JPS6246717B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a vertical centrifugal pump, and more specifically, to a vertical centrifugal pump that prevents liquid from flowing out from a volute chamber through a gap in a shaft hole of a rotating shaft. This invention relates to a rigid centrifugal pump.

(Prior art) A vertical centrifugal pump is equipped with a main blade that rotates within a vortex chamber, and pumps liquid by centrifugal force during rotation, and has been widely used in the chemical industry. ing. However, in this type of vertical centrifugal pump, there is a problem that liquid flows out from the volute chamber through the gap in the shaft hole of the rotating shaft.In order to solve this problem, for example, −8657 was devised.

(Problems to be Solved by the Invention) However, all of them are incomplete, and in the past, there was no rigid centrifugal pump that effectively prevented the outflow, and the above-mentioned problems still remained.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a vertical centrifugal pump in which liquid does not flow out from the vortex chamber to the outside through the gap between the rotating shafts.

(Means for Solving the Problems) A vertical centrifugal pump according to the present invention provides a rotating pump connected to an output shaft of a drive body and located in a volute chamber through a shaft hole formed in a volute chamber partition wall. A disk is attached to the end of the shaft, and one side of the disk is provided with a sealing blade close to the swirl chamber partition wall, and the other side is provided with a main blade for pumping liquid, and the middle part of the rotating shaft is provided with a sealing blade close to the swirl chamber partition wall. is provided with a seal packing formed by a lip portion going around the rotating shaft, and a sliding ring that presses the lip portion with the return force of a spring to close the gap between the rotating shaft and the lip portion. In a vertical centrifugal pump equipped with an opening/closing device that opens the gap by moving this sliding ring by the centrifugal force of a rotating shaft, an air chamber is provided between the seal packing and the vortex chamber, and the air chamber The structure allows air to be introduced from the outside through the gap and communicates with the shaft hole formed in the swirl chamber.

(Function) When the drive body stops rotating, the opening/closing device automatically closes the gap between the shaft holes in the upper partition wall, and then the liquid in the volute chamber flows through the gap between the shaft holes in the lower partition wall. However, when the air pressure in the air chamber and the liquid in the vortex chamber are balanced, the liquid stops entering the air chamber.

Therefore, the air chamber will not be filled with liquid, and the liquid will not flow out through the gap in the shaft hole of the upper partition wall.

On the other hand, the gap in the shaft hole of the upper partition wall is opened by the opening/closing device for the rotating shaft of the drive body, but the liquid in the air chamber is swirled by the rotation of the main blade and seal blade attached to the disk. The rotation of the sealing blades creates a so-called liquid seal between the upper wall of the volute chamber and the sealing blades, so that the air in the air chamber does not enter the volute chamber more than necessary, and the vortex Liquid inside the room will not enter the air chamber.

(Embodiment) The figure shows an embodiment of the present invention, and a vertical centrifugal pump, which is indicated by the reference numeral 1 as a whole in FIG. has been done.

The pump body 2 is covered by an upper casing 3 and a lower casing 4, and a rotating shaft 5 is provided in the center of the pump body 2 along its vertical axis.
is rotatably supported.

The upper end of the rotating shaft 5 is connected to an output shaft (not shown) of a motor M installed on the upper casing 3.

Further, an opening/closing device 6 for opening and closing an air chamber a, which will be described later, is attached to a portion of the rotating shaft 5 located at the upper part of the upper casing 3 below the installation position of the motor M.

As shown in FIG. 3, this opening/closing device 6 includes an upper case 7 and a lower case 8 fixed to the rotating shaft 5, and inside thereof, as shown in FIGS. 3 and 4, An annular space 9 is formed. In addition, a sliding ring 1 is provided at the bottom of the lower case 8.
0 is fitted so that it can be moved up and down.

This sliding ring 10 consists of an outer ring 11 and an inner ring 12 that is integrally screwed with the outer ring 11. A diaphragm-type packing 1 is provided between the two.
3 is being held in place. This patch king 13
Further, a boss 16 is fitted and fixed to the rotating shaft 5.
It is sandwiched between the upper end and the lower end of the lower case 8, and the inner peripheral edge of the packing 13 is connected to the rotating shaft 5.
is in contact with the surrounding surface. This packing 13 prevents the air in the air chamber a (FIGS. 1, 5, and 6, described later) from leaking between the inner ring 12 and the boss 16.

Further, on the upper surface of the sliding ring 10, several guide pins 14 are provided at equal angular intervals in the circumferential direction.
The lower end of the guide pin 14 is fixed, and the guide pin 14 passes upward through the lower case 8 of the opening/closing device 6 and reaches into the space 9. A coiled spring 15 is elastically mounted between the upper case 7 and the upper surface of the outer ring 11 and is fitted onto the guide pin 14 . This spring 15 causes the sliding ring 10
is always given a downward force.

The inner ring 12 of the sliding ring 10 is slidably fitted onto the outer peripheral surface of the boss 16. Further, on the outer peripheral surface near the upper end of the boss 16,
A small diameter portion 17 is formed that has a smaller diameter by one step,
An annular protrusion 12 a formed on the inner circumference of the upper end of the inner ring 12 is in sliding contact with the outer circumferential surface of the small diameter portion 17 .

On the other hand, at an intermediate height position of the upper casing 3 and below the installation position of the opening/closing device 6, an upper partition wall 18 and a lower partition wall 2 are provided vertically at a predetermined interval.
0 is provided between the partition walls 18 and 20, and an air chamber a is formed between the partition walls 18 and 20 to prevent liquid from flowing out from the swirl chamber 30 to the outside through the shaft hole 18a, which will be described later, by adjusting the air pressure. The upper and lower partition walls 18, 2
The rotary shaft 5 is fitted into shaft holes 18a and 20a provided in the center of the rotary shaft 5.

Further, a fixing ring 3 is provided on the upper partition wall 18.
1, the seal packing 19 is fixed via a presser ring 19b. A lip portion 19a of this seal packing 19 extends toward the lower side of the inner ring 12. As shown in FIG. 5, this lip portion 19a is formed so as to go around the rotating shaft 5 and to have a gap therebetween. Further, when the sliding ring 10 is upwardly separated from the upper surface of the lip portion 19a, external air is communicated with the gap. Furthermore, when the vertical centrifugal pump 1 is stopped and the sliding ring 10 is lowered, this seal packing 19 comes into contact with the lower surface of the inner ring 12, and the air in the air chamber a flows upward through the shaft hole 18a. While the holding ring 19b plays the role of preventing escape, the holding ring 19b also plays the role of a brake that quickly stops the rotation by contacting the lower surface of the inner ring 12, and also plays the role of a packing seal by coming into close contact with the inner ring when stopped.

Further, a disk 21 is provided at the lower end of the rotating shaft 5.
is fixed, and the disk 21 is rotatably accommodated in a swirl chamber 29 formed between the lower partition wall 20 and the lower casing 4. A plurality of sealing blades 22 are protruded radially or spirally at equal angular intervals on the upper surface of the disk 21, while a plurality of spiral main blades 23 for pumping liquid are provided on the lower surface of the disk 21. It is formed.

A suction port 24 is formed at the center of the lower surface of the lower casing 4, and a discharge port 25 is formed at one end.
is formed.

By the way, in the space formed between the upper case 7 and the lower case 8 of the opening/closing device 6, several guide pins 26 are arranged radially in the lower case 8 in a state perpendicular to the rotating shaft 5. Both ends of these guide pins 26 are fitted into pin holes 8a formed in the boss portion of lower case 8 and pin holes 8b formed in the inner surface of lower case 7, respectively. A weight collar 27 is slidably fitted onto these guide pins 26. The weight collar 27 has a flange portion 2 at its inner end.
7a and a cylindrical portion 27b at the outer end, and a groove 27C having a conical slope is formed on the outer surface of the flange portion 27a over the entire circumference.

On the other hand, a seal opening/closing pin 28 is fitted on the lower case 8 side at a position where it can engage with the weight collar 27 so as to be movable up and down. At the upper end of this seal opening/closing pin 28, there is a head 28 in the shape of an inverted truncated cone.
a is formed, and the inclination angle of the outer peripheral surface of this head 28a is equal to the groove 27c of the weight collar 27.
is equal to the inclination angle of In addition, the seal opening/closing pin 28
The lower end 28b of is fixed to the upper side of the outer ring 11 of the sliding ring 10. Note that the inner circumferential surface of the fixed ring 31 and the outer circumferential surface of the sliding ring 10 are always separated from each other.

Next, the operation of this embodiment configured as above will be explained.

First, when the motor M rotates, the rotating shaft 5 rotates, and the main blade 23 rotates together with the disk 21.
Liquid is sucked through the suction port 24 and discharged from the discharge port 25 by centrifugal force.

On the other hand, due to the rotation of the rotating shaft 5, the opening/closing device 6 integrated therewith also begins to rotate, and the weight collar 27, which is slidably fitted to the guide pin 26, also begins to move outward, and its inclined surface Groove 2 with
7c and the head 28a of the seal opening/closing pin 28 begin to engage. As the weight collar 27 moves outward, the head 28a of the seal opening/closing pin 28 begins to fit strongly and deeply into the groove 27c, and as a result, the seal opening/closing pin 28 begins to move upward. This movement is performed against the elastic force of the spring 15, and at the same time the sliding ring 10 begins to move upward by the seal opening/closing pin 28. Then,
As shown in FIGS. 1 and 5, until now it has contacted the lip portion 19a of the seal packing 19, elastically deforming it in the direction of the boss 16, and also contacted the upper surface of the retainer ring 19b to maintain the sealed state. The sliding ring 10, which had been
a and the upper surface of the presser ring 19b to release the sealing state, resulting in the state shown in FIG.

That is, as soon as the rotating shaft 5 begins to rotate, the sliding ring 10 is pulled upward and separated from the lip portion 19a of the seal packing 19, so that wear of the lip portion 19a is significantly reduced.

On the other hand, when the seal packing 19 separates from the rotating part, outside air is guided through the opening 3a (FIG. 6) formed in the circumferential surface of the upper casing 3, and this outside air is further passed through the sliding ring 10, the fixed ring 31, and the holding ring 19b, and the lip portion 1
The air chamber a passes between the tip of the air chamber 9a and the boss 16.
guided inside. By the way, during this rotation operation, the liquid in the air chamber a is returned to the swirl chamber 30 due to the centrifugal force effect caused by the rotation of the main blade 23 and the seal blade 22, and the upper surface of the seal blade 22 and the swirl chamber A so-called liquid seal state is created between the upper wall surface of 30, that is, the lower surface of the lower partition wall 20 (upper wall surface of the volute chamber) due to the high pressure liquid L pressed by the centrifugal force of the sealing blades 22, and the liquid in the vortex chamber 30 is However, it does not flow into the air chamber a.

Note that when the motor M stops, the rotation of the rotating shaft 5 also stops, and the centrifugal force on the weight collar 27 also disappears. Therefore, the seal opening/closing pin 28 moves down as the sliding ring 10 is pushed by the spring 15.
The lower surface of the inner ring 12 is the upper surface of the presser ring 19b and the lip portion 19a of the seal packing 19.
As shown in FIGS. 1 and 5, the shaft is completely sealed. At this time, since all rotating parts are stopped, the lip portion 19a of the seal packing 19 will not wear out. Furthermore, since the liquid sealing state caused by the liquid L is also released on the outside of the sealing blade 22 and the disk 21, the liquid flowing back from the discharge port 25 also enters the air chamber a. However, since there is air sealed in this area by the seal packing 19, the liquid will only enter until the air pressure is balanced with the air pressure, and the liquid will be led to the seal packing 19 side. There isn't. Therefore, even if this pump is used to feed a corrosive liquid used in the chemical industry, the liquid in the swirl chamber 30 does not come into contact with the seal packing 19. It will not corrode.

(Effects of the Invention) The vertical centrifugal pump according to the present invention is connected to the output shaft of the drive body and passes through the shaft hole formed in the volute chamber partition wall to the end of the rotating shaft located in the volute chamber. A disk is attached, a sealing blade close to the swirl chamber partition wall is provided on one side of the disk, a main blade for pumping liquid is arranged on the other side, and a lip portion is provided in the middle of the rotating shaft. A seal packing formed around the rotating shaft is provided, and a sliding ring is provided that presses the lip portion with the return force of a spring to close the gap between the rotating shaft and the lip portion. In a vertical centrifugal pump equipped with an opening/closing device that moves a dynamic ring by centrifugal force of a rotating shaft to open the gap, an air chamber is provided between the seal packing and the swirl chamber, and the air chamber is opened through the gap. In addition to allowing air to be introduced from the outside through the vortex chamber, it is also configured to communicate with the shaft hole formed in the vortex chamber, so that when the drive body stops rotating, the opening/closing device automatically closes the gap between the shaft holes in the upper partition wall. After that, the liquid in the vortex chamber enters the air chamber through the gap in the shaft hole of the lower partition wall, but when the air pressure in the air chamber and the liquid pressure in the vortex chamber are balanced, the air chamber closes. Stops liquid from entering.

Therefore, the air chamber will not be full of liquid, and the liquid will not flow out through the gap in the shaft hole of the upper partition wall, when used as a chemical pump to feed acid liquid, alkaline liquid, etc. It is particularly effective in

When the pump is in operation, the air chamber is unsealed by the opening/closing device, allowing the air chamber to communicate with the outside air, and centrifugal force generated by the operation of the main blade and sealing blade causes air to enter the air chamber when the pump is stopped. The liquid that had been inside the vortex chamber is removed, and a liquid seal is formed between the sealing vane and the upper wall of the swirl chamber.
The liquid in the swirl chamber does not flow out through the shaft hole of the rotating shaft or enter the mechanical parts such as the motor M, which has an excellent effect of preventing corrosion of seal packing and various parts. You can get a rigid centrifugal pump with.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is a partially vertical side view, FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a vertical side view of the seal opening/closing device. ,
4 is a cross-sectional view taken along line BB in FIG. 3, FIG. 5 is a vertical side view of the pump in a stopped state, and FIG. 6 is a vertical side view of the pump in an operating state. 1... Rigid centrifugal pump, 2... Centrifugal pump body, 3
...Upper casing, 4...Lower casing, 5...Rotating shaft, 6...Switching device, 7...Upper case, 8...Lower case, 9...Space, 10...Sliding ring, 11...Outer ring, 12...Inner ring, 14 , 26...Guide pin, 15...Spring, 16...Boss, 18...
Upper partition wall, 18a...Shaft hole, 19...Seal packing, 19a...Rip portion, 20...Lower partition wall, 2
0a...Shaft hole, 21...Disk, 22...Seal blade, 23...Main blade, 27...Weight collar, 27
c...groove, 28...seal opening/closing pin, 28a...head,
30...Vortex chamber, a...Air chamber.

Claims (1)

[Claims] 1. A disk is attached to the end of a rotating shaft connected to the output shaft of the drive body and located in the volute chamber through a shaft hole formed in the volute chamber partition wall,
A sealing blade close to the swirl chamber partition wall is provided on one side of the disc, a main blade for pumping liquid is arranged on the other side, and a lip portion is provided in the middle of the rotating shaft and is arranged around the rotating shaft. A seal packing is provided, and a sliding ring is provided that presses the lip portion with the restoring force of a spring to close the gap between the rotating shaft and the lip portion. In a vertical centrifugal pump equipped with an opening/closing device that opens the gap by moving it using the centrifugal force of A vertical centrifugal pump, characterized in that it can be introduced and communicates with a shaft hole formed in the swirl chamber.