JP2616238B2 - Water ring vacuum pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water ring type vacuum pump, and more particularly, to preventing air leakage between blades passing through a gap between both side surfaces of a pump chamber and both side surfaces of an impeller. And a water ring vacuum pump.

[0002]

2. Description of the Related Art As is well known, by rotating a liquid (for example, water) in a pump chamber by an impeller, a gas (for example, air) is sucked and discharged as the liquid moves in a radial direction of the impeller. A water-sealed vacuum pump is known, and a plurality of these pumps are used, and the exhaust port of the first-stage pump communicates with the intake port of the second-stage pump to obtain a higher degree of vacuum than that of the single-stage pump. Various two-stage water-sealed vacuum pumps have been proposed.

As shown in FIG. 9, the water supply of a water-sealed vacuum pump of this type is supplied from a water supply port 21 to a pump chamber 22.
In general, as shown by an arrow, a structure in which the gas flows from a gap between both sides of the impeller 23 and both sides of the pump chamber 22 is generally used. By the way, in this conventional water supply structure, if the gap between both sides of the pump chamber 22 and both sides of the impeller 23 is large, the pump performance tends to be deteriorated. Is small, the sealing between the both sides of the pump chamber 22 and both sides of the impeller 23 by the water sealing is insufficient, and the pump performance is reduced. Note that if the supply of the sealed water is changed from the water supply port 21 to the intake port 24 (water is supplied into the intake pipe), the water supply self-priming property is improved, but in this case, both sides of the pump chamber 22 and both sides of the impeller 23 are provided. Since no sealing can be performed between the surface and the surface by water sealing, internal leakage of air is remarkable and pump performance is reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to prevent air from leaking through a gap between both side surfaces of a pump chamber and both side surfaces of an impeller.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a pump chamber formed between a first casing and a second casing. In a water-sealed vacuum pump provided with an impeller rotatably provided with the blades described above, a partition plate is integrally provided on one side of the impeller, and water is moved to a peripheral wall of the pump chamber on the other side of the impeller. the a Ru water passage which is refluxed to the center of the pump chamber is provided, into the center of the pump chamber
The recirculated water is sealed between the inner surface of the pump chamber and the impeller.
It is characterized in that it is configured to flow into a gap between the outer side surface .

[0006]

[Function] Since the sealed water rotates together with the impeller with a substantially constant thickness in the pump chamber, the pressure of the peripheral wall of the pump chamber becomes higher than the pressure of the central part due to the centrifugal force, and a part of the sealed water is caused by the pressure difference. Flows back from the peripheral wall of the pump chamber to the center through the water passage. The recirculated water seal becomes a thin film between the adjacent blades of the impeller and seals the end surfaces of the blades, so that air leakage from the gap between the blade side surface and the pump chamber side surface is prevented. Further, since one side surface of the impeller is partitioned by a partition plate formed integrally with the blades of the impeller, no air leaks.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the water ring vacuum pump includes a pump unit P and a bearing unit 4. The pump section P is configured to take in air from one side and exhaust in the same direction,
The pump unit P includes a first casing 1 and a second casing 2, and is connected to the bearing unit 4 by bolts 9.

The first casing 1 and the second casing 2
Is formed between the pump chamber 3 and the pump chamber 3.
Is provided with an impeller 6 rotatably. The impeller 6 is fixed to the rotating shaft 8 with a C-shaped retaining ring via a key and a spring. A bearing for rotatably supporting the rotating shaft 8 and a drive motor (not shown) are arranged in the bearing 4.

As shown in FIGS. 1 and 2, the first casing 1 is substantially disc-shaped and has a blind hole 1 at the center pump chamber 3 side.
comprising a a, the obliquely under side of blind hole 1a formed so as to communicate with the intake ports 1c an inlet 1b (supply air and water),
Towards the oblique blind hole 1a is formed so as to communicate with an exhaust port 1d to the exhaust port 1e. Further, between the side surface facing the pump chamber 3 and the blind hole 1a, a water passage 1f communicating the peripheral wall portion and the central portion of the pump chamber 3 is formed.

As shown in FIGS. 1 and 3, the second casing 2 has a substantially disk-shaped mechanical seal box 2a for accommodating a mechanical seal 5 at the center thereof, and a mouth ring 7 is provided between the second casing 2 and the impeller 6. The space 2b is formed. A pump chamber 3 eccentric from the center by a predetermined amount is formed on a side surface facing the first casing 1.

The impeller 6 according to the present invention is shown in FIGS.
As shown in FIG. 5, the blade 6a is composed of a plurality of blades 6a arranged substantially radially, and a partition plate 6b integrated with the blade side surface is provided on one of the blade side surfaces of the blade 6a. A hole 6 d for the rotating shaft 8 is provided at the center of the boss 6 c.
And a plurality of water passage holes 6e are formed therearound. Arrows in the drawing indicate the rotation direction of the impeller 6 and 3a indicates the inner peripheral wall of the pump chamber 3.

Next, the operation and operation of the water ring type pump will be described. When water and air are supplied from the intake port 1b and the impeller 6 is rotated by rotating the rotating shaft 8 by a motor (not shown), the water in the pump chamber 3 flows along the inner peripheral wall of the pump chamber and forms an annular shape. Orbit. Since the center of the impeller 6 is eccentric with respect to the center of the pump chamber 3, a crescent-shaped space is formed between the boss surface of the impeller and the water surface, and the space between the impeller blades and the water surface is the impeller. The air is sucked and discharged by expanding and contracting by the rotation of.

On the other hand, the flow of air will be described.
Air from b is drawn into the pump chamber 3 from the intake port 1c. The air discharged from the pump chamber 3 is supplied from an exhaust port 1 e formed on the inner surface of the first casing 1 to an exhaust port 1.
It will be discharged outside through d.

The function of preventing air leakage according to the present invention will be described. As shown in FIGS. 6 and 7, the water sealed in the pump chamber 3 rotates together with the impeller 6 with a substantially constant thickness. As a result, the pressure at the peripheral wall of the pump chamber becomes higher than the pressure at the center, and a part of the sealed water flows through the water passage 1f formed in the first casing 1 toward the stop hole 1a due to the pressure difference. Since the blind hole 1a is open toward the side surface of the impeller 6, the water sealing flows radially through the gap 3b between the side surface of the impeller 6 and the side surface of the pump chamber 3, and the water seals on the side wall surface of the pump chamber 3. Is formed. The thin film of water is scraped up by the side surface of the blade 6a of the impeller 6, and water flows up to the front end thereof, so that air can be prevented from leaking from the side end of the blade 6a. On the other hand, one side surface of the impeller 6 is partitioned by the partition plate 6b, so that no air leaks.

FIG. 8 shows an embodiment in place of the above embodiment, and is suitable for application when the first casing 1 is manufactured by resin molding or the like. A partition member 10 is interposed between the pump chamber 3 and the first casing 1. A passage 10a is provided in the partition member 10 so as to communicate with the peripheral wall of the pump chamber 3, and a groove-shaped water passage 1f is formed on a side surface of the first casing 1 facing the passage 10a.
Is formed. If the water passage 1f is formed at the same time when the first casing 1 is formed, the processing of the water passage 1f becomes unnecessary. The other configurations and operations are the same as those of the above-described embodiment, and thus the description thereof is omitted.

[0016]

As described above, the present invention has the following advantages. Since a partition plate is provided on one side of the impeller, there is no air leakage from this one side, and a water passage is provided on the other side to communicate the peripheral wall of the pump chamber with the center. The high-pressure sealed water in the peripheral wall of the pump chamber is once returned to the center of the pump chamber, and then returned to the gap between the side face of the pump chamber and the impeller blade side face, thereby preventing air leakage from this gap. Can be prevented.
As described above, since the air leakage from both side surfaces of the pump chamber is prevented, the pump performance can be further improved.
Further, since the sealed water is circulated and used, water can be saved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water ring vacuum pump to which the present invention is applied.

FIG. 2 is a front view of a first casing of FIG. 1;

FIG. 3 is a front view of a second casing of FIG. 1;

FIG. 4 is a front view of the impeller of FIG. 1;

FIG. 5 is a perspective view of the impeller of FIG. 4;

FIG. 6 is an explanatory diagram showing a relationship between the pump chamber of FIG. 1, an impeller during rotation, and water sealing.

FIG. 7 is an enlarged partial cross-sectional view showing a gap between both side surfaces of a pump chamber and both side surfaces of an impeller in FIG. 1;

8 is a cross-sectional view of a water-sealed vacuum pump showing an embodiment that is an alternative to the water-sealed vacuum pump of FIG.

FIG. 9 is a cross-sectional view of a conventional water ring vacuum pump.

[Explanation of symbols]

Reference Signs List 1 first casing 1a blind hole 1f water passage 2 second casing 3b gap 6 impeller 6a blade 6b partition plate

Claims (1)

(57) [Claims] 1. A water seal type wherein a pump chamber 3 is formed between a first casing 1 and a second casing 2, and an impeller 6 having a plurality of blades 6a is rotatably provided in the pump chamber 3.
In the vacuum pump, a partition plate 6 b is integrally provided on one side of the impeller 6, and the sealed water moved to the peripheral wall of the pump chamber 3 is returned to the center of the pump chamber 3 on the other side of the impeller 6. Water passage 1f is provided , and the pump chamber 3
The sealed water refluxed to the central part is
Configuration to flow into gap 3b between outer surface of impeller 6
Water ring vacuum pump, characterized in that the the.