JP5141485B2 - Manufacturing method of cage for rolling bearing for high speed rotation - Google Patents

Description

  The present invention relates to a method of manufacturing a cage incorporated in a rolling bearing for high-speed rotation used to support a main shaft that rotates at high speed, such as a machine tool or an aircraft jet engine.

  Generally, cylindrical roller bearings, angular ball bearings, and the like are used as bearings for machine tool main shafts. The bearings of these bearings are made of a cotton cloth-reinforced phenolic resin machined, polyamide 66 reinforced with reinforcing fibers such as glass fiber, carbon fiber, aramid fiber, polyphenylene sulfide, polyether ether ketone, etc. A synthetic resin cage is used (see, for example, Patent Documents 1 and 2). Synthetic resin cages are advantageous for high-speed rotation because they are lightweight and have a small centrifugal force during rotation and are self-lubricating.

  In addition, a synthetic resin cage made of a material obtained by laminating carbon fiber fabrics and solidifying with resin is used for rolling bearings for aircraft jet engines (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 10-68420 Japanese Patent Laid-Open No. 2004-316813 JP 2000-154826 A

  In recent years, machine tools have a tendency to improve cutting ability and reduce machining time, and accordingly, the tendency to increase the rotational speed of the spindle is remarkable. For this reason, the amount of lubricating oil supplied to the bearing that supports the main shaft also tends to be very small (minimum required amount). However, when the lubricating oil is not supplied from the outside to the inside of the bearing during rotation as in grease lubrication, the lubricating oil film tends to be interrupted temporarily or continuously due to the passage of time. Under such severe lubrication conditions, it is difficult to obtain sufficient lubrication. For this reason, the sliding portion between the cage and the rolling elements (outer ring / inner ring) generates heat and becomes high temperature.

  Such a problem often occurs particularly in the sliding contact portion between the guide surface of the cage and the inner surface of the outer ring or the sliding contact portion between the cage and the rolling element. Therefore, in the synthetic resin cage containing reinforcing fibers, as the wear progresses, the reinforcing fibers are gradually exposed on the cage surface, and the exposed reinforcing fibers cause wear on the raceway guide surface that is the counterpart material. It is assumed that it will move forward, and it is possible that a bearing failure will occur.

  A cage reinforced with a non-damaged cotton cloth will not wear, but the strength of the cage as a whole is insufficient due to the low strength of the cotton thread, and the durability is reliable at ultra-high speed rotation at high temperatures. Sex is not enough.

  The present invention has been made to solve such problems, and has a higher flexibility and strength than those of the prior art, excellent durability, and a cage made of exposed reinforcing fibers even when the cage is worn. An object of the present invention is to manufacture a cage that suppresses wear of a guide surface.

In order to achieve the above object, the present invention provides the following method for producing a rolling bearing cage for high-speed rotation.
(1) A method for manufacturing the cage of a rolling bearing for high-speed rotation that supports a spindle that rotates at high speed and includes a cage, wherein a para-aramid fiber, polyarylate fiber, and polyparaphenylene benz are attached to a cylindrical core rod. Ri Do at least one selected from bis-oxazole fiber, urethane resins, epoxy resins, the filament bundle sizing agent is coated is selected from an acrylic resin or bismaleimide resin, while impregnated with liquid thermosetting resin, the tubular Helical winding that intersects and winds at an angle of 30 to 60 ° with respect to the axis of the cylindrical core rod, and parallel winding that winds while intersecting and winding at an angle of 80 to 88 ° with respect to the axis of the cylindrical core rod Repeatedly, the outermost layer is wound with helical winding and heat-cured, then the cylindrical core rod is pulled out and the resulting cylindrical body is retained A method for producing a rolling bearing cage for high-speed rotation, characterized by processing into a vessel shape.
(2) The high-speed rolling bearing retainer according to (1), wherein the thermosetting resin is at least one selected from an epoxy resin, a bismaleimide resin, a polyaminoamide resin, and a phenol resin. Manufacturing method.

  According to the present invention, it is possible to obtain a cage that is easy to operate, has high flexibility and strength, is excellent in durability, and suppresses wear of the cage guide surface due to exposed reinforcing fibers even when the cage is worn. In addition, in the method of laminating and manufacturing the prepreg used in the carbon fiber laminate (sheet winding method), the outer diameter is controlled by the thickness and the number of turns of the prepreg. In the present invention, the outer diameter is determined by the filament diameter and the number of turns. Since the outer diameter accuracy can be finely controlled because of the control, the cost can be reduced. Furthermore, even if a pocket or the like is finished by cutting, delamination or the like that may be seen between prepregs as seen by the sheet winding method is unlikely to occur, and reliability can be improved.

  Hereinafter, embodiments of the present invention will be described in detail.

  Here, a cage for an angular ball bearing widely used as a rolling bearing for high speed rotation will be described as an example. As shown in a sectional view in FIG. 1, the angular ball bearing has a plurality of balls 3 held by a cage 1 between an outer ring 2 and an inner ring 4. For example, grease (not shown) is used for lubrication. ) Is enclosed. As shown in a perspective view of FIG. 2, the cage 1 has an outer peripheral surface serving as a guide surface 1A, pockets 1C are opened at equal intervals to hold the balls 3, and the sliding contact surfaces of the pockets 1C. 1B and the surface of the ball 3 are in sliding contact.

  The present invention relates to a method for manufacturing the cage 1. The procedure will be described below.

First, as shown in FIG. 3, a filament bundle 50 made of a specific organic fiber, which will be described later, is wound around a cylindrical core rod (mandrill) 40 while being impregnated with a liquid thermosetting resin (not shown). Winding way of the filament bundle 50, as shown in FIG. 3 (A), helical winding wound so as to intersect at an angle θ of 3 0 to 60 ° with respect to the axis of the core bar 40, shown in FIG. 3 (B) as wound-out parallel winding wound at an angle θ of 8 0-88 ° with respect to the axis of the core 40 to alternately several volumes winds the outermost layer in helical winding. In order to wind the filament bundle 50 while impregnating the liquid thermosetting resin, for example, after the filament bundle 50 is immersed in a tank in which the liquid thermosetting resin is stored, the filament bundle 50 to which the liquid thermosetting resin is attached is attached. The method of winding around the cylindrical core rod 40 is simple and efficient.

  Next, the thermosetting resin is cured by heating at the curing temperature of the thermosetting resin. Thereby, filament bundles (not shown) are bound together by the thermosetting resin.

  Next, the tubular core rod 40 is pulled out to obtain a tubular body in which filament bundles are bound together by a thermosetting resin. In order to smoothly pull out the cylindrical core rod 40, wax is applied to the outer surface of the cylindrical core rod 40, a PET film or the like is wound, and the filament bundle is wound as described above.

  And the cage | basket 1 as shown in FIG. 2 is obtained by making the obtained cylindrical body into pieces and opening pocket 1C.

Para-aramid fiber used for the organic fibers, polyarylate fibers, poly-p-phenylene benzobisoxazole (PBO) fiber tensile strength of at least 2 GPa, and a tensile modulus of Ru der least 50 GPa. Table 1 shows the tensile strength and tensile modulus of these fibers. These may be used alone or in combination of two or more. Ultra high molecular weight polyethylene fibers and PAN-based carbon fibers have a tensile strength of 2 GPa or more and a tensile modulus of 50 GPa or more. However , ultra high molecular weight polyethylene fibers have a melting point of about 140 ° C. and are suitable for use alone. No. Moreover, PAN-based carbon fibers have a tensile strength high bur (2.0~7.1GPa), since there is a flaw with resistance to ferrous materials, hardening heat treatment such as the cage guide face made of an iron-based material To increase the cost . Parametric-aramid fiber, polyarylate fiber and PBO fiber, high strength, yet also have a flexibility, heat curing treatment of the wound with resistance without cage guide surface of the iron-based material it is also not necessary, sliding Ru excellent dynamic characteristics. Among these, PBO fibers having a tensile strength close to that of PAN-based carbon fibers are particularly preferable.

  The para-aramid fiber is copolyparaphenylene-3,4′-oxydiphenylene terephthalamide obtained by copolymerizing diamine with polyparaphenylene terephthalamide to improve stretchability. The polyarylate fiber is a wholly aromatic polyester fiber that is a polycondensate of dihydric phenol and aromatic dicarboxylic acid.

  The organic fiber preferably has an average diameter of 6 to 21 μm, more preferably 8 to 15 μm. If the average diameter is less than 6 μm, it is too thin, and since the strength per one is low, stable production is difficult, and the cost is greatly increased, so the practicality is low. On the other hand, when the average diameter exceeds 21 μm, the strength per piece increases, but it becomes difficult to wind the filament bundle flatly.

Further, organic fibers, in order to improve the adhesion between the liquid thermosetting resin, urethane resin, epoxy resin, that is coating the surface with an acrylic resin, bismaleimide resins or we chosen sizing agent.

  Furthermore, some of the above organic fibers are replaced with meta-aramid fibers, polyphenylene sulfide (PPS) fibers, polyimide (PI) fibers, etc., which are inferior in strength but have no damage to iron and are excellent in heat resistance. Also good. Moreover, if it is not arrange | positioned in the outermost layer, a PAN-type carbon fiber can also be used.

  On the other hand, as the thermosetting resin, an epoxy resin, a pismaleimide resin, a polyaminoamide resin, a phenol resin, and the like are preferable because they are excellent in curability, and each is used alone or in combination. Among these, an epoxy resin is preferable. Polyaminoamide resins can also be used as curing agents for epoxy resins.

  Further, the content of the liquid thermosetting resin, that is, the weight of the liquid thermosetting resin in the layer wound with the filament bundle impregnated with the liquid thermosetting resin is preferably 20 to 45% by mass, more preferably 25 to 25% by mass. 40% by mass. If the content of the thermosetting resin is less than 20% by mass, the resin content is too small, the adhesive strength between the filament bundles is insufficient, and it becomes difficult to produce a stable cylindrical body, which is not preferable. Furthermore, in the obtained cage, the organic fibers are exposed and the elasticity becomes low, so that it is easy to break, which is not preferable. On the other hand, when the content of the thermosetting resin exceeds 45% by mass, although the flexibility as the cage is increased, the content of the organic fibers is relatively decreased, and the annular strength is lowered, which is not preferable.

  The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

Example 1
Filament bundle (tensile strength: 3.43 GPa, tensile elasticity: para-aramid fiber with a fiber diameter of 12 μm (copolyparaphenylene-3,4'-oxydiphenylene terephthalamide treated with sizing agent: “Technola” manufactured by Teijin Techno Products) After being immersed in a tank in which a liquid epoxy resin was stored, it was wound around a cylindrical core bar having an outer diameter of 101 mm and an inner diameter of 64 mm while applying tension. The cylindrical core rod is coated with wax on the outer surface and further wrapped with a PET film. At that time, after winding at a thickness of 2 mm with helical winding (angle θ = 45 °) and winding with a thickness of 1 mm with parallel winding (angle θ = 85 °) as one cycle, after repeating 4 cycles The sample was wound at a thickness of 2.5 mm by helical winding (angle θ = 45 °). The content of the epoxy resin is 25% by mass.

  Subsequently, the whole was heated at 150 ° C. for 2 hours to cure the epoxy resin, and the cylindrical core rod was extracted to obtain a cylindrical body. And to make a cage for NSK's angular ball bearing “65BNR10BB (inner diameter 65 mm, outer diameter 100 mm, width 18 mm, contact angle 18 °, 4 rows combined)”, the cylindrical body is cut into 18 mm width. In addition, a cage was formed by forming a pocket (see FIG. 2). Further, the cage was incorporated into an angular ball bearing “65BNR10BB” manufactured by Nippon Seiko Co., Ltd. to obtain a test bearing. The inner and outer rings were made of SUJ2, and MTE grease (Ba complex-ester oil grease) was enclosed for lubrication.

(Example 2)
Using a filament bundle (tensile strength: 3.23 GPa, tensile elastic modulus: 74.6 GPa, elongation: 3.8%) made of polyarylate fiber having a fiber diameter of 10 μm (treated with a sizing agent: “Vectran high strength type” manufactured by Kuraray) A cage and a test bearing were produced in the same manner as in Example 1. The content of the epoxy resin is also 25% by mass.

(Example 3)
Using a filament bundle (tensile strength: 5.80 GPa, tensile elastic modulus: 270 GPa, elongation: 2.5%) made of PBO fibers with a fiber diameter of 12 μm (treated with a sizing agent: “Zeylon HM high elastic modulus type” manufactured by Toyobo) A cage and a test bearing were produced in the same manner as in Example 1. The content of the epoxy resin is also 25% by mass.

(Comparative Example 1)
A retainer having the same shape as in Example 1 was produced using an L-PPS material containing 30% by mass of carbon fiber chopped strands ("Fortron 2130A1" manufactured by Polyplastics). In addition, a similar test bearing was fabricated by incorporating a cage.

(Comparative Example 2)
A cage having the same shape as in Example 1 was prepared using a cotton nonwoven fabric impregnated with 30% by mass of a phenol resin. In addition, a similar test bearing was fabricated by incorporating a cage.

(Comparative Example 3)
A test cage was produced in the same manner as in Example 1 except that the same cage as in Comparative Example 1 was used and the inner ring and outer ring were made of carbonitrided steel SHX.

(Ring strength test)
The ring strength of each cage produced in the examples and comparative examples was measured. The results are shown in Table 2 as relative values with respect to Comparative Example 1.

(Abrasion resistance test)
The test bearings produced in the examples and comparative examples were continuously rotated for 1000 hours at a preload of 300 N and a rotational speed of 15000 min ⁻¹ , and then disassembled to observe the wear state of the outer ring guide surface. The results are shown in Table 3.

  As shown in Table 2, the cage of each example according to the present invention is higher in strength than a cage in which a conventional carbon fiber chopped strand is mixed, or a cage in which a cotton non-woven fabric is impregnated with a thermosetting resin. is there. Further, as shown in Table 3, since the wear of the outer ring guide surface is small, the wear reduction effect equivalent to the carbonitrided steel, which is costly, can be obtained by using an inexpensive SUJ2 material.

It is a longitudinal cross-sectional view which shows an example of an angular contact ball bearing. It is a perspective view of the cage for angular ball bearings shown in FIG. It is a figure which shows the winding method of a filament bundle, (A) shows helical winding, (B) shows parallel winding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cage 1A Guide surface 1B Sliding contact surface with ball 1C Pocket 2 Outer ring 3 Ball 4 Inner ring 40 Cylindrical core rod 50 Filament bundle

Claims (2)

A method of manufacturing the cage of a rolling bearing for high-speed rotation, which supports a spindle that rotates at high speed and includes a cage,
A tubular mandrel, para-aramid fibers, Ri Do at least one selected from a polyarylate fiber and polyparaphenylene benzobisoxazole fiber, urethane resins, epoxy resins, sizing agents selected from an acrylic resin or a bismaleimide resin Helical winding that winds the coated filament bundle intersecting at an angle of 30 to 60 ° with the axis of the cylindrical core rod while impregnating the liquid thermosetting resin, and the axis of the cylindrical core rod Parallel winding that crosses and winds at an angle of 80 to 88 ° is alternately repeated, and after the outermost layer is wound by helical winding and heat-cured, the cylindrical core rod is taken out and the obtained cylinder A manufacturing method of a rolling bearing retainer for high-speed rotation, characterized by processing a shaped body into a cage shape.   The method for producing a rolling bearing cage for high-speed rotation according to claim 1, wherein the thermosetting resin is at least one selected from an epoxy resin, a bismaleimide resin, a polyaminoamide resin, and a phenol resin.

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