JPS5962722A - Method for manufacturing self-aligning bearing - Google Patents

Abstract

PURPOSE:To obtain a proper bearing gap between inner and outer races, by disposing a thermo plastic sysnthetic resin inner race having a convex spherical part in its outer peripheral surface, in a die cavity in which the inner race is heated to be expanded, then by charging a thermo plastic synthetic resin containing a reinforcing filler into the die cavity, with which the outer race is formed, and by finally cooling the inner and outer races. CONSTITUTION:A drag die 10 and a cope die 20 are coupled together to form a cavity 30. A shaft 50 fitted thereonto with and holding an inner race 60 having a convex spherical surface part in the outer peripheral surface thereof, is disposed in the die cavity 30, and the dies are heated in this condition to expand the inner race 60 by a predetermined amount. Then a molten thermo plastic synthetic resin containg a reinforcing filler is charged into the cavity 30 through a filling port 40 to form an outer race 70, and then is cooled. A bearing gap S is formed between the inner and outer races due to the difference between their contraction amounts. If an oil containing polyacetal resin is used for the inner race to form a lubrication film on the slide surface of the inner race, it is effective to to reduce friction. The amount of glass-fiber filler used in the outer race is preferable to be about 30%.

Description

[Detailed Description of the Invention] The present invention provides a method for manufacturing a self-aligning bearing formed by integrally molding a thermoplastic synthetic resin inner ring having a convex sphere UkJ on the outer MI surface and a thermoplastic synthetic resin outer ring containing a strong filler. There's something about it.

Conventionally, self-aligning bearings made entirely of synthetic resin include:
For example, an inner ring and a cylindrical outer ring, each having a convex spherical surface on the outer circumferential surface, are installed in a mold, and the gap between the inner ring outer circumferential surface and the outer ring inner circumferential surface is entirely made of synthetic resin, and the synthetic resin is used between them. A sliding layer is formed to automatically align between the outer circumferential surface of the circular ring and the slide #J, and an outer ring having seven concave spherical surfaces on the inner circumferential surface is installed in a mold. A synthetic resin inner ring is formed by molding synthetic resin into a concave spherical part, and self-alignment is achieved between the outer ring circumferential surface and the inner ring outer circumferential surface.
714 power) etc.

Here, it is recommended that the latter be shown in the drawings.

In Fig. 1 and Fig. 2, 1 is the inner mold 1α and the outer mold 1b.
2 is an outer ring having a concave spherical surface 3 on the inner peripheral surface of the outer ring 2, and 4 is an inner ring J1 of the outer ring 2. d
An inner ring inserted into the surface, 5 is a shaft to which the inner ring 4 is completely fixed, 6 is a gap formed between the concave spherical surface part 3 of the outer ring 2 and the outer peripheral surface of the inner ring 4, and 7 is a nuclear outer mold. An injection port is formed in the hole 1b, and one end thereof opens into the gap 6.

A synthetic resin inner ring 9 having a convex spherical surface portion 8 is then formed by completely molding a synthetic resin, such as a polyamide resin, melted from the injection lower.

In the method described above, the bearing clearance between the concave spherical surface part 3 of the outer ring 2 and the convex spherical surface part 8 of the synthetic resin circular ring 9 must be obtained by fully utilizing the molding shrinkage of the synthetic resin inner ring 9.

However, in the method of fully utilizing the molding shrinkage of the synthetic resin in the bearing clearance, it is extremely difficult to obtain an appropriate bearing clearance because the molding shrinkage i of the synthetic resin is very large.

For example, if polyamide resin is used as the synthetic resin for forming the entire inner ring, the molding shrinkage rate of the polyamide resin is 0.9~
Since it is 1.0%, the maximum inner diameter of the concave spherical part of the outer ring is 3
If 0 m, the maximum outer diameter of the convex spherical part of the synthetic resin ring molded there will decrease by 0.27 m to 0.3 mm due to molding shrinkage, and this decrease will cause the difference between the inner circumferential surface of the outer ring and the outer circumferential surface of the inner ring. This will result in a bearing between the two.

In general, the appropriate bearing clearance for self-aligning bearings made entirely of synthetic resin is 15/10000 of the maximum outer diameter of the circular ring.
Since X D ~30/10000 X D wn, it is difficult to say that the bearing clearance obtained by the above method is appropriate.

The present BA is related to the improvement of the latter method mentioned above.
A thermoplastic synthetic resin ring having a convex spherical surface on the outer circumferential surface and a thermoplastic synthetic street resin outer ring with a reinforcing light cross member are integrally molded, and the adjustment has an appropriate bearing space between the two. The technical challenge is to mount the core bearing on top.

The configuration of the present invention, that is, the technical means for solving the above-mentioned technical problems, is as follows.

A convex spherical surface in the IA circumferential direction in the mold with a hollow part inside! tl
The inner ring of a thermoplastic synthetic resin having an inner ring is fully heated and expanded by δ, and then the outer ring is integrally formed by molding the inner ring with a strong light cross member into a hollow hollow housing. The entire bearing clearance between the inner and outer bearings is formed by the shrinkage of the outer ring.

In the present invention, the bearing capacity between the thermoplastic composite resin and the outer ring depends on the amount of shrinkage of the inner ring after a certain amount of thermal expansion and the amount of molding shrinkage of the outer ring.

In addition, the inner and outer rings are combined to form the entire sliding surface.

Regarding the combination of thermoplastic synthetic resin that forms the entire ring, circle, and outer ring, it is said that certain conditions are required.

09 The thermal expansion n of the thermoplastic synthetic resin that forms the entire outer ring should also be larger than the molding shrinkage amount, 1, of the thermoplastic synthetic resin that forms the entire outer ring.

(2), (n) Since the outer ring is assembled and the entire sliding surface is formed there, a thermoplastic synthetic resin material with excellent friction and wear characteristics should be selected.

■Inner, the IA rings are integrally molded so that they do not melt into each other.

■The inner ring should not be deformed when forming the outer ring.

An example of a combination of outer rings that satisfies the above conditions is shown in the first example.

No.1 Coat *As an oil-impregnated polyacetal resin, for example, % eave beam 7
The one obtained by the manufacturing method of No. 00592 is preferred.

When oil-impregnated polyacetal resin is used for the inner ring,
A film of lubricating oil is automatically formed on the foil a side between the inner and outer @, so #, nose! #It is especially effective and necessary from the viewpoint of wear and tear.

Furthermore, the reason why thermoplastic synthetic resin containing reinforcing light material is used for the outer ring is to improve the strength of the outer ring and to reduce mold shrinkage since the outer ring is fixed to the mounting member.

These objectives can be achieved by filling a large amount of reinforcing filler, for example, galanu fibers. Considering the wear and tear caused by friction with the inner ring, it is preferable that the filling amount is about 3ON.

In the combination of the inner and outer rings shown on the jacket, the maximum outer diameter of the ring was 524 mm, the inner ring was heated to 80°C, expanded a certain amount, and then molded entirely from thermoplastic synthetic resin containing reinforcing filler. The outer ring is completely formed, and the inner ring is obtained by cooling.
The 'rl@receiving clearance i between the outer rings is as shown in Figure 2.

The melting point of the thermoplastic synthetic resin containing strong filler is higher than the melting point of the thermoplastic synthetic resin used for the inner ring. Since it is cooled immediately after the process, a melt layer between the inner and outer rings does not occur, and the result shown in the upper layer is obtained.

From the results of the upper case, as mentioned above, the appropriate bearing clearance is 15/10000 of the diameter of the inner ring's maximum diameter.
From the fact that oo xDm is obtained, it can be seen that the bearing between the inner and outer rings obtained by the present invention can be properly obtained. By taking the above-mentioned technical measures, you can easily find the appropriate bearing according to the desired dimensions by simply understanding the amount of thermal expansion of the thermoplastic synthetic resin used for the inner ring and the amount of molding shrinkage of the thermoplastic synthetic resin used for the outer ring. It is possible to obtain all self-adjusting bearings, even if they are not aligned.

Further, since the self-aligning bearing obtained by the present invention has both inner and outer rings made of thermoplastic synthetic resin, it is extremely lightweight and extremely easy to handle.

What follows is the implementation of the present invention? All drawings are shown in detail.

Fig. 3 shows the mold for manufacturing the mg core bearing metal according to the present invention. They are brought together to form a hollow portion 30 therein.

Reference numeral 40 denotes an injection port for thermoplastic synthetic resin, and 50 denotes a shaft in which an inner ring 60, which is made of thermoplastic synthetic resin and has a convex spherical surface on its outer peripheral surface, is fully inserted and held. It is placed in the mold with its apex positioned in the hollow part 30 of the mold.

In this state, the mold pressure is heated to a certain amount (
It is indicated by the 41st code δ. ) Increase the amount of expansion.

In order to inflate the inner ring by 60 minutes, before inserting paper into the shaft 50 and holding it, heat the inner ring in advance and put an expansion bag in it.
It is also possible to install it in the mold by inserting it into the mold.

Next, the reinforcing filler-containing thermoplastic synthetic resin was melted from the injection port 40 of the mold. Inject and form an outer ring 70 times, and cool.

In response to this, the fcP'3 ring 60 expands and its outer diameter decreases completely at the ring line 0, and the inner diameter of the ring 70 decreases toward the outer circumferential surface of the ring due to molding contraction. The difference in the decreasing cap forms the bearing distance S (Fig. 5) between the inner and outer rings.

It is Toji Tsukino who can give you a detailed example.

Using oil-impregnated polyacetal resin (coefficient of thermal expansion: &45×10 1c) as a thermoplastic synthetic resin, an entire inner ring having a convex spherical portion with a maximum outer diameter of 244 mm was prepared.

After holding the paper insert around this inner ring, it was heated to a temperature of 80° C. and expanded to its maximum outer diameter of 132 degrees.

(24,0mX8.45X'1OX(80℃-15c(
Room temperature) = 0, 132 mm) (expansion amount: δ) This was placed in a therapeutic mold circle heated to a temperature of 80°C, and 30 weight glass fibers were added as a reinforcing filler from the main entrance of the mold. The outer ring was completely molded by injecting the filled polybutylene terephthalate resin.

After cooling it to its full temperature, it was removed from the mold and assembled into an automatic center bearing.

At this time, the maximum inner diameter of the outer ring is 0.072 due to molding shrinkage.
mm (' 24.132 #X O, 3%Cl1iR
The molding shrinkage rate T=0.072 ran) decreases toward the outer diameter of the inner ring, and the difference between the aforementioned expansion amount δ of the inner ring = O-132++m+ and molding shrinkage Jio of the outer ring, 072m, that is, 0.13
2 m - 0,072 am = 0.09 tan is within.

It was formed as a bearing between the outer and outer space.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing a conventional method for manufacturing a self-adjusting bearing; Figure 3 is a cross-sectional view showing the manufacturing method of the self-aligning bearing of the present invention, Figure 4 is a partially enlarged cross-sectional view showing the manufacturing process, and Figure 5 is a diagram showing the advantage obtained by using the uninvented manufacturing method. A partially enlarged cutaway diagram showing the adjustable core bearing. lO: Lower mold 20: Upper mold 302 Hollow part 60: l1
7' i-wheel 70: Foreign export Figure 1 Figure 2 Figure 3 Figure 4 Figure 4 0-L Addressing Figure 5

Claims (2)

[Claims] (1) A thermoplastic synthetic resin inner ring with a convex spherical space WS on the outer peripheral surface is installed in a mold with a hollow part inside, and then a heat aj with a reinforcing filler is placed in the hollow part. The outer ring is integrally formed by plastic joint forming and then cooled, and the inner ring is assembled and the outer ring is molded and compressed to completely form the bearing clearance between the inner and outer rings. ! iEI]
Manufacturing method for leg core bearings. (2) The amount of thermal expansion of the thermoplastic synthetic resin inner ring is greater than the molding shrinkage of the thermoplastic synthetic resin outer ring containing a reinforcing filler. Bearing manufacturing method.