JP2018168921A - Rolling bearing - Google Patents

Abstract

To provide a rolling bearing including a flocked body provided in a bearing constituent member, which can improve lubrication characteristic containing excellent low torque.SOLUTION: A rolling bearing 1 has: an inner ring 2 and an outer ring 3 as a bearing ring; a plurality of rolling bodies 4 interposed between the inner ring 2 and the outer ring 3; a holder 5 holding the rolling bodies 4; and grease 12 encapsulated around the rolling bodies 4. Onto a surface contacting with the grease 12, of at least one member selected from the inner ring 2, the outer ring 3 and the holder 5, a flocked body 6 comprising a plurality of fibers is fixed. The fiber has a lipophilic coat on its surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing lubricated with lubricating oil or grease.

  A rolling bearing is generally composed of an inner ring, an outer ring, rolling elements, and a cage. In order to prevent the entry of foreign matter from the outside or to prevent the lubricant enclosed inside from flowing out, a seal member may be provided at the opening end. The inside of the bearing is lubricated with a lubricant such as oil or grease, and various measures have been taken to improve the lubrication characteristics of the bearing (longer life, lower torque, etc.).

  For example, Patent Document 1 has been proposed as a technique for improving the lubricant retention and reducing the rotational torque of the bearing. In Patent Document 1, by providing a member (planted body) formed by flocking fibers at a predetermined site in a rolling bearing, grease and lubricating oil are held at the lubricated site, and stirring and shearing of the grease are suppressed. Thus, a low torque and a long life are realized (see Patent Document 1).

JP-A-2015-194256

  With the technology of Patent Document 1, it is possible to reduce torque without significantly changing the grease type and the amount of grease charged from the existing product. However, depending on the form of flocking utilized as a lubricant holding member, for example, its characteristics and formation location, the effect may not be sufficient, and further development of improved technology is desired.

  The present invention has been made to cope with such a problem, and provides a rolling bearing that can improve lubrication characteristics including excellent torque reduction in a rolling bearing in which a flocking body is provided on a bearing component. For the purpose.

  The rolling bearing according to the present invention includes an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, a cage that holds the rolling elements, and a lubrication that is supplied to or enclosed in the bearing inner space. A rolling bearing comprising an agent, wherein in at least one bearing component selected from the inner ring, the outer ring, and the cage, the surface of the member is made of a plurality of fibers. The flocked body is fixed, and the fiber is a fiber having a lipophilic film on the surface.

  The lipophilic film is a film containing silicone oil.

  The flocked body is fixed to at least one surface selected from an inner diameter surface and an outer diameter surface of the cage. In particular, the flocked body is fixed to a portion excluding a region facing the non-orbital portion of the raceway on at least one surface selected from an inner diameter surface and an outer diameter surface of the cage. To do.

  The flocked body is provided on a shoulder adjacent to a raceway surface of the raceway.

  The rolling bearing according to the present invention includes an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, a cage that holds the rolling elements, and a lubrication that is supplied to or enclosed in the bearing inner space. And at least one bearing component selected from the inner ring, the outer ring, and the cage, and having a flocked body made of a plurality of fibers fixed to the surface of the member that contacts the lubricant Since the fiber has a lipophilic film on its surface, grease and lubricating oil can be easily stored in the fiber, and the stirring resistance can be suppressed. As a result, torque can be further reduced as compared with a case where a normal flocked body such as polyamide fiber is used as it is.

  In particular, since the lipophilic film is a film containing silicone oil, the lipophilic film is high in lipophilicity, and the lubricant retention is increased as compared with a flocked body made of only ordinary resin fibers.

  In addition, by providing the flocked body on the inner and outer diameter surfaces of the cage and not in the region facing the non-race portion of the race, while supplying oil from the flocked body on the inner and outer diameter surfaces of the cage to the rolling elements Also, an increase in torque can be suppressed.

  In addition, by providing the flocked body on the shoulder adjacent to the raceway surface (rolling surface) of the raceway, grease or lubricating oil that has exuded from the flocked body is partially supplied to the raceway surface through the shoulder. Excellent surface lubrication.

It is a partial cross section figure of the rolling bearing which concerns on one Example of this invention. FIG. 2 is a partial perspective view of the cage in FIG. 1. It is a partial cross section figure of the rolling bearing which concerns on the other Example of this invention. It is a partial cross section figure of the rolling bearing which concerns on the other Example of this invention. It is a partial perspective view of the holder | retainer in FIG.

  An example of the rolling bearing of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of a deep groove ball bearing incorporating a crown-shaped cage as a rolling bearing of the present invention, and FIG. 2 is a partial perspective view of the crown-shaped cage. As shown in FIG. 1, in the rolling bearing 1, an inner ring 2 having a raceway surface 2a on an outer peripheral surface and an outer ring 3 having a raceway surface 3a on an inner peripheral surface are arranged concentrically. A plurality of rolling elements 4 are disposed between the raceway surface 2 a of the inner ring 2 and the raceway surface 3 a of the outer ring 3. The plurality of rolling elements 4 are held by a crown-shaped cage 5. Further, the rolling bearing 1 includes an annular seal member 11 provided at both axial openings of the inner and outer rings, and in the bearing inner space constituted by the inner ring 2, the outer ring 3, the cage 5, and the seal member 11. It is lubricated by the enclosed grease 12. In this embodiment, the flocked body 6 is bonded and fixed to the inner and outer diameter surfaces of the cage 5.

  As shown in FIG. 2, the crown-shaped cage 5 is formed with a pair of opposed holding claws 8 on the upper surface of the annular main body 7 at a constant pitch in the circumferential direction, and the opposed holding claws 8 approach each other. And a pocket 9 for holding a ball as a rolling element between the holding claws 8 is formed. A flat portion 10 serving as a rising reference surface of the holding claw 8 is formed between the back surfaces of the holding claws 8 adjacent to each other formed at the edge of the adjacent pocket 9. As shown in the figure, the flocked body 6 is bonded and fixed to the outer diameter surface 5 a of the cage 5 and the inner diameter surface 5 b of the cage 5.

  The flocked body in the present invention is formed by flocking fibers (short fibers). Fixing is done with an adhesive. As a method for flocking, there are electrostatic flocking and electrostatic flocking, and a known method can be adopted. Electrostatic flocking uses a base material (bearing component) coated with an adhesive as a counter electrode, creates an electrostatic field with a high-voltage electrode, and flies short fibers with its electrostatic attraction force to form a part coated with adhesive. It is a method of raising hair. In addition to this electrostatic attraction force, electrostatic spraying is a method of flocking a forming portion to which an adhesive is applied while forcing short fibers to fly with air. In any method, a drying step, a finishing step, etc. are performed after flocking.

  As a short fiber for flocking, a fiber having a lipophilic film on its surface is used. Any lipophilic film may be used as long as it can exhibit higher lipophilicity than the original short fibers. In particular, it is preferable to form a lipophilic film by a silicone oil-based coating containing silicone oil. Further, any material can be adopted as the fiber itself as long as the coating is possible. Examples of short fibers for flocking that can be used include inorganic fibers such as synthetic resin fibers, carbon fibers and glass fibers, regenerated fibers such as rayon and acetate, and natural fibers such as cotton, silk, hemp, and wool.

  Among the synthetic resin fibers, it is preferable to use polyester resin fibers. The polyester resin is higher in lipophilicity and has a higher lubricant retention force than the polyamide resin that is often used as a flocked short fiber. Therefore, by using the polyester resin fiber, it is possible to suppress a decrease in the lubricant holding power even when the lipophilic film on the fiber surface is peeled off. In addition, since the polyester resin has low water absorption as compared with the polyamide resin, it is hardly affected by water or an aqueous cleaning solution in the production process.

  A well-known method can be employ | adopted for formation of the said lipophilic film in a flocked body. The lipophilic film may be formed on the surface of the fiber material before forming the flocked body, or may be formed so as to cover the whole after flocking the flocked body to the bearing component. By forming the flocked body after adhering and fixing, the fibers can be prevented from dropping off.

  The shape of the short fiber is not particularly limited as long as it does not interfere with other members that adversely affect the bearing function at the place where the flocked body is formed. As a specific shape, for example, those having a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex are preferable, and the density of short fibers of the flocked body is occupied by fibers per planted area. A ratio of 1 to 30% is preferable. The cross-sectional shape of the short fiber includes a circular shape and a polygonal shape. By using the short fibers having a polygonal cross section, the surface area can be made larger than that of the short fibers having a circular cross section, and it becomes easier to hold grease and lubricating oil.

  Examples of the adhesive include an adhesive mainly composed of urethane resin, epoxy resin, acrylic resin, vinyl acetate resin, polyimide resin, silicone resin and the like. For example, urethane resin solvent adhesive, epoxy resin solvent adhesive, vinyl acetate resin solvent adhesive, acrylic resin emulsion adhesive, acrylate-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive , Urethane resin emulsion adhesive, epoxy resin emulsion adhesive, polyester emulsion adhesive, ethylene-vinyl acetate copolymer adhesive and the like. These may be used independently and 2 or more types may be used together.

  The flocked body can supply lubricating oil (base oil) from the retained grease. As for the holding mode of grease, etc., it is held by the grease sealed in the bearing when it is used, and the whole grease or only its base oil is held (attached) or impregnated in advance before using the bearing. I can leave.

  The example shown in FIG. 2 is a crown-shaped cage, but in the rolling bearing of the present invention, a flocked body may be formed in a cage such as a corrugated cage, a ball cage, or a roller cage. Moreover, about the material of a holder | retainer, arbitrary materials, such as a metal material and a resin material, are employable. The crown-shaped cage shown in FIG. 2 is made of resin. For example, a polyamide resin such as polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) resin, thermoplastic polyimide resin, polyamideimide resin, nylon 66 resin, nylon 46 resin is used as a resin base material, and carbon fiber, glass fiber, etc. It is manufactured by injection molding using a resin composition containing reinforced fibers and other additives.

  The rolling bearing of the present invention is lubricated with a lubricant (lubricating oil or grease). These lubricants are supplied and sealed in the space between the inner and outer rings, and lubricated by being interposed in the rolling surface. Any lubricating oil can be used without particular limitation as long as it is usually used for rolling bearings. For example, mineral oil such as paraffinic mineral oil and naphthenic mineral oil, polybutene oil, poly-α-olefin oil, hydrocarbon synthetic oil such as alkylbenzene oil and alkylnaphthalene oil, or natural fats and oils, polyol ester oil, phosphate ester oil And non-hydrocarbon synthetic oils such as diester oil, polyglycol oil, silicone oil, polyphenyl ether oil, alkyl diphenyl ether oil, and fluorine oil. These lubricating oils may be used alone or in combination of two or more.

  When grease is used as the lubricant, examples of the base oil constituting the grease include the above-described lubricating oil. Further, as the thickening agent constituting the grease, for example, a metallic soap thickener such as aluminum soap, lithium soap, sodium soap, composite lithium soap, composite calcium soap, composite aluminum soap, diurea compound (aliphatic, fatty acid). Cyclic, aromatic diurea, etc.), urea compounds such as polyurea compounds, and fluororesin powders such as PTFE resins. These thickeners may be used alone or in combination of two or more.

  Known additives can be added to the lubricant as necessary. Examples of additives include extreme pressure agents such as organic zinc compounds and organic molybdenum compounds, antioxidants such as amine-based, phenol-based and sulfur-based compounds, anti-wear agents such as sulfur-based and phosphorus-based compounds, and polyhydric alcohols. Examples include rust preventives such as esters, viscosity index improvers such as polymethacrylate and polystyrene, solid lubricants such as molybdenum disulfide and graphite, and oily agents such as esters and alcohols.

  Another example of the rolling bearing of the present invention will be described with reference to FIG. FIG. 3 is a partial cross-sectional view of a deep groove ball bearing. In the example shown in FIG. 3, flocked bodies 6 are respectively formed on the shoulder 2 b of the inner ring 2 and the shoulder 3 b of the outer ring 3 of the rolling bearing 1 ′. It is preferable that the flocked body 6 makes only the tip part of the fiber contact the surface of the rolling element 4. Further, by providing a flocked body on the shoulder near the raceway surface, the grease that has oozed out of the flocked body is easily supplied to the raceway surface through the shoulder.

  Another example of the rolling bearing of the present invention will be described with reference to FIG. FIG. 4 is a partial cross-sectional view of a deep groove ball bearing incorporating a crown-shaped cage and a seal member. In the example shown in FIG. 4, the rolling bearing 1 ″ includes a plurality of rolling elements 4 disposed between the raceway surface 2 a of the inner ring 2 and the raceway surface 3 a of the outer ring 3. 5 is held. Further, the rolling bearing 1 ″ includes annular seal members 11 a and 11 b provided at openings in both axial ends of the inner and outer rings. The pocket opening side of the crown-shaped cage 5 is the seal member 11a, and the non-pocket opening side is the seal member 11b. The inner ring 2, the outer ring 3, the cage 5, and the seal members 11 a and 11 b form a bearing inner space (inside the bearing), and lubrication is performed by grease (not shown) held in the space.

  In this embodiment, the flocked body 6 is bonded and fixed to a part of the inner and outer diameter surfaces of the cage 5 and the bearing inner space side surface of the seal member 11a. By providing the flocked body 6 at these portions, the grease can be sufficiently retained inside the bearing. The oil held by the flocked body of the seal member is supplied to the raceway surface from the contact portion with the outer ring through the shoulder of the outer ring by surface tension. Further, in the flocked body 6 provided at the edge portion of the pocket on the inner and outer diameter surfaces of the cage 5, it is preferable to bring the tip of the fiber into contact with the surface of the rolling element 4.

  As shown in FIG. 4, in the crown-shaped cage 5, the distance between the seal member 11a on the pocket opening side and the seal member 11b on the non-pocket opening side is different, and the distance between the sealing member 11b on the non-pocket opening side is more Is close and the gap is small. In order to increase the amount of grease held inside the bearing, it is considered preferable to provide a flocking body uniformly on both seal members. However, as described above, since the gap between the seal member on the non-pocket opening side and the retainer is small, if a flocked body is provided also on this seal member, the flocked body of the seal member and the retainer interfere and contact each other. There is a risk. Therefore, in this embodiment, it is set as the structure which does not dare provide a flocking body about the sealing member of the pocket non-opening side. In addition, in this embodiment, although the flocked body 6 is provided in the radial direction whole range of the sealing member 11a, it is good also as a form provided in a part of radial direction. Similarly, the circumferential direction can be provided in the entire circumferential range or a partial range.

  The retainer 5 of this embodiment will be described in detail based on FIG. FIG. 5A is a partial perspective view of the cage, and FIG. 5B is a development view of the cage. As shown in FIG. 5A, the crown-shaped cage 5 has substantially the same shape as the cage of FIG. In this embodiment, the cage 5 is a rolling element guide type, and the inner and outer diameter surfaces thereof are surfaces that do not come into contact with the race rings (inner ring and outer ring). As shown in FIGS. 4 and 5, the cage 5 includes a region 5 c close to the raceway surface 2 a of the inner ring 2 or the raceway surface 3 a of the outer ring 3, a shoulder portion 2 b of the inner ring 2, a shoulder portion 3 b of the outer ring 3, and the like. And a region 5d close to the non-orbital portion (non-orbital surface). On the inner diameter surface of the cage 5, a flocked body 6 is formed in a region 5c close to the raceway surface of the inner ring, and a flocked body is formed in a region 5d facing the shoulder 2b of the inner ring 2 that is a non-race portion of the raceway ring. It has not been. Similarly, on the outer diameter surface of the cage 5, the flocked body 6 is formed in a region close to the raceway surface of the outer ring 3, and the flocked body is not formed in a region facing the shoulder 3b of the outer ring 3. .

  As shown in FIG. 5, the region 5d facing the shoulder portions of the inner and outer rings is located on the non-opening side of the pocket 9 of the main body 7, and is a region that occupies a certain range in the axial direction and continues in the circumferential direction. 9 is a region in a range partially corresponding to 9. When a flocked body is formed in the region 5d, the flocked body and the inner and outer ring shoulders may slide. By not providing a flocked body in this region 5d, an increase in torque due to contact with the inner and outer rings can be prevented.

  As described above, the flocked body can be provided on the surface of a cage, raceway ring, seal member, or the like. Moreover, in one rolling bearing, you may form a flocking body in the some member which comprises this, respectively.

  The rolling bearing of the present invention can be widely used as a rolling bearing in various applications because it can improve lubrication characteristics including excellent torque reduction in a rolling bearing provided with a flocked body on a bearing component.

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner ring 3 Outer ring 4 Rolling body 5 Cage 6 Flocking body 7 Cage body 8 Holding claw 9 Pocket 10 Flat part 11, 11a, 11b Seal member 12 Grease

Claims (5)

Rolling comprising an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, a cage that holds the rolling elements, and a lubricant that is supplied to or enclosed in the bearing inner space. A bearing,
In at least one bearing component selected from the inner ring, the outer ring, and the cage, a flocked body made of a plurality of fibers is fixed to a surface of the member that contacts the lubricant,
The rolling bearing according to claim 1, wherein the fiber is a fiber having a lipophilic film on a surface thereof.   The rolling bearing according to claim 1, wherein the lipophilic film is a film containing silicone oil.   The rolling bearing according to claim 1, wherein the flocked body is fixed to at least one surface selected from an inner diameter surface and an outer diameter surface of the cage.   The flocked body is fixed to a portion of at least one surface selected from an inner diameter surface and an outer diameter surface of the cage except for a region facing a non-track portion of the raceway. Item 4. A rolling bearing according to Item 3.   The rolling bearing according to claim 1, wherein the flocked body is provided on a shoulder portion adjacent to a raceway surface of the raceway.

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