JPH07293556A - Submerged bearing device - Google Patents

Abstract

PURPOSE:To be excellent in abrasion resistance, capable of preventing damage caused by britlleness, and thereby enhance reliability and safety. CONSTITUTION:A sleeve 10 where the outer circumference of its rotating shaft 7 is applied with ceramic coating, is provided, and a bearing 9 which has ceramic coating applied on its surface, and is divided in the circumferential direction, is provided for the circumference of the sleeve 10. The bearing 9 is supported by a pivot 11 and elastic bodies 12 at one place or on the circumference respectively, besides, a rotary disc is provided for the sleeve 10, a partitioning plate is set in a bearing housing 8, the bearing 9 is supported by the bearing housing 8 via the elastic bodies 12, and grooves are provided obliquely at positions parted from each split surface with respect to the bearing formed into a two-piece housing structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible bearing device used for a water-lubricated bearing in a hydraulic machine such as a water turbine or a pump water turbine, and is particularly excellent in wear resistance and capable of preventing damage due to brittleness. The present invention relates to a high-performance submersible bearing device capable of improving reliability and safety.

[0002]

2. Description of the Related Art Conventionally, submersible bearing devices have been used for water-lubricated bearings in hydraulic machines such as hydraulic turbines and pump turbines. FIG. 9 is a sectional view showing a configuration example of an underwater bearing device of this type of turbine and pump turbine.

In FIG. 9, the fluid as a lubricant flowing from the casing 1 into the stay vane 2 passes through a guide vane 5 installed between the upper cover 3 and the lower cover 4 for the purpose of adjusting the flow rate and the flow direction. By flowing into the runner 6 and rotating the runner 6, the generator is rotated via the rotary shaft 7 directly connected to the runner 6 to generate electricity.

In general, a submersible bearing device is configured to support the rotating shaft 7 by using a bearing 9 provided in a bearing housing 8 with water as a lubricant. That is, the rotating shaft 7
Between the bearing and the bearing 9, water is supplied from the lubricant supply means,
The rotating shaft 7 is supported through this water.

By the way, since water has a lower viscosity than oil, the load capacity of the bearing 9 (the weight of the rotating shaft that can be supported by the pressure of the lubricant in the bearing) is small, and when the rotating shaft 7 is started or stopped. Also, there is a problem that during a so-called transient when an external force is applied to the rotating shaft 7, the rotating shaft 7 and the bearing 9 are likely to come into contact with each other and the lubricating film of the bearing 9 is easily damaged.

Therefore, the bearing 9 is usually made of a material that can withstand contact with the rotating shaft 7. That is,
A metal material such as white metal is used for the bearing 9, and 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 is used for the bearing 9.
And a lubrication water supply means for supplying fresh water as a lubricant.

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 of rivers or the like, or recovery and maintenance of the oil supply / exhaust oil system. I have a problem.

Further, in a bearing device using a lubrication water supply means in which a soft synthetic resin such as a phenol resin is used for the bearing 9 and fresh water is used as a lubricant, since the bearing 9 has low wear resistance, especially slurry or the like is mixed. When such water is used as a lubricant, there is a problem in reliability and safety due to wear of the bearing member.

Therefore, as a bearing device for solving such a problem, 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, in such a bearing, the lubricant must be continuously supplied in order to eliminate foreign matters, and if the supply of the lubricant is insufficient, there is a risk of burning and burning.

Further, in these bearings, the surface pressure (load per unit area) is limited, and it is difficult to support the high-load rotating shaft 7. Further, in order to reduce the surface pressure, it is necessary to set the length of the surface of the bearing 9 larger than the diameter of the bearing 9, and there are structural restrictions, and the degree of freedom in design is limited. .

On the other hand, recently, there has been proposed a bearing device in which a bearing body is formed into a cylindrical shape using a ceramic material having an ultra-hard property and is fixed in the bearing housing 8.
However, in such a bearing, since the ceramic itself is fragile, there is a problem that the bearing body using the ceramic material as it is is broken by an impact or the like.

[0013]

As described above, the conventional submersible bearing device has a problem of low reliability and safety. An object of the present invention is to provide a high-performance underwater bearing device which has excellent wear resistance, can prevent damage due to brittleness, and can improve reliability and safety.

[0014]

In order to achieve the above object, in a submersible bearing device used for a water lubricated bearing in a hydraulic machine such as a water turbine or a pump turbine, first,
In the invention according to, provided on the outer periphery of the rotary shaft of the hydraulic machine,
A sleeve with a cemented carbide material or ceramics coating on the surface, a bearing that is circumferentially divided around the sleeve and is coated with a cemented carbide material or ceramics on the surface, and the bearing is supported at one place each And a resilient body that supports the bearing at both axial ends thereof.

According to a second aspect of the present invention, in the submersible bearing device according to the first aspect of the present invention, the elastic body is arranged in the vicinity of the pivot position for supporting the bearings at one place, and the bearing is provided for the pivot. I am trying to support it.

Further, in the invention according to claim 3, in the submersible bearing device of the invention according to claim 1, the pivot is formed into a ring shape so as to be circumferentially divided so as to support the bearing together with the elastic body. I have to.

On the other hand, in the invention according to claim 4, a sleeve provided on the outer periphery of the rotary shaft of the hydraulic machine, the surface of which is coated with a cemented carbide material or ceramics, and the sleeve are circumferentially divided and arranged. And a bearing whose surface is coated with a cemented carbide material or ceramics,
A bearing housing that supports the bearing through elastic bodies that are divided in the circumferential direction, a rotating disk that serves as a stirring plate that is provided in the sleeve, a partition plate that is provided in the bearing housing, and an elastic body. And a passage for allowing a fluid as a lubricant to pass from the water supply side to the drain side.

Further, in the invention according to claim 5, in the submersible bearing device of the invention according to claim 4, the bearing has a two-divided structure, and the direction of rotation of the rotary shaft is arranged at positions separated from the divided surface. Grooves are provided obliquely in the direction in which the fluid flows from the water supply side to the drainage side.

[0019]

Therefore, in the submersible bearing device of the present invention, by dividing the bearing in the circumferential direction and supporting the bearing by the pivot, there is no problem of misalignment, and a lubricating film is always provided in the gap between the sleeve and the bearing. It is formed, and good bearing characteristics can be obtained.

Further, the fluid flowing in from the water supply side of the bearing is subjected to viscous centrifugal action by the rotating disk, so that foreign matter having a large mass contained in the fluid does not enter the bearing and supports the bearing. The lubricating film is guided by the elastic body and passes through this gap, so that the lubricating film is not broken.

Further, by elastically supporting the bearing with this elastic body, even if an instantaneous impact load is generated by an external force, the elastic body deforms while absorbing this external force, so that the bearing characteristics change rapidly. There is no.

On the other hand, the bearing has a two-divided structure, and the grooves are obliquely provided at positions distant from the divided surfaces.
The load capacity of the bearing is larger than that of a bearing having longitudinal grooves at several axial positions, and the bearing characteristics can be improved.

Further, since the sliding surface between the sleeve and the bearing is coated with a cemented carbide material or ceramics, the ceramics also have abrasion resistance. Further, the bulk material is made of ceramics. Compared to the case, the shock resistance is improved, and since the sleeve is supported via the elastic body, the shock resistance can be further improved.

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

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view showing a structural example of a submersible bearing device according to a first embodiment of the present invention. The same elements as those in FIG. However, only different parts will be described here.

That is, in FIG. 1, a sleeve 10 having a surface coated with a cemented carbide material or a ceramic material (hereinafter referred to as a ceramic coating) is installed on the outer circumference of the rotary shaft 7, and the sleeve 10 is surrounded by the sleeve 10. A bearing bearing 9 whose surface is coated with ceramics is disposed by being divided in the circumferential direction.

Further, a spherical surface is formed in the substantially central portion of the outer peripheral portion of the bearing 9, and the spherical surface portion is pivoted to the pivot 11
Each supports in one place. Furthermore, the bearing 9
Elastic bodies 12 are provided between the pivot 11 and the pivot 11 at both axial ends of the bearing 9 to support the bearing 9 together with the pivot 11.

Although the pivot 11 is also spherically processed like the bearing 9, the pivot 11 has a slightly smaller spherical curvature than the bearing 9. Next, the operation of the submersible bearing device of the present embodiment configured as described above will be described.

In FIG. 1, when there is a change in the sleeve 10, the bearing 9 inclines with the support of the pivot 11 as a fulcrum as the sleeve 10 moves, and the sleeve 1
Since the gap between 0 and the bearing 9 is always in a state where a lubricating film is easily formed, good bearing lubrication characteristics can be obtained.

Next, the elastic body 12 installed between the bearing 9 and the bearing housing 8 is rotated in a state in which the rotating shaft 7 is tilted due to an external impact applied to the rotating shaft 7 to generate an instantaneous impact load. In this case, that is, in the case of a misalignment state, the ceramic coating is deformed while absorbing the external force, so that the ceramic coating receives the impact load of the external force as a relaxation load without directly receiving it at the end of the bearing 9. . Thereby, brittle fracture due to impact of the ceramic coating can be prevented.

Further, since the coated ceramics are also deformed to some extent with respect to the deformation of the bearing 9 main body which is the base material, the brittleness is superior to that of the bearing 9 itself made of a ceramic material. As described above, the elastic body 12 can further prevent the brittle fracture due to the impact of the ceramic coating.

(Second Embodiment) FIG. 2 is a sectional view showing a structural example of a submersible bearing device according to a second embodiment of the present invention. The same elements as those in FIG. Description is omitted, and only different parts will be described here.

That is, in FIG. 2, the elastic body 12 is arranged in the vicinity of the position of the pivot 11, and the elastic body 12 has a ring-shaped cross section, and the pivot 1 is located in the central hollow portion.
1 is installed. This allows the bearing 9 to pivot
Supports with.

The cross-sectional shape of the elastic body 12 may be any shape such as a square or a rectangle as long as it is hollow so that the pivot 11 can be installed at the center.
Next, the operation of the submersible bearing device of the present embodiment configured as described above will be described.

In FIG. 2, when there is a change in the sleeve 10, the bearing 9 inclines with the support of the pivot 11 as a fulcrum as the sleeve 10 moves, and the sleeve 1
Since the gap between 0 and the bearing 9 is always in a state where a lubricating film is easily formed, good bearing lubrication characteristics can be obtained.

Next, the elastic body 12 installed between the bearing 9 and the bearing housing 8 is rotated in a state in which the rotary shaft 7 is tilted by the external force applied to the rotary shaft 7 to generate an instantaneous impact load. In this case, that is, in the case of a misalignment state, the ceramic coating is deformed while absorbing the external force, so that the ceramic coating receives the impact load of the external force as a relaxation load without directly receiving it at the end of the bearing 9. . Thereby, brittle fracture due to impact of the ceramic coating can be prevented.

Further, since the coated ceramics are deformed to some extent with respect to the deformation of the main body of the bearing 9 which is a base material, the brittleness is superior to that of the bearing 9 itself made of a ceramic material. As described above, the elastic body 12 can further prevent the brittle fracture due to the impact of the ceramic coating.

(Third Embodiment) FIG. 3 is a sectional view showing a structural example of a submersible bearing device according to a third embodiment of the present invention. The same elements as those in FIGS. 1 and 2 are designated by the same reference numerals. The description thereof will be omitted, and only different parts will be described here.

That is, in FIG. 3, the bearing 9 has a two-part structure. Further, the elastic body 12 installed between the bearing 9 and the bearing housing 8 forms a passage for communicating the water supply side and the water discharge side.

FIG. 4 is a cross sectional view showing an example of the structure of the bearing portion shown in FIG. That is, in FIG. 4, the partition plate 14 is installed on the bearing water supply side of the bearing housing 8. Several holes are provided on the circumference of the partition plate 14 on the circumference. This hole is for connecting the water supply side and the drainage side.

On the upstream side of the shaft water supply side of the rotary shaft 7, a rotary disk 13 as a stirring plate is installed in the sleeve 10. When the rotary disk 13 is installed close to the water supply side end of the bearing 9, the partition plate 14 may be unnecessary.

Next, the operation of the submersible bearing device of the present embodiment constructed as described above will be described. In FIG. 3, the fluid that flows in from the bearing water supply side contains slurry (foreign matter) smaller than the mesh of the strainer that filters the fluid, and the bearing 9 is agitated as the rotary shaft 7 rotates.
Although being supplied to the portion, the fluid flowing in the vicinity of the rotating shaft 7 is subjected to viscous centrifugal action by the rotating disk 13 attached to the sleeve 10, and the direction thereof is changed to the bearing housing 8 side.

At this time, a centrifugal force (F = mrω ²
Here, m is mass, r is radius, and ω is angular velocity. )
Works. Therefore, among the slurries, those having a large mass have a centrifugal effect and flow toward the bearing housing 8 side. Since the fluid flowing in from the bearing water supply side is continuously flowing, the slurry moved to the bearing housing 8 side by the rotating disk 13 passes through the hole on the outside of the partition plate 14 as it is, and the elastic body It flows into the passage formed by 12 and flows to the discharge side.

Even if the partition plate 14 is not installed on the bearing housing 8, if the rotating disk 13 is installed on the sleeve 10 in the vicinity of the water supply side end of the bearing 9, the slurry will rotate on the rotating circle. It moves to the bearing housing 8 side by the plate 13, flows into the passage formed by the elastic body 12 as it is, and flows to the discharge side.

In this way, most of the slurry passes through the passage, does not flow into the gap between the rotary shaft 7 and the bearing 9, and the slurry flowing into this gap is much smaller than the water film thickness. Since it does not break the water film, it does not affect fluid lubrication.

Next, FIG. 5 is a developed view of the inner peripheral surface of the bearing 9. From FIG. 5A, representative of the kinds of groove shapes when the inner peripheral surface of the bearing 9 is provided with oblique grooves, It shows in (f). Also,
The arrow in FIG. 5 indicates the case where the load of the rotary shaft 7 is applied to the center of the bearing 9 (the load is applied to the center with the groove).

Further, FIG. 6 is a developed view of the inner peripheral surface of the bearing 9 as in FIG. 5, but the direction in which the load of the rotary shaft 7 is applied to the groove shape in FIG. It represents the case when multiplied by. Further, in the figure, corresponding to (a) to (f) of FIG. 5, they are indicated by (a ') to (f').

On the other hand, FIG. 7 shows the bearing load with respect to the eccentricity ε (the eccentricity e of the rotating shaft 7 from the center of the bearing 9 / the radial clearance C between the bearing 9 and the rotating shaft 7) for each oblique groove shape shown in FIG. Fig. 6 shows an example of the result of calculation by fluid lubrication.

In FIG. 7, when the eccentricity ε is 0, the rotating shaft 7 rotates about the center of the bearing 9, and when the eccentricity ε is 1, the rotating shaft 7 is in contact with the bearing 9. I mean. Therefore, a bearing having a large bearing load at a small eccentricity ε has a large load capacity of the bearing 9, and the bearing characteristics are improved. As shown in FIG. 7, the bearing load is highest in the oblique groove shape (a), then in the groove shape in (b), and in the order of (c), (f), (d), and (e). Has become. In addition,
Although not shown here, in the case of the vertical groove, the result is considerably smaller than the value of the bearing load in (e).

Similar to FIG. 7, FIG. 8 shows the eccentricity ε (the amount of eccentricity e of the rotary shaft 7 from the center of the bearing e /
It shows an example of the result of calculating the bearing load for the radial gap C) between the bearing 9 and the rotating shaft 7 by fluid lubrication.

As shown in FIG. 8, the bearing load is highest when the oblique groove shape is (e '), and next is the groove shape (f'), which is the following (a ') (b') (c). The order is ') (d').

Comprehensively judging from the above FIG. 7 and FIG. 8, (f) is the most suitable as the oblique groove shape of the bearing 9. When the bearing 9 is divided into two parts,
The portion shown by the arrow in FIG. 6 and the position 180 ° from this portion are subjected to deburring (thread chamfering) on the bearing 9 surface side of the split mating surface so that the mating surface does not become a large vertical groove.

As described above, in the submersible bearing device according to each of the embodiments, even when an impact load due to an external force is generated in the bearing 9, it can be changed to a relaxation load, and the characteristic due to the brittleness of the ceramic coating against misalignment can be obtained. It is possible to greatly improve.

Further, it is possible to prevent foreign matter from being mixed in during fluid lubrication, and it is possible to effectively exhibit the wear resistance of ceramics. Further, due to the optimum shape of the bearing 9 formed by the oblique groove, it is possible to obtain a high performance and highly reliable submersible bearing device.

[0055]

As described above, according to the present invention, a sleeve having a surface coated with a cemented carbide material or ceramics is provided on the outer circumference of the rotary shaft of a hydraulic machine, and the sleeve is circumferentially surrounded by the sleeve. Bearings whose surface is coated with cemented carbide material or ceramics are divided and arranged, and each of these bearings is supported by a pivot at one place, and the bearings are supported by elastic bodies at both axial ends or elastically. Place the body near the pivot position to support the bearing together with the pivot, or divide the pivot shape into a ring and divide it in the circumferential direction to support the bearing together with the elastic body, while supporting the rotating disc on the sleeve. A partition plate is installed on the bearing housing, and the bearing is supported by the bearing housing via elastic bodies that are divided in the circumferential direction. Fluid is supplied from the water supply side to the drain side. A passage is provided to allow passage, and the bearing is divided into two parts, and grooves are diagonally provided at positions distant from the divided surface in the rotational direction and the direction in which the fluid flows from the water supply side to the drain side. Therefore, it is possible to provide a high-performance underwater bearing device which has excellent wear resistance, can prevent damage due to brittleness, and can improve reliability and safety.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a submersible bearing device according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the submersible bearing device according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the submersible bearing device according to the present invention.

FIG. 4 is a transverse cross-sectional view showing a configuration example of a bearing portion in the submersible bearing device according to the third embodiment.

FIG. 5 is a development view of the bearing in the groove direction load due to various oblique grooves of the bearing.

FIG. 6 is a bearing development view of a grooveless load due to various oblique grooves of the bearing.

7 is a diagram showing an example of calculation results of eccentricity and bearing load in the fluid lubrication of FIG.

8 is a diagram showing an example of calculation results of eccentricity and bearing load in the fluid lubrication of FIG.

FIG. 9 is a cross-sectional view showing a configuration example of a conventional underwater bearing device.

[Explanation of Codes] 1 ... Casing, 2 ... Stay vanes, 3 ... Top cover, 4
... lower cover, 5 ... guide vane, 6 ... runner, 7 ... rotating shaft, 8 ... bearing housing, 9 ... bearing, 10 ... sleeve,
11 ... Pivot, 12 ... Elastic body, 13 ... Rotating disk, 14
... a partition board.

Claims (5)

[Claims] 1. A submersible bearing device used for a water-lubricated bearing in a hydraulic machine such as a hydraulic turbine or a pump hydraulic turbine, which is provided on the outer periphery of a rotary shaft of the hydraulic machine and has a surface coated with a cemented carbide material or ceramics. A bearing that is circumferentially divided around the sleeve and has a surface coated with a cemented carbide material or ceramics; and a pivot that supports each of the bearings at one location; An underwater bearing device comprising: an elastic body supported by a section. 2. The submersible bearing device according to claim 1, wherein the elastic body is arranged in the vicinity of a pivot position for supporting each of the bearings at one place, and the bearing is supported together with the pivot. An underwater bearing device characterized by the above. 3. The submersible bearing device according to claim 1, wherein the shape of the pivot is a ring shape and is circumferentially divided, and the bearing is supported together with the elastic body. Submersible bearing device. 4. A submersible bearing device used for a water-lubricated bearing in a hydraulic machine such as a water turbine or a pump turbine, which is provided on the outer periphery of a rotary shaft of the hydraulic machine and has a surface coated with a cemented carbide material or ceramics. A bearing that is circumferentially divided around the sleeve and has a surface coated with a cemented carbide material or ceramics; and the bearing is supported via an elastic body that is circumferentially divided and arranged. Bearing housing, a rotating disk as a stirring plate provided on the sleeve, a partition plate provided on the bearing housing, and a fluid formed of the elastic body as a lubricant from the water supply side to the drain side. An underwater bearing device comprising: a passage for passing the underpass. 5. The submersible bearing device according to claim 4, wherein the bearing has a two-divided structure, and the bearing is separated from the divided surface in the rotation direction of the rotating shaft and from the water supply side to the drain side. The submersible bearing device is characterized in that a groove is obliquely provided in the direction in which the fluid flows of the above.