JP2000120663A - Bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of corrosion in a bonding surface by lining a buffer material in the inner peripheral surface of a cylindrical backup shell made of aluminum or the aluminum alloy, and forming an oxide film in a bonding surface of the shell to the buffer material. SOLUTION: This bearing has a cylindrical backup shell 10, a nearly cylindrical buffer material 12 made of the elastomer or the plastic material and formed for lining of the inner peripheral surface of the backup shell, and a segment 14 made of teflon and fitted to a recessed part 12a formed in the inner peripheral surface of the buffer material 12 with the predetermined space in the circumferential direction. This inner peripheral surface works as a sliding surface to a shaft S. The shell 10 made of aluminum or the aluminum alloy is used for a vessel made of aluminum or the aluminum alloy, and even it contacts with the sea water having the lubricating work, corrosion due to a contact of different metals is not generated. A bonding surface of the shell 10 to the buffer material 12 is formed with an oxide film having excellent corrosion resistance and 30-100 μm of film thickness. Corrosion of the bonding surface is thereby prevented, and the growth of the aluminum oxide inside of a clearance between the shell 10 and the buffer material 12 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical backing shell, such as a water-lubricated circular bearing for a pump or a ship, which is lined with a cushioning material made of an elastomer such as rubber or a plastic material on the inner peripheral surface thereof. Bearings.

[0002]

2. Description of the Related Art For example, aluminum or aluminum alloy is widely used in a hull of a high-speed boat in order to reduce the weight. On the other hand, a copper alloy is generally used for a backup shell of a water-lubricated circular bearing. Here, when this bearing having a backup shell made of copper alloy is used for a hull made of aluminum or aluminum alloy,
Since the environment is seawater, dissimilar metal contact corrosion occurs, and this corrosion promotes hull corrosion.

For this reason, it is desirable to use a bearing having a backup shell made of aluminum or an aluminum alloy, similarly to a hull, for a hull made of aluminum or aluminum alloy.

[0004]

However, when a bearing is formed by bonding a buffer material made of rubber or the like to the inner peripheral surface of a backup shell made of aluminum or an aluminum alloy, the interface between the two is industrially microscopic. Since there is a void, and aluminum or aluminum alloy easily forms aluminum hydroxide when it comes into contact with seawater, aluminum hydroxide (aluminum hydroxide) is formed in the microscopic void at the interface between the backup shell and the buffer material. )
Is generated.

[0005] When aluminum hydroxide is generated at the interface between the backup shell and the cushioning material as described above, the aluminum hydroxide causes a wedge effect, and peeling of the cushioning material from the inner peripheral surface of the backup shell progresses. The aluminum hydroxide is formed on the surface, and peeling grows. As the aluminum hydroxide grows, the inner diameter of the bearing shrinks, and high surface pressure acts between the friction and wear surface of the bearing and the sleeve, causing not only abnormal wear and even seizure, but also aluminum or aluminum. Distortion also occurs on the outer peripheral surface of the aluminum alloy backup shell, and there is a problem that it is difficult to remove the bearing from the bearing case.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and prevents corrosion at a joint surface of a backup shell made of aluminum or an aluminum alloy with a cushioning material, so that the inside of a gap between the backup shell and the cushioning material can be prevented. It is an object of the present invention to provide a bearing capable of inhibiting the growth of aluminum oxide.

[0007]

According to a first aspect of the present invention, there is provided a bearing in which a cushioning material is lined on an inner peripheral surface of a cylindrical backup shell made of aluminum or an aluminum alloy. A bearing having an oxide film formed on a joint surface. Accordingly, by forming an oxide film having excellent corrosion resistance on the joint surface of the backup shell made of aluminum or aluminum alloy with the cushioning material in advance, it is possible to prevent corrosion at this joint surface. This oxide film can be easily formed by subjecting the inner peripheral surface of the backup shell to electrolytic treatment.

According to a second aspect of the present invention, the surface of the backup shell joined to the cushioning material is subjected to an unevenness forming process such as a blast process prior to the formation of an oxide film. A bearing according to claim 1. Thereby, fine irregularities are formed on the joint surface between the backup shell and the cushioning material, and the degree of adhesion between the cushioning material and the backup shell can be increased. The roughness of the unevenness is 3
It is preferably about 0 to 100 μm.

The invention according to claim 3 is the bearing according to claim 1 or 2, wherein the oxide film has a thickness of about 30 to 100 μm.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bearing according to an embodiment of the present invention will be described below with reference to the drawings. The bearing includes a cylindrical backup shell 10, a substantially cylindrical cushioning material 12 made of an elastomer such as rubber or a plastic material lined on an inner peripheral surface of the backup shell 10, and an inner periphery of the cushioning material 12. The surface has a segment 14 made of, for example, Teflon attached to a concave portion 12a formed at a predetermined interval in the circumferential direction on the surface, and the inner surface of the segment 14 is a sliding surface for the axis S.

The backup shell 10 is made of aluminum or an aluminum alloy, so that it can be used for a hull made of aluminum or an aluminum alloy, for example, so that even when it comes into contact with seawater (working fluid) that performs a lubricating action, it comes into contact with dissimilar metals. Does not occur.

An oxide film 16 having a thickness of, for example, about 30 to 100 μm and having excellent corrosion resistance is formed on a bonding surface (inner peripheral surface) of the backup shell 10 with the cushioning material 12.
Thereby, the cushioning material 12 of this backup shell 10
Corrosion of the joint surface with the shell is prevented, and the backup shell 1
The structure is such that aluminum oxide does not grow inside the gap between the zero and the buffer material 12. In other words, even if seawater enters the microscopic gap at the interface between the backup shell 10 and the buffer material 12, the corrosion is prevented by the anticorrosive action of the oxide film 16 here.

The oxide film 16 is formed by performing an oxide film forming process on the joint surface (inner peripheral surface) of the backup shell 10 with the buffer material 12. For example, anodization is performed by flowing a current in sulfuric acid using the inner peripheral surface of the backup shell 10 as an anode. Thereby, the backup shell 10
An oxide film is grown on the inner peripheral surface of the substrate. At this time, the temperature is maintained at a relatively low temperature of about ° C. to form a dense film.

As a pre-treatment prior to the surface oxidation treatment, the inner peripheral surface of the backup shell 10 is subjected to an alumina blast treatment to form a large number of fine irregularities on the inner surface thereof.
It is desirable to increase the degree of adhesion between the power supply and the backup shell 10. In order to increase the degree of adhesion between the cushioning material 12 and the backup shell 10, it is desirable not to perform the sealing treatment after the alumite treatment.

[0015]

Example: Aluminum alloy A5052 with inner diameter of 200m
m backup shell having an average particle diameter of 75 μm is applied to the inner peripheral surface thereof, and then an oxide film is formed by the above-described method to form an oxide film having a thickness of 75 μm on the inner peripheral surface of the backup shell. The film was grown. Then, a rubber cushioning material was lined on the inner peripheral surface, and a Teflon segment was fitted on the inner peripheral surface of the cushioning material to produce a bearing.

When this bearing was used in seawater for three years, it was confirmed that no aluminum hydroxide was generated at the interface between the backup shell and the cushioning material. On the other hand, when a bearing using a backup shell having no oxide film formed thereon was used in seawater for 3 years as a comparative material, white aluminum hydroxide was observed at the interface between the backup shell and the buffer material.

[0017]

As described above, according to the present invention,
Corrosion at the joint surface of the backup shell made of aluminum or aluminum alloy with the cushioning material can be prevented, and the growth of aluminum oxide inside the gap between the backup shell and the cushioning material can be prevented. Can be extended. In addition, the deformation of the outer periphery of the backup shell can be prevented, and the bearing can be easily replaced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a bearing according to an embodiment of the present invention.

FIG. 2 is a right side view of FIG.

[Explanation of symbols]

 Reference Signs List 10 backup shell 12 cushioning material 14 segment 16 oxide film S axis

Claims (3)

[Claims] 1. A bearing in which a cushioning material is lined on an inner peripheral surface of a cylindrical backup shell made of aluminum or an aluminum alloy, wherein an oxide film is formed on a joint surface of the backup shell with the cushioning material. bearing. 2. The bearing according to claim 1, wherein the surface of the backup shell joined to the cushioning material is subjected to a surface unevenness forming treatment prior to the formation of an oxide film. 3. The oxide film has a thickness of 30 to 100 μm.
The bearing according to claim 1, wherein the degree of the bearing is reduced.