JPH0560128A - Underwater bearing device - Google Patents

Abstract

PURPOSE:To provide a high-performance underwater bearing device capable of changing an impact load into a relaxation load when the impact load due to an external force is generated on a bearing section, capable of preventing the damage due to brittleness while exerting the abrasion resistance of ceramic, and having improved reliability and safety. CONSTITUTION:A sleeve 2 coated with ceramic 3 is provided on the outer periphery of a rotary shaft 1. Bearings 4 coated with ceramic on the surface and split in the peripheral direction are arranged on the periphery of the sleeve 2. A spherical recess is machined on the outer periphery of the bearing 4, and this portion is supported by a screw type pivot 5 fixed to a bearing housing 6 by the screw section of the bearing housing 6 and a double nut 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater bearing device used as a water lubrication bearing or the like in a hydraulic machine such as a water turbine or a pump water turbine.

[0002]

2. Description of the Related Art Generally, a submerged bearing device is configured to support a rotating shaft by a bearing member provided in a bearing casing, using water or seawater as a lubricant. That is, water, seawater, or the like is supplied from the lubricant supply means between the rotating shaft and the bearing member, and the rotating shaft is supported via this water.

By the way, since water has a lower viscosity than oil, the load capacity of the bearing (the weight of the rotating shaft that can be supported by the pressure of the lubricant in the bearing) is small, and the starting or stopping of the rotating shaft or rotation During a so-called transition when an external force is applied to the shaft, there is a problem that the rotating shaft and the bearing member are likely to come into contact with each other and the lubricating film of the bearing member is easily damaged. For this reason, a material that can withstand contact with the rotating shaft is used for the bearing member. That is, while using a metal material such as white metal for the bearing member, a bearing device provided with a lubricating oil supply means for supplying grease or lubricating oil, or a soft synthetic resin such as phenol resin for the bearing member, In addition, a lubricating water supply means for supplying water as a fresh water lubricant is provided.

[0004]

However, in the above bearing device using grease or lubricating oil, the grease or lubricating oil flows out from the bearing device to cause environmental pollution such as rivers, Or there is a problem in the collection and maintenance of the oil supply / drainage system.

Further, in a bearing device using a lubrication water supply means which uses a soft synthetic resin such as phenol resin for the bearing member and supplies water as a fresh water lubricant, since the bearing member has a low wear resistance, especially a slurry or the like is used. When water mixed with is used as a lubricant, there is a problem in reliability and safety due to wear of bearing members.

As a bearing device which solves this point, a hard rubber bearing developed especially as a bearing for ships has been proposed. In this bearing, foreign matter such as slurry is dealt with by deformation of rubber. However, regarding this bearing, the lubricant must be continuously supplied in order to eliminate foreign matter, and if the supply of the lubricant is insufficient, there is a possibility of burning and burning. Further, in these bearings, the surface pressure (load per unit area) is limited, and it is difficult to support a high-load rotating shaft. Further, in order to reduce the surface pressure, it is necessary to set the length of the bearing surface to be larger than the diameter of the bearing, so that structural restrictions occur and there is a limit to the degree of freedom in design.

There has been proposed a bearing device in which a bearing body is formed in a cylindrical shape by using a ceramic material having an ultra-hard property and is fixed in a bearing casing. However, since the ceramic itself is fragile, the bearing body using the ceramic material as it is has a problem such as breakage due to impact or the like.

The present invention has been made in view of the above circumstances, and provides a submersible bearing device which is excellent in wear resistance, can prevent damage due to brittleness, and can improve reliability and safety. With the goal.

[0009]

In order to solve the above-mentioned problems, the present invention provides a submersible bearing device according to the present invention, wherein a surface of a submerged bearing device is coated with a cemented carbide material or ceramics.
And a bearing that is circumferentially divided around this sleeve and has an elastic body with a cemented carbide material or ceramics coated on the surface, and is fixed to the bearing housing by a double nut. The screw type pivot is provided, and each of the bearings is supported by the screw type pivot at one place.

[0010]

In the present invention having the above structure, the bearing is divided in the circumferential direction, and the bearing is pivotally supported.
A lubricating film is always formed in the gap between the sleeve and the bearing without the problem of misalignment, and good bearing characteristics can be obtained.
Further, since this pivot is a screw type pivot, centering of the bearing with respect to the shaft center can be easily performed.

Further, since the sliding surfaces of the sleeve and the bearing are coated with a cemented carbide material or ceramics, the ceramics also have abrasion resistance and the bulk material is made of ceramics. Compared to the one used, shock resistance is improved, and since the sleeve is supported via an elastic body, further consideration is given to shock resistance.

Therefore, the wear resistance of the ceramics can be effectively exhibited, the bearing lubrication characteristics can be improved, and the reliability and safety of the bearing device can be greatly improved.

[0013]

An embodiment of the present invention will be described with reference to the drawings. 1 and 2 show an embodiment of a hydrodynamic bearing device according to the present invention. In this embodiment, the present invention is applied to a submersible bearing device.

In FIG. 1, a sleeve 2 is installed on a rotary shaft 1, and a cemented carbide material or a ceramic material 3 (hereinafter referred to as a ceramic coating 3) is coated on the surface of the sleeve 2. A bearing 4 having a ceramic coating 3 on the surface of a split type (in the present embodiment, divided into four in the circumferential direction) is provided around the bearing. A spherical surface is formed in the center of the outer peripheral portion of the bearing 4, and this portion is supported by a screw type pivot 5. The screw type pivot 5 is also spherically processed like the bearing 4, but the spherical surface curvature of the screw type pivot 5 is slightly smaller than that of the bearing 4.
The threaded pivot 5 is fixed to the bearing housing 6 by a threaded portion of the bearing housing 6 and a double nut 7. An elastic body 8 is inserted between the ceramic coating 3 side and the screw type pivot 5 side of the bearing 4. Next, the operation of this embodiment having the above structure will be described.

When the sleeve 2 fluctuates, the bearing 4 tilts with the support of the screw type pivot 5 as a fulcrum as the sleeve 2 moves, and the gap between the sleeve 2 and the bearing 4 is always kept. Since a lubricating film can be easily formed, good bearing lubricating characteristics can be obtained.

Next, the ceramic coating 3 of the bearing 4
The elastic body 8 inserted between the side and the screw type pivot 5 side,
When an external impact is applied to the rotating shaft 1 and an instantaneous impact load is generated, the rotating shaft 1 is deformed while absorbing this external force, so that the ceramic coating 3 receives the impact load of the external force as a relaxation load without directly receiving it. . As a result, brittle fracture of the ceramic coating 3 due to impact can be prevented. Further, since the coated ceramics are deformed to some extent with respect to the deformation of the base material (the bearing 4 in this embodiment), the brittleness is superior to that of the bearing 4 itself made of a ceramic material. As described above, the prevention of brittle fracture due to the impact of the ceramic coating 3 is further improved by the elastic body 8.

Further, since the elastic body 8 gives a degree of freedom to the bearing portion and the bearing 4 can be positioned by the screw type pivot 5, the accuracy of the shaft center on the rotary shaft side and the shaft side on the bearing side at the time of assembly is improved.

[0018]

As described above, according to the submersible bearing device according to the present invention, the assembling accuracy of the bearing portion is improved, and even if an impact load due to an external force is generated on the bearing portion, it can be changed to a relaxation load, so that the ceramics can be used. The characteristics due to brittleness of the coating can be greatly improved. Further, since the wear resistance of ceramics can be effectively exerted, it is possible to provide a high performance and highly reliable submersible bearing device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an underwater bearing device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 ... Rotary shaft 2 ... Sleeve 3 ... Ceramics coating 4 ... Bearing 5 ... Screw pivot 6 ... Bearing housing 7 ... Double nut 8 ... Elastic body

Claims (1)

[Claims] 1. A sleeve having a surface coated with a cemented carbide material or ceramics and circumferentially divided around the sleeve, and the surface coated with the cemented carbide material or ceramics. A bearing in which an elastic body is inserted and a screw type pivot fixed by a double nut arranged in the bearing housing are provided, and each of the bearings is supported at one place by the screw type pivot. Submersible bearing device.