JPH07139491A - Magnet driven pump - Google Patents

Abstract

PURPOSE:To provide a magnet driven pump which can perform the excellent and stable pumping function over a long period irrespective of the conditions of use such as the property of the liquid to be pumped. CONSTITUTION:In a magnet driven pump, an impeller shaft 4 mounted on a pump part 1 is interlockingly connected to a driving shaft 5 mounted on a driving part 2 through the magnetic effect between a magnet 8 on the impeller shaft side and a magnet 9 on the driving shaft side which are opposite to each other across a circumferential wall 7a of a can 7 mounted on a casing 3 of the pump part 1. The can 7 is formed into a bottomed cylindrical shape of ceramics such as SiC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet drive pump designed to completely prevent liquid leakage from a pump section, and more specifically, to an impeller shaft provided in the pump section. A magnet drive in which the drive shaft provided in the drive unit is interlocked and coupled by the magnetic force action of the impeller shaft side magnet and the drive shaft side magnet that face each other with the peripheral wall of the bottomed cylindrical can attached to the pump casing. It is about pumps.

[0002]

2. Description of the Related Art In a magnet drive pump, an impeller shaft is installed inside a casing of a pump unit and a cylindrical can having a bottom which is concentrically attached to the casing of the pump unit to completely shield the pump unit from the outside world. The impeller shaft and the drive shaft provided in the drive unit with their axes aligned with each other are interlocked by the magnetic force between the impeller shaft side magnet and the drive shaft side magnet, which are provided opposite to each other with the circumferential wall of the can interposed therebetween. In this way, it has a completely leak-free structure devised to completely prevent liquid leakage from the bearing part of the impeller shaft, and it is used in various fields where pump liquid leakage is disliked, for example, in the chemical industry dealing with corrosive liquids. It is preferably used in fields such as the semiconductor industry where chemicals are treated.

In the conventional magnet drive pump, since the corrosive liquid or the chemical liquid as described above is handled,
As a constituent material of the can, it is common to use a metal such as stainless steel having excellent corrosion resistance or a plastic such as polypropylene or fluororesin.

[0004]

However, when a metal can is used, the magnetic force is easily absorbed, so that the efficiency of power transmission from the drive shaft to the impeller shaft is low and output loss is likely to occur. is there. Further, in the magnet driven pump, a part of the pump liquid is forcedly circulated between the pump chamber and the can in order to lubricate the bearing portion of the impeller shaft, but When the pump liquid is made of metal, the can portion between the magnets generates heat. Therefore, when the pump liquid is a low boiling point liquid such as ammonia liquid, the heat generated by the can causes the pump liquid to vaporize,
Pump capacity is reduced. Therefore, depending on the properties of the pump liquid, there is a possibility that a good pump function may not be exhibited.

On the other hand, a plastic can has a problem in durability and cannot exhibit a stable pump function for a long period of time. That is, when the high temperature liquid or the slurry liquid containing a solid substance is handled, the can may be thermally deformed or worn in combination with the forced circulation of a part of the pump liquid as described above. . In addition, it has a low pressure resistance and is difficult to apply to high-pressure pumps.

The present invention has been made in view of the above points, and provides a good and stable pump function for a long period of time without causing an output loss, regardless of the pump use conditions such as the properties of the pump liquid. It is an object of the present invention to provide a magnet-driven pump that can be demonstrated.

[0007]

In the magnet drive pump of the present invention which solves this problem, it is particularly proposed that the can is made of ceramics.

[0008]

[Function] Since the ceramic can is superior in wear resistance, heat resistance and pressure resistance to the plastic can, it does not cause thermal deformation or wear unlike the plastic can. It can also be applied to high-pressure pumps. Further, unlike a metal can, it does not absorb the magnetic force and does not cause output loss. Furthermore, unlike a metal can, there is no danger of heat generation, and even when the pump liquid is a low boiling point liquid, the pump liquid does not vaporize and the pumping capacity does not decrease. Therefore, a good and stable pump function can be exerted for a long period of time regardless of the use conditions such as the properties of the pump liquid and the pump pressure.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be specifically described below with reference to the embodiments shown in FIGS.

As shown in FIG. 1, the magnet drive pump of this embodiment has a pump portion 1 having the same pump structure as that of a centrifugal pump, including a pump chamber 3a and an impeller 4a installed therein, and an impeller 4a with an axis. The drive shaft 5 that is aligned with the rotation axis of the appropriate drive system (drive motor, etc.)
And a drive unit 2 configured to be rotationally driven by.

An impeller shaft 4 having an impeller 4a mounted on a casing 3 of the pump portion 1 is rotatably supported by a bearing 6.
In addition, a bottomed cylindrical can 7 for concentrically covering the impeller shaft portion protruding from the casing 3 including the bearing portion 6 is attached, and the pump portion 1 is surrounded by the casing 3 and the can 7. It has a completely leak-free structure that is cut off from. A suction port 3b and a discharge port 3c communicating with the pump chamber 3a are formed in the casing 3. Further, the casing 3 is formed with a plurality of circulation passages 3d ... Which connect the impeller back surface region and the can inner region in the pump chamber 3a to force pump liquid between the pump chamber 3a and the can 7. Bearings 6
It has been devised so that it can be lubricated.

As shown in FIG. 1, the impeller shaft 4 and the drive shaft 5 are interlockingly connected by the magnetic force action of the impeller shaft side magnet 8 and the drive shaft side magnet 9 which face each other with the peripheral wall 7a of the can 7 interposed therebetween. .

That is, a disc body 10 concentric with the can 7 is attached to the impeller shaft portion in the can 7, and the outer periphery of the disc body 10 is provided over the entire circumference or substantially the entire circumference thereof. The impeller shaft side magnet 8 which is a permanent magnet is attached with a very small fixed gap between the can peripheral wall 7a and the inner peripheral surface of the can peripheral wall 7a. Also, the drive shaft 5
A bottomed cylindrical body 11 concentrically crowning the can 7 is attached to the can side portion of the can, and the inner peripheral part of the cylindrical body 11 is provided with a can. Perimeter wall 7
The drive shaft side magnet 9, which is a permanent magnet, is attached in a state where there is a very small constant gap between the outer peripheral surface of a and the magnet 8 and is directly opposed to the impeller shaft side magnet 8. By driving the shaft 5, the magnet 9 is revolved along the can peripheral wall 7a. Therefore, when the drive shaft 5 is driven, the magnetic force of both magnets 8 and 9 causes the impeller shaft-side magnet 8 to follow the drive shaft-side magnet 9 and revolve along the can peripheral wall 7a, so that the impeller shaft 4 is driven. It is made to rotate synchronizing with 5.

The can 7 is made of ceramics according to the present invention, but in this embodiment, among the ceramics, SiC (β-type Si) which is particularly excellent in thermal shock resistance is used.
It is molded in C), and its mounting structure to the pump casing 11 is configured as follows.

That is, as shown in FIGS. 1 and 2, the can 7 has a bottomed end in which an annular flange portion 7b is projectingly formed at an opening end portion and an annular mating portion 7c is bulged in the vicinity thereof. It is shaped like a cylinder. As shown in FIG. 2, the collar portion 7b has a trapezoidal cross section that gradually becomes thicker in the inner diameter direction. The joint portion 7d to the outer peripheral surface of the can peripheral wall 7a has an arc shape, and the collar portion 7b will be described later. As described above, it is devised to reduce the stress concentration when tightened in the casing 3 and prevent the occurrence of cracks as much as possible. By the way, the thickness of the can peripheral wall 7a is appropriately set on the condition that sufficient strength can be ensured against the internal pressure acting on the can 7 and the magnetic action between the magnets 8 and 9 can be appropriately maintained. Specifically, it is preferably 1 to 15 mm (more preferably 5 to 10 mm), and in this embodiment, it is set to 6 mm. Since the can 7 made of SiC has excellent wear resistance, heat resistance, and pressure resistance as compared with a plastic material, it causes thermal deformation and wear like a plastic can. It can also be applied to high-pressure pumps. Further, unlike a metal can, it does not absorb the magnetic force and does not cause output loss. Furthermore, unlike a metal can, there is no danger of heat generation, and even when the pump liquid is a low boiling point liquid, the pump liquid does not vaporize and the pumping capacity does not decrease. Therefore, a good and stable pump function can be exerted for a long period of time regardless of the use conditions such as the properties of the pump liquid and the pump pressure.

As shown in FIGS. 1 and 2, the can 7 has a metal mounting ring 12 shrink-fitted to the fitted portion 7c and a resin between the mounting ring 12 and the collar portion 7b. The material 13 is injected and filled, and then the mounting ring 12 is mounted on the pump casing 3 by tightening the mounting ring 12 on the pump casing 11 with a plurality of square hole bolts 14.

That is, the mounting ring 12 has an L-shaped cross section, which is composed of a thick-walled main body portion 12a having a bolt insertion hole 12c and a thin-walled fitting portion 12b connected to the inner peripheral portion thereof. When the fitting portion 12b is shrink-fitted to the fitted portion 7c, the main body portion 12a, the fitting portion 12b, and the flange portion 7b
The filling space 15 for the resin material 13 is surrounded by and the can 7 including the end face of the main body 12a and the flange 7a is formed.
And the end surface 7e of the same are flush with each other. Further, the inner diameter of the main body portion 12a is set to be slightly larger than the outer diameter of the flange portion 7b, and when the fitting portion 12b is shrink-fitted to the fitted portion 7c, it is between the main body portion 12a and the flange portion 7b. It is devised so that the annular resin material injection port 16 is formed. By the way, when there is a manufacturing error between the inner diameter of the fitting portion 12b and the outer diameter of the fitted portion 7c and the shrink fitting of both portions 7b and 12b cannot be properly performed, the fitted portion 7c is Adjust the outer diameter by cutting. The fitted portion 7c is bulged from the can peripheral wall 7a in consideration of such an adjustment allowance. Therefore, when no adjustment is required, the fitted portion 7c can be formed flush with the outer peripheral surface of the can peripheral wall 7a.

The filling material 13 can be attached to the mounting ring 12 by means of a can 7.
After being shrink-fitted into the
Is injected and filled, and the space 15 is densely filled and hardened. The filler 13 is not particularly limited in terms of material as long as it is hardened after injection. Generally, thermosetting resins such as epoxy, phenol, polyester, nylon, PP
Thermoplastic resins such as S, PP and PE are used.

According to this mounting structure, since the collar portion 7b of the can 7 is fastened to the casing 3 by the mounting ring 12 via the hardened filling material 13, the mounting ring 12 is shrink-fitted to the can 7. Combined with this, the can 7 is firmly attached to the casing 3, and can sufficiently withstand even when the internal pressure acting on the can 7 is high.

That is, when the collar portion 7b is fixed to the casing 3 by tightening the mounting ring 12 in this manner, the collar portion 7b (particularly, the collar portion) which is the fixing portion of the can 7 is fixed by the internal pressure acting on the can 7. Stress is likely to be concentrated on the joint portion 7d) between the peripheral wall 7a and the peripheral wall 7a, and the can 7 may be damaged from the stress-concentrated portion due to the nature of ceramics. However, in the above mounting structure, the mounting ring 12
Is shrink-fitted into the can portion 7c distant from the collar portion 7b, and the space 15 between the collar portion 7b and the mounting ring 12 is densely filled with the resin material 13, and therefore acts on the can 7. The stress is not concentrated on the collar portion 7b. Therefore, in combination with the arcuate shape of the joint portion 7d, even when the internal pressure acting on the can 7 is high, the can 7 is not damaged due to stress concentration and has sufficient pressure resistance. Can be secured.

Each constituent member of the pump portion 1a except the can 7 is made of a corrosion resistant material (for example, a corrosion resistant resin material such as PVDF, a ceramic material, etc.), and the impeller shaft side magnet in the liquid contact area. It is the same as in the conventional magnet drive pump that 8 is subjected to appropriate anticorrosion treatment (for example, coating treatment with a PVDF film).

The present invention is not limited to the above embodiment.
It does not mean that the invention does not depart from the basic principle of the present invention.
It can be improved and changed as appropriate. For example,
As the constituent material of the can 7, in addition to β-type SiC, α-type SiC
Or Si with excellent thermal shock resistance ₃N_FourOr heat resistance, breakage
Zr, TiC, WC, Al with excellent fracture toughness₂O₃Etc.
Ceramics for seed structural materials can be used. Well
Also, in the mounting structure of the can 7, the filling space 15 is filled.
It is molded with the same material as this without filling and filling the filler 13.
Alternatively, a resin ring may be inserted. this
In this case, fit the resin ring on the outer peripheral surface of the collar 7b and
The portion that comes into pressure contact with the thing 3 (filled in the inlet 16
Having a shape corresponding to the filling material 13 portion)
As a matter of course, this part allows the seal between the casing 3 and
It is also possible to do so. Well
In addition, the O-ring 17 is a part of the molding ring as described above.
The casing 3 and the can 7
It is not always necessary to secure the sealing property. Furthermore
In addition, the mounting ring 12 should be shrink-fitted to the can peripheral wall 7a.
Instead, they may be simply fitted together.

[0023]

As is apparent from the above description, according to the magnet drive pump of the present invention, the can is made of ceramics such as SiC. Therefore, the conventional metal can and the plastic can have drawbacks. Can be eliminated, regardless of the pump liquid properties and pump operating conditions such as pump pressure, no output loss occurs, and there is no damage due to thermal shock even in an environment such as a rapid cooling, and for a long period of time. It is possible to exert a good and stable pump function.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing an embodiment of a magnet drive pump according to the present invention.

FIG. 2 is a detailed view showing an enlarged main part of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pump part, 2 ... Drive part, 4 ... Impeller shaft, 5 ... Drive shaft, 7 ... Can, 8 ... Impeller shaft side magnet, 9 ... Drive shaft side magnet.

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[Procedure amendment]

[Submission date] November 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

The present invention is not limited to the above embodiment.
It does not mean that the invention does not depart from the basic principle of the present invention.
It can be improved and changed as appropriate. For example,
As the constituent material of the can 7, in addition to β-type SiC, α-type SiC
Or Si with excellent thermal shock resistance ₃N_FourOr heat resistance, breakage
Excellent toughnessZrO ₂ , TiC, WC, Al₂O₃etc
Various types of ceramics for structural materials can be used.
Further, in the mounting structure of the can 7, the filling space 15
Filling material 13 is not injected and filled, but molded with the same material.
You may make it insert the inserted resin ring. This
In the case of, the resin ring is fitted on the outer peripheral surface of the collar portion 7b, and
The portion that comes into pressure contact with the housing 3 (filled in the inlet 16)
Having a shape corresponding to the filling material 13 part)
As a result, this part allows the seal between the casing 3 and
It is also possible to set the rules. Well
In addition, the O-ring 17 is a part of the molding ring as described above.
The casing 3 and the can 7
It is not always necessary to secure the sealing property. Furthermore
In addition, the mounting ring 12 should be shrink-fitted to the can peripheral wall 7a.
Instead, they may be simply fitted together.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Fukui 1 of 541, Shimuchi Shinji, Uchiba, Mita City, Hyogo Prefecture Japan Pillar Industry Co., Ltd. Mita Factory

Claims (1)

[Claims] 1. An impeller shaft-side magnet and a drive shaft that oppose an impeller shaft provided in a pump part and a drive shaft provided in a drive part with a peripheral wall of a cylindrical can having a bottom attached to a casing of the pump part. A magnet drive pump in which a can is made of ceramics in a magnet drive pump that is interlocked and coupled by a magnetic force action with a side magnet.