JPH07180690A - Leakless pump - Google Patents

Abstract

PURPOSE:To simplify recycle passages and circulate a transfer fluid in cycle the re f4' passages with high force-feeding force and moreover enable transfer regardless of the sort and property of the transfer fluid by providing a guide vane at the end face of a rotor on the opposite side to an impeller. CONSTITUTION:An intake port 14 and a discharge port 15 are provided, and a can 11 formed of a bottomed cylindrical body is placed at a casing 10 to form a pump chamber 16. A main shaft 8 is erected in the pump chamber 16. A rotor 2 provided with driven magnets 5 is rotatably fitted to the outside of the main shaft 8. The tip part of this rotor 2 is formed of an impeller 3, and a guide vane 20 is provided at the end face of the rotor 2 on the opposite side to the impeller 3. Part of a fluid from the intake port 14 is sucked by rotating the rotor 2, circulated in reflux passages formed between the main shaft 8 and rotor 2 and between the rotor 2 and can 11, and discharged from the discharge port 15. The force-feeding force of the transfer fluid need not therefore depend on the discharge pressure of the rotor 2, so that the reflux passages can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak-free pump most suitable for the transfer of slurry liquids and corrosive liquids.

[0002]

2. Description of the Related Art Conventionally, a leak-free leak-free pump has been used in the chemical industry that handles fluids such as slurry liquid and corrosive liquid, and the petrochemical industry where there is a risk of ignition due to leakage. ing.

The leak-free pump has a casing 10 having a suction port 14 and a discharge port 15 as shown in FIG.
A main shaft 8 is horizontally arranged in a pump chamber 16 formed by a can 11 having a bottomed tubular body, and an impeller 3 and a sleeve 4 are integrally formed on the main shaft 8, and an outer periphery of the sleeve 4 is formed. A rotor 2 provided with a driven magnet 5 is rotatably supported via two underwater bearings 7a and 7b, and fixed bearings 9a and 9b are arranged in front of and behind the rotor 2 to restrict movement in a thrust direction. It is supposed to do. Further, on the outer periphery of the can 11, a cylindrical body 12 having a drive magnet 13 in an inner hole is arranged in an externally fitted shape, and the cylindrical body 12 is connected to an electric motor (not shown), When the electric motor is started and the drive magnet 13 is rotated, the driven magnet 5 included in the rotor 2 is magnetically coupled with the drive magnet 13 to rotate the rotor 2, and the fluid is transferred from the suction port 14 to the discharge port 15. It was like this.

Further, the casing 1 of the leak-free pump 50 described above.
At 0, an inner hole 40 communicating with the discharge port 15 is bored, and the inner hole 40 further communicates with the hollow hole 41 of the main shaft 8,
A part of the transfer fluid sent to the discharge port 15 is part of the inner hole 4
It is taken from 0 to the hollow hole 41 and supplied to the grooves 42a and 42b formed in the submersible bearings 7a and 7b, respectively. Then, the groove 42a is directly connected to the intake port 14, and the groove 42b is composed of the rotor 2 and the can 11. Pass through the passages 43a and 43b,
A return passage is provided for discharging each from a discharge hole 17 formed in the impeller 3 to the suction port 14, and continuously supplies a transfer fluid to the submersible bearings 7a and 7b so as to have a cooling and lubricating function. 62-37992, Japanese Patent Publication No. 1-144439).

[0005]

However, since the leak-free pump 50 supplies the transfer fluid to the submersible bearings 7a and 7b, the hollow hole communicating with the inner hole 40 in the casing 10 and the inner hole 40 in the main shaft 8 is provided. Each of the holes 41 is formed, and the discharge hole 17 is also formed in the impeller 3, so that the reflux passage for supplying the transfer fluid to the submersible bearings 7a and 7b is very complicated. Moreover, it has been difficult to further reduce the size of the pump 50 due to the complexity of the reflux passage.

Further, the transfer fluid is pumped to the return passage by the discharge pressure accompanying the rotation of the rotor 2. However, since the return passage is complicated, the pumping force is weakened midway, and the underwater bearing 7a is used. , 7b could not be supplied with sufficient transfer fluid. Therefore, the underwater bearing 7
Since a and 7b were easily worn, they had to be replaced in a short period of time.

Further, when the transfer fluid is a high-concentration slurry liquid having a slurry concentration of 10% by weight or more, there are the following problems, and the leak-free pump 50 cannot be used to transfer the slurry liquid.

That is, the passages 43a and 43b forming the return passages.
The grooves 42a and 42b of the submersible bearings 7a and 7b, the inner hole 40 of the casing 10 and the hollow hole 41 of the main shaft 8 are very narrow, and the pumping force weakens in the middle, so the slurry liquid is clogged. There is a problem that the submerged bearings 7a and 7b are worn early.

Moreover, since the slurry liquid has a large specific gravity and easily solidifies, when the pump is stopped, the slurry liquid accumulates in the reflux passage, and if left undisturbed, it solidifies to block the passage, or worse, rotate the rotor 2. However, there was a problem that the pump function could not be fulfilled.

An object of the present invention is to provide a leak-free pump which can be transferred regardless of the type or property of the transferred fluid.

[0011]

In view of the above problems, therefore, in the present invention, a main shaft is erected in a pump chamber formed by a casing having a suction port and a discharge port, and a can having a bottomed cylindrical body. Rotating the rotor by externally rotatably fitting a rotor having a driven magnet on the main shaft and having an impeller at the tip, and providing guide vanes on the end surface of the rotor opposite to the impeller to rotate the rotor. Thus, a part of the fluid from the suction port is sucked, circulated in the recirculation passage formed between the main shaft and the rotor and between the rotor and the can, and discharged from the discharge port.

[0012]

According to the present invention, since the rotor is arranged in the vertical direction, when the rotor is rotated, the self-supporting force is exerted and the rotor can be supported by one submerged bearing.

Further, since the recirculation passages formed by the rotor and the can and the rotor and the main shaft are formed in the vertical direction, the transfer fluid flowing in these recirculation passages is respectively delivered to the suction port and the discharge port by its own weight. Even if the pump is stopped and the pump is stopped, the transfer fluid does not accumulate in the reflux passage.

Further, according to the present invention, since the guide vanes are provided on the end surface of the rotor on the side opposite to the impeller, when the rotor is rotated, a suction action works in the recirculation passage to forcibly circulate the transfer fluid. Can be made.

[0015]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a leak-free pump 1 according to an embodiment of the present invention.
FIG. However, the same parts as those of the conventional example are indicated by the same reference numerals.

As shown in FIG. 1, a leak-free pump 1 according to the present invention comprises a suction port 14 and a discharge port 15, and the suction port 1 described above.
A can 11 having a cylindrical body with a bottom is placed on a casing 10 in which a boss 10a is arranged at the center of the pump chamber 16 to form a pump chamber 16, and a main shaft 8 is erected at the center of the pump chamber 16. The upper end of the main shaft 8 is press-fitted into the bottom portion 11a of the can 11, and the lower end is fitted and fixed in a fixed bearing 9 provided on the boss 10a of the casing 10.

An impeller 3 and a sleeve 4 are integrally formed on the main shaft 8, a driven magnet 5 is provided on the outer circumference of the sleeve 4, and a cylinder is provided on the outer circumference of the sleeve 4 so as to surround the driven magnet 5. A rotor 2 having a body 6 fitted therein and having a guide vane 20 on an end surface formed by the sleeve 4 and the tubular body 6 is provided on a side of an impeller 3 of a through hole 2a formed in a central portion of the rotor 2. The rotor 2 is externally fitted through the submerged bearing 7 which is fitted therein, and the rotor 2 is supported by the fixed bearing 9 of the boss 10a. The force acting in the horizontal direction of the rotor 2 is regulated by the submerged bearing 7, and the vertical direction is controlled. Force acting on the fixed bearing 9
It is regulated by. The rotor 2 is attached to the main shaft 8
The impeller 3 forming the tip portion of the rotor 2 is arranged so as to face the suction port 14 of the casing 10 when it is externally fitted.

Further, a cylindrical body 12 having a drive magnet 13 in its inner hole is fitted around the outer periphery of the can 11, and the drive magnet 13 of the cylindrical body 12 and the driven magnet 5 of the rotor 2 are opposed to each other. The cylindrical body 12 is attached to a rotating shaft of an electric motor (not shown).

When the electric motor is started and the drive magnet 13 is rotated, the driven magnet 5 provided in the rotor 2 receives the magnetic coupling effect to rotate the rotor 2.
The blades 3a provided on the impeller 3 are swirled, and the transfer fluid is sucked from the suction port 14 and pressure-fed to the discharge port 15. Further, as the rotor 2 rotates, the guide blade 20 formed on the end surface on the side opposite to the impeller 3 also swirls, so that part of the transferred fluid is penetrated from the suction port 14 to the fixed bearing 9 and the through hole 4 is formed.
5 and the groove 42 formed in the submersible bearing 7, respectively, and then the passage 44 formed by the rotor 2 and the main shaft 8 and the passages 43a, 43b formed by the rotor 2 and the can 11.
It is configured to be forcibly discharged to the discharge port 15 through.

Thus, the leak-free pump 1 according to the present invention
On the end surface of the rotor 2 on the side opposite to the impeller 3
By providing the above, the suction action can be generated in the recirculation passage at the same time as the rotation of the rotor 2, and sufficient pumping force can be obtained. Therefore, it is not necessary to rely on the discharge pressure of the rotor 2 for the pumping force of the transferred fluid, so that the recirculation passage can be simplified and sufficient transferred fluid can be supplied to the submersible bearing 7 and the fixed bearing 9. Since it can be used, it can be used for its original life. Moreover, since a large pressure-feeding force can be obtained, even if the transfer fluid is a fluid having a large specific gravity such as a slurry liquid, the reflux passage is not clogged.

Further, since the leak-free pump 1 according to the present invention has a structure in which the rotor 2 is arranged in the vertical direction, an underwater bearing 7 and a fixed bearing 9 for supporting the rotation of the rotor 2 are provided on the impeller 3 side of the rotor 2. It is sufficient to provide only one, and the structure can be simpler. Moreover, when the rotor 2 rotates, the blades 3a provided in the impeller 3 swivel to generate a lift force, and a self-supporting force acts on the rotor 2. Therefore, it is possible to reduce wear caused by sliding of the submerged bearing 7 and the fixed bearing 9.

Further, the passage 43 forming a part of the return passage.
Since a, 43b, 44 are formed in the vertical direction, the transfer fluid flowing in these passages 43a, 43b, 44 can be discharged to the discharge port 15 by its own weight,
Even if the pump 1 is stopped, the transfer fluid does not accumulate in the passages 43a, 43b, 44.

In the leak-free pump 1 according to the present invention,
Although the air may accumulate in the passage 43a when the pump 1 is stopped by arranging the rotor 2 in the vertical direction, the guide vanes 20 of the rotor 2 force the air accumulated in the passage 43a simultaneously with the rotation of the rotor 2. Can be discharged.

By the way, the leak-free pump 1 according to the present invention
Is a casing 10, a boss 10a, a can 11, which comes into contact with a fluid so that the fluid can be used even if the fluid is a corrosive liquid.
The impeller 3, the sleeve 4, the tubular body 6, the main shaft 8, the underwater bearing 7, and the fixed bearing 9 are all formed of ceramics such as alumina, zirconia, or silicon nitride.

That is, since these ceramics are excellent in corrosion resistance and are non-magnetic materials, they are not corroded even if they are in contact with a corrosive liquid for a long period of time, and the driven magnet 5 and the drive magnet 13 are not damaged. There is no adverse effect on the magnetic force generated during.

However, it is preferable that the underwater bearing 7 and the fixed bearing 9 which are required to have slidability and wear resistance are formed of silicon carbide or silicon nitride.

The member which comes into contact with the transfer fluid may be a corrosion-resistant alloy material, a corrosion-resistant resin such as an epoxy resin or a fluorine resin, or a metal surface coated with a corrosion-resistant resin. The pump 1 may be formed of a combination of these materials and ceramics.

Next, the guide vanes 20 formed on the rotor 2 will be described in detail.

2 (a) and 2 (b) are a rear view and a side view of the rotor 2 shown in FIG. 1, with eight plate-like bodies 21 and 22 on the rear end surface of the sleeve 4 and the tubular body 6, respectively. Are radially formed in a standing state, and when the tubular body 6 is fitted on the sleeve 4, the plate-shaped bodies 21 and 22 are aligned in a straight line and integrated to form the guide blade 20. To do.

In FIG. 2, eight guide blades 2 are provided.
Although the rotor 2 having 0 is shown, it is not limited to this, and if the rotor 2 is provided with at least one guide blade 20, a sufficient suction action can be obtained. However, rotor 2
For more stable rotation, it is desirable to provide two or more guide vanes 20 and arrange them at equal intervals.

By the way, the height h of the guide blade 20 is
It is preferable to provide in the range of 1 to 5 mm, and if the height h is in this range, a sufficient suction action can be obtained.

That is, when the height h of the guide vanes 20 is less than 1 mm, even if the rotor 2 rotates, a negative pressure cannot be generated in the passage 43a and a sufficient suction action cannot be obtained. On the contrary, if the height h of the guide vanes 20 is larger than 5 mm, the pump 1 itself becomes large and an extra load is applied to the electric motor.

Further, the thickness width w of the guide blade 20 is 1 mm or more when the guide blade 20 is made of metal or resin, and is 3 mm or more when it is made of ceramics in terms of strength. there is no problem.

However, in the ceramic guide vane 20, it is preferable to form the edge portions 20a and 20b into a curved surface of 0.5R or more in order to prevent chipping or cracking of the inlet / outlet portion due to collision with a fluid.

Further, in the rotor 2 shown in FIG. 2, eight guide blades 23 are radially provided on the back surface of the impeller 3 as well, so that the suction action is further enhanced. However, if the guide blade 23 is made of ceramics, the edge portion 23a of the outlet portion is formed into a curved surface of 0.5R or more like the guide blade 20 to prevent the occurrence of chipping or cracking. The number of guide blades 23 formed on the back surface of the impeller 3 does not have to be the same as the number of guide blades 20 formed on the rear end surface of the rotor 2, and may be appropriately provided as necessary.

The guide vane 20 shown in FIG. 2 is of a split type in which the plate-like bodies 21 and 22 are formed on the sleeve 4 and the tubular body 6, respectively, but the plate-like body 2 is formed on the rear end surface of the tubular body 6.
It is also possible to form a guide vane 20 in which 1 and the plate-like body 22 are integrated and to fit the tubular body 6 on the sleeve 4. Further, only one of the sleeve 4 and the tubular body 6 is provided with a plate. The guide blades 20 may be formed by forming the bodies 21 and 22.

Next, another embodiment of the guide vanes 20 formed on the rotor 2 will be described.

3 (a) and 3 (b) are a rear view and a side view of the rotor 2 having another guide blade 20, respectively.
0 is formed in a spiral shape in the direction opposite to the rotation direction of the rotor 2 indicated by the arrow. A spiral guide vane 23 is also formed on the back surface of the impeller 3. The guide blade 20
The height h and the thickness width w of the guide blade 23 and the edge portions 20a, 20b and 23a of the entrance and exit are formed in the same range as the guide blade 20 and the guide blade 23 shown in FIG.

By thus forming the guide blades 20 and 23 in a spiral shape, the shock due to the collision with the fluid can be absorbed and the fluid can be smoothly guided in the outer peripheral direction, so that the vibration of the rotor 2 can be further suppressed. be able to.

Furthermore, another leak-free pump 1 according to the embodiment of the present invention is shown in FIG. The structure is the same as that of FIG. 1 except for the rotor 2 and the can 11, and thus the description thereof is omitted.

In FIG. 4, the rear edge portion of the rotor 2 of FIG. 1 is formed in a large taper shape, and the straight guide vane 20 is formed in this taper portion. Also, can 11
The bottom surface 11a is also formed in a taper shape having the same angle as the taper portion of the rotor 2.

By tapering the rear end of the rotor 2 in this manner, the guide action of the fluid by the guide vanes 20 and the flow action by the weight of the fluid are obtained, so that the transferred fluid can be discharged more smoothly. Is. Moreover, when the pump 1 is stopped, the transfer fluid in the passage 43a is discharged to the discharge port 15 through the passage 43b by its own weight, so that the transfer fluid does not accumulate in the passage 43a.

Experimental Example Here, a leak-free pump 1 shown in FIG. 1 was prototyped and a transfer test was conducted using a slurry liquid as a transfer fluid.

As the above slurry liquid, silica sand slurry having a slurry concentration of 5% by weight, 20% by weight and 35% by weight was used, and the operating conditions were a suction port diameter of 80 mm, a maximum lift of 55 m, a flow rate of 1000 liter / min, and a rotation speed of 3500 rpm. Fifty
When a 0-hour transfer test was performed, even if the transfer fluid was a slurry liquid having a slurry concentration of 35% by weight, the reflux passage was not clogged, and no abnormality was observed even after 500 hours of operation.

[0046]

As described above, in the leak-free pump according to the present invention, the main shaft is erected in the pump chamber formed by the casing having the suction port and the discharge port and the can having the bottomed cylindrical body,
The main shaft is provided with a driven magnet and a rotor having an impeller at its tip is rotatably fitted to form a leak-free pump, and a guide vane is provided on the end surface of the rotor on the side opposite to the impeller. Since the passage can be simplified and the transfer fluid can be circulated in the reflux passage with high pumping force, even if the transfer fluid is a high-concentration slurry liquid, it can be clogged or accumulated in the reflux passage of the pump. Since it is possible to always supply sufficient transfer fluid to the submerged bearing and the fixed bearing that support the rotation of the rotor, it is possible to prevent early wear of the bearing.

Therefore, if the leak-free pump according to the present invention is used, it is possible to transfer a high-concentration slurry liquid regardless of the kind of the transfer fluid, and
A stable fluid transfer is possible over a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a leak-free pump according to the present invention.

FIG. 2 (a) is a back view showing a rotor of a leak-free pump according to the present invention, and FIG. 2 (b) is a side view thereof.

3A is a back view showing another rotor of the leak-free pump according to the present invention, and FIG. 3B is a side view thereof.

FIG. 4 is a vertical cross-sectional view showing another leak-free pump according to the present invention.

FIG. 5 is a vertical cross-sectional view showing a conventional leak-free pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leak-free pump 2 Rotor 3 Impeller 4 Sleeve 5 Driven magnet 6 Cylindrical body 7 Underwater bearing 8 Main shaft 9 Fixed bearing 10 Caging 11 Can 12 12 Cylindrical body 13 Drive magnet 20 Guide vanes 43a, 43b, 44 Passage

Claims (1)

[Claims] 1. A main shaft is erected in a pump chamber formed by a casing having a suction port and a discharge port, and a can having a bottomed cylindrical body, and the main shaft is provided with a driven magnet and an end portion is an impeller. A leak-free pump in which a rotor is rotatably fitted to the outside and magnetically rotates the rotor by rotating a drive magnet arranged to face the driven magnet to suck fluid from the suction port to the discharge port. And a guide vane is provided on the end surface of the rotor opposite to the impeller, and the rotor is rotated so that a part of the fluid from the suction port is formed between the main shaft and the rotor and between the rotor and the can. A leak-free pump characterized in that it is circulated inside and discharged from a discharge port.