JP2018017306A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing provided with a flocked body in a bearing constituent, which can improve a lubrication characteristic containing excellent low torque.SOLUTION: A rolling bearing includes an inner ring and an outer ring 3 as a bearing ring, a plurality of balls interposed between the inner and outer rings, a holder 5 holding the balls, and lubricant supplied or sealed into a bearing inner space. The holder 5 has a flocked body 6 comprising a plurality of fibers fixed to an outer ring guide surface 5d; tip parts 6a of the fibers of the flocked body 6 contact with the outer ring 3 as a mating member; and the tip parts 6a of the fibers of the flocked body 6 are curved into a circular-arch shape.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing in which a flocking body is provided on a bearing constituent member.

  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 lubrication characteristics by improving the structure of a bearing component. In Patent Document 1, in an angular ball bearing in which the cage is an outer ring guide used at high speed rotation, the cage is guided by the inner peripheral surface at one end side in the axial direction of the outer ring, while the other end side in the axial direction of the outer ring. The gap between the inner peripheral surface of the inner ring and the outer peripheral surface of the cage is limited to a narrow range with respect to the inner diameter of the outer ring. This configuration makes it easy to keep grease on the raceway surface and cage, and the grease flows out to the seal shoulder and the groove shoulder of the outer ring, and there is insufficient grease to lubricate the rolling elements and raceway surface, resulting in seizure. It can be prevented (see Patent Document 1).

  Further, Patent Document 2 has been proposed as a technique for improving lubrication characteristics by forming a lubricant film on the cage. Patent Document 2 discloses a predetermined lubricating film made of a solid lubricant on the surface of an outer member, an inner member, a rolling element, etc. in order to prevent smearing, seizure, wear, and peeling under high speed and high load. Describes a rolling device formed by shot peening (see Patent Document 2). Patent Document 3 has been proposed as a technique for improving lubrication characteristics by changing a lubricant, a lubrication condition, and the like. Patent Document 3 discloses a predetermined blending amount of a predetermined ester oil and a diurea compound as a grease composition for a bearing that is excellent in peeling resistance and grease leakage and can suppress premature seizure even when used in an outer ring rotary bearing. (See Patent Document 3).

  Further, Patent Document 4 has been proposed as a technique for improving the lubricant retention and reducing the rotational torque of the bearing (hereinafter also simply referred to as “torque”). In Patent Document 4, by providing a member (planted body) formed by flocking fibers at a predetermined part in a rolling bearing, grease or lubricating oil is held at the lubricating part, and stirring and shearing of the grease are suppressed. Thus, a low torque and a long life are realized (see Patent Document 4).

JP, 2015-203474, A Japanese Patent No. 5045806 Japanese Patent No. 3330755 JP-A-2015-194256

  However, in the bearing of Patent Document 1, although it is easy to keep the grease on the raceway surface by optimizing the gap width between the bearing constituent members, depending on the use conditions such as temperature and rotation speed, the type of lubricant, etc. There is a possibility that sufficient effect cannot be exhibited. Further, in the rolling device of Patent Document 2, since a lubricating coating is formed on the rolling contact surface (the raceway surface of the raceway and the rolling surface of the rolling element itself) in the members constituting the device, the coating film is highly accurate. Therefore, the manufacturing cost is increased.

  In Patent Document 3, the lubrication characteristics are improved by improving the sealed grease. However, when a semi-solid lubricant such as grease is used, the torque increases due to the stirring resistance caused by the lubricant. 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.

  On the other hand, in the technique of Patent Document 4, it is possible to reduce torque without greatly changing the grease type and the amount of grease charged from the existing product. However, depending on the form of flocking used as a grease retaining member, for example, its shape and the contact state with other members, it may adversely affect the reduction in torque and the effect may be suppressed. It is rare.

  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 plurality of fibers fixed to a surface of the member in contact with the lubricant in at least one bearing component selected from the inner ring, the outer ring, and the cage A tip of the fiber of the flocked body is contacted with a mating member other than the bearing constituent member provided with the flocked body among the bearing constituent members, and the fiber of the flocked body The tip portion of each is curved in an arc shape.

  In the tip part of the fiber of the flocked body, the direction of the arc-shaped curve from the fixed side to the tip side of the plurality of fibers constituting the flocked body is the same direction.

  Further, in the tip of the fiber of the flocked body, the bearing constituting member provided with the flocked body in the mating member has an arcuate curved direction from the fixed side to the tip side of the plurality of fibers constituting the flocked body. With respect to the relative rotation direction, the fixed side is the upstream side in the rotational direction and the tip side is the downstream side in the rotational direction.

  The bearing constituting member provided with the flocked body is the cage, and the mating member is the inner ring and / or the bearing ring.

  The fiber is a synthetic resin fiber, and is bonded and fixed to the surface of the bearing constituent member provided with the flocked body.

  The rolling bearing of the present invention has a flocked body composed of a plurality of fibers fixed to a surface in contact with a lubricant in at least one bearing constituent member selected from an inner ring, an outer ring, and a cage, and the fibers of the flocked body Since the tip of each of the bearings is in contact with a mating member that is a member other than the bearing constituent member provided with the flocked body among the bearing constituent members, and the tip of the fiber of the flocked body is curved in an arc shape, the flocked body Grease and lubricating oil are held in the bearing, while improving the lubrication characteristics while using existing bearing shapes and lubricants, the sliding resistance can be reduced even when the bearing component contacts the fiber tip, Torque can be reduced. Further, the base oil of grease held on the flocked body from the fiber tip can be supplied to the raceway surface, and excess grease on the raceway surface can be scraped off at the fiber tip.

  At the tip of the fiber of the flocked body, the direction of the arc-shaped curve from the fixed side to the tip side of the plurality of fibers constituting the flocked body is the same direction, and in particular, the direction of the curve is the flocked hair in the mating member Since the fixed side is the upstream side in the rotational direction and the front end side is the downstream side in the rotational direction with respect to the relative rotational direction with respect to the bearing component provided with the body, further torque reduction can be achieved.

  Since the bearing constituent member provided with the flocked body is a cage and the mating member is an inner ring and / or a bearing ring, when guiding the cage with the bearing ring, lubrication characteristics (frictional force) on the guide surface of the cage It is excellent in reduction and noise suppression.

  The fibers that make up the flocked body are synthetic resin fibers and are adhesively fixed to the surface of the bearing component provided with the flocked body, so that the fibers are chemically stable and less susceptible to swelling and dissolution by the lubricating oil. Yes, and firmly fixed to the surface of the member.

It is a partial sectional view of an angular contact ball bearing concerning an example of the present invention. FIG. 2 is a partially enlarged view of the angular ball bearing in FIG. 1. It is a partial cross section figure of the angular ball bearing concerning other examples of the present invention. It is a partial perspective view of the angular ball bearing in FIG. It is a partial enlarged view of the part which provided the flocked body.

  An embodiment of the rolling bearing of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of an angular ball bearing incorporating a cage having a flock body (guide surface) as an example of the rolling bearing of the present invention, and FIG. 2 is a partially enlarged view of the angular ball bearing. is there. In the angular ball bearing 1 shown in FIG. 1, a plurality of balls 4 are arranged in a circumferential direction in a raceway space between an inner ring 2 and an outer ring 3, and the inner ring 2, the outer ring 3, and the balls 4 have a predetermined contact angle. It is provided with θ. These balls 4 are held at equal intervals in the circumferential direction by a cage 5. The cage 5 is an outer ring guide system, and is guided to the outer ring 3 when the outer ring guide surface 5 d of the cage 5 contacts the inner diameter surface 3 a of the outer ring 3. The outer ring guide surface 5d is provided on a part (one side in the axial direction) of the outer diameter surface 5a of the cage 5. This angular ball bearing 1 does not use a seal member, and its lubrication type is air oil lubrication or oil mist lubrication that constantly supplies lubricating oil from the outside of the bearing to the inside of the bearing.

  In the angular ball bearing 1 of this form, the flocked body 6 made of a plurality of fibers is provided on the outer ring guide surface 5 d of the cage 5. The flocked body 6 is formed by flocking fibers by a predetermined method. As shown in FIG. 2, there is a certain gap (clearance) between the outer ring guide surface 5d of the cage 5 and the inner diameter surface 3a of the outer ring 3, and the flocked body 6 is provided in this gap. By providing the flocked body 6 on the outer ring guide surface 5d, the flocked oil is held in the flocked body, and the occurrence of friction due to the direct sliding contact between the outer ring 3 and the cage 5 can be prevented.

  Another embodiment of the rolling bearing of the present invention will be described with reference to FIGS. FIG. 3 is a partial cross-sectional view of an angular ball bearing (with a seal member) incorporating a resin cage having a flocked body (guide surface) as an example of the rolling bearing of the present invention. FIG. It is a partially expanded view of a bearing. The angular ball bearing 1 of the form shown in FIG. 3 and FIG. 4 has a pair of seal members 7 at both axial opening portions between the inner and outer rings, and seals the bearing space. Grease 8 is sealed in the bearing space. The cage 5 is an outer ring guide system, and is guided to the outer ring 3 when the outer ring guide surface 5 d of the cage 5 comes into contact with the inner diameter surface of the outer ring 3. The outer ring guide surface 5d is provided at a part (both ends in the axial direction) of the outer diameter surface 5a of the cage 5. The other overall configuration is the same as that of the angular ball bearing of the form shown in FIG.

  In the angular ball bearing 1 of this form, the flocked body 6 made of a plurality of fibers is provided on the outer ring guide surface 5 d of the cage 5. As shown in FIG. 4, there is a certain gap (clearance) between the outer ring guide surface 5d of the cage 5 and the inner diameter surface 3a of the outer ring 3, and the flocked body 6 is provided in this gap. By providing the flocked body 6 on the outer ring guide surface 5d, the flocked body retains the grease in the bearing space, and can prevent the occurrence of friction due to the direct sliding contact between the outer ring 3 and the cage 5.

  In addition, in the form shown in FIGS. 1-4, in addition to the flocked body provided in the holder | retainer guide surface, you may provide a flocked body also in the width | variety surface 5b of the holder | retainer 5, and the internal diameter surface 5c of the holder | retainer 5, for example. By providing a flocked body on the surface that is not in contact with other members, it is unlikely to fall off, and the amount of lubricating oil and grease held in the cage increases, resulting in lubrication characteristics on the rolling surface. Will improve.

  By providing the flocked body as shown in FIGS. 1 to 4, the grease is fixedly held on the flocked body and rotates together with the cage without being sheared, so that no agitation resistance occurs and there is no flocked body Compared to the case, the torque can be reduced. In addition, the grease softens and easily releases oil when subjected to shearing and the lubrication life is shortened. However, in the present invention, the grease is held by the flocked body and is not easily subjected to shearing, thereby extending the lubrication life. Also, when using oil lubrication, if the flocked body absorbs lubricating oil, a sufficient amount of lubricating oil can be retained inside the bearing without supplying oil from the outside, and rotation can be achieved like grease lubrication. Since there is no semi-solid substance that becomes resistance, the torque is lower.

  Based on FIG. 5, the form of the flocked body in the rolling bearing of this invention is demonstrated in detail. FIG. 5 is a partially enlarged cross-sectional view (a cross section perpendicular to the axial direction) of a portion where the flocked body in FIGS. 1 to 4 is provided. As shown in FIG. 5, the tip 6a of the fiber constituting the flocked body 6 is curved in an arc shape. The curved fiber tip 6a is in contact with the inner diameter surface 3a of the mating member (outer ring 3) which is a member other than the bearing constituent member (cage 5) provided with the flocked body. In addition, the flocked body 6 is in a raised state in which the base of the main body 6b is fixed to the member surface (the outer ring guide surface 5d of the cage 5) by the adhesive 9. The flocked body 6 can supply the base oil of the grease held therein to the bearing raceway surface, and can scrape off excess grease on the raceway surface. The mating member is at least one member selected from members other than the bearing constituent member provided with the flocked body.

  By making the front end portion 6a of the fiber constituting the flocked body 6 into a curved shape (convex curved shape) as described above, the flocked body is formed from straight hair-shaped fibers in which the front end portion 6a is directly stretched on the main body portion 6b. Compared with the case where it is configured, since there is less catching between the tip portion 6a and the mating member surface, the resistance is low, the torque can be reduced, and the wear of the fiber tip portion is also reduced. Moreover, as shown in FIG. 5, in the front-end | tip part 6a of the fiber of the flocked body 6, it goes to the front end side (front-end | tip part 6a side) from the fixed side (main body part 6b side) of the some fiber which comprises this flocked body 6. The torque can be further reduced by setting the direction of the arcuate curve to the same direction (clockwise in the figure).

  In particular, as shown in FIG. 5, the direction of the bending of the fiber tip portion 6 a of the flocked body 6 is such that the fixed side (the body portion 6 b side) is the rotation direction with respect to the rotation direction of the counterpart member (black arrow in the figure) It is preferable that the front end side (the front end portion 6a side) on the upstream side is oriented to be the downstream side in the rotation direction. Here, the “rotation direction” is a relative rotation direction with respect to the bearing constituent member provided with the flocked body in the counterpart member. In FIG. 5, the outer ring 3 rotates in the direction opposite to the black arrow in the figure relative to the outer ring 3 to which the cage 5 is fixed, so that the outer ring 3 rotates relative to the cage 5 in the direction of the black arrow in the figure. Will do. In this way, by setting the direction of bending to the direction along the rotation direction of the mating member, the resistance due to the contact between the flocked body and the mating member is further reduced, and the torque can be further reduced.

  The flocked body is formed by flocking fibers (short fibers). 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 this method, when the adhesive is pierced into the adhesive from one end face of the short fiber by electrostatic attraction, the fiber is slightly tilted and fixed with respect to the substrate surface with air. Compared with the case of electrostatic flocking, a single short fiber covers the base material surface in a wide range, so the number of short fibers on the base material surface is reduced and the density is lowered. In any method, a drying step, a finishing step, etc. are performed after flocking. Moreover, after fixing the straight-hair-shaped fiber by these methods, the flocked body in which the tip portion is curved can be formed by pressing the pressing member against the tip portion.

  The short fiber used for flocking is not particularly limited as long as it can be used as a short fiber for flocking. For example, (1) polyolefin resin such as polyethylene and polypropylene, polyamide resin such as nylon, aromatic polyamide resin, polyethylene terephthalate, Polyester resin such as polyethylene naphthalate, polyethylene succinate, polybutylene terephthalate, synthetic resin fiber such as acrylic resin, vinyl chloride, vinylon, (2) inorganic fiber such as carbon fiber, glass fiber, (3) rayon, acetate, etc. And natural fibers such as cotton, silk, hemp and wool. These may be used independently and 2 or more types may be used together. It is preferable to use synthetic resin fiber among the above because it is difficult to cause swelling and dissolution with oil, is chemically stable, can produce a large amount of homogeneous fibers, and can be obtained at low cost.

  The shape of the short fiber is not particularly limited as long as the shape of the tip portion can be realized. 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. In the case where low torque is more important than grease retention, the above ratio is more preferably about 1 to 5%. By adopting electrostatic spraying as a flocking method, the above-mentioned ratio of about 1 to 5% can be achieved, and it becomes difficult to increase the torque at the time of contact with the mating member. The cross-sectional shape of the short fiber includes a circular shape and a polygonal shape. By using short fibers having a polygonal cross section, the surface area can be made larger than that of short fibers having a circular cross section, and the lubricant can be more easily retained. Moreover, about the short fiber length of the flocked body provided in a holder guide surface like the case shown in FIGS. 1-5, it is set as length that a curved part of a fiber front-end | tip part contacts a track ring.

  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 cage 5 is a machined type cage, and pocket portions for holding balls as rolling elements are provided at regular intervals in the circumferential direction on an annular resin cage body. The resin cage is made of, for example, a polyamide resin such as a phenol resin, a polyether ether ketone (PEEK) resin, a polyphenylene sulfide (PPS) resin, a thermoplastic polyimide resin, a polyamideimide resin, a nylon 66 resin, or a nylon 46 resin. It is manufactured by injection molding using a resin composition containing a reinforcing fiber such as carbon fiber or glass fiber and other additives as a material. The material of the cage is not limited to resin, and any material such as a metal material can be adopted. Further, the cage type is not particularly limited, and may be a crown-shaped cage or a corrugated cage. According to the material and form of the cage, the above-mentioned short fiber material and adhesive type used for the flocked body are determined.

  In addition to the cage, the flocked body may be provided on the surface of the race. Even if it is provided on any member, it is provided on the surface that comes into contact with the lubricant, and the tip of the fiber of the flocked body contacts the mating member that is a member other than the bearing constituent member provided with the flocked body among the bearing constituent members. The configuration.

  As described above, 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.

  For example, a low-viscosity oil, an alicyclic / aromatic urea thickener, or the like is preferably used for lubrication on the guide surface of an angular ball bearing that rotates at high speed. As described above, depending on the type and usage conditions of the rolling bearing, the lubricant is usually optimized and the type of lubricant is often limited. On the other hand, in the present invention, a flocked body of a predetermined shape is provided on the cage guide surface and the like, and the flocked body is held with a lubricant. Without depending on it, it is possible to improve the lubrication characteristics (especially low torque) on the cage guide surface and the like.

  Further, in the rolling bearing of the present invention, grease or lubricating oil can be held in advance in the flocked body before use. Since the flocked body in the present invention has a shape in which the fiber tip is curved, it is difficult to take in grease or the like in the vicinity of the root as compared with a straight hair shape. On the other hand, by retaining a sufficient amount of lubricating oil in the vicinity of the root in advance, the lubricating oil is gradually released over a long period of time, and the lubricating characteristics can be maintained.

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

  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.

1 Angular contact ball bearings (rolling bearings)
2 Inner ring 3 Outer ring 4 Ball 5 Cage 6 Flocked body 7 Seal member 8 Grease 9 Adhesive

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 composed of a plurality of fibers fixed to a surface of the member that contacts the lubricant,
The tip of the fiber of the flocked body and a mating member that is a member other than the bearing constituent member provided with the flocked body among the bearing constituent members are in contact,
A rolling bearing characterized in that the tip of the fibers of the flocked body is curved in an arc shape.   The rolling bearing according to claim 1, wherein the direction of the arc-shaped curve from the fixed side to the tip side of the plurality of fibers constituting the flocked body is the same direction at the tip of the fiber of the flocked body. .   The tip of the fiber of the flocked body has an arcuate curved direction from the fixed side to the tip side of the plurality of fibers constituting the flocked body, and the bearing constituting member provided with the flocked body in the counterpart member The rolling bearing according to claim 2, wherein the fixed side is oriented in the rotational direction upstream and the tip side is oriented in the rotational direction downstream relative to the relative rotational direction.   The bearing component member provided with the flocked body is the cage, and the mating member is the inner ring and / or the raceway ring, according to any one of claims 1 to 3. Rolling bearing.   The rolling bearing according to any one of claims 1 to 4, wherein the fiber is a synthetic resin fiber, and is bonded and fixed to a surface of a bearing constituent member provided with the flocked body.

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