WO2017047770A1

WO2017047770A1 - Rolling bearing

Info

Publication number: WO2017047770A1
Application number: PCT/JP2016/077497
Authority: WO
Inventors: 智彦小畑; 藤原　宏樹; 光生川村
Original assignee: Ntn株式会社
Priority date: 2015-09-18
Filing date: 2016-09-16
Publication date: 2017-03-23

Abstract

The present invention pertains to a rolling bearing (101) comprising: an inner race (102) and an outer race (103) which constitute the bearing ring; a plurality of rolling elements (104) interposed between the inner and outer races; a cage (105) which holds the rolling elements (104); and grease (113) packed into the internal spaces of the bearing. A grease holding body comprising a fibrous material or a porous material is formed on at least one among the inner diameter surface or the outer diameter surface of the cage (105) on regions (105a, etc.) excluding the regions (105b) facing shoulder parts (102b, 103b) of the inner race. The grease holding body is not formed in said regions (105b). The present invention thus enables the use of a simple means to improve lubrication characteristics, including lowering torque, without negatively impacting torque.

Description

Rolling bearing

The present invention relates to a rolling bearing lubricated with grease and 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. The inside of the bearing is lubricated with a lubricant such as grease or oil, and various measures have been taken to improve the lubrication characteristics of the bearing.

For example, Patent Document 1 has been proposed as a technique for improving lubrication characteristics by forming a lubricant film on a cage. Patent Document 1 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 1). Further, Patent Document 2 has been proposed as a technique for improving lubrication characteristics by changing a lubricant, lubrication conditions, and the like. Patent Document 2 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 peel resistance and grease leakage and can suppress premature seizure even when used in an outer ring rotary bearing. (See Patent Document 2).

In addition, Patent Document 3 has been proposed as a technique for improving lubrication characteristics by changing the shape of the cage. In Patent Document 3, as a means for reducing the rotational torque of a bearing (hereinafter, also simply referred to as “torque”), it is composed of two annular holding plates formed by a steel plate press, and has a polygonal pocket portion or the like. A deep groove ball bearing provided with a formed cage is described (see Patent Document 3).

Further, Patent Document 4 discloses a lubricating composition for bearings, which is a technique for improving lubrication characteristics by using solid grease, which is obtained by heating and melting a mixture of ultrahigh molecular weight polyethylene and lubricating grease, and then cooling and solidifying the mixture. (See Patent Document 4).

Japanese Patent No. 5045806 Japanese Patent No. 3330755 JP 2007-292195 A Japanese Patent Publication No. 63-23209

However, in the rolling device of Patent Document 1, 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 is highly accurate. Therefore, the manufacturing cost is increased. In addition, Patent Document 2 improves the lubrication characteristics by improving the enclosed 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.

In response to this problem, torque can be reduced by using a specially shaped cage as disclosed in Patent Document 3. 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 costs and a decrease in bearing life, so technologies that improve lubrication characteristics (especially torque reduction) without significantly changing the bearing shape, type of grease, and the amount of grease charged from existing products. Development is desired.

Also, torque may increase due to excessive grease adhering to the rolling element surface during operation or contact between members due to improvement of the grease holding structure.

The present invention (the following first and second inventions) has been made in order to cope with such problems. Lubricating characteristics including a reduction in torque without adversely affecting torque by simple means. An object of the present invention is to provide a rolling bearing capable of improving the above.

In addition, as described above in relation to Patent Document 2, the rolling bearings used in recent automobiles, industrial equipment, and the like reduce torque while ensuring sufficient lubrication life in order to save energy. That is an important issue. In response to this problem, as described above, the torque can be reduced by using a specially shaped cage as in Patent Document 3. 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 4 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, it is essential to resupply the lubricant. For this reason, development of oil-lubricated and maintenance-free bearings is desired.

The present invention (the third invention described below) is made to cope with such a problem. As a rolling bearing for oil lubrication, the rolling torque is reduced and the rolling life is long without resupply of lubricating oil. An object is to provide a bearing.

The rolling bearing according to the first invention of the present application is enclosed in 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 bearing inner space. A rolling bearing provided with grease, wherein at least one surface selected from an inner diameter surface and an outer diameter surface of the cage excluding at least a part of a region facing the non-track portion of the bearing ring A grease holder made of a fiber material or a porous material is formed in A, and a grease holder made of a fiber material or a porous material is not formed in the other region B, or the grease in the region A The present invention is characterized in that a grease holder made of a fiber material or a porous material is formed, in which the sliding resistance with the non-track portion of the raceway is reduced as compared with the case where the holder is formed.

The region A is a region excluding at least a part of the region facing the shoulder portions of the inner and outer rings, which are non-orbital portions of the bearing ring, and the region B is provided with a grease holder made of a fiber material or a porous material. It is not formed. In particular, the region A is a region excluding the entire region facing the inner and outer ring shoulders which are non-orbital portions of the bearing ring.

The cage is a crown-shaped cage having a plurality of pockets that are open on one side in the axial direction and hold the rolling elements on an annular cage body, and the region B is the shape of the cage body. It is located on the non-opening side of the pocket.

The grease holding body is characterized by planting short fibers of synthetic resin as the fiber material.

The rolling bearing of the second invention of the present application is supplied to 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 bearing inner space. A rolling bearing comprising a lubricant made of grease or lubricating oil, wherein at least one bearing component selected from the inner ring, the outer ring, and the cage has fibers on the surface in contact with the lubricant It has a flocked part formed by flocking, The ratio of the said fiber area occupied per formation area of the said flocked part is 1% or more and less than 5%, It is characterized by the above-mentioned. In particular, the fibers of the flocked portion are in contact with at least one of the bearing constituent members.

The flocked portion is characterized in that it is formed on a part or the whole of the inner diameter surface and / or outer diameter surface of the cage. Moreover, the said hair transplant part is not formed in at least one part of the area | region facing the non-orbit part of the said track ring among the surfaces in which the said hair transplant part was formed, It is characterized by the above-mentioned.

The hair transplanting part is formed in a part or the whole of an edge part of a pocket for holding the rolling element in the cage.

In addition, it is preferable that the said fiber is a synthetic resin fiber. This is because if the fibers in the flocked portion are synthetic resin fibers, they are chemically stable and hardly swell or dissolve due to oil.

A rolling bearing according to a third invention of the present application is a rolling bearing comprising (A) an inner ring and an outer ring that are raceways, a plurality of rolling elements interposed between the inner and outer rings, and a cage that holds the rolling elements. In at least one member selected from the inner ring, the outer ring, and the cage, a bearing or a porous material is formed on a bearing inner space side surface other than a contact surface with the rolling element of the member. A rolling bearing characterized in that the oil holding body is bonded and fixed, and the oil holding body is preliminarily held or impregnated with lubricating oil, or (B) an inner ring and an outer ring that are track rings; A rolling bearing comprising a plurality of rolling elements interposed between the inner and outer rings, a cage for holding the rolling elements, and seal members provided at both axial openings of the inner ring and the outer ring. The inner ring, the above In at least one member selected from a ring, the cage, and the seal member, an oil holder made of a fiber material or a porous material is provided on the surface in the bearing inner space other than the contact surface with the rolling element of the member. It is a rolling bearing characterized in that it is bonded and fixed, and the oil holder is previously held or impregnated with lubricating oil. In addition, the part (surface) which adheres and fixes an oil holding body is other than a contact surface with a rolling element, and a part of oil holding body formed there may contact with a rolling element.

The oil retainer is bonded and fixed to at least one selected from an inner diameter surface and / or an outer diameter surface of the cage and a shoulder surface of the raceway.

The retainer has, on an annular retainer body, a pocket that opens to one side in the axial direction to hold the rolling element, and an inter-pocket groove formed between the adjacent pockets on the opening side of the pocket. The oil retainer is bonded and fixed to at least a part of the groove between the pockets. Further, in the crown-shaped cage having the same configuration, it has a pocket anti-opening side groove formed on a surface of the cage body on the side opposite to the opening of the pocket, and at least a part of the pocket anti-opening side groove, The oil holding body is bonded and fixed.

In addition, as an embodiment of the rolling bearing of the third invention of the present application, there is a case where the oil holder is formed by planting short fibers of synthetic resin as the fiber material, and between pockets in the crown-shaped cage. Except in the case of a groove part and a pocket opposite opening side groove part, the case where the fiber front-end | tip of the said oil holding body contacts the surface of the said rolling element is mentioned. When the fiber in the flocked portion is a synthetic resin fiber, it is chemically stable and hardly swells or dissolves due to oil. Further, when the fiber tip of the oil holding member comes into contact with the surface of the rolling element, the lubricating oil can always be supplied to the rolling element and the raceway, so that the life can be extended.

In addition, said (B) includes especially the case where the said oil holding body is adhesively fixed to the bearing inner space side surface of this seal member.

In the rolling bearing of the first invention of the present application, the fiber is provided in the region A excluding at least a part of the region facing the non-race portion of the bearing ring on at least one surface selected from the inner surface and outer surface of the cage. Since the grease holding body made of a material or a porous material is formed, the grease holding body holds grease and lubricating oil, and the lubrication characteristics can be improved while using existing bearing shapes and lubricants. Specifically, grease agitation and shearing can be suppressed. It is also possible to prevent excessive grease from being supplied onto the rolling elements. As a result, the rolling bearing of the first invention of the present application has a low torque and a long life.

Furthermore, a grease holder made of a fiber material or a porous material is not formed in a region other than the region A, that is, a region B that is at least a part of a region facing the non-orbital portion of the raceway, or a region A grease holder made of a fiber material or a porous material is formed which has a sliding resistance with the non-track portion of the raceway ring smaller than when the grease holder of A is formed. Thus, it is possible to prevent contact with the non-track portion of the race, or even when contact is made, sliding resistance can be reduced, and steady torque can be reduced.

The region A is a region excluding at least a part (region B) of the region facing the inner and outer ring shoulders which are non-orbital portions of the bearing ring, and the region B holds grease made of fiber material or porous material. Since the body is not formed, contact between the grease holder of the cage and the shoulders of the inner and outer rings of the races can be prevented, and steady torque can be reduced. Particularly, the region A is a region excluding the entire region (region B) facing the shoulder portions of the inner and outer rings, and a grease holder made of a fiber material or a porous material is not formed in the region B. The contact between the grease holder and the inner and outer ring shoulders of the bearing ring can be completely prevented, and the steady torque can be further reduced.

Since the grease holder is made by implanting short fibers of the synthetic resin, which is the fiber material, the surface area is easily increased and the grease holding property is excellent. In addition, swelling and dissolution due to the base oil in the grease hardly occur, and it is chemically stable.

The rolling bearing according to the second invention of the present application has a flocked portion formed by flocking fibers on the surface in contact with the lubricant in at least one bearing component selected from an inner ring, an outer ring, and a cage. Grease and lubricating oil are retained, and the lubrication characteristics can be improved while using existing bearing shapes and lubricants. Specifically, in grease lubrication, the agitation and shearing of the grease can be suppressed, resulting in a low torque and a long life. In addition, the movement of the grease itself in the bearing can be suppressed, and grease leakage can be reduced. In oil lubrication, the torque is lower than in grease lubrication. Furthermore, since the ratio of the fiber area to the formation area of the flocked portion is 1% or more and less than 5%, the sliding resistance can be reduced and the steady torque can be reduced even when the bearing constituent member and the fiber are in contact with each other. I can plan.

Since the flocked portion is formed on the inner diameter surface and / or outer diameter surface of the cage, a lubricant such as grease adheres to the flocked portion and rotates together with the cage without being sheared, so that stirring resistance does not occur. . Further, in this embodiment, since the flocked portion is not formed in at least a part of the region facing the non-orbital portion of the raceway ring in the surface where the flocked portion is formed, the flocked portion of the cage and the orbital Contact between the inner and outer ring shoulders of the wheel can be prevented, and steady torque can be reduced.

Since the flocked part is formed on part or all of the edge of the pocket that holds the rolling element in the cage, excessive grease on the surface of the rolling element is scraped off at this part, and the grease is transferred between the rolling element and the raceway. Can be suppressed from being sheared, and the steady torque can be reduced. Further, similarly to the above, since the ratio of the fiber area per formation area of the flocked portion of the edge portion is 1% or more and less than 5%, it is difficult to increase the torque at the time of contact with the rolling element. Furthermore, it becomes easy to supply oil to the rolling element surface from the grease held in the flocked portion.

In the case of (A) in the rolling bearing of the third invention of the present application, the rolling bearing includes an inner ring and an outer ring that are race rings, a plurality of rolling elements interposed between the inner and outer rings, and a cage that holds the rolling elements. In at least one member selected from an inner ring, an outer ring, and a cage, an oil holding body made of a fiber material or a porous material is bonded and fixed to the bearing inner space side surface other than the contact surface with the rolling element of the member Since the lubricating oil is previously held or impregnated in the oil holder, the lubricating oil can be retained inside the bearing, 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.

By arranging oil retainers in combination at multiple locations inside the bearing, a large amount of lubricating oil can be retained inside the bearing, and the service life can be extended.

The same applies to the rolling bearing of the third invention of the present application (B).

It is a partial cross section figure of the rolling bearing which concerns on an example of 1st invention of this application. It is a partial perspective view etc. which show the form of the holder | retainer in FIG. It is a partial perspective view etc. which show the other form of a holder | retainer. It is a partial perspective view etc. which show the other form of a holder | retainer. It is an expanded view which shows the other form of a holder | retainer. It is a partial perspective view etc. which show the form of the holder | retainer of a comparative example. It is a figure which shows the time-dependent change of a torque. It is a partial cross section figure of the rolling bearing which concerns on an example of the 2nd invention of this application. It is a partial perspective view etc. which show the form of the holder | retainer in FIG. It is a partial perspective view etc. which show the other form of a holder | retainer. It is a partial perspective view which shows the other form of a holder | retainer. It is a figure which shows the time-dependent change of a torque. It is a partial schematic sectional drawing of the rolling bearing which concerns on one Example of 3rd invention of this application. It is a partial schematic sectional drawing of the rolling bearing which concerns on the other Example of 3rd invention of this application. It is a photograph of the holder | retainer of an Example. It is a figure which shows the result of a high-temperature high-speed life test. It is a partially expanded perspective view of the cage of the rolling bearing according to another embodiment of the third invention of the present application. It is a partially expanded perspective view of the cage of the rolling bearing according to another embodiment of the third invention of the present application.

First, the rolling bearing of the first invention of the present application will be described.

An example of the rolling bearing of the first invention of the present application will be described with reference to FIG. FIG. 1 is a partial cross-sectional view of a deep groove ball bearing incorporating a predetermined crown-shaped resin cage as a rolling bearing. As shown in FIG. 1, in the rolling bearing 101, an inner ring 102 having a raceway surface 102a on an outer peripheral surface and an outer ring 103 having a raceway surface 103a on an inner peripheral surface are arranged concentrically. A plurality of rolling elements 104 are arranged between the inner raceway surface 102a and the outer raceway surface 103a. The plurality of rolling elements 104 are held by a crown-shaped cage 105. The cage 105 is a rolling element guide type. The cage 105 is close to the raceway surface 102a of the inner ring 102 or the region 105a close to the raceway surface 103a of the outer ring 103, and a non-track portion (non-track surface) such as the shoulder portion 102b of the inner ring 102 or the shoulder portion 103b of the outer ring 103. Region 105b to be used. In addition, the rolling bearing 101 includes annular seal members 112 provided at openings in both axial ends of the inner and outer rings, and in a bearing inner space constituted by the inner ring 102, the outer ring 103, the cage 105, and the seal member 112. It is lubricated by the enclosed grease 113.

Details of the cage 105 will be described with reference to FIG. FIG. 2A is a partial perspective view of the cage, and FIG. 2B is a development view of the cage. As shown in FIG. 2 (a), a crown-shaped cage 105 is formed on an annular cage body 107 with a pocket 109 opened on one side in the axial direction to hold a rolling element and a pocket between adjacent pockets. 109 and a groove 111 formed on the opening side. More specifically, a pair of opposing holding claws 108 are formed on the annular cage body 107 at a constant pitch in the circumferential direction, and the opposing holding claws 108 are bent in a direction approaching each other, and A pocket 109 for holding a ball as a rolling element is formed between the holding claws 108. A flat portion 110 serving as a rising reference surface of the holding claw 108 is formed between the back surfaces of the holding claws 108 adjacent to each other formed at the edge of the adjacent pocket 109, and the groove portion is formed by the holding claw 108 and the flat portion 110. 111 is configured. That is, the back surface (the side opposite to the pocket) of the holding claw 108 constitutes the inner surface of the groove portion 111, and the surface of the flat portion 110 constitutes the bottom surface of the groove portion 111.

As shown in FIGS. 2A and 2B, a grease holder 106 indicated by a shaded portion is formed on the entire area 105a on the inner surface of the cage 105. Although not shown, the grease holder 106 is formed in the same range on the outer diameter surface. A structure in which the grease holder 106 is formed on the inner and outer diameter surfaces prevents the grease from being held in the groove, and prevents agitation and shearing of the grease and excessive supply of grease on the rolling element. And the steady torque can be reduced. Further, on the inner and outer diameter surfaces of the cage 105, the grease retaining body 106 is not formed in the region 105b. When the grease holder 106 is formed in the region 105b, the grease holder 106 and the inner and outer ring shoulders may slide, and the friction torque increases. Therefore, in this embodiment, the grease holder 106 is formed only in the region 105a without being formed in the region 105b.

In FIG. 1, on the inner and outer diameter surfaces of the cage 105, a region 105b close to a non-orbital portion such as the shoulder 102b of the inner ring 102 or the shoulder 103b of the outer ring 103 is a region facing these non-orbital portions. Further, on the inner and outer diameter surfaces of the cage 105, the region excluding the region 105b is a region 105a adjacent to the track surface 102a of the inner ring 102 or the track surface 103a of the outer ring 103. As shown in FIG. 2, in the present invention, the area where the grease holder 106 is formed is the area A and the area where the grease holder is not formed is the area B on the inner and outer diameter surfaces of the cage 105. In the form shown in FIG. 2, the region (region 105a) excluding the entire region 105b facing the non-orbital portion of the raceway is the region A. In addition, the region B is located on the non-opening side of the pocket 109 of the cage body 107, occupies a certain range in the axial direction and is continuous in the circumferential direction, and is a region that partially covers the pocket 109. .

The grease holder 106 is made of a fiber material or a porous material. By using these, the surface area is increased and the grease 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 grease holder made of 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 grease 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 adhesion of the grease holder 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, acrylic ester-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive And urethane resin emulsion adhesives, epoxy resin emulsion adhesives, polyester emulsion adhesives, ethylene-vinyl acetate copolymer adhesives, and the like. These may be used independently and 2 or more types may be used together.

Among the above fiber materials, since it is difficult to swell and dissolve due to the base oil in the grease, it is chemically stable, can produce a large amount of homogeneous fibers, and can be obtained at low cost. It is preferable to use short fibers. Furthermore, by using a polyamide resin widely used as a material for a resin crown-shaped cage among synthetic resins, it is possible to use the bearing without lowering the use conditions of the bearing.

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 grease holder is formed. The specific shape is preferably, for example, a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex, and the density of fibers in the flocked portion as a holding body is about the area of the flocked area. The proportion of fibers is preferably 1 to 40%. In particular, the length is preferably 0.6 to 1.5 mm, particularly preferably 0.6 to 1.0 mm.

In addition, for the material of the cage, any material such as a metal material or a resin material can be adopted. The crown-shaped cage shown in FIGS. 1 to 4 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 grease holder in the present invention is formed in a region A excluding at least a part of a region facing the non-track portion of the raceway on at least one surface selected from an inner diameter surface and an outer diameter surface of the cage. That's fine. In a region other than the region A, that is, in a region B that is at least a part of a region facing the non-orbital portion of the race, it is preferable not to form a grease holder. A grease holder may be formed in region B, but in that case, it is different from the grease holder formed in region A in order to avoid an increase in sliding resistance due to contact with the non-race portion of the bearing ring. For example, the grease holder is configured such that the sliding resistance with the non-race portion of the bearing ring is reduced as compared with the case where the grease holder in the region A is formed.

As a configuration to reduce sliding resistance, when configuring a grease holder with a fiber material, shorten the fiber length so that it does not substantially contact, and if contacted, decrease the fiber density, narrow the fiber, fiber length It is possible to adopt a method such as shortening the length or using a soft fiber material. By this means, the contact with the inner and outer ring shoulder portions which are non-track portions of the raceway ring is suppressed to light contact, and the sliding resistance can be reduced. Similarly, in the case of being made of a porous material, it is possible to adopt a means such as making the shape almost non-contact or using a soft porous material in the case of contact.

Further, a grease holder may be formed in other parts (for example, the groove part 111 in FIG. 2). However, it is preferable not to fix the grease holding body to the pocket surface that is in direct contact with the rolling element. This is because the shape of the pocket collapses, and the rolling element can be scratched by the restraint of the rolling element or the contact between the adhesive used for fixing and the rolling element.

Based on FIG. 3 and FIG. 4, another embodiment of the cage in which the grease holder is formed at different locations will be described. 3 and 4 are a partial perspective view and a developed view of a crown-shaped resin retainer in which a grease retainer is formed, as in FIG. In the cage 105 of the form shown in FIG. 3, the grease holder 106 is not formed in the region B which is a part of the region facing the non-race portion of the raceway on the inner and outer diameter surfaces of the cage 105. In a region A that is a portion other than the region B, a grease holder 106 is formed. In this embodiment, the region B is located on the non-opening side of the pocket 109 of the cage body 107, occupies a certain range in the axial direction and is continuous in the circumferential direction, and is a region that does not cover the pocket 109. .

In the cage 105 of the form shown in FIG. 4, the grease holder 106 is not formed in the region B that is a part of the region facing the non-race portion of the raceway on the inner and outer diameter surfaces of the cage 105. In a region A that is a portion other than the region B, a grease holder 106 is formed. In this embodiment, the region B is a plurality of rectangular regions that are located on the non-opening side of the pocket 109 of the cage main body 107 and are spaced apart at a predetermined interval in the circumferential direction.

The examples shown in FIGS. 2 to 4 are crown-shaped cages. However, in the rolling bearing of the present invention, a grease retaining body is formed in a cage such as a corrugated cage, a ball cage, or a roller cage. It is good also as a form. Based on FIG. 5, the holder | retainer used for these aspects is demonstrated. In FIG. 5A, the grease retainer 106 is located in a region (region B) along the circumferential direction at both axial ends of the portion constituting the pocket 109 on the inner and outer diameter surfaces of the corrugated cage 105 ′. The grease holding body 106 is formed in the other region (region A) which is not formed.

In FIG. 5 (b), a grease holder is provided in a region (region B) along the circumferential direction at both axial end portions of the ring on the inner and outer diameter surfaces of the ball retainer 105 ". 106 is not formed, and a grease holding body 106 is formed in the other region (region A). The region B is a region that covers a part of the pocket 109.

In FIG. 5 (c), in the inner and outer diameter surfaces of the roller (milling) cage 105 ′ ″, the region along the circumferential direction (region B) at both axial end portions of the ring (region B) holds grease. The body 106 is not formed, and the grease holding body 106 is formed in the other region (region A). Area B is an area that does not cover pocket 109.

¡The rolling bearing of the present invention is lubricated with grease. Grease is sealed in the bearing inner space and lubricated by being interposed in the raceway surface. The base oil constituting the grease can be used without particular limitation as long as it is usually used for rolling bearings. For example, mineral oils such as paraffinic mineral oils and naphthenic mineral oils, polybutene oils, poly-α-olefin oils, hydrocarbon synthetic oils such as alkylbenzene oils and alkylnaphthalene oils, natural fats and oils, 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 the thickener constituting the grease, for example, aluminum soap, lithium soap, sodium soap, composite lithium soap, composite calcium soap, composite aluminum soap and other thickening agents such as diurea compounds and polyurea compounds. Fluorine resin powders such as urea compounds and PTFE resins can be mentioned. These thickeners may be used alone or in combination of two or more.

Also, known additives can be added to the grease as needed. 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.

The amount of grease charged is not particularly limited as long as desired lubrication characteristics can be ensured, but is preferably about 50% to 80% (volume ratio) of the static space volume in the bearing inner space. In the present invention, the shearing resistance of the grease can be reduced by the arrangement of the predetermined grease holder, so that the torque can be reduced while keeping the amount of grease filled in the above range.

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, angular contact 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.

Hereinafter, examples and comparative examples of the first invention of the present application will be described.

Example 1-1
A resin crown cage having the shape of FIG. 2 that can be used for a 6204 rolling bearing (deep groove ball bearing) was manufactured by injection molding. The resin material is polyamide 66 resin (containing 25% by volume of glass fiber). An adhesive is applied to the position (area A) shown in FIG. 2 of the cage, and a flocked portion made of short fibers of polyamide 66 resin (fiber length 0.8 mm, thickness 3.3 dtex) by electrostatic flocking ( A grease holder was formed. This cage is incorporated into a 6204 rolling bearing (deep groove ball bearing), grease (lithium soap + ester oil) is sealed in the bearing space in a volume ratio of 70% by volume, and sealed with a shield plate to obtain a test bearing. . The obtained test bearing was subjected to the following torque measurement test, and the change with time of the torque was examined.

<Torque measurement test>
The test bearing was fixed, the rotational speed was 3600 rpm, the room temperature (25 ° C.) atmosphere, an axial load of 20 N was applied to the outer ring and restrained by the load cell, and the torque (N · mm) generated in the bearing was calculated as the inner ring rotation.

Comparative Example 1-1
A resin crown cage having the shape of FIG. 6 that can be used for a 6204 rolling bearing (deep groove ball bearing) was manufactured by injection molding. As shown in FIG. 6, a grease holder 106 indicated by a shaded portion is formed on the entire inner and outer diameter surfaces of the cage 105. This cage has the same configuration as that of Example 1-1 except that the flocked portion is formed on the entire inner and outer diameter surfaces. This cage is incorporated into a 6204 rolling bearing (deep groove ball bearing), grease (lithium soap + ester oil) is sealed in the bearing space in a volume ratio of 70% by volume, and sealed with a shield plate to obtain a test bearing. . The obtained test bearing was subjected to the same torque measurement test as in Example 1-1, and the change with time in torque was examined.

Fig. 7 shows the results of the torque measurement test. In FIG. 7, the horizontal axis represents operating time (time (h)), and the vertical axis represents torque (N · mm).

As shown in FIG. 7, in Comparative Example 1-1, the shoulder portions of the inner and outer rings and the flocked portion as a grease holding body were in contact with each other, and the steady torque was about 4 N · mm. On the other hand, in Example 1-1, the steady torque could be reduced to about 2 N · mm by removing the flocked portion that was in contact with the inner and outer ring shoulders.

Hereinafter, the rolling bearing of the second invention of the present application will be described.

An example of the rolling bearing of the present invention will be described with reference to FIG. FIG. 8 is a partial cross-sectional view of a deep groove ball bearing incorporating a crown-shaped resin retainer having a flocked portion as a rolling bearing of the present invention. As shown in FIG. 8, in the rolling bearing 201, an inner ring 202 having a rolling surface 202a on the outer peripheral surface and an outer ring 203 having a rolling surface 203a on the inner peripheral surface are arranged concentrically. A plurality of rolling elements 204 are disposed between the inner ring rolling surface 202a and the outer ring rolling surface 203a. The plurality of rolling elements 204 are held by a crown-shaped holder 205. The rolling bearing 201 includes an annular seal member 212 provided at both axial openings of the inner and outer rings, and in the bearing inner space formed by the inner ring 202, the outer ring 203, the cage 205, and the seal member 212. It is lubricated by the enclosed grease 213. In this embodiment, a flocked portion 206 formed by flocking fibers is formed on the surface of the cage 205 that contacts the grease 213 (the surface in the bearing space).

Details of the holder 205 will be described with reference to FIG. FIG. 9A is a partial perspective view of the cage, and FIG. 9B is a development view of the cage. As shown in FIG. 9 (a), a crown-shaped cage 205 is formed on a ring-shaped cage body 207 with a pocket 209 that opens to one side in the axial direction and holds a rolling element, and a pocket between adjacent pockets. 209 and a groove 211 formed on the opening side of 209. More specifically, a pair of opposing holding claws 208 are formed on the annular cage body 207 at a constant pitch in the circumferential direction, and the opposing holding claws 208 are bent in a direction approaching each other, and A pocket 209 for holding a ball as a rolling element is formed between the holding claws 208. Between the back surfaces of the holding claws 208 adjacent to each other formed at the edge of the adjacent pocket 209, a flat portion 210 is formed as a rising reference surface of the holding claws 208, and the groove portion is formed by the holding claws 208 and the flat portion 210. 211 is configured.

As shown in FIGS. 9A and 9B, a flocked portion 206 indicated by a shaded portion is formed on the entire inner diameter surface (side surface of the inner ring) of the cage 205. Although not shown in the drawing, a flocked portion is also formed in the same range on the outer diameter surface (side surface of the outer ring). The inner and outer diameter surfaces of the cage 205 are not contact surfaces with balls that are rolling elements. In addition, the inner and outer diameter surfaces of the cage 205 are not surfaces positioned outside the bearing, but are surfaces on the bearing inner space side constituted by the inner ring, the outer ring, the cage, and the seal member, and come into contact with the sealed grease. The surface. Further, since the cage 205 of this form is a rolling element guide, the inner and outer diameter surfaces are surfaces that do not contact the raceway (the inner ring 202 and the outer ring 203 in FIG. 8).

¡Grease is fixed and held on the flocked portion, and rotates together with the cage without being subjected to shearing, so that stirring resistance does not occur and torque can be reduced compared to the case where there is no flocked portion. In addition, the grease is softened and easily separated from oil when subjected to shearing and the lubrication life is shortened. However, in the present invention, the grease is held by the flocked portion and is not easily subjected to shearing, thereby extending the lubrication life. Also, when using oil lubrication, if the flocked part 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.

The flocked part is formed by flocking short fibers. There are electrostatic flocking and electrostatic spraying flocking methods. Electrostatic flocking is a method in which a base material coated with an adhesive is used as a counter electrode, an electrostatic field is created by a high voltage electrode, and short fibers are caused to fly by the electrostatic attraction force and napped on the adhesive. Electrostatic spraying is a method in which, in addition to this electrostatic attraction force, the short fiber is forcedly blown with air and the adhesive is implanted. In this method, when the adhesive is pierced from one end face of the short fiber by electrostatic attraction force, the fiber is inclined 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.

The flocked portion in the present invention is formed by this electrostatic spraying flocking. Thereby, the ratio (fiber density) of the fiber area which occupies per formation area of the flocked part is lowered as compared with the case of electrostatic flocking, and the torque increase at the time of contact between the bearing constituent member and the fiber is suppressed.

In this invention, the ratio (fiber density) of the fiber area which occupies per formation area of a flocked part is 1% or more and less than 5%. In electrostatic spraying flocking, it is difficult to count the number of fibers because the fibers have fallen. For this reason, the fiber density in electrostatic spraying flocking is calculated in the following procedure, for example.
(1) First, a method for calculating the fiber density (%) in the case of electrostatic flocking will be described. The flocked portion is observed with a microscope, the number of fibers occupying the formation area of the flocked portion is counted, and the following formula is calculated. In the following formula (A), (number of fibers in the flocked portion × fiber diameter ² × π / 4) is the area of the fiber portion on the formation surface (adhesion surface) of the flocked portion.

Fiber density of electrostatic flocking (%) = ((number of fibers in flocked portion × fiber diameter ² × π / 4) / formation area of flocked portion) × 100 −−− (A)

(2) Using this, the fiber density in the case of electrostatic spraying is calculated. Prepare electrostatic flocking using the same kind of short fibers and electrostatic spraying flocking for the same area. Next, the adhesive is removed with a solvent, and only the fibers are taken out. The respective weights of the electrostatic flocking and the electrostatic sprayed fibers are measured, and the ratio of the electrostatic spraying to the electrostatic flocking is measured. This ratio is multiplied by the fiber density of the electrostatic flocking obtained by the above formula (A) to calculate the fiber density of the electrostatic spraying flocking.

Fiber density of electrostatic sprayed flocking (%) = (Fiber weight of electrostatic sprayed flocking / Fiber weight of electrostatic flocking) × Fiber density of electrostatic flocking ---- (B)

When forming a flocked portion on the inner and outer diameter surfaces of the cage, the numerical value varies depending on the curvature of the ring. If the curvature is small, the density is high. The fiber density of electrostatic sprayed flocking is about 30 to 50% lower than the fiber density of electrostatic flocking. In the present invention, the preferred range of the fiber density is 1% to 3%.

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.

Among the above short fibers, 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. It is preferable to use it. Furthermore, by using a polyamide resin widely used as a material for a resin crown-shaped cage among synthetic resins, it is possible to use the bearing without lowering the use conditions of the bearing.

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 portion is formed. The specific shape is preferably, for example, a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex.

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, acrylic ester-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive And urethane resin emulsion adhesives, epoxy resin emulsion adhesives, polyester emulsion adhesives, ethylene-vinyl acetate copolymer adhesives, and the like. These may be used independently and 2 or more types may be used together.

About the formation part of the hair transplant part in the holder | retainer 205, it is not limited to the form shown in FIG. 9, The form formed only in an inner diameter surface and only an outer diameter surface, Other arbitrary places (For example, the groove part 211 etc. of FIG. 9). You may form in. However, it is desirable that the adhesive for flocking does not adhere to the portion of the cage 205 that contacts the rolling element. As a part where the holder 205 and the rolling element are in contact with each other, a pocket portion 209 of the holder 205 can be cited. For example, when an adhesive adheres to the pocket part 209, the shape of the pocket part 209 may collapse, and the rolling element may be damaged due to restraint of the rolling element or contact between the rolling element and the adhesive.

Based on FIG. 10, another embodiment of the cage in which the flocked portion is formed will be described. FIG. 10 is a partial perspective view and a developed view of a crown-shaped resin retainer in which a flocked portion is formed, as in FIG. 9. As shown in FIGS. 10 (a) and 10 (b), on the inner diameter surface of the cage 205, a flocked portion 206 is formed in a region 205a close to the raceway surface of the inner ring, and the inner ring is a non-race portion of the raceway ring. In the region 205b facing the shoulder portion, no flocked portion is formed. In addition, although not shown, a flocked portion is formed in a region close to the raceway surface of the outer ring on the outer diameter surface of the cage 205, and a flocked portion is not formed in a region facing the shoulder portion of the outer ring. This region 205b is located on the non-opening side of the pocket 209 of the cage body 207, is a region that occupies a certain range in the axial direction and continues in the circumferential direction, and is a region that partially covers the pocket 209. If a hair transplant part is formed in the region 205b, the hair transplant part and the inner ring shoulder part may slide. In the present invention, the torque is reduced by reducing the fiber density of the flocked portion as described above, but the torque can be further reduced by not forming the flocked portion in the region.

Referring to FIG. 11, another form of the cage will be described. FIG. 11 is a partial perspective view of a crown-shaped resin retainer in which a flocked portion is formed. The retainer 205 in FIG. 11A is formed by adding a flocked portion 206 to the edge portion 209a of the pocket 209 in addition to the portion shown in FIG. An edge portion 209 a of the pocket 209 is a boundary portion between the inner and outer diameter surfaces of the cage 205 and the pocket 209. Similarly, the retainer 205 of FIG. 11B is formed by adding a flocked portion 206 to the edge portion 209a of the pocket 209 in addition to the location of FIG. By the flocking of the edge portion, all or a part of the grease adhering to the surface of the rolling element can be scraped off and excessive grease on the surface of the rolling element can be removed. Since the contact between the rolling element and the flocked part may lead to an increase in torque, it is preferable that the rolling element is not contacted or only the fiber tip of the flocked is contacted (light contact). In addition, since the ratio of the fiber area which occupies per formation area also in the hair transplant part of this edge part is 1% or more and less than 5%, it is hard to increase a torque at the time of contact with a rolling element.

The examples shown in FIGS. 9 to 11 are crown-shaped cages, but in the rolling bearing of the present invention, a hair transplantation part may be formed in a cage such as a corrugated cage or a machined cage. 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. 9 to 11 is made of resin. This resin material is the same as the crown type cage of the rolling bearing of the first invention.

The hair transplanting part may be formed on the surface of the bearing ring or the seal member in addition to the cage. When forming in any member, it forms in the surface which contacts a lubricant other than the contact surface with a rolling element. Moreover, in one rolling bearing, you may form a hair transplant part in the some member which comprises this, respectively.

¡The rolling bearing of the present invention is lubricated with lubricating oil or grease. These lubricants (lubricating oil / grease) are supplied and sealed in the bearing inner space, and are 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 oils such as paraffinic mineral oils and naphthenic mineral oils, polybutene oils, poly-α-olefin oils, hydrocarbon synthetic oils such as alkylbenzene oils and alkylnaphthalene oils, natural fats and oils, 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.

Grease can be used without particular limitation as long as it is usually used for rolling bearings. Examples of the base oil constituting the grease include the above-described lubricating oil. Further, as the thickener constituting the grease, for example, aluminum soap, lithium soap, sodium soap, composite lithium soap, composite calcium soap, composite aluminum soap and other thickening agents such as diurea compounds and polyurea compounds. Fluorine resin powders such as urea compounds and PTFE resins can be mentioned. These thickeners may be used alone or in combination of two or more.

Also, 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.

The amount of lubricant enclosed is not particularly limited as long as desired lubrication characteristics can be ensured, but is preferably about 50% to 80% (volume ratio) of the static space volume in the bearing inner space. In the present invention, since the stir resistance of the grease can be reduced by forming the flocked portion, the torque can be reduced while keeping the amount of the lubricant enclosed within the above range.

As mentioned above, although embodiment (deep groove ball bearing (with a sealing member)) of this invention was described based on each figure etc., the rolling bearing of this invention is not limited to these. For example, angular contact 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. In addition, these rolling bearings can be applied regardless of the presence or absence of a seal member (shield plate). Similarly, even in an open type that does not have a seal member, a retaining effect such as lubricating oil by the flocked portion is obtained. It is done.

As described above, the rolling bearing of the present invention is characterized in that the fiber density of the flocked portion is lower than that formed by electrostatic flocking. Moreover, in order to obtain such a rolling bearing, the method for manufacturing a rolling bearing according to the present invention is characterized by a method for forming the flocked portion. That is, when manufacturing a rolling bearing in which a flocked portion is formed on a bearing constituent member, for the formation of the flocked portion, an adhesive is applied to an adhesive surface that is a flocked portion forming portion in the bearing constituent member, and then the charged fibers are air-filled. It is supplied to the bonding surface by being transported by a fluid such as, and a flocked portion is formed (electrostatic sprayed flocking).

Hereinafter, examples and comparative examples of the second invention of the present application will be described.

Example 2-1 and Example 2-2
A resin crown cage having the shape of FIG. 11 that can be used for a 6204 rolling bearing (deep groove ball bearing) was manufactured by injection molding. The resin material is polyamide 66 resin (containing 25% by volume of glass fiber). In Example 2-1, an adhesive was applied to the position shown in FIG. 11 (a) of the cage, and in Example 2-2, an adhesive was applied to the position shown in FIG. 11 (b). A flocked portion made of short fibers of polyamide 66 resin (fiber length 0.8 mm, thickness 3.3 dtex) was formed by electrosprayed flocking. The flocked portion at the edge of the pocket was in a state where the fiber tip protruded into the pocket space and contacted with the rolling elements. The fiber density of the flocked part was 2 to 3% by the calculation method described above. This cage is incorporated into a 6204 rolling bearing (deep groove ball bearing), grease (lithium soap + ester oil) is sealed in the bearing space in a volume ratio of 70% by volume, and sealed with a shield plate to obtain a test bearing. . The obtained test bearing was subjected to the following torque measurement test, and the change with time of the torque was examined.

Comparative Example 2-1 and Comparative Example 2-2
A resin crown cage having the shape of FIG. 11 that can be used for a 6204 rolling bearing (deep groove ball bearing) was manufactured by injection molding. The structure of Comparative Example 2-1 is the same as that of Example 2-1 except that the flocked portion is formed by electrostatic flocking. The cage of Comparative Example 2-2 is the same as that of Example 2-2 except that the flocked portion is formed by electrostatic flocking. The fiber density of the flocked part was more than 5% by the above calculation method. This cage is incorporated into a 6204 rolling bearing (deep groove ball bearing), grease (lithium soap + ester oil) is sealed in the bearing space in a volume ratio of 70% by volume, and sealed with a shield plate to obtain a test bearing. . The obtained test bearing was subjected to the same torque measurement test as in Example 2-1, and the change with time in torque was examined.

Fig. 12 shows the results of the torque measurement test. In FIG. 12, the horizontal axis represents the operating time (time (h)), and the vertical axis represents the torque (N · mm).

As shown in FIG. 12, in Comparative Example 2-1, the fiber and the inner ring shoulder, the fiber and the rolling element were in contact, and the steady torque was about 7 N · mm. On the other hand, in Example 2-1, although the contact was made at the same location, the density of the short fibers to be contacted was low, so the steady torque was about 3 N · mm. In Comparative Example 2-2, the short fiber and the rolling element were in contact with each other, and the steady torque was about 4 N · mm. In Example 2-2, the steady torque could be reduced to about 2 N · mm by lowering the density of the short fibers and reducing the adhesion surface.

From the results of torque and density, a good steady torque was obtained by reducing the fiber density by about 50% in the 6204 cage. From this, it is considered that good torque results can be obtained at a density of 50% or less from the density of electrostatic flocking.

Hereinafter, the rolling bearing of the third invention of the present application will be described.

The rolling bearing according to the present invention includes a fibrous material or a porous material on a bearing internal member other than the rolling element (inner ring, outer ring, cage, seal member) on the bearing inner space side surface other than the contact surface of the member with the rolling element. An oil holder made of a material and held or impregnated in advance in a state where the lubricating oil can be discharged is bonded and fixed. 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.

Lubricating oil can be retained inside the bearing by retaining the lubricating oil in the oil retaining body. During operation, the 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. 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.

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.

An oil holding body (planted portion) made of a fiber material is formed by planting 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 the adhesive fixing of the oil holder 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, acrylic ester-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive And urethane resin emulsion adhesives, epoxy resin emulsion adhesives, polyester emulsion adhesives, ethylene-vinyl acetate copolymer adhesives, 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. The specific shape is preferably, for example, a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex, and the density of fibers in the flocked portion as a holding body is about the area of the flocked area. 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. Further, the fibers having a polygonal cross-sectional shape have a large surface area or a high ability to retain lubricating oil compared to a circular cross-section.

The location which forms the oil holding body (planted part) which consists of fiber materials is demonstrated based on FIG. FIGS. 13A to 13C are partial schematic cross-sectional views of rolling bearings. This form of rolling bearing 301 includes an inner ring 302 and an outer ring 303 that are raceways, a plurality of rolling elements 304 interposed between the inner and outer rings, and a cage 305 that holds the rolling element 304. Further, the rolling bearing 301 includes an annular seal member (shown only in FIG. 13C: reference numeral 307) provided at both axial opening portions of the inner and outer rings, and an oil retaining member is provided on the raceway surface and the rolling surface. Lubricating oil that has oozed out from the flocked portion 306 is supplied and lubricated. The material and formation method of the flocked portion 306 are as described above.

In FIG. 13A, a flocked portion 306 is formed in the vicinity of the raceway surface of the raceway shoulder portion, and the lubricating oil held in the flocked portion 306 is mainly supplied to the raceway surfaces of the inner ring 302 and the outer ring 303. Yes. In FIG. 13B, the flocked portion 306 is formed on the inner diameter surface, the outer diameter surface, and the width surface of the cage 305, and the lubricating oil held by the flocked portion 306 is mainly on the rolling surface of the rolling element 304. Has been supplied to. FIG. 13C shows a flocked portion 306 formed on the bearing inner space side surface (rolling element side end surface) of the seal member 307, and the lubricating oil held by the flocked portion 306 is the flocked portion forming surface of the seal member 307. And is supplied to the raceway surfaces of the inner ring 302 and the outer ring 303.

The other part which forms the oil holding body (flocked part) which consists of fiber materials is demonstrated based on FIG. 14 (a) and 14 (b) are partial schematic cross-sectional views of the rolling bearing, in which the rolling elements and the fiber tip are in contact with each other. As in the case of FIG. 13, the rolling bearing 301 in this form includes an inner ring 302 and an outer ring 303 that are raceways, a plurality of rolling elements 304 interposed between the inner and outer rings, and a holding that holds the rolling elements 304. And a container 305. In FIG. 14A, the flocked portion 306 is formed on the shoulder adjacent to the raceway surface (rolling surface) of the raceway (inner ring 302 and outer ring 303), and the fiber tip of the flocked portion 306 contacts the rolling element 304. is doing. In FIG. 14 (b), the flocked portion 306 is formed at the edge of the pocket of the retainer 305, and the fiber tip of the flocked portion 306 is in contact with the rolling element 304. As shown in FIG. 14, by making the rolling element and the fiber lightly contact each other, lubricating oil can always be supplied to the rolling element and the race, helping to form an oil film and extending the life.

13 (a) to (c) and FIGS. 14 (a) and 14 (b) may be employed individually or in any combination.

The other part which forms the oil holding body (flocked part) which consists of fiber materials is demonstrated based on FIG. 17 and FIG. 17 and 18 are partially enlarged perspective views of a crown-shaped cage of a rolling bearing. As shown in FIG. 17, a crown-shaped cage 305 is formed on a ring-shaped cage body 305 b with a pocket 305 d opened on one side in the axial direction to hold a rolling element, and an opening of the pocket 305 d between adjacent pockets. And an inter-pocket groove 305a formed on the side. More specifically, a pair of opposing holding claws 305c are formed on the annular cage body 305b at a constant pitch in the circumferential direction, and the opposing holding claws 305c are bent in a direction approaching each other, A pocket 305d for holding a ball as a rolling element is formed between the holding claws 305c. A flat portion 305e serving as a rising reference surface of the holding claw 305c is formed between the back surfaces of the holding claws 305c adjacent to each other formed at the edge of the adjacent pocket 305d, and the pocket is formed by the holding claw 305c and the flat portion 305e. An inter-groove portion 305a is formed. That is, the back surface (the side opposite to the pocket) of the holding claw 305c constitutes the inner surface of the inter-pocket groove portion 305a, and the surface of the flat portion 305e constitutes the bottom surface of the inter-pocket groove portion 305a.

17, in the crown-shaped cage 305 having the structure, the flocked portion 306 is bonded and fixed in the inter-pocket groove 305a. The shaded portion shown in FIG. 17 is the maximum formation location of the flocked portion 306 that is an oil holding body. When the oil is held on the fibers in the flocked part before the bearing operation, the oil can be held on the fibers even during the operation due to the surface tension of the fibers. Moreover, since the cage itself is in contact with the rolling elements, oil can always be supplied to the lubricating surface. As a result, the life can be extended.

In the form shown in FIG. 18, the cage 305 has a pocket anti-opening side groove 305g on the surface 305f on the non-opening side of the pocket 305d of the cage main body 305b. The pocket non-opening side groove 305g is formed on the surface 305f on the non-opening side of the pocket 305d of the cage main body 305b as a thinned portion when the cage is injection-molded. In the crown-shaped cage 305 having this structure, a flocked portion 306 is bonded and fixed in the pocket opposite opening side groove portion 305g. The shaded portion shown in FIG. 18 is the maximum formation location of the flocked portion 306 that is an oil holding body. The effect similar to the case of the form of FIG. 17 is acquired by forming the flocked part 306 in this part, and hold | maintaining lubricating oil.

17 and 18 may be employed individually or in combination. Further, these forms, and FIGS. 13 (a) to 13 (c) and FIGS. 14 (a) and (b) may be arbitrarily combined.

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 oils and naphthenic mineral oils, polybutene oils, poly-α-olefin oils, hydrocarbon synthetic oils such as alkylbenzene oils and alkylnaphthalene oils, natural fats and oils, 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.

Also, known additives can be added to the lubricating oil as necessary. 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, deep groove ball bearing, angular 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 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.

Hereinafter, examples and comparative examples of the third invention of the present application will be described.

Example 3-1 to Example 3-3, Comparative Example 3-1
15 (a) and 15 (b) show short fibers of polyamide 66 resin on the inner and outer diameter surfaces of the crown-shaped cage made of resin (polyamide 66 resin (containing 25% glass fiber)) and the inner surface of the shield bearing. The Example which formed the hair transplant part which consists of (fiber length 0.8mm and thickness 3.3 dtex) is shown. Example 3-1 is a bearing in which flocked portions are provided on the inner and outer diameter surfaces of the cage and oil is held in the fibers (FIG. 15A). Example 3-2 is a bearing in which a flocked portion is provided on the shield and oil is held in the fiber (FIG. 15B). Example 3-3 is a bearing in which a flocked portion is provided in the cage and the shield, and oil is held in the fiber (the flocked portion for each of the cage and the shield is shown in FIGS. 15A and 15B). Same as). The comparative example is a bearing in which oil is sealed in a standard bearing (without fiber) before the test. The test used 6204 shield bearings. These bearings were subjected to the following high-temperature high-speed life test.

<High-temperature high-speed life test>
The bearing outer ring was operated at a rotational speed of 10,000 min ⁻¹ under an outer ring outer diameter temperature of 150 ° C., a radial load of 67 N, and an axial load of 67 N, and the time (h) until seizure was measured. The oil was ester oil, and it was not re-supplied after sealing before the bearing operation.

Fig. 16 shows the results of the high-temperature high-speed life test. In FIG. 16, the horizontal axis represents the amount of oil enclosed, and the vertical axis represents the lifetime (time (h)). As shown in FIG. 16, the life time when 0.6 to 0.7 g of oil was sealed was 220 hours for Example 3-1, 150 hours for Example 3-2, and 70 hours for Comparative Example 3-1. In the examples, the flocked portion retained the oil inside the bearing, and the life result was more than twice that of the comparative example. The reason why a particularly long life was obtained in Example 3-1 was that oil leached from the fibers of the hair transplantation part of the cage was supplied to the balls to help form an oil film. In Example 3-3, since the oil was held by the two flocked portions of the cage and the shield, the amount of oil retained inside the bearing increased and the life was long.

The rolling bearings of the first and second inventions of the present application can improve lubrication characteristics including low torque without adversely affecting the torque by using simple means while using existing bearing shapes. It can be widely used as a rolling bearing in various applications. The rolling bearing according to the third invention of the present application has a long life even without resupply of lubricating oil while reducing the rotational torque as an oil-lubricated rolling bearing while using an existing bearing shape. It can be widely used as a rolling bearing.

DESCRIPTION OF SYMBOLS 101 Rolling bearing 102 Inner ring 103 Outer ring 104 Rolling body 105 Cage 106 Grease holder 107 Cage body 108 Holding claw 109 Pocket 110 Flat part 111 Groove part 112 Seal member 113 Grease 201 Rolling bearing 202 Inner ring 203 Outer ring 204 Rolling element 205 Cage 206 Flocked portion 207 Cage body 208 Holding claw 209 Pocket 210 Flat portion 211 Groove portion 212 Seal member 213 Grease 301 Rolling bearing 302 Inner ring 303 Outer ring 304 Rolling body 305 Cage 306 Flocked portion 307 Seal member

Claims

A rolling bearing comprising an inner ring and an outer ring, which are raceways, a plurality of rolling elements interposed between the inner and outer rings, a cage for holding the rolling elements, and grease sealed in a bearing inner space. And
In at least one surface selected from an inner diameter surface and an outer diameter surface of the cage,
A grease holder made of a fiber material or a porous material is formed in the region A excluding at least a part of the region facing the non-track portion of the raceway,
A grease holder made of a fiber material or a porous material is not formed in the other region B, or the sliding resistance with the non-track portion of the raceway is larger than when the grease holder in the region A is fixed. A rolling bearing characterized in that a grease holding body made of a fiber material or a porous material is reduced.
The region A is a region excluding at least a part of a region facing the inner and outer ring shoulders which are non-orbital portions of the bearing ring,
The rolling bearing according to claim 1, wherein a grease holder made of a fiber material or a porous material is not formed in the region B.
3. The rolling bearing according to claim 2, wherein the region A is a region excluding the entire region facing the inner and outer ring shoulder portions which are non-track portions of the bearing ring.
The retainer is a crown-shaped retainer having a plurality of pockets that are open on one side in the axial direction and hold the rolling elements on an annular retainer body,
The rolling bearing according to claim 1, wherein the region B is located on a non-opening side of the pocket of the cage body.
2. The rolling bearing according to claim 1, wherein the grease holder is formed by planting short fibers of synthetic resin as the fiber material.
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 made of grease or lubricating oil supplied to the bearing inner space. A rolling bearing provided,
In at least one bearing component selected from the inner ring, the outer ring, and the cage, a flocked portion is formed by flocking fibers on a surface that contacts the lubricant,
A rolling bearing characterized in that a ratio of the fiber area to the formation area of the flocked portion is 1% or more and less than 5%.
The rolling bearing according to claim 6, wherein the fibers of the flocked portion are in contact with at least one of the bearing constituent members.
The rolling bearing according to claim 6, wherein the flocked portion is formed on a part or the entire surface of the inner diameter surface and / or outer diameter surface of the cage.
The rolling bearing according to claim 8, wherein the flocked portion is not formed in at least a part of a region of the surface on which the flocked portion is formed and facing the non-orbital portion of the raceway ring.
The rolling bearing according to claim 6, wherein the flocked portion is formed on a part or the whole of an edge portion of a pocket for holding the rolling element in the cage.
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 a cage that holds the rolling elements,
In at least one member selected from the inner ring, the outer ring, and the cage, an oil holder made of a fiber material or a porous material is provided on a bearing inner space side surface other than a contact surface of the member with the rolling element. It is glued and fixed
A rolling bearing, wherein lubricating oil is previously held or impregnated in the oil holder.
Inner and outer rings that are raceways, a plurality of rolling elements interposed between the inner and outer rings, a cage that holds the rolling elements, and seal members that are provided at openings in both axial ends of the inner and outer rings A rolling bearing comprising:
In at least one member selected from the inner ring, the outer ring, the cage, and the seal member, the bearing inner space side surface other than the contact surface with the rolling element of the member is made of a fiber material or a porous material. The oil holder is fixed by adhesion,
A rolling bearing, wherein lubricating oil is previously held or impregnated in the oil holder.
The said oil holding body is adhesively fixed to at least one selected from an inner diameter surface and / or an outer diameter surface of the cage and a shoulder surface of the bearing ring. Item 13. A rolling bearing according to Item 12.
The retainer has, on an annular retainer body, a pocket that opens to one side in the axial direction to hold the rolling element, and an inter-pocket groove formed on the opening side of the pocket between the adjacent pockets. Have
The rolling bearing according to claim 11 or 12, wherein the oil holding body is bonded and fixed to at least a part of the groove portion between the pockets.
The retainer is formed on an annular retainer body on one side in the axial direction to hold the rolling element, and a pocket anti-opening formed on a surface of the retainer body on the side opposite to the opening of the pocket. Having side grooves,
The rolling bearing according to claim 11 or 12, wherein the oil retaining body is bonded and fixed to at least a part of the pocket opposite opening side groove portion.