阅读说明：本技术 滚动轴承的附带树脂被膜的保持器 (Resin film-attached cage for rolling bearing ) 是由 木村大碁 于 2019-08-01 设计创作，主要内容包括：为在保持器(1)的合成树脂制的基材的表面的局部或者整体设置有聚脲树脂被膜(7)的附带树脂被膜的保持器。通过聚脲树脂被膜和基材的复合,形成耐磨性、耐冲击性和抗拉能力强且具有适度的抗拉特性的被膜,能够充分提高保持器的机械强度和耐久性。(The resin-coated retainer is provided with a polyurea resin coating (7) partially or entirely on the surface of a synthetic resin base material of the retainer (1). The polyurea resin coating and the base material are combined to form a coating film having high wear resistance, impact resistance and tensile strength and appropriate tensile characteristics, and the mechanical strength and durability of the retainer can be sufficiently improved.)

1. A resin-coated cage for a rolling bearing, characterized in that,

the cage is an annular cage which rotatably holds rolling elements interposed between an inner ring and an outer ring of a rolling bearing in pockets, and the cage is formed by providing a polyurea resin film on a part or the whole of a base material surface of the cage.

2. The resin-coated cage for rolling bearing according to claim 1, wherein the cage is a cage having a resin coating film,

the polyurea resin coating is formed by oleophilic rough surface.

3. The resin-coated cage for rolling bearing according to claim 1 or 2, wherein,

the polyurea resin coating film has a thickness of 0.3 to 2.0 mm.

4. The resin-coated cage for rolling bearing according to any one of claims 1 to 3, wherein,

the retainer has a part of a surface of a base material, which is a surface of a corner of a rectangular pocket, a fused portion of a resin base material, or a contact portion with the rolling elements.

5. The resin-coated cage for rolling bearing according to any one of claims 1 to 4, wherein,

the base material of the retainer is steel or synthetic resin.

Technical Field

The present invention relates to a resin film-attached cage for a rolling bearing, which is improved in strength and the like by providing a resin film on a surface of a cage for a rolling bearing.

Background

In general, a cage of a rolling bearing is a member in which rolling elements interposed between an inner ring and an outer ring are rotatably held in pockets, and the cage is made of metal such as steel or synthetic resin, and a crown-shaped or iron plate-shaped cage for a ball bearing, a basket-shaped cage for a roller bearing, a comb-shaped cage for a double row roller bearing, and the like are also known.

The cage of such a rolling bearing is required to have wear resistance, self-lubricity, or lubricant oil retention to withstand contact with the rolling elements such as balls or rollers, and therefore, surface treatment may be performed.

For example, a steel basket-shaped cage for a tapered roller bearing used in a drive device of a railway vehicle is subjected to a taff bath carbonitriding (nitriding) treatment on the surface thereof to increase hardness and thereby to improve the breakage strength and wear resistance (patent document 1).

Further, it is known to form a porous film made of a polyamide-imide resin or the like impregnated with a liquid lubricant on a contact surface of a metal or synthetic resin cage with a rolling element (patent document 2).

Further, it is known that a coating film made of a synthetic resin composition containing fullerene and disulfide is formed on a ball guide surface of a corrugated cage made of an iron plate for a ball bearing to improve wear resistance (patent document 3).

In addition, as a metal comb-shaped retainer for a roller bearing, a roller bearing retainer having a resin coating made of nylon (polyamide), polyimide, polypropylene or the like formed on the surface of a core material thereof and having improved lubricity is known (patent document 4).

Patent document 1: japanese patent laid-open publication No. 2006-250184

Patent document 2: japanese patent No. 4536650

Patent document 3: japanese patent application laid-open No. 2010-65816

Patent document 4: japanese laid-open patent publication No. 9-177794

However, in the surface treatment of the above conventional retainer, the treatment with the resin coating is used, and the resin is made to contain a liquid lubricant or a solid lubricant, whereby the lubricity and wear resistance required for the pocket of the retainer can be improved.

Further, the taff salt bath carbonitriding treatment for metal cannot be applied to the resin-made cage.

Disclosure of Invention

Accordingly, an object of the present invention is to solve the above-described problems, and to provide a method for improving the strength of a cage made of metal or resin, that is, a method for improving the mechanical strength including the wear resistance and the impact resistance of a cage including a rolling bearing by a relatively simple method, regardless of the material of the cage.

In order to solve the above problems, the present invention provides a resin film-attached cage for a rolling bearing, which is an annular cage in which rolling elements interposed between an inner ring and an outer ring of the rolling bearing are rotatably held in pockets, and which is formed by providing a polyurea resin film partially or entirely on a base material surface of the cage.

In the resin film-attached cage of the rolling bearing of the present invention configured as described above, the polyurea resin film provided on a part or the whole of the base material surface of the cage is formed rapidly and cured stably by mixing isocyanate and amine and utilizing a reaction mainly involving urea bonding.

Therefore, the resin-coated cage of the rolling bearing of the present invention is formed with a coating having high wear resistance, impact resistance and tensile strength and appropriate tensile properties by combining the polyurea resin coating and the base material, and the mechanical strength and durability of the cage made of the metal base material or the resin base material can be sufficiently improved.

In order to retain the lubricating oil on the surface of the retainer and improve the liquid lubricity, the polyurea resin coating is preferably formed of a rough surface having oleophilicity.

In addition, in order to sufficiently improve the mechanical strength and durability of the entire retainer, the polyurea resin coating film preferably has a thickness of 0.3 to 2.0 mm. This is because the polyurea resin film having a thickness of less than 0.3mm is not preferable because the effect such as tensile strength is not expected, and the film thickness is likely to be uneven in the case of a thick film having a thickness of more than 2.0 mm.

Such a polyurea resin film is preferably provided on the entire surface of the base material of the cage, but in order to provide the polyurea resin film efficiently with as little as possible, it may be provided on a part of the surface of the base material of the cage such as a corner of a rectangular pocket, a surface of a fused portion of the resin base material, or a surface of a contact portion with the rolling element. These necessary portions are portions of the base material of the retainer that require relatively high mechanical strength or weld lines at which the strength of the base material made of synthetic resin is weakened, and reinforcing these portions can efficiently improve the strength of the entire retainer.

When the base material of the retainer is made of any one of steel and synthetic resin, the polyurea resin coating film having such an action effect can be formed.

The present invention provides a retainer comprising a metal base material or a resin base material, a polyurea resin coating film provided on a part or the whole of the surface of the base material of the retainer, and a composite material of the polyurea resin coating film and the base material, thereby forming a coating film having high wear resistance, impact resistance and tensile strength and appropriate tensile characteristics, and sufficiently improving mechanical strength and durability of the retainer for either the metal base material or the resin base material.

Drawings

Fig. 1 is a perspective view of embodiment 1.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a sectional view taken along line III-III of fig. 1.

Fig. 4 is a perspective view of a tapered roller bearing according to embodiment 1, with a main portion cut away.

Fig. 5 is a perspective view of embodiment 2.

Fig. 6 is a perspective view of embodiment 3.

Fig. 7 is an explanatory view of a pocket tensile test of the retainer.

Fig. 8 is an explanatory view of a loop tensile test of the retainer.

Fig. 9 is a graph showing the results of the pocket tensile test in example 1 and comparative example 1.

FIG. 10 is a graph showing the results of the ring tensile test of examples 1 to 3 and comparative example 1.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

As shown in fig. 1 to 4, embodiment 1 is a cage 1 of a conical truncated cone shape which holds rolling elements 4 interposed between an inner ring 2 and an outer ring 3 of a conical rolling bearing rotatably in pockets 5. The resin-coated retainer of embodiment 1 is configured by providing a polyurea resin coating 7 on the entire surface of the synthetic resin base material 6 of the retainer 1.

The synthetic resin serving as the base material of the cage 1 preferably has strength and ease of molding which withstand the operating temperature of the bearing and also withstand vibration and impact load received during rotation, and thus, for example, there are: polyamide resins, polyoxymethylene resins, polybutylene terephthalate resins, fluorine resins, and the like. The synthetic resin reinforced with glass fiber, carbon fiber, or the like can be recommended. The molding method is not particularly limited, but a resin having such conditions that injection molding can be performed is preferable.

The base material of the retainer 1 may be a metal such as a steel material, and the type thereof is not particularly limited, but a cold rolled or hot rolled steel plate press-punched retainer is preferable in terms of formability, and a stainless steel plate is preferable because it has good durability. The cut-out holder may be made of carbon steel for machine structural use, high-strength brass, aluminum alloy, or the like. When the strength of the retainer is required, a heat-treated product of SNCM (nickel-chromium-molybdenum steel) is preferably used.

The polyurea resin coating film 7 used in the embodiment can be formed by forming a polyurea resin on the surface of the base material of the retainer 1 by a known coating film forming method and coating the polyurea resin.

The coating method is preferably a coating method using a spray gun so that a polyurea resin coating film is rapidly formed by a reaction mainly involving urea bonding by mixing isocyanate and amine, and the mixing and discharging can be performed simultaneously.

In the spray coating using the spray gun as described above, the fine particles formed by spraying the polyurea resin adhere to the surface of the base material of the retainer before the spray particles are gelled, the flatness is somewhat irregular, and fine irregularities (dents) are formed on the surface to form a coating surface consisting of an oleophilic rough surface. By roughening the coated surface in this way, the holding force of the lubricating oil or grease is greater than that of the smooth surface, and the lubricity is improved. Further, if the curing time of the coated surface is adjusted as necessary, the coating surface may be formed by embossing a pattern having an uneven pattern on the surface.

The polyurea resin is a coating film-forming material which can form a coating film by applying an isocyanate component and a polyamine component (isocyanate group and amino group) at a predetermined mixing ratio by a spray device of high-pressure two-liquid collision mixing, and causing a urea bonding reaction.

For example, a known aromatic polyurea spray can be used which is composed of an MDI-based polyisocyanate produced by reacting an excessive amount of 4, 4 '-and/or 2, 4' -diisocyanate diphenylmethane (MDI) with polyoxypropylene glycol, a chain extender containing diethyltoluenediamine (DETDA) as a main component, and a polyamine component including polyoxypropylene polyamine.

In addition, the aromatic polyurea spray has a disadvantage of yellowing due to ultraviolet exposure, and thus polyurea resin modified using aliphatic isocyanate is preferably used.

For example, a polyurea resin obtained by reacting a semi-prepolymer obtained by reacting a polyoxypropylene polyamine with a stoichiometric excess of an aliphatic polyisocyanate such as isophorone diisocyanate (IPDI) or m-tetramethylxylylene diisocyanate (m-TMXDI), and a polyamine composed of isophorone diamine or 1, 4-diaminocyclohexane and a polyoxyalkylene polyamine can also be used.

The polyurea resin used in the present invention can be obtained by using a commercially available product, for example, Line-X (registered trademark) which is a trade name manufactured by Line X, usa, and the preferable results as in the following examples can be obtained.

The 2 nd embodiment shown in fig. 5 is obtained by forming the cage of the 1 st embodiment as a basket-shaped cage 8 for a cylindrical roller bearing, and the 3 rd embodiment shown in fig. 6 is formed by forming the cage of the 1 st embodiment as a comb-shaped cage 9 for a double row roller bearing, and other configurations including the polyurea resin film 7 provided on the entire surface of the base material are completely the same as those of the resin film-attached cage of the 1 st embodiment.

The retainer to which the present invention can be applied is not limited to the above-described embodiment, and can be applied to other known forms of retainers such as a crown retainer.

Examples

[ example 1]

A retainer with a resin coating film of a roller bearing (the form shown in FIG. 1) was produced by using a retainer made of a polyamide resin (PA) for a tapered roller bearing (inner diameter: 130mm, outer diameter: 240mm, width: 80mm) (hereinafter referred to as a standard retainer) as a base material, and spraying "a polyurea resin composed of a component containing an aliphatic polyisocyanate and a component containing a polyoxyalkylene polyol having an amino group as a terminal group and a chain extender" (manufactured by LinE-X, manufactured by Line X) onto the entire surface of the base material of the retainer by a two-liquid collision mixing type spray gun (GX, manufactured by Gasmer corporation, USA) and reacting and curing the polyurea resin to form a polyurea resin coating film having an average film thickness of 1.0 mm.

[ example 2]

A resin-coated cage for a roller bearing was produced in exactly the same manner as in example 1, except that a polyurea resin coating having an average film thickness of 0.5mm was formed.

[ example 3]

A resin-coated cage for a roller bearing was produced in exactly the same manner as in example 1, except that a polyurea resin coating having an average film thickness of 1.8mm was formed.

Comparative example 1

In example 1, a standard retainer made of polyamide resin (PA) used as a base material was used as the retainer of comparative example 1 without forming a polyurea resin coating film.

The following tensile tests (1) and (2) were carried out using the retainers of examples 1 to 3 and comparative example 1 as test subjects, and the results are shown in fig. 9 and 10.

(1) Tensile test for each pocket

As shown in fig. 1 and 7, the retainer of example 1 and comparative example 1 was designed such that the pocket numbers were sequentially marked in the circumferential direction from any 1 of the 18 pockets, the odd-numbered pocket portions were used as test subjects, and a pair of upper and lower bar-shaped tools 10, 10 'and tensile tools 11, 11' capable of pulling the paired pillar portions forming the pockets of each test subject in the direction of separating from each other were arranged, and tensile force was applied in the arrow (upper and lower) direction at a tensile speed of 10 (mm/min) to examine the breaking load (N) until the base material broke, and the result was shown in fig. 9.

(2) Tensile test for annular portion of retainer

The retainers of examples 1 to 3 and comparative example 1 were divided into two portions in the axial direction near the center of each column portion, and only the large-diameter side rib was used as a ring-shaped test piece for the tensile test. As shown in fig. 8, a pair of upper and lower tensile tools 13 and 13 'each having a semicircular split tool 12 and 12' were arranged, and the annular test pieces of examples 1 to 3 (sample number: 1) and comparative example 1 (sample number: 3) were fitted, and tensile force was applied in the radial direction (arrow in the figure) at a tensile speed of 10 (mm/min), and the breaking load (N) until the base material broke was examined, and the result of setting the breaking load ratio of comparative example 1 to 1 was shown in fig. 10.

As can be seen from the results of fig. 9, assuming that the average breaking load of comparative example 1 is 1, the strength (average breaking load ratio) evaluated by the tensile test of each pocket of example 1 is improved to 1.33.

As can be seen from the results of fig. 10, the cage according to examples 1 to 3 had strengths such that the breaking load in the radial direction was 1.13, 1.25, and 1.45 times the average breaking load of comparative example 1 (sample number 3), respectively, and the strength was higher as the film thickness was larger.

Industrial applicability of the invention

The present invention can be used as a general-purpose retainer having excellent durability, which can be applied to a retainer of a relatively large rolling bearing requiring durability, such as a rolling bearing used for a drive device of a railway vehicle, an axle bearing, or the like, or a sprocket bearing used for a running gear of a construction machine.

Description of the reference numerals

1. A holder; an inner ring; 3.. an outer ring; a rolling body; a pocket; a substrate; a polyurea resin coating film; 10. a wand-like tool; 11. 11 ', 13'. the stretching tool; 12. a semi-circular segmented tool.