JPH10274237A - Submerged bearing and sleeve attaching structure of rotary shaft supported thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly increase sealing ability by arranging a first oil seal, a grease filing part, a second oil seal, a metallic gasket and a rubber gasket in recurrence in positions symmetrical in an axial direction in both sides of a bearing section. SOLUTION: When a submerged bearing is attached to a rotary driving device used in waste water containing many muddy components and rotated, the incursion of the sand components into the inside is prevented by a rubber gasket 7 arranged in the outermost side of a submerged bearing seal structure. Also, the incursion of the sand components is prevented by a metallic gasket 6 held by a spacer 9. Further, by an oil seal 5 and grease having flowability filling the inside of a grease filling part 4, water entering the inside through the metallic gasket 6 is prevented. Then, sealing ability is improved by a double lip type first oil seal 3, and the incursion of water or muddy and sandy components into a rolling rearing 1 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing structure of a rotary drive device, such as a flocculator used in a water purification plant, which is disposed and used in water containing sludge, and a sleeve of a rotary shaft supported by the bearing. Related to the mounting structure.

[0002]

2. Description of the Related Art For example, in a floc formation pond of a water purification plant,
In order to separate and remove impurities that cause turbidity and color of the wastewater, a flocculant is added to the wastewater and stirred to increase the particle diameter of the impurities to flocculate and precipitate.
The stirrer used in such a floc formation pond is required to prevent the infiltration of sludge into the bearing portion because it is disposed in the sewage.
Underwater bearings such as those described in No. Microfilm (hereinafter referred to as conventional examples) have been put to practical use.

FIG. 7 is an explanatory view showing the structure of the underwater bearing described in the above-mentioned conventional example. As shown in FIG. 7, the underwater bearing has a ball bearing 101 disposed at the center thereof.
The first oil seal 102, the water pool 103, the second oil seal 104, the metallic packing 105, and the sheet packing 106 are arranged in this order symmetrically (on both left and right sides) from 01 in the axial direction. The sheet packing 106 and the metallic packing 105 seal off moisture and sand and mud from the outside. Nevertheless, the moisture and sand and mud that have invaded the inside through the pipe 107 connected to the flood pool 103. Is to be discharged.

However, such a conventional underwater bearing is effective when the amount of infiltration of water and sand is small, but the sealing function of the sheet packing 106 and the metallic packing 105 is reduced, and the water pool
If a large amount of water and sand and mud enter the inside of the pipe 3, the discharge capacity of the pipe 107 will be exceeded, and the sealing function will be significantly reduced. Further, since the inside of the flooded pool 103 is set to a negative pressure as compared with the outside, it is easy to draw in moisture and sand and mud. Furthermore, the above-mentioned underwater bearing has a disadvantage that the entire seal structure is a solid-to-solid contact seal and cannot cope with fluctuations in the shaft center level due to wear of the bearing or the like.

On the other hand, the rotating shaft supported by the underwater bearing as described above has a sleeve 108 at a frictional portion between the bearing and the bearing.
Is fixed. Conventionally, the sleeve 108 is fixed to the rotating shaft 109 by tightly fitting. However, in the case of fixing by tightening, the rotating shaft 10
9 is completely adhered, the replacement work cannot be easily carried out on site even when the misalignment is caused by aging. Therefore, when replacing the rotating shaft 109,
It is necessary to remove and transport it to a predetermined work place, repair it, and then reinstall it, which is very troublesome and troublesome. Therefore, even when the bearing part is actually maintained, the sleeve 108 for connecting the shaft is actually used. At present, no action is taken. Therefore, no matter how much the bearing portion is repaired during maintenance to improve the sealing performance, a high sealing performance cannot be ensured if the sleeve 108 supported by the bearing is misaligned due to friction or the like.

[0006]

As described above, the conventional underwater bearing has a disadvantage that a high sealing property cannot be obtained when a large amount of moisture or sand or mud enters the water pool 103. . The sleeve 108 supported by this bearing is tightly fitted to the rotating shaft 1.
09, it is difficult to replace it on site even if the sleeve 108 causes misalignment, and if it is used as it is, even if the sealing structure of the bearing is repaired, the sealing property cannot be improved after all. was there.

The present invention has been made to solve such a conventional problem, and a first object of the present invention is to provide an underwater bearing having a seal structure capable of further improving the sealing performance. . A second object is to provide a sleeve mounting structure for a rotating shaft that allows the sleeve to be easily replaced on site.

[0008]

In order to achieve the above object, an underwater bearing according to the present invention is an underwater bearing for supporting a rotating shaft of a rotating mechanism used underwater, wherein a bearing portion is provided at a central portion in an axial direction. And a first oil seal, a grease-filled portion, a second oil seal, a metallic packing, and a rubber packing are arranged in this order on both sides of the bearing at axially symmetric positions. It is characteristic.

In the sleeve mounting structure for a rotary shaft according to the present invention, the sleeve mounting structure for mounting a sleeve on a sliding portion of a rotary shaft with a bearing is formed in a circumferential direction of a sleeve mounting portion of the rotary shaft. Having two or more grooves, an O-ring to be fitted in the grooves, and a sleeve having a cylindrical shape and an inner diameter substantially equal to the shaft diameter of the rotating shaft;
The sleeve is tightly fitted in the sleeve mounting portion of the rotating shaft, and a sleeve is fixed to the rotating shaft by tightening a screw into a screw hole formed from the outside to the inside of the sleeve.

In the underwater bearing of the present invention configured as described above, water tightness is maintained by using a solid sealing material such as a rubber packing, a metallic packing, and an oil seal. Sealed with filled fluid grease, so even if solid sealing material such as rubber packing, metallic packing, etc. deteriorates due to abrasion and moisture and sand and mud enter, it will not The above approach can be prevented, and extremely high sealing performance can be ensured. Further, even when the bearing portion is misaligned due to a change with time, the bearing is sealed with the fluid grease, so that the sealing performance can be maintained.

Further, in the rotary shaft sleeve mounting structure of the present invention, after the O-ring is mounted in the groove formed in the circumferential direction of the rotary shaft, the sleeve is fixed by clearance, and further fixed by screws. Therefore, maintenance becomes easy and the efficiency of repair work can be significantly improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are explanatory views showing the configuration of an underwater bearing according to an embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a partially cutaway front view, FIG. 3 is a side view, and FIG. Each shows a sectional view in the axial direction. As shown in FIGS. 1 to 3, the underwater bearing has a shape molded by a bearing casing 11 and a seal cap 10 so that a sleeve 21 attached to a rotating shaft 22 is supported in water. Has become.

Further, as shown in FIG. 4, the underwater bearing has a rolling bearing 1 (bearing portion) disposed substantially at the center. The first oil seal (double lip type) 3, the grease filling portion 4, the second oil seal 5, and the left and right symmetrical positions along the axial direction of the rotary shaft 22 with the rolling bearing 1 as the center. The metallic packing 6, the rubber packing 7, and the packing holding plate 8 are arranged in this order. Spacers 9 are provided on both sides of the metallic packing 6.
Is further disposed, and a seal cap 10 is disposed so as to cover the first oil seal 3, the grease filling portion 4, the second oil seal 5, and the peripheral portion of the metallic packing 6, and is fixed by the O-ring 14. ing. A bearing casing 11 is mounted around the rolling bearing 1, and the rolling bearing 1 and the seal cap 10 are fixed by the bearing casing 11.

The seal cap 10 is provided with a plug 12 which can communicate with the grease filling portion 4 and can be supplemented with grease. The bearing casing 11 has a plug 13 which can communicate with the rolling bearing 1 and can be filled with grease. Have been. The grease filling section 4 is filled with grease having fluidity used for, for example, a food machine. Next, the operation of the underwater bearing configured as described above will be described. Now, when the above-mentioned underwater bearing is attached to a rotary drive device installed and used in wastewater containing a large amount of sand and mud such as a flocculator used in a sewage treatment facility and driven to rotate, the underwater bearing seal structure However, the rubber packing 7 disposed on the outermost side can prevent the sand from entering the inside. In addition, the metallic packing 6 held by the spacer 9 prevents intrusion of moisture. Further, the second oil seal 5 and the fluid grease filled inside the grease filling portion 4 can prevent moisture that has passed through the metallic packing 6 and entered inside. Next, the double lip type first oil seal 3 improves the sealing performance, and prevents the infiltration of moisture and sand and mud into the rolling bearing 1.

Thus, in this embodiment, the rubber packing 7, the metallic packing 6, the oil seals 3, 5, etc.
In addition to the sealing material that comes into contact with the sleeve 21 between the solids, the grease filling portion 4 is filled with a grease having fluidity so that the grease is filled in contact with the fluid. It does not deteriorate, can withstand long-time use, and can reliably maintain sealing properties. In addition, rolling bearing 1
Even if misalignment occurs due to abrasion or the like, the grease having fluidity filled in the grease filling portion 4 maintains water tightness, so that even if a slight misalignment occurs, it can be followed. Can be. Further, even when the grease filled in the grease filling portion 4 flows out, the plug 1
Since grease can be appropriately filled from No. 2, maintenance is easy. In the above embodiment, the rolling bearing 1 has been described as an example of the bearing, but the present invention is not limited to this, and it is obvious that a ball bearing or the like may be used.

FIG. 5 is an explanatory view showing the structure of one embodiment of the sleeve mounting structure for the rotating shaft according to the present invention, and FIG. 6 is a detailed view of a portion "A" in FIG. As shown in each figure,
Grooves 23 are formed at four locations on the sleeve 21 of the rotating shaft 22 along the circumferential direction, and an O-ring 24 is fitted in each groove 23. The sleeve 21 fixed to the rotating shaft has an inside diameter substantially equal to the shaft diameter of the rotating shaft 22, and a screw hole 25 communicating between the inside and the outside is formed at an appropriate position at both ends. ing. When the sleeve 21 is fixed to the rotating shaft 22, first, the O-ring 24 is inserted into the groove 23 of the rotating shaft 22,
The rotating shaft 22 is inserted into the sleeve 21 and a screw 26 is screwed into the screw hole 25 and tightened.
To the sleeve 21. As a result, the sleeve 21 is firmly fixed to the rotating shaft 22. According to the sleeve mounting structure for the rotating shaft according to the present embodiment configured as described above, the sleeve 21 is fixed to the rotating shaft 22 by clearance instead of tightly fitting as in the related art. By loosening it, it can be easily removed and maintenance becomes easy. Therefore, repair on site is possible, and workability is significantly improved.

[0017]

As described above, in the underwater bearing according to the present invention, in addition to a solid sealing material such as a rubber packing, an oil seal, and a metallic packing, a seal is formed by a fluid grease filled in a grease filling portion. Therefore, it is possible to withstand long-term use, and it is possible to reliably prevent moisture and sand and mud from entering the bearing. In addition, even when a misalignment occurs between the rotating shaft and the bearing, the sealing performance can be maintained. Furthermore,
In the sleeve mounting structure for the rotating shaft according to the present invention, the sleeve is fixed to the rotating shaft not by tight fitting but by clearance fitting, so that maintenance is easy and the workability is significantly improved. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view of an underwater bearing to which the present invention is applied.

FIG. 2 is a partially broken front view of an underwater bearing to which the present invention is applied.

FIG. 3 is a side view of the underwater bearing to which the present invention is applied.

FIG. 4 is an axial sectional view of a submerged bearing to which the present invention is applied.

FIG. 5 is an explanatory diagram showing a configuration of an embodiment of a sleeve mounting structure to which the present invention is applied.

FIG. 6 is a detailed view of an “A” part in FIG. 5;

FIG. 7 is a sectional view showing a configuration of a conventional underwater bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling bearing (bearing part) 3 1st oil seal (double lip type) 4 Grease filling part 5 2nd oil seal 6 Metallic packing 7 Rubber packing 8 Packing holding plate 9 Spacer 10 Seal cap 11 Bearing casing 12, 13 Plug 14 O-ring 21 Sleeve 22 Rotary shaft 23 Groove 24 O-ring 25 Screw hole 26 Screw

Claims (2)

[Claims] An underwater bearing for supporting a rotating shaft of a rotating mechanism used underwater, having a bearing portion at a central portion in an axial direction, and having a bearing portion on both sides of the bearing portion in the axial direction. An underwater bearing, wherein a first oil seal, a grease filling portion, a second oil seal, a metallic packing, and a rubber packing are arranged in this order at symmetric positions. 2. A sleeve mounting structure for mounting a sleeve on a sliding portion of a rotating shaft with a bearing, wherein at least two grooves formed in a circumferential direction of a sleeve mounting portion of the rotating shaft are fitted in the grooves. An O-ring, and a sleeve having a cylindrical shape and having an inner diameter substantially the same as the shaft diameter of the rotating shaft, wherein the sleeve is tightly fitted in a sleeve mounting portion of the rotating shaft, and from the outer side to the inner side of the sleeve. A sleeve mounting structure for a rotating shaft, wherein a screw is fastened to a drilled screw hole to fix the sleeve to the rotating shaft.