JPS5818530B2 - Bearing body manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a bearing body used in, for example, an electric motor or a generator, and particularly a bearing body interposed with an insulator.

As is well known, a shaft current is generated in a bearing part of a large capacity electric motor or electric machine.

In order to prevent this shaft current, it is necessary to make the bearing body an insulating structure.

Its general structure will be explained with reference to FIG.

In the figure, reference numeral 1 denotes a cylindrical inner peripheral member that supports a rotating shaft (not shown), and has a through hole 2 in the center thereof into which the shaft is inserted.

Reference numeral 3 denotes an outer circumferential member that supports the inner circumferential member 2 via an insulator 4, and has a flange 5 for attachment at one end thereof.

Reference numeral 6 denotes an oil supply hole provided so that the outer circumferential member 3, the insulator 4, and the inner circumferential member 1 communicate with each other.

The properties required of a bearing body constructed in this way include mechanical strength, especially shear strength, vibration resistance, insulation properties, heat resistance, needle and oil resistance, etc. However, due to the usage conditions of the bearing,
Regarding the above-mentioned characteristics, it is particularly strongly required that there be no deterioration over time.

It is the insulator 4 that greatly influences the performance of the above-mentioned required characteristics, and it is no exaggeration to say that the insulator 4 controls all the characteristics.

Regarding the material of this insulator 4, organic materials have an unavoidable weakness of aging.

In other words, even if the temperature is within a temperature range that is judged to have no effect on insulation properties, if the temperature rises and falls for a long period of time, a very small amount of volumetric contraction will occur due to differences in the number of expansion walls and other factors. arise.

This phenomenon is directly related to mechanical properties and leads to significant property deterioration, resulting in a lack of long-term reliability.

This phenomenon is particularly noticeable when the shape is large.

Because the material itself has unavoidable fatal flaws,
In particular, if the shape is large, it cannot be used in reality.

In this respect, inorganic materials are extremely desirable materials because they hardly exhibit the phenomenon of aging, but porcelain materials are difficult to manufacture and have major weaknesses in mechanical impact characteristics, so they are not used. It is possible.

On the other hand, glass obtained by using a mixed powder of vitreous powder and mica powder as a raw material, heating this raw material to a temperature at which the glass material softens and flows under pressure, and then press-forming in the heated state,
Mica plastic bodies have no fear of deterioration over time, and
Unlike a single glass, this material is essentially elastic, so it is not as brittle as porcelain, yet has great mechanical strength, and perfectly retains heat resistance, oil resistance, and insulation properties. Therefore, it can be said to be completely ideal as an insulator for this type of bearing body.

However, this insulator has the unavoidable drawback that it is extremely difficult to mold it using conventional manufacturing methods, and that large-sized products in particular require large equipment and increase production costs.

A conventional method for manufacturing a bearing body using such a glass or mica plastic body will be explained with reference to FIG.

In the figure, 7 is a frame, 8 is a split wall 9 is a holder for supporting the inner circumferential member 1 and outer circumferential member 3, 10 is a core metal, and 11 is a pressurizing metal, and the above-mentioned parts constitute a mold.

In order to manufacture a bearing body using a mold configured in this way, first, as shown on the left side of FIG. Filled with raw material powder 12 made of a mixture of
Place it on top and heat the whole thing in electricity.

When the heating is completed, the entire body is taken out of the furnace, transferred directly to a press, pressurized by pressurizing metal 11, and heated raw material powder 12 is transferred between inner circumferential member 1 and outer circumferential member 30 as shown on the right side of FIG. The void 13 is filled to form the insulator 4.

After cooling, the mold is disassembled, the molded product is taken out, and the required parts are machined to complete manufacturing.

When using the conventional manufacturing method as described above, there are the following problems, which directly lead to defects.

First, as shown in FIG. 2, it is necessary to prepare a mold consisting of a frame 7, a split wall 8, and a core bar 10 that can accommodate the outer circumferential member 3. This is less of a problem if the bearing itself is small, but the bearing becomes larger, and the outer diameter of the outer peripheral member is, for example, 400 to 500 m.
m, when the length is 200 to 300 mtrt, the size of the mold is 600 to 800 mvt in outer diameter and 300 to 300 m in height.
It is more than 400u, and it is extremely difficult to make the partition wall 8 in particular, and the cost is enormous.

As mentioned above, in the manufacturing process, raw material powder is filled into a mold and heated together with the mold in an electric furnace, but since the mold is large and heavy, heating requires large electric furnace equipment that can accommodate the mold. Moreover, large-scale equipment is required for its transportation.

The next important thing is the heating temperature of the mold.

The higher the heating temperature, the lower the viscosity of the glass in the raw material, so it is desirable, but the heating temperature is limited by the strength of the mold at high temperatures, so the upper limit of the heating temperature is 500°C to 550°C.
That's about it.

In this case, since the viscosity of the glass in the raw material does not decrease much, the injection of the raw material naturally depends on the pressure, which is about 3000 to 5000 kg/CI? A large pressurization of t is required.

The mold needs to have enough strength to withstand this pressure, which is why it is so large.

This is not just a flaw in that it is economically expensive; there is a limit to the size that can be manufactured due to restrictions on equipment such as electric furnaces and pressurizing presses, and it is inevitable that it will be impossible to manufacture anything that exceeds the limit. There was a fatal flaw.

This invention was completed by fundamentally examining the conventional manufacturing method of bearing bodies, including investigating the basic characteristics of the material, and repeating many experiments. The purpose of the present invention is to provide a manufacturing method that completely eliminates the unavoidable fatal defect that conventionally cannot be manufactured due to its large shape.

According to the present invention, the bearing body obtained can obtain far superior haze characteristics compared to those produced by conventional manufacturing methods.

The pressing mold for explaining the manufacturing method according to the present invention with reference to FIG. A cylindrical outer metal member 14 having a shoulder portion that fits, and a cylindrical outer metal member 14 having an outer diameter smaller than the outer diameter of the inner circumferential member 1 and four shoulder portions at one end thereof that fit into the inner circumferential edge of the inner circumferential member 1. Prepare a deposit of 15 yen.

Next, as for raw material preparation, as a specific example, PbO1.0 mol, B2030.8 mol, l! Powder 55% (weight percent, hereinafter referred to as times) obtained by pulverizing a glassy material having a composition of 0.2 mol of F3 to a viscosity of 200 mesh or less, and powder 4 obtained by pulverizing synthetic fluorine-containing phlogopite to a viscosity of 60 to 100 mesh.
Mix 5% using a ball mill, add about 5% water to make it wet, use a general press mold, and mix at room temperature for 50%.
At a pressure of 0 kg/d, it is molded into a shape that can be inserted into the space formed by the inner circumferential member 1, outer circumferential member 3, outer metal 14, and inner metal 15 as shown on the left side of Fig. 3, and then dried and prepared. A molded body 16 is created.

In the manufacturing process, as shown on the left side of FIG.
, the outer peripheral member 3 is placed on the receiving metal 9, the outer metal 14 and the inner metal 15
are placed on the inner circumferential member 1 and the outer circumferential member 3, respectively, and heated to about 450° C. in an electric furnace.

On the other hand, the preformed body 16 is placed on a porcelain plate or the like for about 70 minutes.
Heat to 00°C.

When heating of both is completed, the preformed body 16 is filled as shown on the left side of FIG. 3, and a pressurized metal 11 separately heated to 450° C. is placed on top of the preformed body 16.

When the pressurized metal 11 is pressurized at a pressure of about 500 yu/cr/l, the preform 16d is injected into the space 13 under pressure to form the insulator 4, as shown on the right side of FIG.

After cooling, the mold is disassembled, the integrally molded bearing body is taken out, and the necessary parts are machined to complete the manufacturing process.

As mentioned above, the feature of the present invention is that the pigment powder is pressurized to form the preformed body 16, and the preformed body 16 is formed into the inner circumferential member 1,
The preformed body 16 is heated independently of the outer peripheral member 3.
In other words, at the time of pressurization, the viscosity is lowered and the fluid becomes easier to flow.

For this reason, the pressure required for injection is significantly reduced, and specifically, the pressure required for injection is 3,000 to 5,000
The pressure of 000 kg/c11 yen is reduced to approximately 50 yen by the method of the present invention.
The pressure can be as low as 0 kg/ffl.

Since the required pressure is reduced to about 1/6 to 1/10 in this way, it is no longer necessary for the pressing die to maintain a large pressure resistance, and as a result, the pressing die structure can be simplified and made smaller.

As a result, the density of the insulator 4 made of glass or mica plastic molded into the space 13 is higher and more uniform than that of conventional products, and the properties are further improved.

For example, when manufacturing a bearing body in which the outer circumferential member 3 has an outer diameter of 450 f, the collar portion 5 has an outer diameter of 550 f, the inner circumferential member 1 has an inner diameter of 300 mm, and the outer circumferential member 3 has a length of 2001 m, the method according to the present invention may be used. According to the total weight of the mold and metal fittings is approximately 300.
It's time.

According to the conventional method, the total weight would be about 700 to 5 ooy, making it practically impossible to manufacture, but the method of the present invention can be manufactured, and the effect is extremely large.

Moreover, such a large bearing body is required to satisfy the conditions of approximately 40 tons or more as an axial shear strength and 500 kg or more as a rotational shear strength with respect to the insulator 4, which can be achieved by the method of the present invention. The product completely satisfied these characteristics.

In the above example, Pb01.0 mol, B2030.8
Although a glass material having a composition of 30.2 moles of AlF was used, the composition is not limited to this.

Any vitreous material can be used as long as it has a low softening temperature and does not cause devitrification due to heating.

Regarding mica powder, it coexists with glassy powder.
When heated to a high temperature such as 00° C., natural mica decomposes and reacts with glass, and the viscosity does not decrease. Therefore, synthetic mica, which does not react with glass or decompose, is preferable.

Furthermore, it goes without saying that the heating temperature and the dimensions of the inner circumferential member 1 and the outer circumferential member 30 are not limited to those described above.

In addition, regardless of the type of bearing (roller core, steel IJ--y"), it can be used for all types of bearings that require insulation.

As explained above, according to the present invention, even a large-sized bearing with an insulator interposed therebetween can be easily manufactured.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the general structure of a bearing body having an insulation mechanism, Fig. 2 is a sectional view illustrating an example of a conventional manufacturing method using a mold, and Fig. 3 is a sectional view showing the manufacturing method of the present invention. FIG. 2 is a cross-sectional view illustrating one embodiment of the method. In Figure β■, 1 is an inner peripheral member, 3 is an outer peripheral member, 4 is an insulator,
13 is a cavity, 14 is an outer metal, 15 is an inner metal, and 16 is a preform. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. The more the inner circumferential member supporting the rotating shaft and the outer circumferential member surrounding the inner circumferential member through the gap are heated, the more the vitreous powder to be filled in the gap increases. ``pressing a mixture containing mica powder as a main component to obtain a preformed body'', at a heating temperature higher than the heating temperature of the inner circumferential member and the outer circumferential member, and independently of the heating of the inner circumferential member and the outer circumferential member. A method for manufacturing a bearing body, comprising the steps of: heating a preform to a state where it can easily flow when pressurizing the preform; and filling the heated preform into the void under pressure. 2. During pressurized filling, a receiver that supports the inner circumferential member at one end thereof, and an inner metal that has an outer diameter smaller than the outer diameter of the inner circumferential member and is in circumferential contact with the other end of the inner circumferential member. 2. The method of manufacturing a bearing body according to claim 1, wherein an outer metal having an inner diameter larger than the inner diameter of the outer circumferential member and surrounding the other end of the outer circumferential member is used.