JPS60146918A - Manufacture of sealing material for bearing - Google Patents

Abstract

PURPOSE:To enable a sealing material for use of bearing to be mass-produced, by winding a fiber on the peripheral part of a cylindrical structure, consisting of synthetic rubber or the like, when it it placed out of the die of an extruding machine which extrudes the cylindrical structure and cutting it to a desired thickness in the radial direction. CONSTITUTION:An extrusion molding machine extrudes from its die C a material of desired hardness, consisting of synthetic rubber, synthetic resin, etc., to a cylindrical shape hollowly forming the central part of the material, molding it into a cylindrical structure A. Here the extrusion molding machine extrudes the cylindrical structure while winding organic and inorganic fibers 1 of polyamide fiber, aromatic polyamide fiber, etc., having flexibility and elasticity, to be tightened on a peripheral part of the cylindrical structure A when it is extruded out of the die C of the extrusion molding machine, obtaining the cylindrical structure A in a desired length and contour. Then a ring-shaped seal material B is obtained by cutting said cylindrical structure A in its radial direction to a desired thickness by an edge tool 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IM manufacturing method for a bearing seal, which makes it easy to obtain a seal for a bearing, most preferably a seal for a miniature bearing.

Conventionally, the method for manufacturing sealing materials for bearings was to provide the desired shape of the sealing material in the upper and lower molds, supply synthetic rubber and synthetic resin into the upper and lower molds, and then remove them from the molds. For this reason, it was necessary to prepare several molds for koji (many molds are needed at the same time to mold a large number of molds), and a large number of seals could be obtained in one molding. Obtaining the material was difficult, mold costs were high, and mass production was limited. Particularly in recent years, miniature bearings have become rapidly popular due to the miniaturization and high performance of machines, and sealing materials for these bearings have become widely used, but conventional manufacturing methods are cumbersome. Another disadvantage was that it was expensive and could not be produced by Taisha. In addition, this manufacturing method requires material injection,
Alternatively, a burr may be formed due to material protrusion, and in extremely small sizes, if this burr forms on the seal lip side, it becomes a serious hindrance and also has the disadvantage of reducing the sealing effect. Therefore, the removal of this paris was a tedious task.

The present invention eliminates these drawbacks and is capable of mass production.
The present invention also provides an inexpensive method for producing a sealing material for a bearing.

When the present invention is explained based on the drawings, as shown in Fig. 1,
A material having a desired hardness made of synthetic rubber, synthetic resin, etc. is extruded from a die O of an extrusion molding machine into a cylindrical shape with a hollow center to form a cylindrical body At1. When it comes out of the tube, organic and inorganic fibers 1 having flexibility and elasticity such as polyamide fibers, aromatic polyamide fibers, polyimide fibers, polyamide-imide fibers, carbon fibers, etc. are wound around the outer periphery of the cylinder A and extruded while being tightened. A cylinder f$h of desired length and thickness is obtained by the filament winding method. Note that the filament winding device is omitted in the drawing for ease of understanding.

A sealing material for a bearing characterized in that a cylinder A extruded by the filament winding method is cut in the radial direction to a desired thickness with a knife 2 to obtain a ring-shaped sealing material B, as shown in FIG. This is the manufacturing method. At this time, if the material is synthetic resin, the desired sealing material B can be obtained by simply cutting the cylinder A with a knife after molding, but if the material is synthetic rubber, the cylinder A is vulcanized in the state. It is up to you whether to vulcanize or cut into sealing material B and then vulcanize it, depending on the molding method, the hardness of the synthetic rubber, etc.

Further, as shown in Fig. 3, in the cylinder f$h which is extruded into a cylindrical shape from synthetic rubber, synthetic resin, etc., the cylinder A has a two-layer integral structure of an outer cylinder A1 and an inner cylinder A2, They are integrally extruded so that one layer is made of a relatively soft material and the other layer is made of a relatively hard material. This two-layer structure cylindrical body A is cut in the radial direction to a desired thickness using a knife 2.
A ring-shaped sealant 3 is obtained.

If desired, the inner circumferential side or outer circumferential side of these sealing materials B obtained by the methods shown in FIGS. 2 to 6 described above may be lip-cut using a lip-forming knife 6 as shown in FIG. 4 to form a seal. It is also possible to easily form the lip 4 to make it a contact type.

In addition, the cylinder A is extruded by a filament winding method in which the fibers are immersed in epoxy resin or urethane resin to adhere the resin to the outer circumference of the cylinder A, and then the fibers are wrapped in a filament winding method. By cutting the ring-shaped sealing material using a cutter, a sealing material having strength and appropriate flexibility can be obtained, and it is also more effective to maintain heat resistance and oil resistance. Thermosetting resins are suitable as those satisfying this condition, and among them, epoxy resins and urethane resins are most suitable, but they are not particularly limited. If the epoxy resin is particularly required to be heat resistant and oil resistant, the purpose can be achieved by using an aromatic amine such as metaphenylene diamine as a curing agent.

After wrapping the fibers, the resin of cylinder A is cured in an oven.
It is preferable to use less than, but there is no particular limitation in this regard.

In this way, the cylinder A, formed into a cylinder by extrusion molding and wrapped around the fibers 1 and tightened, is cut in the radial direction to the desired thickness using the knife 2 to obtain the ring-shaped sealing material B. Since the sealing material B has a symmetrical shape on the front and back, it is easy to align the directions, and as shown in FIG. 5, it is easy to fit the sealing material B into the sealing material fitting groove 5 of the bearing. It can be easily and reliably fitted and installed. The sealing material B at this time is preferably of a non-contact type with a labyrinth structure. Moreover, since it is molded into a cylindrical shape by extrusion, it is possible to obtain a completely ring-shaped sealing material without having unnecessary burrs on the outer periphery while having a sealing effect. In addition, since the sealing material is not molded one by one, it is made by cutting a long cylinder into rings, so the molding can be done continuously, making mass production possible.
It is effective in reducing costs because there is no need for a complete molding fee.Furthermore, even when bearings with the same diameter are of different types and have different thicknesses, conventionally all molds had to be manufactured, but with this invention. This can be done simply by changing the width of the cut, and small differences in the inner and outer diameters can be easily cut with a knife, so the difference is large and can be said to be an economical manufacturing method, especially for miniature bearings.

Note that the hardness and material of the sealing material B are optimally selected depending on the size, thickness, and usage conditions to ensure effective sealing performance. For example, synthetic rubbers and synthetic resins include fluororubber, silicone rubber, acrylic rubber, nitrile rubber, epichlorohydrin rubber, etc., chlorosulfonated polyethylene, fluororesin, nylon resin, etc., and their geothermal plastic elastomers, such as polyester Examples include elastomers based on elastomers, propylene elastomers, etc., and a desired one is selected from these depending on the conditions of use, but there is no particular limitation on elastomers other than these when used for special purposes.

Further, the hardness of the material is desired to be high since no core metal is used, but it is also necessary that the material has appropriate elasticity. These are also determined by the usage conditions, but for example, the sealing material used for miniature bearings has an outer diameter of 3.5ff.
1O, inner diameter 2.5NO1a, diameter of 0.2 cod, the optimum value is 8o or more on the J-S hardness tester, preferably about 95, but this is not limited either.

However, in addition to these features, an important effect of the present invention is that synthetic rubber or synthetic resin sealing materials, especially sealing materials for miniature bearings, have the drawback of lacking dimensional stability because they do not have a core metal. The sealing material whose outer periphery is held and strengthened by the fibers of the present invention has greatly improved dimensional stability and can stably exhibit sealing performance over a long period of time.

In addition, in order to achieve dimensional accuracy, the molded ¥1iif4cA
It is also possible to polish it, and in this case, the fibers also have the effect of helping to achieve precision.

As described above, the manufacturing method according to the present invention is an excellent and ideal manufacturing method that enables mass production, saves the total mold cost, and easily obtains a sealing material with excellent dimensional stability using a simple method. be.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the process of making the cylindrical body of the present invention. FIG. 2 is a cross-sectional view of the cylindrical body of the present invention when cut. FIG. 3 is a cross-sectional view of an embodiment of the invention. FIG. 4 is a cross-sectional view of a method of forming a sealing lip. FIG. 5 is a sectional view of a state in which the sealing material obtained according to the present invention is fitted into a bearing. A... Cylindrical body B... Sealing material 1st... Fiber 2... Cutlery patent applicant Uchiyama Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] 1. A method for producing a sealing material for a bearing made of synthetic rubber, synthetic resin, etc., which fits into a fixed, sealed fitting groove provided in the inner ring or outer ring of the bearing. In: Synthetic rubber, synthetic fiJtm resin, etc. are extruded into a cylindrical shape to obtain a cylindrical body, and fibers are wound around the outer periphery of the cylindrical body when it comes out of the die of the extruder that extrudes the cylindrical body. A method for manufacturing a sealing material for a bearing, characterized in that a cylinder is obtained by extrusion molding while tightening, and the cylinder is cut in the radial direction to a desired thickness using a knife to obtain a ring-shaped sealing material. 2. A cylindrical body is obtained by immersing the above-mentioned fibers in an epoxy resin or urethane resin to attach the resin to the fibers and winding the fibers around the outer periphery of the cylindrical body.
A method for producing a sealing material for a bearing as described in . 3. A cylindrical body extruded from synthetic rubber, synthetic resin, etc., has a two-layer integral structure on the inner and outer circumferential sides, one layer being made of a relatively soft material, and the other layer being made of a relatively soft material. 3. The method of manufacturing a bearing sealing material according to claim 1, wherein the layer is made of a relatively hard material.