JPH0262417A - Bearing device in water - Google Patents

Abstract

PURPOSE:To obtain a bearing device in water with excellent wear resistance and less vibration by discharging foreign alien substances in the water together with a part of water from a foreign substance discharge hole by the centrifugal force generated in relation to the rotation of a rotation shaft. CONSTITUTION:When slurry water is supplied from a water supply hole 11a on a shaft, the slurry water reaches circumferential water supply grooves 12a by means of centrifugal force at a next radial water supply hole 11b because a rotation shaft 11 is rotating. Heavy and hard foreign substances are scattered and separated to the outer circumferential side of the circumferential water supply grooves 12a by a centrifugal effect, and they are discharged from foreign substance discharge hole 12c together with a part of water. Then, the slurry water with less amount of the foreign substances are supplied sequently from a water supply groove 12b on the shaft to the next circumferential water supply grooves 12a and finally supplied from a water supply hole 12d on a bearing to a central groove 15a, and they perform lubrication and cooling action between a bearing 15 and a rotating sleeve 12. Thereafter, they are discharged to a bearing box 14 and returned back to a water tank from a exit port 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Field of Industrial Application) The present invention relates to an underwater bearing device using slurry water as a lubricant.

(Prior art) In general, in underwater bearing devices, when it is possible to supply fresh water and the load applied to the bearing is light, a water film that counters the applied load due to the viscosity of the supplied fresh water and the rotational effect of the rotating shaft is used. Pressure develops and a water film forms. In this state, there is no contact between solid objects on the sliding surfaces of the rotating shaft and the underwater bearing, so there is no wear on the sliding surfaces of the rotating shaft and the underwater bearing, and it can be used semi-permanently. Further, this water film exhibits an extremely large vibration damping effect due to the spring force and damping force caused by the water film pressure.

However, river water and seawater containing foreign substances such as sediment (
In underwater bearing devices that use slurry water (hereinafter referred to as slurry water) as a lubricant, the water film easily ruptures due to the introduction of hard foreign matter, and the amount of wear on the sliding surfaces of the rotating shaft and underwater bearing rapidly increases. Moreover, the distribution effect due to the water film rapidly decreases, which poses a serious problem, especially in rotating machines with large unbalanced forces exceeding the -th order critical speed.

Therefore, when using slurry water, conventionally, as shown in FIG. 5, a coarse filter 3, a water tank 4, a water pump 5,
A fine filter 6 is provided to remove foreign substances from the slurry water 7. That is, slurry water 7 from river source 1 first passes through coarse filter 3 and is supplied to water tank 4 . Next, the slurry water 7 in the water tank 4 is supplied to the submersible bearing device 2 by a water supply pump 5 through a fine filter 6 . Most of the slurry water 7 that has lubricated and cooled the underwater bearing device 2 is returned to the water tank 4 again, but a portion becomes leakage water 8 and flows out to the outside.

However, the amount of foreign matter mixed into the slurry water 7 is extremely large, and the size of the foreign matter particles ranges over a wide range. For this reason, selection of the mesh size of the fine filter 6 becomes extremely difficult. That is, by installing a fine fine filter 6, it is possible to remove most of the foreign substances, but since clogging occurs immediately, it is necessary to make the fine filter 6 extremely large. In addition, microorganisms live in the slurry water 7, and the aggregate of microorganisms clogs the fine filter 6, so that the fine filter 6 lacks long-term reliability.

For these reasons, it is impossible to use a fine filter as the fine filter 6, and a filter of about 100 mesh is usually used as the fine filter 6. Therefore, foreign objects passing through the underwater bearing device 2
This results in accelerated wear of the bearing and rotating shaft.

In addition, in the past, resin-based or rubber-based materials were used as underwater bearing materials, and highly hard stainless steel-based metal materials were used for rotating shafts, but recently various ceramic materials have been used as underwater bearing materials. Countermeasures against wear are taken by coating the surface of the rotating shaft with cemented carbide, such as tungsten carbide (VC). However, even such ceramic materials and cemented carbide are subject to gradual wear.

(Problems to be Solved by the Invention) As mentioned above, in conventional underwater bearing devices that use slurry water, it is difficult to sufficiently remove foreign substances from the slurry water, and the formation of a water film is inhibited by these foreign substances. There were problems such as wear and vibration on the rotating shaft and bearings.

The present invention has been made in response to such conventional circumstances, and it is possible to suppress the inhibition of water film formation due to foreign substances in slurry water, without increasing the frequency of maintenance or increasing the size of the equipment. The present invention aims to provide an underwater bearing device with excellent wear resistance and low vibration.

[Structure of the Invention] (Means for Solving the Problems) That is, the present invention provides an underwater bearing device that rotates the rotating shaft while supplying water to a gap between the rotating sleeve and the bearing section provided on the rotating shaft. A flow path for the water is provided between the rotating shaft and the rotating sleeve, and the water is supplied to the gap through the flow path, and
A foreign matter discharge hole is provided outward from the flow path, and the foreign matter in the water is discharged from the foreign matter discharge hole along with a portion of the water by centrifugal force generated as the rotating shaft rotates. Features.

(Function) In the underwater bearing device of the present invention having the above configuration, it is possible to suppress the inhibition of water film formation due to foreign substances in slurry water without increasing the frequency of maintenance or increasing the size of the device.
It has excellent wear resistance and can reduce vibration.

(Example) Hereinafter, the details of the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical cross section of an underwater bearing device according to an embodiment of the present invention, and FIG.
, and FIG. 3 each show a Z-Z cross section.

A rotating sleeve 12 whose outer circumferential surface is coated with cemented carbide is fitted on the outside of the rotating shaft 11 . A bearing 15 made of a cylindrical ceramic member is provided. Further, a drainage chamber 16 is installed in the bearing box 14.

The rotating shaft 11 is provided with a shaft water supply hole 11a for supplying slurry water, and a plurality of radial water supply holes 11b radially continuous with the shaft water supply hole 11a. Further, the rotating sleeve 12 is provided with a circumferential water supply groove 12a so as to be continuous with the radial water supply hole 11b. Note that a plurality of circumferential water supply grooves 12a are provided, and these circumferential water supply grooves 12a are connected by a plurality of axial water supply grooves 12b. In addition, each circumferential water supply groove 12a has this circumferential water supply groove 1.
A large number of small diameter foreign matter discharge holes 12c are provided which open into a drainage chamber 16 provided on the outside of the drain chamber 2a. Furthermore, the shaft water supply groove 12b is provided with a bearing water supply hole 12d that opens approximately at the center of the bearing 15, and a central groove 15a is provided in the portion of the bearing 15 that faces the bearing water supply hole 12d. There is.

A plurality of bearing water supply grooves 15b are also provided in the axial direction of the sliding surface of the bearing 15.

Further, the bearing box 14 and the drain chamber 16 each have a drain port 14.
a s 16 a is provided.

In the underwater bearing device of this embodiment having the above configuration, slurry water containing fine foreign matter that cannot be removed by a filter (not shown) is supplied from the shaft water supply hole 11a provided in the rotating shaft 11.

Since the rotating shaft 11 is rotating, the next radial water supply hole 1
The centrifugal force at 1b exerts a centrifugal pump effect, and the slurry water reaches the circumferential water supply groove 12a of the rotary sleeve 12. In this circumferential water supply groove 12a, due to the centrifugal force effect, heavy and hard foreign substances are scattered toward the outer circumferential side of the circumferential water supply groove 12a and separated. The foreign matter scattered around the outer periphery is discharged from the foreign matter discharge hole 12c along with some water. On the other hand, the slurry water with a reduced amount of foreign matter is sequentially supplied from the shaft water supply groove 12b to the next circumferential water supply groove 12a, and finally the slurry water with a reduced amount of hard foreign matter is supplied from the bearing water supply hole 12d. , water is supplied to the central groove 15a of the bearing 15. The slurry water supplied to the central groove 15a fills the bearing water supply groove 15b, and after lubricating and cooling the bearing 15 and the rotating sleeve 12, is discharged to the bearing box 14, and is discharged to the drain port 14a.
Return to the aquarium.

Further, the slurry water containing a large amount of foreign matter discharged from the foreign matter discharge hole 12c is discharged to the outside from the drain port 16a of the drainage chamber 16.

That is, in the underwater bearing device of this embodiment described above,
The centrifugal force caused by the rotation of the rotating shaft 11 and the rotating sleeve 12 can remove fine, heavy, and hard foreign substances from the slurry water before water is supplied to the bearing 15, making it easier to form a water film and reducing the fluid flow. The range of use in lubrication can be expanded. Therefore, it has excellent wear resistance and can reduce vibration.

Furthermore, even under load conditions where a water film cannot be formed, there are few foreign substances in the slurry water supplied between the rotating sleeve 12 and the bearing 15, so that the rotating sleeve 12 and the bearing 15 are
The amount of wear can be significantly reduced compared to conventional methods.

Furthermore, due to the centrifugal pump effect of the rotating shaft 11, the capacity of the water supply pump can be reduced or eliminated, and depending on the conditions, conventional water tanks, fine filters, etc. can also be eliminated, making maintenance and management easy. and the cost can be reduced.

FIG. 4 shows the main structure of an embodiment in which the present invention is applied to a chamber-shaft rotary machine such as a water wheel in which slurry water cannot be supplied from the center of the rotary shaft.

In the underwater bearing device of this embodiment, the rotary shaft 21 and the rotary sleeve 22 are formed with a small diameter portion and a large diameter portion in a stepped manner, and the small diameter portion is configured to separate and remove foreign matter in the slurry water. There is.

That is, the water supply tank 2 is located at the upper end of the small diameter portion of the rotating sleeve 22.
2a, and a plurality of circumferential water supply grooves 22d having a plurality of axial water supply grooves 22b1 and a large number of foreign matter discharge holes 22c are provided continuously to the water supply tank 22a. A plurality of water supply ports 23 provided on the upper side of the water tank 22a
Water is supplied to the water tank 22a from the draining plate 23 having a diameter of 100 mm, foreign matter in the slurry water is separated and removed through the foreign matter discharge hole 22c of the circumferential water supply groove 22d, and the slurry is discharged from the drain chamber 24 through the drain port 24a, and the foreign matter has been removed. Water is supplied from a bearing water supply hole 22e formed in a large diameter portion of the rotating sleeve 22 to a central groove 26a and a bearing water supply groove 26b of a bearing 26 fixed to a bearing base metal 25.

In the underwater bearing device of this embodiment having the above configuration, slurry water is directly supplied to the rotating sleeve 22 from the stationary side.
Since this is smaller than the shaft diameter of the bearing water supply hole 22e, water is automatically supplied to the central groove 26a of the bearing 26 due to the difference in centrifugal force.

In addition, since it is a standing support, gravity acts on the slurry water, and sufficient water can be supplied even at low speed rotation.

[Effects of the Invention] As explained above, according to the underwater bearing device of the present invention,
It is possible to suppress the inhibition of water film formation due to foreign matter in slurry water without increasing the frequency of maintenance or making the device extremely large, and it is possible to have excellent wear resistance and reduce vibration.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an underwater bearing device according to an embodiment of the present invention;
FIGS. 2 and 3 are XX and Z-2 sectional views of the underwater bearing device shown in FIG. 1, respectively, and FIG. FIG. 5 is a configuration diagram of a foreign matter removal device for explaining the prior art. 11... Rotating shaft 11a... Axis water supply hole 11, b... Radial water supply hole 12...
......Rotating sleeve 12a...
Circumferential water supply hole 12b...Shaft water supply groove 12c...Foreign matter discharge hole 12d...Bearing water supply hole 13... ...Bearing base metal 14...
......Bearing box 14a...Drain port 15...Bearing 15a...Central groove 15b...・・・・・・Bearing water supply groove 16・・・・・・・・・Drain chamber 16a・・・・・・・・・Drain port agent Patent attorney Ken Nori Chika Same as right Ken Daishimaru Figure 1

Claims (1)

[Claims] (1) In an underwater bearing device that rotates the rotating shaft while supplying water to a gap between the rotating sleeve and the bearing provided on the rotating shaft, the water is removed between the rotating shaft and the rotating sleeve. A flow path is provided, and the water is supplied to the gap through the flow path, and a foreign material discharge hole is provided outward from the flow path, and a foreign material discharge hole is provided from the foreign material discharge hole as the rotation shaft rotates. A submersible bearing device characterized in that it is configured to discharge foreign matter in the water along with a portion of the water by centrifugal force generated by the submerged bearing device.