JPH0712236A - Shaft seal device - Google Patents

Abstract

PURPOSE:To make in-the-air iterative operation stable for a long period of time without requiring supply of lubricating water from outside of a pump by furnishing a water reserving tank having a lubricating water supplying part on the back of a sliding member on the rotating side, and equipping the sliding member with a communication hole to put the water reserving tank in communication with the slide surface. CONSTITUTION:When a pump is put in operation, a rotary shaft 1, a flange 4 secured thereto, and a seal ring on the rotation side are rotated. At this time, a centrifugal force due to rotation acts on the lubricating water 8 in a water reserving part 11 which is installed in the flange 4, so that the surface of the lubricating water 8 passes the opening of the part 11 and further a communication hole 9 furnished in a seal ring 6 on the rotating side to reach the slide surface. Accordingly the condition filled with lubricating water 8 can be maintained in the part 11 even though the pump is stopped after operation, so that the maintenance-free operation can be accomplished, which enables the in-the-air iterative operations even without supplying water externally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating water supply mechanism for a sliding surface of an end face type shaft sealing device used in a rainwater drainage pump or the like when operating in the air.

[0002]

2. Description of the Related Art Due to recent rapid urbanization, the inflow of rainwater into drainage pump stations is becoming large and rapid. In order to deal with such a situation, there is an increasing demand for the drainage pump to be operated in advance and standby. In the drainage pump that performs the preceding standby operation, the pump is activated and the main shaft is rotated, but the pump is not pumped, that is, the operation is performed in the air for a long time. During this time, since the lubricating water is not supplied to the shaft sealing device by pumping water, abnormal wear of the sliding member and deterioration of sealing performance due to dry sliding cannot be avoided.

As a means for solving such a problem, conventionally, the methods shown in FIGS. 5 and 6 have been adopted. In the method shown in FIG. 5, the lubricating water in the lubricating water tank 20 installed outside is supplied to the pipe 17 and the water supply hole 16 by the water supply pump 19.
The bottom part of the shaft sealing device is detected with a full water detector, etc., by pouring water into the sliding part via the If is detected, stop water injection. On the other hand, the method shown in FIG.
When the pump is stopped and operating in air, the rubber bellows 13 is used to push down the seal ring so that the sliding parts do not come into contact, and when water is pumped, the pressure receiving plate 15 is used to press the seal ring upward using the water pressure of the pumped water. It is a method of sealing.

[0004]

However, in the shaft sealing device of the method as shown in FIG. 5, water is constantly poured into the shaft sealing portion during air operation, so that lubrication is required when air operation is performed for a long time. It has the drawback of requiring a large amount of water. In addition, there is a drawback that the cost becomes high when fresh water is used as the lubricating water.
Furthermore, since it has a full water detector, a water supply pump, a water supply piping system, etc., it is considered that maintenance of these auxiliary machines becomes necessary.

On the other hand, in the structure in which the sliding members are not brought into contact with each other at the time of stop and air operation as shown in FIG. 6, dust and the like may be accumulated on the sliding surface when the period during which the pump is not operating becomes long. . If the sliding surface is scratched by this dust or the like, it may cause surface roughness or abnormal wear, and it may be impossible to maintain sufficient sealing performance.

Therefore, in the structure of the conventional shaft sealing device as described above, it is possible to satisfactorily achieve the purpose of stable and repeated air operation for a long time without supplying lubricating water from the outside of the pump. could not.

An object of the present invention is to provide a maintenance-free shaft seal device which can be stably operated repeatedly in the air for a long time without supplying lubricating water from the outside of the pump.

[0008]

In order to achieve the above object, the present invention can operate the shaft sealing device in a stable state for a long time even when the pump is operating in air and without supplying lubricating water from the outside. In addition, a mechanism is provided to supply lubricating water to the sliding surface by rotating the main shaft so that sufficient sealing performance can be obtained even when pumping water.

That is, by providing a storage tank for lubricating water or pumped water on the back surface of the sliding member on the rotating side and providing a communicating hole for communicating the water tank with the sliding surface on the sliding member, the rotation of the main shaft is prevented. Lubricating water in the water storage tank is supplied to the sliding surface by utilizing the centrifugal force obtained in step 1. At this time, it is desirable that the sliding member is made of a material having excellent water lubrication characteristics such as ceramics.

[0010]

In the shaft sealing device of the present invention, the lubricating water in the water reservoir provided on the back surface of the rotating-side sliding member moves to the outer peripheral side by the centrifugal force due to the rotation of the main shaft, and is provided in the axial direction of the sliding member. Since it is supplied to the sliding surface through the established communication hole, problems such as seizure and surface roughness of the sliding member due to dry sliding do not occur. In addition, for the supply of lubricating water to the water tank, it is necessary to supply the lubricating water to the water tank from the outside only during installation, but during normal operation pumped water or leak water from the sliding surface
There is no particular problem because it has a structure that accumulates in the water storage section. In the present invention, an external water supply piping system is unnecessary, and maintenance of piping and auxiliary equipment is not required. Further, since the elements constituting the shaft sealing device do not have a movable part such as a bellows, the reliability of the entire device is improved. Therefore, it is possible to provide a highly reliable shaft sealing device that does not require water injection from the outside and can be stably operated for a long time even when the air operation without pumping is repeated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of a shaft sealing device according to the present invention. A flange 4 containing a water reservoir 11 is fixed to the rotary shaft 1, and a rotary seal ring 6 is fixed to the upper portion of the flange 4. A water supply unit 10 is provided downward on the inner peripheral side of the water storage unit 11, and the inside of the water storage unit 11 is filled with lubricating water 8.

The bottom surface of the water storage portion 11 is curved upward as it goes to the outer peripheral side, and the upper surface, that is, the surface facing the back surface of the rotary seal ring 6 is an opening. Further, the rotation side seal ring 6 has an axial communication hole 9
Is provided to connect the water storage section 11 and the sliding surface. On the other hand, the fixed-side seal ring 5 is fixed to the upper portion of the rotary-side seal ring 6 in the seal case 3 at an opposing position. Further, these shaft sealing device components are surrounded by the casing 2 and the housing 7. When the time from the start of pump operation to pumping is long and air operation is forced, as represented by the preceding atmospheric operation, the sliding surface formed by the fixed side sealing ring 5 and the rotating side seal ring 6 is a dry surface. It will be in a sliding state. However, in the present invention, when the operation of the pump is started, the rotary shaft 1, the flange 4 fixed to the rotary shaft 1, and the rotary seal ring 6 rotate. At this time, the centrifugal force due to the rotation acts on the lubricating water 8 in the water storage portion 11 built in the flange 4, so that the water surface of the lubricating water 8 is as shown in FIG.
It moves to the outer peripheral side along the bottom surface of 1. The lubricating water 8 passes through the opening of the water storage portion 11 and further passes through the communication hole 9 provided in the rotation side seal ring 6 to reach the sliding surface. The lubricating water 8 that has reached the sliding surface diffuses in the circumferential direction and the outer peripheral direction due to the rotation, so that most of the sliding surface can be wetted. As a result, a fluid film is generated on the sliding surface to bring about boundary lubrication or fluid lubrication, so that the sliding surface is kept sound. Under actual operating conditions, a normal operating state with pumped water is obtained after such an air operation. In a normal operating state, pumped water flows into the water storage section 11 from the water supply section 10 provided in the water storage section 11. By the way, the bottom surface of the water storage portion 11 is curved upward as described above. This is to wet the sliding surface with a smaller amount of lubricating water,
There is no problem even if the amount of the lubricating water 8 in the water storage section 11 decreases due to evaporation or the like. Therefore, even if the pump is stopped after the operation, the state where the water reservoir 11 is filled with the lubricating water 8 can be maintained, so that the air operation can be repeatedly performed without supplying water from the outside.

FIG. 3 shows another embodiment of the present invention. In the first embodiment, the water supply section is provided downward on the inner peripheral side of the water storage section and has a structure for taking in pumped water. The water supply unit 10 in the present embodiment faces upward from the inner peripheral portion of the water storage unit 11, and the tip thereof is provided between the rotary side seal ring 6 and the rotary shaft 1. Also in this embodiment, the lubricating water 8 in the water storage portion 11 receives the centrifugal force due to the rotation of the rotary shaft 1 to lubricate the sliding surface. The method of supplying the lubricating water 8 to the sliding surface and the lubricating action are described above. The same as in the first embodiment. In this embodiment, since the water supply unit 10 is provided at the upper portion, the lubricating water 8 takes in the pumped water leaked from between the fixed side seal ring 5 and the rotary side seal ring 6 at the time of pumping. Further, in the present embodiment, there is a problem that the lubricating water 8 in the water storage portion 11 evaporates more easily than in the structure of the first embodiment, but a small amount of lubricating water is supplied from the clearance between the seal case 3 and the rotary shaft 1. It is possible to respond by doing. As a result, as in the first embodiment, even if the pump is stopped after the operation, the state in which the water reservoir 11 is filled with the lubricating water 8 can be maintained, so that water is not supplied from the outside. It becomes possible to repeatedly perform air operation. The examples are limited to the description of claims 1 and 3, but claim 2
However, the same operation and effect as the embodiment described in FIG. 3 can be obtained.

FIG. 4 shows an embodiment in which the shape of the bottom surface of the water storage section 11 is changed, and the shape goes upward in a straight line toward the outer peripheral side. Even in this case, as in the first and second embodiments, the action of the lubricating water 8 in the water storage portion 11 receiving the centrifugal force due to the rotation of the rotating shaft 1 to lubricate the sliding surface does not change. The same effect as that of the first and second embodiments can be obtained. In the above-mentioned embodiment, only the case of the curved shape and the straight shape is explained, but since the centrifugal force due to the rotation is used, the same applies if the bottom surface of the water storage section becomes higher toward the outer circumference. The action and effect of can be obtained. In the above examples, the material of the seal ring is not particularly limited, but it is preferable to use a material having excellent wear resistance such as ceramics and also excellent in water lubricity, and a more reliable shaft seal. You can get the device.

[0015]

According to the present invention, the shaft sealing device can be operated in a stable state for a long time even when the pump is operated in the air and the lubricating water is not supplied from the outside, and the sealing performance is sufficient even when pumping water. Therefore, the lubricating water can be supplied to the sliding surface by the rotation of the main shaft.

Further, since the shaft sealing device has a mechanism for supplying the lubricating water to the sliding surface by the rotation of the pump shaft itself, the sliding surface can be damaged without supplying the lubricating water from the outside. Instead, it is possible to perform a long-time aerial operation represented by the preceding standby operation. Further, in the present invention, since an external water supply device and its piping system are unnecessary, maintenance of these auxiliary machines and piping is not necessary. Further, since the elements constituting the shaft sealing device do not have a movable part such as a bellows, the reliability of the entire device is improved. Therefore, it is possible to provide a highly reliable shaft-sealing device and a drainage pump that do not require water injection from the outside even when repeatedly performing air operation and can stably operate the pump for a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a shaft sealing device according to an embodiment of the present invention.

FIG. 2 is an explanatory view of the action of lubricating water in the embodiment of the present invention.

FIG. 3 is a vertical sectional view of a shaft sealing device according to another embodiment of the present invention.

FIG. 4 is a vertical sectional view of a shaft sealing device according to another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a conventional shaft sealing device.

FIG. 6 is a vertical cross-sectional view of a conventional shaft sealing device.

[Explanation of symbols]

1 ... Rotary shaft, 2 ... Casing, 3 ... Seal case, 4 ...
Flange, 5 ... Fixed side seal ring, 6 ... Rotation side seal ring, 7 ... Housing, 8 ... Lubricating water, 9 ... Communication hole, 1
0 ... water supply section, 11 ... water storage section.

Claims (6)

[Claims] 1. A rotary shaft, a flange fixed to the rotary shaft, a rotary-side sliding member fixed to the flange end surface, and a fixed-side sliding member facing and fixed to the sliding member. In a shaft sealing device for a vertical axis rotating machine configured by a member, a water storage tank for storing lubricating water is provided on the rotation shaft side with respect to the outer peripheral surface of the sliding member on the rotation side inside the flange, The shaft sealing device, wherein the sliding member has a communication hole between the water storage tank and the sliding surface. 2. A rotary shaft, a flange fixed to the rotary shaft, a rotary-side sliding member fixed to the flange end surface, and a fixed-side sliding member facing and fixed to the sliding member. In the shaft sealing device of the vertical shaft rotating machine composed of members,
A water tank formed by the inner peripheral side of the sliding member on the rotating side, the flange end surface and the outer peripheral surface of the rotating shaft;
The shaft sealing device, wherein the rotating-side sliding member has a communication hole between the water storage tank and the sliding surface. 3. The shaft sealing device according to claim 1, wherein the water storage tank includes a water storage section and a water supply section. 4. A drainage pump comprising the shaft sealing device according to claim 1. 5. A drainage pump comprising the shaft sealing device according to claim 2. 6. A drainage pump comprising the shaft sealing device according to claim 3.