JP2995180B1 - Seal structure of vertical pump - Google Patents

Abstract

When a pump is stopped, a rotor fixed to a rotating shaft side and a flap fixed to a body tube side are airtightly adhered to prevent leakage of a chemical solution or corrosive gas from inside the body tube, and the pump is operated. The inside functions as a kind of shaft sealing device with no rotating contact. A rotor fixed to an upper portion of a rotating shaft, and a flap fixed to a body tube corresponding to the rotor.
The magnets 10 and 12 are respectively incorporated in the
Can be moved toward and away from a position where the air-tight seal is formed on the lower surface of the rotor and away from the position below the rotor to form a gap s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure of a vertical pump, and more particularly to a seal structure of a vertical pump suitable for transferring chemicals that pollute the environment or highly corrosive chemicals. is there.

[0002]

2. Description of the Related Art A motor is provided above a cylindrical body tube, a pump chamber is formed in a casing connected to a lower end of the body tube, and an impeller provided in the pump room is connected to the motor via a rotating shaft. Vertical pumps are characterized by having a small number of main components and no sliding parts in the liquid contact part, and are environmentally friendly pumps with excellent corrosion resistance, wear resistance and mechanical strength. Transfer of contaminated chemicals or highly corrosive chemicals, etc.
For example, it is widely used for circulating a chemical solution such as an etching machine, circulating a plating solution of a plating apparatus, or circulating a chemical solution such as an exhaust gas absorption tower.

[0003] As a seal structure of a conventional vertical pump used for the circulation of a chemical solution of this kind, a gas seal plate having a hollow disk shape is attached to the inside of the upper end surface of a body tube, and the gas seal plate is rotated. The shaft and the shaft are sealed with a gas seal, and an O-ring is interposed between the outer peripheral portion of the gas seal plate and the upper end surface of the body tube, so that the chemical solution or corrosive gas leaks from the body tube to the outside. Has been prevented. (For example, see Japanese Utility Model Publication No. 7-20393 as prior art)

[0004]

The gas seal used for the seal portion of the conventional vertical pump as described above is generally made of rubber, and this gas seal has a certain preload. The purpose is to prevent corrosive gas from the body tube and casing from leaking to the outside by contacting the gas seal plate with the gas seal plate. Backflow of the chemical toward the pump may start, and a part of the liquid may pass through the pump casing and the back surface of the impeller, rise inside the body pipe, and leak to the outside from the gas seal portion provided at the upper part of the body pipe. In addition, the corrosive gas in the body tube may be pushed out from the gas seal portion by the chemical liquid rising in the body tube.

Therefore, it is recommended to install a check valve in the discharge pipe in order to prevent the backflow of the chemical solution to the pump side when the pump is stopped. In this case, depending on the liquid quality, the check valve may not be installed. Crystals may form on the sealing seat and its effect may be reduced. Further, as a structure of the pump itself, a shaft sealing device, for example, a mechanical seal or a packing seal can be provided between the rotating shaft and a fixed portion of the body tube or the casing. Product value as a vertical pump pursuing maintenance-free is reduced by half.

Accordingly, an object of the present invention is to provide a method in which the operation of the pump is stopped and, at the same time, the rotor fixed to the rotary shaft and the flap fixed to the body tube are airtightly contacted.
The purpose is to prevent the leakage of chemicals and corrosive gas from the inside of the body tube and to provide a vertical pump seal structure that functions as a kind of shaft sealing device without rotating contact during pump operation. is there.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a rotor having a built-in magnet is fixed to an upper portion of a rotating shaft of a vertical pump, and a rotor corresponding to the rotor is provided. And fix the flap with a built-in magnet to the body tube,
The magnets built into each rotor and flap are
And S poles are arranged alternately in plane to correspond
With both rotors and flaps stationary
The attraction between the magnets causes the rotor and flap to rotate in a state where the rotor rotates from a position where the rotor is airtightly adhered to the lower surface of the rotor.
The magnet is characterized in that it can be deformed, contacted and moved to a position separated below the rotor by a repulsive force acting between the two magnets .

[0008] Here, as a vertical pump, a motor is provided above a cylindrical body pipe, a pump chamber is formed in a casing connected to a lower end of the body pipe, and an impeller provided in the pump chamber is provided with a rotating shaft. The basic configuration of a pump connected to a motor via a pump and having a suction port at the lower part of the pump chamber and a discharge port at the side of the pump chamber is known.

According to the present invention, a disk-type magnet coupling type seal portion is formed by a rotor and a flap, each of which has a built-in magnet, and when the upper surface of the flap is in close contact with the lower surface of the rotor, both surfaces are perpendicular to the rotation axis, that is, , It is arranged to be horizontal.

Since the rotation shaft is free to rotate while the pump is stopped, that is, when the motor is not energized, the rotor is integrated with the rotation shaft and the rotors correspond to the N and S poles of the magnet in the flap. At a position where the attractive force acts between the magnets.
In other words, when the rotor is stationary (while the pump is stopped), an attractive force acts between the magnets of both the rotor and the flap, so that the upper surface of the flap generates a certain surface pressure on the lower surface of the rotor and tightly adheres tightly to the seal. Demonstrate.

Therefore, at the same time when the pump during operation is stopped, the upper surface of the flap is airtightly adhered to the lower surface of the rotor by the attraction of the magnets of both the rotor and the flap. Even if the chemical liquid level rises inside the body tube due to backflow, it is prevented from leaking to the outside through the space between the rotor and the flap to the upper part of the body tube. Also, the corrosive gas in the body tube is compressed by the chemical liquid rising in the body tube and the pressure is increased, but is not pushed out from between the rotor and the flap and leaks to the outside.

Next, when the rotor tries to rotate integrally with the rotating shaft by energizing the motor, the magnet in the rotor is separated (removed) from the magnet in the flap on which the attracting force is acting. As a result, a step-out phenomenon as a magnet coupling occurs, and due to the repulsive force of the same polarity of the magnet, the weight of the flap and the negative pressure in the body tube generated during the operation of the pump, the upper surface of the flap is separated below the rotor and between the rotors. Form voids. In this way, the rotor rotates without contact with the flap, and functions as a kind of shaft sealing device having no portion in rotational contact during the operation of the pump.

The number and size of the magnets incorporated in the rotor and the flap are experimentally set according to the capacity of the applied pump, the size of the body tube, and the like. It is set so that a certain attractive force as a magnetic coupling acts between the flap and the flap.

Further, as the contact Hanaredo flap upper surface relative to the rotor bottom surface, it is required to be entirely performed in unison. Therefore, as in the invention of claim 2, wherein the rotor
The flap is made of a rubber material, and extends and contracts in the axial direction between the outer peripheral portion of the flap fixed to the body tube of the flap and the main flap main body containing the magnet to make the flap main portion hang down and separate from the rotor lower surface. It is preferable to adopt a configuration in which the elastic portion is provided.

With this configuration, while the pump is stopped,
When the upper surface of the flap is in airtight contact with the lower surface of the rotor ,
A constant surface pressure is uniformly applied to the rubber contact surface between
Thus, the effects of the invention according to claim 1 are more effectively achieved.
Make things. Also, when the upper surface of the flap separates below the rotor, the expansion and contraction portion extends and the main flap portion corresponding to the rotor hangs down to form a gap between the main flap portion and the lower surface of the rotor. Therefore, the movement from this position until the flap main portion comes into close contact with the lower surface of the rotor is always performed all at once.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a vertical pump according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a seal portion according to the embodiment of the present invention.

In FIG. 1, a vertical pump 1 has a motor 5 disposed above a cylindrical body tube 4 and a pump chamber 7 formed in a casing 6 connected to the lower end of the body tube 4. The suction port 2 is opened, and the discharge port 3 is opened on the side of the pump chamber 7. An impeller 8 disposed in the pump chamber 7 is connected to the motor 5 via a rotating shaft 9.

It should be noted that the rotating shaft 9 of the embodiment is
It is configured to prevent a chemical solution or corrosive gas from entering the main shaft portion in the inside.

In the present invention, a rotor 11 having a magnet 10 built therein is fixedly mounted on the rotating shaft 9.
A flap 13 containing a magnet 12 is fixed to the body tube 4 in correspondence with the above. The rotor 11 and the flap 13 are made of a rubber material, and the N pole and the S pole of the magnets 10 and 12 incorporated therein are alternately arranged in a plane so as to correspond to each other. The rotor 11 and the flap 13 constitute a disk-type magnetic coupling type seal portion.

Here, the flap 13 is provided between a flap outer peripheral portion 13a fixed to the body tube 4 and a flap main portion 13b having a magnet 12 and a rotary shaft through hole 14 at the center.
An elastic portion 13c that expands and contracts in the axial direction is provided, and the rotor lower surface 1
When the flap main part 13b in close contact with 1a separates below the rotor, the expansion and contraction part 13c expands and makes the flap main part 13b hang down to create a gap s (see FIG. 4) between the flap main part 13b and the rotor lower surface 11a. It is formed. Although not shown, a flap main part 1 is provided by a stopper provided on the body tube 4 side corresponding to the flap main part 13b.
The drooping amount of 3b is appropriately set.

The operation of the embodiment having the above configuration is shown in FIG.
This will be described with reference to FIGS.

FIG. 3A shows a state in which the pump is stopped and the rotor 11 is stationary with the rotating shaft 9. (B) The north pole and the south pole of both the magnets 10 and 12 of the rotor 11 and the flap 13 generate an attractive force corresponding to each other, and the upper surface of the flap 13 generates a constant surface pressure on the lower surface 11a of the rotor, so that the rotor is airtight. Closely adhered. In this state, the rotor 11 and the flap 13
Sealing properties are exhibited between them.

FIG. 4: (a) The rotor 11 is integrated with the rotating shaft 9.
Shows the state during operation of the pump in which is rotating. (B) The rotation of the rotor 11 causes a step-out phenomenon as a magnet coupling, the repulsive force between the same poles of the two magnets 10, 12 and the weight of the flap 13 and the inside of the body tube 4 generated during the pump operation. Due to the negative pressure, the flap 1
3 form a gap s between the rotor 11 and the flap 13. The rotor 11 rotates in this state without contact with the flap 13.

FIG. 5 (a) shows a state immediately after the pump during operation is stopped and the rotor 11 is stopped integrally with the rotating shaft 9. (B) The rotating shaft 9 is released from the load, becomes free to rotate, and the magnets 10, 1 of both the rotor 11 and the flap 13
The N-pole and S-pole of No. 2 act on each other, and a suction force is applied, and the flap 13 is pulled up and the flap 1
(3) The upper surface generates a certain surface pressure and tightly adheres tightly to exhibit sealing properties. Therefore, even if there is a reverse flow of the chemical solution immediately after the pump is stopped, the leakage of the chemical solution or corrosive gas in the body tube 4 to the outside is prevented.

[0026]

The present invention is embodied in the form described above. According to the present invention, a rotor and a flap each having a built-in magnet are provided between the upper part of the body tube of the vertical pump and the rotating shaft. secured together to constitute a sealing portion of the disk-shaped magnet coupling form, at the time the pump is stopped, the rotor and the flat
The attraction force acts between both magnets of the fan and the upper surface of the flap tightly adheres to the lower surface of the rotor to exhibit sealing properties.
Effectively applied to pipeline systems that handle corrosive fluids or odorous chemicals that can reliably prevent leakage of chemicals and corrosive gases in the body tube due to backflow of chemicals immediately after the pump stops, and that handle corrosive fluids or odorous chemicals. It is.

During the operation of the pump, a step-out phenomenon as a magnet coupling occurs due to the rotation of the rotor,
Since the rotor forms a gap between the flaps and rotates in a non-contact state, wear of the seal member and the like can be reduced, and the seal portion becomes stable for a long period of time.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a main part showing the embodiment of the present invention.

FIGS. 3A and 3B are explanatory views illustrating a sealing function in a sealing portion of a vertical pump.

FIGS. 4A and 4B are explanatory diagrams illustrating a sealing function in a sealing portion of the vertical pump.

FIGS. 5A and 5B are explanatory views illustrating a sealing function in a sealing portion of a vertical pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical pump 2 Suction port 3 Discharge port 4 Body pipe 5 Motor 6 Casing 7 Pump room 8 Impeller 9 Rotating shaft 10 Magnet 11 Rotor 11a Rotor bottom surface 12 Magnet 13 Flap 13a Flap outer peripheral part 13b Flap main part 13c Deformable part 14 rotation Shaft through hole

Claims (2)

(57) [Claims] A rotor having a built-in magnet is fixed to the upper part of a rotating shaft of a vertical pump, and flaps containing a magnet are fixed to a body tube corresponding to the rotor.
N poles and S poles are arranged alternately in a plane.
The flaps are locked while the rotor is stationary.
Attraction force acts between both the magnets of the rotor and the flap, and the rotor rotates from the position where it tightly adheres to the lower surface of the rotor.
Repulsion between the magnets on both the rotor and flap
A vertical pump seal structure characterized in that it can be deformed and moved to and away from a position below the rotor. Wherein the rotor and the flap is made of rubber material, off
Built-in magnet with flap outer periphery fixed to lap body tube and magnet
Between the flap main part and the
The main part is suspended from the bottom of the rotor.
Sealing structure Vertical pump according to claim 1, wherein the provided.