is 12 to 18%. A mixture of perfluoroalkyl containing 2 to 6% by mass of each is preferred. As the alkoxysilane, for example, methyltrimethoxysilane is preferable.

The oil-repellent coating may be produced from an aqueous emulsion containing a surfactant and a catalyst together with the fluorocarbon silane and alkoxysilane as described above. As the surfactant, for example, a nonionic surfactant represented by R—CH ₂ CH ₂ —O— (CH ₂ CH ₂ O) ₁₁ —H is preferable. Here, R is a perfluoroalkyl group having 3 to 18 carbon atoms. The catalyst is preferably an acid or an alkali.
An oil-repellent coating is obtained when this aqueous emulsion is placed in the form of a film on the surface to be treated by dipping, coating, spraying, or the like and cured by heating. Such an oil-repellent coating has high adhesion to the base and is resistant to chemical and physical damage, so that it is difficult for the lubricant to leak out from the deep groove ball bearing over a long period of time. Ball bearings have a long life.

  In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, the minute unevenness and the oil-repellent coating are opposed to the inner end 5 b facing the inner ring 1 in the sealing device 5 and the inner end 5 b of the sealing device 5 among the surfaces of the inner ring 1. Although formed on at least one of the facing surface 1b, the present invention is not limited to this configuration.

  For example, minute irregularities and an oil-repellent coating may be formed on at least one of the entire surface of the sealing device 5 and the entire surface of the inner ring 1. In such a deep groove ball bearing, in addition to the fact that the lubricant hardly leaks from the gap between the sealing device 5 and the inner ring 1, the process of forming minute irregularities and the process of coating the oil-repellent coating are members. Since it is applied to the entire surface of (sealing device 5, inner ring 1), a deep groove ball bearing can be manufactured at low cost and easily. Further, when the entire surface of the sealing device 5 is covered with an oil repellent coating, the lubricant in the bearing inner space is repelled on the inner surface of the sealing device 5, and the raceway surfaces 1 a and 2 a and the rolling elements 3 are moved. Since it is supplied to the sliding portion, the lubricity of the deep groove ball bearing is excellent. Further, when the entire surface of the inner ring 1 is covered with an oil repellent coating, rust is unlikely to occur on the inner ring 1.

In such a deep groove ball bearing, only the raceway surface 1a of the projection process in which the projection material is sprayed on the entire surface of the inner ring 1 to form minute irregularities and the entire surface of the inner ring 1 in which the minute irregularities are formed by the projection process. Can be manufactured by a method comprising: a finishing process in which a polishing process is applied to the inner ring 1 and an oil-repellent coating process in which the entire surface of the inner ring 1 having the raceway surface 1a finished by the finishing process is coated.
According to such a method, the deep groove ball bearing is less prone to leakage of the lubricant because the process of forming minute irregularities and the process of coating the oil repellent film are performed on the entire surface of the member (sealing device 5, inner ring 1). Can be manufactured easily at low cost. In other words, in order to form minute irregularities on a part of the member by spraying the projection material, masking etc. is required, which increases the number of steps, but when the projection material is sprayed on the entire surface of the member to form minute irregularities Is easy to manufacture with less man-hours. Further, as a method of arranging the oil repellent in a film shape on the surface of the member, the dipping method is most preferable because the man-hour is small and a stable film thickness is obtained. However, even if the entire surface of the member is covered with the oil repellent film. It is preferable because an immersion method can be employed.

  In addition, minute irregularities and an oil-repellent coating may be formed on at least one of the entire surface of the sealing device 5 and the entire surface of the inner ring 1 excluding the raceway surface 1a. In such a deep groove ball bearing, in addition to the fact that the lubricant hardly leaks from the gap between the sealing device 5 and the inner ring 1, the process of forming minute irregularities and the process of coating the oil-repellent coating are members. Since it is applied to almost the entire surface of (sealing device 5, inner ring 1), it can be manufactured at low cost and easily. Further, since the raceway surface 1a is not covered with the oil repellent coating, the formation of the lubricating oil film at the sliding portion between the raceway surface 1a and the rolling element 3 is not hindered. Further, when the entire surface of the sealing device 5 is covered with an oil repellent coating, the lubricant in the bearing inner space is repelled on the inner surface of the sealing device 5, and the raceway surfaces 1 a and 2 a and the rolling elements 3 are moved. Since it is supplied to the sliding portion, the lubricity of the deep groove ball bearing is excellent. Furthermore, when the entire surface except the raceway surface 1a of the inner ring 1 is covered with an oil repellent coating, the inner ring 1 is unlikely to rust.

Such a deep groove ball bearing has a projection process in which a projection material is sprayed on the entire surface of the inner ring 1 to form minute irregularities, and an entire surface of the inner ring 1 on which the minute irregularities are formed by the projection process. An oil repellent treatment step for coating an oil coating and a finishing step for polishing only the raceway surface 1a out of the entire surface of the inner ring 1 coated with the oil repellent coating by the oil repellent treatment step. Can do.
According to such a method, the process of forming minute irregularities and the process of coating the oil-repellent film are performed on the entire surface of the member (sealing device 5, inner ring 1), and thereafter the polishing process is performed only on the raceway surface 1a. Therefore (at this time, the oil-repellent coating formed on the raceway surface 1a is removed), and for the same reason as described above, it is possible to easily manufacture a deep groove ball bearing that is less prone to lubricant leakage. Further, since the raceway surface 1a is not covered with the oil repellent coating, the formation of the lubricating oil film at the sliding portion between the raceway surface 1a and the rolling element 3 is not hindered.

Furthermore, minute irregularities and an oil-repellent coating are formed on the portion of the outer ring 2 where the sealing device 5 is attached (grooves formed at both axial ends of the inner peripheral surface of the outer ring 2) and its peripheral portion. Also good. Although the lubricant may leak from the portion where the sealing device 5 is attached (particularly when the sealing device 5 is a metal shield and attached to the race ring by caulking), the portion where the sealing device 5 is attached If the oil repellent coating is coated on the periphery thereof, the lubricant is repelled, so that leakage of the lubricant from the portion can be almost suppressed. When the outer end portion 5a of the sealing device 5 is swaged and inserted into the groove, the oil repellent coating film may be peeled off from the portion of the outer ring 2 where the sealing device 5 is attached or the portion of the sealing device 5 that is swaged. However, if the oil repellent coating is coated on the peripheral portion of the outer ring 2 and a portion on the inner end portion 5b side of the portion to which the sealing device 5 is caulked, leakage of the lubricant can be hardly suppressed. It is. Further, when the oil repellent film is coated on the entire surface of the outer ring 2 or the entire surface of the outer ring 2 except the raceway surface 2a, the outer ring 2 is hardly rusted.
Furthermore, the deep groove ball bearing may or may not include a cage. Furthermore, the trajectory may be a single row or a double row.

[Second Embodiment]
FIG. 3 is a partial longitudinal sectional view showing a structure of a cylindrical roller bearing which is another embodiment of the rolling bearing according to the present invention. The configuration and operation of the cylindrical roller bearing of this embodiment are substantially the same as the deep groove ball bearing of the first embodiment except that the types of bearings are different. Description of is omitted. In FIG. 3, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  The cylindrical roller bearing shown in FIG. 3 includes an inner ring 1 having a raceway surface 1a, an outer ring 2 having a raceway surface 2a facing the raceway surface 1a, and a plurality of rolling rollers arranged between the raceway surfaces 1a and 2a. A moving body (cylindrical roller) 3, a cage 4 that holds the rolling element 3 between the inner ring 1 and the outer ring 2, and non-contact type sealing devices 5 and 5 (for example, a seal and a shield) are provided. In the bearing inner space surrounded by the inner ring 1, the outer ring 2, and the sealing devices 5, 5, the lubricant 6 that lubricates between the raceway surfaces 1 a and 2 a and the rolling surface 3 a of the rolling element 3. (For example, lubricating oil, grease) is arranged.

  The sealing device 5 is a substantially annular member, and an outer end portion 5 a thereof is attached to both axial end portions of the inner peripheral surface of the outer ring 2. In FIG. 3, the outer end portion 5 a of the sealing device 5 is caulked and inserted into grooves formed at both axial end portions of the inner peripheral surface of the outer ring 2. The inner end 5 b of the sealing device 5 is opposed to the outer peripheral surface of the inner ring 1 with a gap. The outer ring 2 corresponds to “one race ring (a race ring to which a sealing device is attached)” which is a constituent requirement of the present invention, and the inner ring 1 corresponds to “the other race ring (sealing device) which is a constituent requirement of the present invention. Corresponds to an orbiting ring facing with a gap). The inner end 5b of the sealing device 5 may be attached to the inner ring 1 and the outer end 5a may be opposed to the inner peripheral surface of the outer ring 2 with a gap.

At least one of the facing portion 5b (inner end portion 5b) facing the inner ring 1 of the sealing device 5 and the facing surface 1b facing the inner end portion 5b of the sealing device 5 among the surfaces of the inner ring 1 is minute. Irregularities (not shown) are formed. Then, an oil repellent film (not shown) made of an oil repellent is coated on the portion where the minute irregularities are formed (see FIG. 2).
Since such cylindrical roller bearings have a large surface area due to the formation of minute irregularities, the oil-repellent coating coated thereon is less than when no minute irregularities are formed. The oil repellency is high.

  Therefore, it is difficult for the lubricant to leak out from the gap between the sealing device 5 and the inner ring 1 (labyrinth gap), and the leakage is sufficiently suppressed even if the lubricant is a lubricating oil having a low viscosity. Further, since the sealing device 5 is a non-contact type, the cylindrical roller bearing has a low torque. If the lubricant is a lubricating oil having a low viscosity, the cylindrical roller bearing has a lower torque. Further, since the lubricant hardly leaks, the cylindrical roller bearing has excellent lubricity and a long life. Since the other points are substantially the same as the deep groove ball bearing of the first embodiment, the description thereof is omitted.

  In addition, although the deep groove ball bearing was illustrated and demonstrated in the first embodiment and the cylindrical roller bearing in the second embodiment, the present invention can be applied to other types of various rolling bearings. . For example, radial roller bearings such as angular contact ball bearings, self-aligning ball bearings, tapered roller bearings, needle roller bearings, self-aligning roller bearings, and thrust-type rolling bearings such as thrust ball bearings and thrust roller bearings is there.

〔Example〕
The present invention will be described more specifically with reference to the following examples. A deep groove ball bearing (inner diameter 30 mm, outer diameter 72 mm, width 19 mm) having a nominal number 6306 equipped with a stainless non-contact seal was manufactured as follows. The lubricant used is a poly α-olefin oil having a kinematic viscosity at 40 ° C. of 48 mm ² / s.

  Example 1: A minute unevenness was formed by projecting a projection material on the entire surface of the inner ring at an injection pressure of 4.0 MPa for 10 minutes. The projection material is silicon carbide fine particles having an average particle diameter of 40 μm. An oil-repellent coating was coated on the entire surface of the inner ring having minute irregularities by applying an aqueous emulsion containing fluorocarbon silane, alkoxysilane, surfactant, and catalyst and heating.

  Specifically, it is as follows. 100 parts by mass of fluorocarbon silane and 30 parts by mass of a surfactant were dissolved in 80 parts by mass of water. While stirring the obtained emulsion, 2.5% by mass of fluorocarbon silane was slowly added to the emulsion to keep the fluorocarbon silane hydrolyzed while suppressing self-condensation of the fluorocarbon silane. The phosphoric acid was added there until it became pH3. Next, methyltrimethoxysilane was added so that the mole fraction of alkoxysilane to fluorocarbonsilane was 0.45, and the mixture was stirred for 4 hours to complete an aqueous emulsion. When the aqueous emulsion thus obtained was applied in the form of a film over the entire surface of the inner ring and cured by, for example, heating at 200 ° C. for 30 minutes, an oil-repellent coating was obtained.

  Then, only the raceway surface of the entire surface of the inner ring was polished to finish (that is, minute irregularities and oil repellent coating on the raceway surface were removed by the polishing process). Such an inner ring, an outer ring, a ball as a rolling element, and a non-contact seal having the same projection and oil-repellent coating as those described above were assembled to form a deep groove ball bearing. The non-contact seal was attached to both axial end portions of the inner peripheral surface of the outer ring. Further, at the time of assembly, 3.0 g of a lubricant was sealed in the bearing internal space.

  Example 2: By the same projection as in Example 1, minute irregularities were formed on the entire surface of the inner ring. Of the entire surface of the inner ring, only the raceway surface was polished to finish (that is, minute irregularities on the raceway surface were removed by the polishing process). Then, the same oil repellent coating as in Example 1 was coated on the entire surface of the inner ring. Such an inner ring, an outer ring, a ball as a rolling element, and a non-contact seal having the same projection and oil-repellent coating as those described above were assembled to form a deep groove ball bearing. The non-contact seal was attached to both axial end portions of the inner peripheral surface of the outer ring. Further, at the time of assembly, 3.0 g of a lubricant was sealed in the bearing internal space.

  Comparative Example 1: The same oil repellent coating as in Example 1 was coated on the entire surface of the inner ring. Such an inner ring, an outer ring, a ball as a rolling element, and a non-contact seal coated with the same oil-repellent coating as described above were assembled into a deep groove ball bearing. In addition, neither the inner ring nor the non-contact seal is projected, and no minute unevenness is formed. Moreover, the non-contact seal was attached to both axial ends of the inner peripheral surface of the outer ring. Furthermore, at the time of assembly, 3.0 g of lubricant was sealed in the bearing internal space.

Comparative Example 2: The configuration is the same as that of Comparative Example 1 except that the entire surface of the inner ring and the entire surface of the non-contact seal are not covered with the oil repellent coating. That is, it is a general bearing in which minute irregularities and an oil repellent film are not formed on either the inner ring or the non-contact seal.
Comparative Example 3: The configuration is the same as that of Example 1 except that the entire surface of the inner ring and the entire surface of the non-contact seal are not covered with the oil repellent coating.

  Comparative Example 4: The surface of the inner ring and the entire surface of the non-contact seal are not formed with minute irregularities, and the oil repellent coating coated on the entire surface of the inner ring and the entire surface of the non-contact seal is a perfluoroalkyl. Example 2 is the same as Example 2 except that it is formed by application of an ethyl acrylate copolymer (Nox Guard ST-430 manufactured by NOK Corporation, see Chemical Formula 2 for chemical structure). It is the same composition. In addition, l, m, and n in the following chemical formula are each an integer of 1 to 30.

These bearings were allowed to stand for one month, and the weight loss due to leakage of the lubricant sealed in the bearing internal space was measured. As a result, each of Examples 1 and 2 had a weight loss of 0.1 g, while Comparative Examples 1 to 4 had a weight loss of 0.2 g, 1.0 g, 1.5 g, and 1.2 g, respectively. It was.
Further, in place of the deep groove ball bearing having the nominal number 6306, a cylindrical roller bearing having the nominal number NU306EW (with an inner diameter of 30 mm, an outer diameter of 72 mm, and a width of 19 mm) provided with a stainless non-contact seal is used. Thus, the weight loss due to leakage of the lubricant sealed in the bearing internal space was measured. As a result, each of Examples 1 and 2 had a weight loss of 0.2 g, while Comparative Examples 1 to 4 had a weight loss of 0.3 g, 1.1 g, 1.6 g, and 1.3 g, respectively. It was.

Next, the influence of minute irregularities formed on the surface on the wettability of the lubricating oil was investigated. That is, 3 μL of poly α-olefin oil having a kinematic viscosity at 40 ° C. of 48 mm ² / s was dropped onto the surface of a carbon steel test piece, and the contact angle between the droplet and the surface of the test piece was measured. . The atmospheric temperature is 25 ° C., and the contact angle is measured 6 seconds after the dropping of the poly α-olefin oil.
The test piece A has fine irregularities formed on the surface by the same projection as in Example 1 described above, and the same oil-repellent coating as in Example 1 is coated thereon. The surface roughness Ra is 0.311 μm. The test piece B is not formed with minute irregularities, and is only covered with the same oil-repellent coating as in Example 1 described above. The surface roughness Ra is 0.004 μm. The test piece C has fine irregularities formed on the surface by the same projection as in Example 1, but the oil repellent film is not covered. The surface roughness Ra is 0.311 μm. The test piece D has neither fine irregularities nor an oil-repellent coating. The surface roughness Ra is 0.004 μm.

  The measured contact angles were 103.86 ° for test piece A, 82.27 ° for test piece B, 16.51 ° for test piece C, and 29.44 ° for test piece D. From this result, the surface of the lubricating oil with low wettability (that is, the surface having the property of repelling the lubricating oil) is further reduced in wettability with the lubricating oil by forming minute irregularities, and It can be seen that the surface with high wettability is further improved in wettability with the lubricating oil by forming minute irregularities.

It is a fragmentary longitudinal cross-section which shows the structure of the deep groove ball bearing which is one Embodiment of the rolling bearing which concerns on this invention. It is a principal part enlarged view of the rolling bearing of FIG. It is a fragmentary longitudinal cross-section which shows the structure of the cylindrical roller bearing which is another embodiment of the rolling bearing which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 1a Raceway surface 1b Opposite surface 2 Outer ring 2a Raceway surface 3 Rolling element 3a Rolling surface 5 Sealing device 5a Outer end 5b Opposite part (inner end)
6 Lubricant

Claims (14)

An inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the other one that is attached to one of the race rings of the inner ring and the outer ring A non-contact type sealing device facing the raceway with a clearance, and a bearing inner space surrounded by the inner ring, the outer ring, and the sealing device, and rolling of both raceway surfaces and the rolling elements. In a rolling bearing comprising a lubricant that lubricates between the surfaces,
Minute concavities and convexities are formed on at least one of a facing portion of the sealing device facing the other bearing ring and a facing surface of the surface of the other bearing ring facing the facing portion of the sealing device. A rolling bearing characterized in that it is coated with an oil repellent film made of an oil repellent. An inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the other one that is attached to one of the race rings of the inner ring and the outer ring A non-contact type sealing device facing the raceway with a clearance, and a bearing inner space surrounded by the inner ring, the outer ring, and the sealing device, and rolling of both raceway surfaces and the rolling elements. In a rolling bearing comprising a lubricant that lubricates between the surfaces,
At least one of the entire surface of the sealing device and the entire surface of the other race ring is formed with minute irregularities and is coated with an oil repellent film made of an oil repellent. . An inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the other one that is attached to one of the race rings of the inner ring and the outer ring A non-contact type sealing device facing the raceway with a clearance, and a bearing inner space surrounded by the inner ring, the outer ring, and the sealing device, and rolling of both raceway surfaces and the rolling elements. In a rolling bearing comprising a lubricant that lubricates between the surfaces,
At least one of the entire surface of the sealing device and the entire surface of the other raceway ring except the raceway surface is formed with minute irregularities and covered with an oil repellent film made of an oil repellent. A rolling bearing characterized by   4. The oil repellent film made of an oil repellent agent is coated on a portion where the sealing device is attached and a peripheral portion of the one raceway ring, according to claim 1. Rolling bearings.   The rolling bearing according to claim 1, wherein the minute unevenness is formed by spraying a projection material.   The rolling bearing according to claim 5, wherein the projecting material is silicon carbide fine particles.   The rolling bearing according to any one of claims 1 to 6, wherein the oil-repellent coating contains fluorocarbon silane as a main component and a copolycondensate of fluorocarbon silane and alkoxysilane.   The oil repellent coating film is obtained by placing an aqueous emulsion containing a fluorocarbon silane, an alkoxysilane, a surfactant, and a catalyst on the surface to be treated, and heating the film. The rolling bearing as described in any one of Claims 1-7. An inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the other one that is attached to one of the race rings of the inner ring and the outer ring A non-contact type sealing device facing the raceway with a clearance, and a bearing inner space surrounded by the inner ring, the outer ring, and the sealing device, and rolling of both raceway surfaces and the rolling elements. A method of manufacturing a rolling bearing comprising a lubricant that lubricates between surfaces,
A projection step of spraying a projecting material over the entire surface of the other race ring to form minute irregularities, and only the raceway surface among the entire surface of the other race ring formed with the minute irregularities by the projection step And a finishing step of performing a polishing process, and an oil-repellent treatment step of covering an entire surface of the other race ring whose surface has been finished by the finishing step with an oil-repellent coating made of an oil-repellent agent. A method for manufacturing a rolling bearing. An inner ring, an outer ring, a plurality of rolling elements that are freely rollable between a raceway surface of the inner ring and a raceway surface of the outer ring, and the other one that is attached to one of the race rings of the inner ring and the outer ring A non-contact type sealing device facing the raceway with a clearance, and a bearing inner space surrounded by the inner ring, the outer ring, and the sealing device, and rolling of both raceway surfaces and the rolling elements. A method of manufacturing a rolling bearing comprising a lubricant that lubricates between surfaces,
A projection step of spraying a projection material over the entire surface of the other race ring to form minute irregularities; and a surface of the other race ring where the minute irregularities are formed by the projection step. An oil-repellent treatment step for coating the oil coating; and a finishing step for polishing only the raceway surface of the entire surface of the other raceway ring coated with the oil-repellent coating by the oil-repellent treatment step. A method of manufacturing a rolling bearing characterized by the above.   The rolling bearing production according to claim 9 or 10, further comprising a step of spraying a projecting material over the entire surface of the sealing device to form minute irregularities and then coating an oil-repellent film made of an oil-repellent agent. Method.   The method of manufacturing a rolling bearing according to any one of claims 9 to 11, wherein the projection material is silicon carbide fine particles.   The rolling bearing according to any one of claims 9 to 12, wherein the oil-repellent coating contains fluorocarbon silane as a main component and a copolycondensate of fluorocarbon silane and alkoxysilane. Production method.   The oil-repellent coating is obtained by placing an aqueous emulsion containing a fluorocarbon silane, alkoxysilane, a surfactant, and a catalyst on the surface to be treated, and heating the film. A method for manufacturing a rolling bearing according to any one of claims 13 to 14.

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