JP2017180717A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing capable of sufficiently keeping a lubricant inside the bearing while reducing rotation torque as the rolling bearing of the lubricant, and stably supplying the lubricant to a lubrication region.SOLUTION: A rolling bearing includes an inner ring and an outer ring as raceway rings, a plurality of rolling elements disposed between the inner and outer rings, and an annular cage 5 for retaining the rolling elements. The cage 5 has a recessed portion 10 of the shape recessed from the face on a part of the face of at least one face selected from an inner diameter face and an outer diameter face, an oil holding body 6 composed of a fiber material or a porous material and holding or impregnated with a lubricant in advance is fixed to the recessed portion 10, and the recessed portion 10 is formed between pockets 9 adjacent to each other, as a space for connecting the pockets 9.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing lubricated with lubricating oil.

  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. Grease is often used as the lubricant inside the bearing. Grease is easy to handle and simplifies the design of the sealing device. Grease does not need to be re-supplied and is easy to maintain. However, it is known that friction torque increases and heat is generated due to the stirring resistance of grease sealed in the bearing. As techniques for reducing friction torque and the like, techniques such as Patent Documents 1 to 3 have been proposed.

  Patent Document 1 discloses a technique for improving lubrication characteristics by changing a lubricant and lubrication conditions, and is excellent in peeling resistance and grease leakage, and for bearings that can suppress early seizure even when used in an outer ring rotary bearing. A grease composition containing a predetermined ester oil and a diurea compound in a predetermined blending amount is described (see Patent Document 1).

  In Patent Document 2, as a means for reducing the rotational torque of the bearing by changing the shape of the cage, etc., it is composed of two annular holding plates formed by a steel plate press, and a polygonal pocket portion or the like is formed. A deep groove ball bearing provided with a cage is described (see Patent Document 2). Patent Document 3 discloses a lubricating composition for bearings, which is a technique for improving lubrication characteristics by using solid grease, in which a mixture of ultrahigh molecular weight polyethylene and lubricating grease is heated and melted and then cooled and solidified. (See Patent Document 3).

Japanese Patent No. 3330755 JP 2007-292195 A Japanese Examined Patent Publication No. 63-23209

  However, Patent Document 1 improves the lubrication characteristics by improving the sealed grease. However, when a semi-solid lubricant such as grease is used, the torque is large due to the stirring resistance caused by the lubricant. Become. In rolling bearings used in automobiles and industrial equipment in recent years, it is an important issue to reduce torque while ensuring a sufficient lubrication life in order to save energy.

  With respect to this problem, the torque can be reduced by using a specially shaped cage as in Patent Document 2. The torque can also be reduced by optimizing the type of grease or reducing the amount of grease itself. However, these lead to an increase in manufacturing cost and a decrease in bearing life.

  Patent Document 3 attempts to reduce rotational torque by using thermally solidified grease. However, under high temperature conditions, there is a drawback that oil spills increase and the service life is short. Further, in the full pack specification, the composition contracts during cooling and solidification and entrains the rolling elements, which may increase the torque.

  Also, by using oil lubrication without using grease, problems such as increased torque due to grease can be solved. However, oil lubrication has a shorter lubrication life compared to grease lubrication which can release the base oil from the thickener component. In order to extend the service life, resupply of lubricating oil is usually essential. For this reason, it is desired that the lubricating oil can be sufficiently retained in the bearing so as not to require resupply. Further, in order to maintain the lubricating performance for a long period of time, it is also desired that the lubricating oil can be stably supplied to the lubricating portion while sufficiently retaining the lubricating oil.

  The present invention has been made to cope with such problems, and as a rolling bearing for oil lubrication, while reducing rotational torque, the lubricating oil can be sufficiently retained inside the bearing, and the lubricating oil can be lubricated at a lubrication site. An object of the present invention is to provide a rolling bearing that can be supplied stably.

  A rolling bearing according to the present invention is a rolling bearing comprising an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, and an annular cage that holds the rolling elements. The retainer has at least one surface selected from an inner diameter surface and an outer diameter surface, and has a recessed portion having a shape recessed from the surface in a part of the at least one surface, and the recessed portion includes a fiber material or a porous material. An oil holding body made of a material and pre-held or impregnated with lubricating oil is fixed.

  The retainer has a plurality of pockets that are opened on one side in the axial direction to hold the rolling elements on an annular retainer body, and the concave portion has these pockets between the adjacent pockets. It is provided as a space that communicates.

  The oil retaining member is a flocked portion made of a synthetic resin short fiber as the fiber material. Further, the lubricating oil is characterized in that it is held or impregnated in the oil holder in a state where no additive is added or an additive is contained.

  A 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, and an annular cage that holds the rolling elements. In addition, at least one surface selected from an inner diameter surface and an outer diameter surface has a recess having a shape recessed from the surface in a part of the surface, and the recess is made of a fiber material or a porous material and holds lubricating oil in advance. Alternatively, since the impregnated oil holding body is fixed, the lubricating oil can be sufficiently held inside the bearing (the oil holding body in the recess), and continuous operation can be performed for a long time without resupply of the lubricating oil. Further, since the grease is not sealed in the bearing inner space, the torque becomes low.

  The cage has a plurality of pockets that open on one side in the axial direction to hold the rolling elements on the annular cage body, and the concave portion serves as a space for communicating these pockets between adjacent pockets. Since it is provided, the lubricating oil can be stably supplied from the oil holding body of the recess into the pocket, and the lubricating performance can be maintained over a long period of time.

  Since the fibers in the flocked portion are short fibers of synthetic resin, they are chemically stable and hardly swell or dissolve with oil.

It is a partial cross section figure of the rolling bearing which concerns on one Example of this invention. It is a partial perspective view which shows one form of a holder | retainer. It is a partial perspective view which shows the other form of a holder | retainer. It is a partial perspective view which shows the other form of a holder | retainer.

  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 in which a predetermined resin crown-shaped cage is incorporated 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 rolling surface 2a on the outer peripheral surface and an outer ring 3 having a rolling surface 3a on the inner peripheral surface are arranged concentrically. A plurality of rolling elements 4 are disposed between the rolling surface 2a of the inner ring and the rolling surface 3a of the outer ring. The plurality of rolling elements 4 are held at equal intervals in the circumferential direction by a crown-shaped cage 5.

  As shown in FIG. 2, the crown-shaped cage 5 includes a pocket 9 on an annular cage body 7 that opens on one side in the axial direction and holds a ball as a rolling element. More specifically, a pair of opposed holding claws 8 are formed on the annular cage body 7 at a constant pitch in the circumferential direction, and the opposed holding claws 8 are bent in a direction approaching each other, A pocket 9 is formed between the holding claws 8. Here, a recess 10 is formed between adjacent pockets 9. The recess 10 has a shape that is recessed from the inner diameter surface 7a of the cage 5, and is provided as a space that communicates with the pockets 9 at both ends of the recess. That is, the recess 10 has a part of both ends thereof in the pocket 9 and communicates with the pocket 9 at the communication port 10a. Moreover, the recessed part 10 is made into the shape opened to the end surface 7b by the side of the pocket opposite opening of the holder | retainer 5. FIG.

  In the form shown in FIG. 1 and FIG. 2, in the crown-shaped cage 5 having the structure, an oil retaining body 6 such as a flocked portion made of a fiber material is bonded and fixed in a recess 10. The shaded portion shown in the figure is the maximum formation location of the oil retainer 6. By providing the oil holder 6 in the recess 10, the lubricating oil can be sufficiently held inside the bearing (the oil holder of the recess). For example, when the oil retaining body is a flocked portion, if the lubricating oil is held on the fiber before the operation, the oil can be held on the fiber even during the operation due to the surface tension of the fiber and the capillary phenomenon between the fibers. In addition to this, the concave portion is easy to accumulate lubricating oil, and the holding power of the lubricating oil is enhanced by the presence of an oil retaining body such as a flocked portion. Since the cage is in contact with the rolling elements, the lubricating oil can always be supplied to the lubricating surface. As a result, the life can be extended.

  Another example of a crown-shaped cage will be described with reference to FIG. FIG. 3 is a partial perspective view of the crown-shaped cage. As in FIG. 2, the cage 5 shown in FIG. 3 is formed on the annular cage body 7 between a pocket 9 that opens on one side in the axial direction and holds a ball as a rolling element, and an adjacent pocket. And a recess 10 formed. The recess 10 has a shape that is recessed from the inner diameter surface 7a of the cage 5, and is provided as a space that communicates with the pockets 9 at both ends of the recess. An oil holding body 6 such as a flocked portion made of a fiber material is bonded and fixed in the recess 10. The shaded portion shown in the figure is the maximum formation location of the oil retainer 6.

  In this embodiment, the communication port 10a with the pocket 9 in the recess 10 is set to a small range as compared with the case of FIG. For this reason, in the pocket 9, the ball | bowl which is a rolling element can be hold | maintained more stably. Even when the communication port 10a is small, by forming a flocked portion in this portion, lubricating oil is stably supplied into the pocket through the fiber due to the surface tension of the fiber and the capillary phenomenon between the fibers.

  Further, a flat portion 11 that is a rising reference surface of the holding claw 8 is formed between the back surfaces of the adjacent holding claws 8 formed at the edges of the adjacent pockets 9. Thus, a groove 12 between the pockets is formed. That is, the back surface (the side opposite to the pocket) of the holding claw 8 constitutes the inner surface of the groove portion 12, and the surface of the flat portion 11 constitutes the bottom surface of the groove portion 12. In addition to the recess 10, an oil holder may be formed in the groove 12.

  2 and 3 exemplify the structure in which the concave portion 10 is provided on the inner diameter surface 7a of the cage 5, the concave portion 10 may be provided on the outer diameter surface. The recess 10 may be formed on both the inner diameter surface and the outer diameter surface.

  As shown in FIG. 4, when the oil holder 6 is directly formed on the inner and outer diameter surfaces of the cage 5 (the shaded portion in the figure), depending on the cage guide type, the oil holder and the inner and outer rings may contact each other. There is a risk of increased torque. On the other hand, as shown in FIG. 2 and FIG. 3, by forming a concave portion that is recessed from the inner and outer diameter surfaces of the cage and forming an oil retaining body in the concave portion, the above contact can be avoided and torque increases Can be prevented. Moreover, when making an oil holding | maintenance body a hair transplant part, it is good also as a form from which only the front-end | tip of a hair transplant fiber protrudes from the inside of a recessed part. In particular, by adopting a form in which only the tip of the flocked fiber protrudes from the communicating port of the recess into the pocket, the ball that is the rolling element and the fiber are in light contact, and the lubricating oil held in the oil holding member of the recess is used as a ball. Smooth supply between pockets.

  The oil holding body is made of a fiber material or a porous material, and is held or impregnated in advance in a state where the lubricating oil can be released. In the case of the fiber material, the lubricating oil is held between the fibers, and in the case of the porous material, the lubricating oil is impregnated in the communication hole. Although it cannot be said that the lubricating oil taken up in the closed cells which are not in communication with the surface can be released, the lubricating oil contained in the surface communicating hole can be released even in that case. Therefore, except when the lubricating oil is completely taken in or completely solidified, the lubricating oil is used when it is held between the fibers of the fiber material or impregnated in the communicating hole of the porous material. It can be said that it is held or impregnated in a releasable state.

  The lubricating oil can be retained inside the bearing by holding the lubricating oil in the oil holder and fixing (adhering or the like) the concave portion of the cage. Lubricating oil is gradually released from the oil holder, and excess lubricating oil is again held by the oil holder. As a result, the lubricating oil is efficiently used without waste, and continuous operation is possible without resupply of the lubricating oil from the outside. In particular, in the structure as shown in FIG. 2 or FIG. 3, the lubricating oil can be stably supplied from the oil holding body 6 of the recess 10 into the pocket 9 through the communication port 10a. The rolling bearing of the present invention is not initially filled with grease or lubricating oil other than that contained in this oil holder, and grease or lubricating oil is supplied to the bearing internal space from other than this oil holder. It can be in a form that is not done.

  The oil holder is made of a fiber material or a porous material. By using these, the surface area is increased and oil retention is improved. As fiber materials, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, aromatic polyamide resins, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, polyester resins such as polybutylene terephthalate, acrylic resins, vinyl chloride, Examples include synthetic resin fibers such as vinylon, inorganic fibers such as carbon fibers and glass fibers, regenerated fibers such as rayon and acetate, and natural fibers such as cotton, silk, hemp, and wool. In addition, as the porous material, foamed synthetic resins such as polyurethane, polystyrene, polyolefin, phenol and polyvinyl chloride, and rubbers such as natural rubber, chloroprene rubber, ethylene propylene rubber, nitrile rubber, silicon rubber and styrene butadiene rubber. The foam obtained is obtained.

  A flocked portion which is an oil holding body made of a fiber material is formed by flocking these fibers. Fixing is done with an adhesive. Spraying or electrostatic flocking can be employed as a flocking method. It is preferable to employ electrostatic flocking at the edge portion and the like because a large amount of fibers can be densely flocked in a short time. As the electrostatic flocking method, a publicly known method can be adopted.For example, an adhesive is applied to a range where electrostatic flocking is performed, the fibers are charged, and after flocking substantially perpendicularly to the adhesive application surface by an electrostatic force, drying is performed. The method of performing a process, a finishing process, etc. is mentioned. Electrostatic spraying (fiber coating) can also be employed. In addition, the oil holding body made of a porous material is provided by bonding and fixing a previously formed and processed shape with an adhesive or the like.

  Examples of the adhesive used for fixing the oil holding member 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.

  Among the above fiber materials, it is difficult to cause swelling and dissolution due to oil, is chemically stable, can produce a large amount of homogeneous fibers, and can be obtained at low cost. It is preferable to use it. In addition, when a resin cage is used as a cage and an oil retaining body is formed on this surface, a polyamide resin, which is widely used as a material for resin cages, is used among synthetic resins. It is possible to use the bearing without reducing the use conditions.

  The shape of the fiber (short fiber) is not particularly limited as long as it does not interfere with other members that adversely affect the bearing function at the location where the oil retainer 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. The proportion of fibers is preferably 1 to 40%. The short fiber has a straight type and a bend type (a fiber tip is bent), and a cross-sectional shape includes a circular shape and a polygonal cross-sectional shape. Bend type fibers have a higher ability to retain lubricant than straight fibers. Moreover, since the fiber of polygon cross-sectional shape has a large surface area compared with a circular cross section, the capability to hold | maintain lubricating oil is high.

  The rolling bearing of the present invention is lubricated by the lubricating oil held by the oil holder. Here, when the lubricating oil is held and impregnated in the oil holding body, the greased lubricating oil may be held and impregnated. In this case, the grease is held and impregnated so as not to be detached from the oil holder. Any lubricating oil can be used without particular limitation as long as it is usually used for rolling bearings. For example, mineral oils 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 oils and fats, polyol ester oils, phosphate ester oils , Non-hydrocarbon synthetic oils such as diester oil, polyglycol oil, silicone oil, polyphenyl ether oil, alkyl diphenyl ether oil, and fluorinated oil. These lubricating oils may be used alone or in combination of two or more. Further, as described above, the thickening agent used for forming a grease can be used without particular limitation as long as it is a thickening agent (metal soap, urea compound, etc.) generally used for a lubricant for rolling bearings.

  Moreover, a well-known additive can be added to lubricating oil as needed. In this case, the lubricant containing the additive is held and impregnated in the oil holder. 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. In particular, by adding an antioxidant, deterioration of the lubricating oil can be suppressed and the life can be extended.

  As mentioned above, although embodiment of this invention was described based on each figure etc., the rolling bearing of this invention is not limited to these. For example, bearing types include deep groove ball bearings, angular ball bearings, thrust ball bearings, cylindrical roller bearings, needle roller bearings, thrust cylindrical roller bearings, thrust needle roller bearings, tapered roller bearings, thrust tapered roller bearings, self-aligning The present invention can be applied to any type of rolling bearing such as a ball bearing, a spherical roller bearing, and a thrust spherical roller bearing. Moreover, the presence or absence of a seal member (shield plate) can be applied to these rolling bearings.

  The example shown in each figure is a crown-shaped cage, but in the rolling bearing of the present invention, in a cage such as a corrugated cage or a machined cage, oil retaining such as a flocked portion is held in a concave portion on the inner and outer diameter surfaces. It is good also as a form which forms a body. Moreover, about the material of a holder | retainer, arbitrary materials, such as a metal material and a resin material, are employable. The type of adhesive is determined according to the cage material, short fiber material, and the like. The crown-shaped cage shown in FIGS. 2 and 3 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 can be used as an oil-lubricated rolling bearing while reducing the rotational torque and sufficiently holding the lubricating oil inside the bearing, and can stably supply the lubricating oil to the lubrication site. It can be widely used as a rolling bearing.

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner ring 3 Outer ring 4 Rolling body 5 Cage 6 Oil holder 7 Cage body 8 Holding claw 9 Pocket 10 Recess 11 Flat part 12 Groove part

Claims (4)

A rolling bearing comprising an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, and an annular cage that holds the rolling elements,
The retainer has a concave portion having a shape recessed from the surface in a part of the at least one surface in at least one surface selected from an inner diameter surface and an outer diameter surface,
A rolling bearing, characterized in that an oil holding body made of a fiber material or a porous material and previously held or impregnated with lubricating oil is fixed to the recess.   The cage has a plurality of pockets that are opened on one side in the axial direction on the annular cage body to hold the rolling elements, and the concave portion has these pockets between the adjacent pockets. The rolling bearing according to claim 1, wherein the rolling bearing is provided as a communicating space.   The rolling bearing according to claim 1, wherein the oil retaining body is a flocked portion made of a short fiber of synthetic resin that is the fiber material.   The rolling bearing according to any one of claims 1 to 3, wherein the lubricating oil is held or impregnated in the oil holder in a state where no additive is added or an additive is contained. .

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