JPH07208378A - Disc type magnet pump - Google Patents

Abstract

PURPOSE:To provide a disc type magnet pump which has no possibility of water leakage, has excellent wear resistance and corrosion resistance, does not cause stress cracking while insuring dimensional accuracy, can surely stop rotation without run-out or the like, and is not limited in the bore of a connected piping. CONSTITUTION:This disc type magnet pump is provided with a separation plate 7 partitioning it into a pump chamber and a motor part, a fixed shaft 9 in the pump chamber, an impeller rotatably journaled on the fixed shaft 9, a flat shaped driven magnet on the motor side of the impeller, and a flat plate shaped driving magnet making a pair with the driven magnet provided on the motor. It is constituted also by providing a holder receiving recessed part A being formed by drawing the center of the separation plate 7, a holder 17 received in the holder receiving recessed part A and supporting the fixed shaft 9, and a holder rotation stopping means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk type magnet pump for discharging liquid by utilizing the magnetic coupling force of a flat plate-shaped magnet as a power transmission means.

[0002]

2. Description of the Related Art Magnet pumps include a cylinder type in which a driving side magnet and a driven side magnet are arranged in an inner and outer ring shape, and a disk type in which they are axially opposed to each other. Among them, the disk type magnet pump is difficult to deal with when the magnetic coupling is out of step or there is a start failure.
At present, cylinder type magnet pumps are more popular. This is because in disk type magnet pumps, variations in each part and assembly greatly affect the coupling torque, so minute and precise magnet gap control is required to deal with the above problems, but cylinder type This is because the magnet pump has a constant magnet gap and is large in size, so it is not necessary to consider this. However, the wave of space saving is also rushing to the pumps, and expectations are increasing from the large cylinder type magnet pump to the disk type magnet pump that can be downsized.

Therefore, first, the structure and operation of a conventional disk type magnet pump will be described with reference to the drawings. As shown in FIGS. 6 and 7, a plate-shaped drive magnet 4 is fixed to a shaft 2 of an electric motor 1 via a housing 3. A pump casing 6 and a separating plate 7 are fixed to the bracket 5, and the first O-ring 8 seals the separating plate 7 and the pump casing 6. That is, the separating plate 7 partitions the pump chamber constituted by the electric motor part on the electric motor 1 side and the pump casing 6. The fixed shaft 9 has a threaded portion 9a on the separating plate 7.
And the nut 15, and the opposite end extends from the pump casing 6 and is formed in the pump suction port.
It is held by a. An impeller 10 is rotatably supported on the fixed shaft 9 via a bearing 12.
On the side of the separating plate 7 of the impeller 10, a flat plate-shaped driven magnet 11 that faces the driving magnet 4 and forms a pair.
Are fixed, and both magnets are magnetically coupled via the separating plate 7. A boss formed in the center of the impeller 10,
A bearing 12 is provided between the fixed shafts 9. The bearing 12 is fixed in the boss of the impeller 10 and rotationally slides on the fixed shaft 9 together with the impeller 10.
Further, a first thrust bearing plate 13 and a second thrust bearing plate 14 are interposed between the bearing 12 and the pump casing side shaft support 6a and between the bearing 12 and the separation plate 7. These are thrust bearing plates that receive the magnetic coupling force of the drive magnet 4 and the driven magnet 11 and the axial thrust force caused by the rotation of the impeller 10 at their end faces. Both of them are prevented from rotating by a D-cut structure provided on the fixed shaft 9.

The operation of these structures of the conventional example will be described. The bearing 12 rotates and slides on the fixed shaft 9 as a center, and both shaft end faces of the bearing 12 have the first thrust bearing plate 1.
3 and the surface of the second thrust bearing plate 14 so as to face and slide. By the way, since the distance between the first thrust bearing plate 13 and the second thrust bearing plate 14 is formed to be slightly longer than the entire length of the bearing 12 fixed in the impeller 10, there is a slight distance between the two. Gap P is present. As a result, the gap between the first thrust bearing plate 13 and the second thrust bearing plate 14 becomes shorter than the entire length of the bearing 12 due to variations in component dimensions, etc., so that the bearing 12 does not burn, and further, the impeller 10 is not locked. In the pump stopped state, the impeller 10 holding the driven magnet 11 on its back side is attracted to the separation plate 7 side by the magnetic attraction force of both magnets, and the gap P is biased to the pump chamber side. ing. That is, the magnetic attraction force between the two magnets brings the bearing 12 fixed to the center of the impeller 10 and the opposing surface of the second thrust bearing plate 14 into contact with each other, and the magnetic attraction force is applied to the contact portion. Become. Therefore, when the pump is started, the bearing 12 and the fixed shaft 9 start to rotate and slide around the fixed shaft 9,
The end surface of the bearing 12 and the facing surface of the second thrust bearing plate 14 also start sliding at the same time. However, when the impeller 10 reaches a steady rotation speed, an axial thrust force is generated in the impeller 10 in the direction of the pump casing 6 due to the pressure difference between the suction port and the discharge port of the pump casing 6, so that the impeller 10 moves toward the pump casing 6 side. Try to move. That is, the axial thrust due to the pump drive becomes larger than the magnetic attraction between both magnets, and the impeller 10 moves to the pump casing 6 side by the gap P. Therefore, the bearing 12 and the second thrust bearing plate 14 slide at the time of starting, but the bearing 12 rotates and slides on the facing surface of the first thrust bearing plate 13 by the movement of the impeller 10 at the time of operation. .

Next, the fixing structure of the fixed shaft 9 and the separating plate 7 of the conventional disk type magnet pump will be described with reference to FIG. The material of the fixed shaft 9 and the separation plate 7 is stainless steel, and a screw portion 9a is provided at the tip of the fixed shaft 9 on the separation plate 7 side. In addition, the second thrust bearing plate 14
In order to stop the rotation of the fixed shaft 9, the fixed shaft 9, which is a non-circular portion, is D-cut. The screw portion 9a is inserted into a through hole located in the center of the separation plate 7 with the second thrust bearing plate 14 interposed therebetween, and is tightened and fixed by a nut 15. As a result, the fixed shaft 9 and the second thrust bearing plate 14 are prevented from rotating with the rotation of the impeller 10. In addition, the second O-ring 16 is provided so that water does not leak from the through hole.
It is sealed by.

[0006]

However, the conventional disk type magnet pump has the following problems. The problem is explained as follows.

[0007] First, the advantage of this disk type magnet pump is that there is no sliding wear of mechanical parts over time, which occurs with the widely used mechanical seal system, and water leakage does not occur even at the end of life. However, in the conventional disk type magnet pump, since the through hole for fixing the fixed shaft 9 is present in the center of the separation plate 7, although it is lighter than the mechanical seal method, it takes time. The second that seals after the passage
There was a risk that the O-ring 16 of No. 1 would deteriorate and cause water leakage. There is also a risk that water leakage may occur due to lack of seals due to defective parts or the like.

Secondly, in the conventional disc type magnet pump, the fixed shaft 9 has a screw portion 9a cut at the tip end thereof, penetrates the separation plate 7 and is fixed by the nut 15, so that the pump output is 20W to 60W. If it is a class, it is necessary to give it strength, and at least an M4 fixing screw is required. Further, since it is necessary to form the second O-ring 16, the fixed shaft 9 that houses the second O-ring 16 and the receiving portion of the separation plate 7, in this case, the outer diameter of the fixed shaft 9 must be at least φ10 or more.

By the way, the tip portion on the opposite side of the fixed shaft 9 is supported by the shaft support 6a of the pump casing 6 as described above. In addition to ensuring smooth flow, the pump casing 6 is often molded from resin, and the suction port inner diameter must be larger than the diameter of the outer periphery of the shaft support 6a due to the structure of the mold during manufacturing. . Therefore, if the outer diameter of the fixed shaft 9 is φ10 and the thickness of the shaft support 6a is 1.
If the wall thickness of the outer diameter of the suction port is 5 mm and the outer diameter of the suction port is 2 mm on each side, the size of the connecting pipe must be at least φ17 or more. In other words, the lower limit of the diameter of the connecting pipe will be limited.

Thirdly, in the conventional disc type magnet pump, the threaded portion 9a is formed on the fixed shaft 9 and is inserted and fixed in the through hole of the separating plate 7. However, as described above, due to the second problem. Since the outer diameter of the fixed shaft 9 cannot be increased more than necessary, it is practically difficult to provide a guide for positioning the fixed shaft 9 with respect to the separation plate 7, and misalignment occurs and vibration occurs as the impeller 10 rotates. It happened.

Fourthly, in the conventional disk type magnet pump, the material used for the rotary sliding portion is mostly carbon in the bearing 12, but the fixed shaft 9 is made of stainless steel as described above. It has been found that a combination of carbon and ceramic is the best combination of materials for the bearing 12 and the fixed shaft 9 from the viewpoint of wear resistance.
When the material of the fixed shaft 9 is ceramic, the strength of the ceramic screw is not sufficient, which may result in a damage accident during operation. That is, it is extremely dangerous to select ceramic as the material of the bearing 12 in the conventional disk type magnet pump, and it is hesitant to realize it.

By the way, as a method of solving such a problem, it is easy to think that the fixing shaft 9 may be fixed without providing a through hole in the separating plate 7.
It has been considered difficult in the past due to circumstances that hinder this. To explain this circumstance, since the disk type magnet pump is magnetically driven, the material of the separation plate 7 must be non-magnetic and have abrasion resistance and corrosion resistance. Therefore, the material of the separation plate 7 is practically limited to resin or the like in addition to stainless steel. However, as described in the conventional example, when the material of the separating plate 7 is made of stainless steel to solve this problem, a small D-shaped drawing is performed on the separating plate 7 made of stainless steel in order to fix the fixed shaft 9 and prevent rotation. Although it must be done, it is difficult to draw in stainless steel because the shape of drawing is not cylindrical, and stress cracking often occurs, and it is difficult to secure dimensional accuracy by this. . Even if the size of the draw-formed portion is increased in order to facilitate the draw-forming, there is a limit to the upper limit in freely selecting the size of the draw-formed portion in relation to the fixed shaft 9. Then, as shown in FIG. 8, it suffices to use a resin for the separating plate 7, and in this case, another problem in strength arises. And it is not only a problem of its own strength, there is a danger that the separator plate 7 is largely deformed due to the high internal pressure applied to the pump chamber and comes into contact with the tip of the shaft 2 or the housing 3 to damage the pump. It even causes it. In order to avoid this, the strength of the separating plate 7 made of resin is structurally increased. However, even if a rib is provided on the separating plate 7 or the wall thickness is increased to increase the strength, the driving magnet 4 and the driven magnet 4 are used. It was necessary to make the gap r with 11 small so that it could not be sufficiently reinforced.

Because of these reasons, it has been conventionally necessary to provide a through hole in the separation plate 7 and fix the fixed shaft 9.

The present invention solves the above-mentioned conventional problems. It has no risk of water leakage, is excellent in wear resistance and corrosion resistance, does not cause stress cracking while ensuring dimensional accuracy, and has a core. An object of the present invention is to provide a disk type magnet pump that can reliably prevent rotation without wobbling.

Further, according to the present invention, there is no risk of water leakage, it has excellent wear resistance and corrosion resistance, stress cracking does not occur while ensuring dimensional accuracy, and there is no run-out of the core, etc. Another object of the present invention is to provide a disk type magnet pump that does not have a restriction on the diameter of the connecting pipe.

[0016]

In order to achieve the above object, a disk type magnet pump according to the present invention supports a fixed shaft which is housed in a holder accommodating recess formed by drawing the center of a separation plate. The technical means of providing the holder and the holder rotation preventing means is taken.

Further, in the disk type magnet pump of the present invention, the separating plate is made of a metal plate made of stainless steel, and the holder accommodating recess has a square shape having arcuate portions at four corners, and the radius of curvature of the arcuate portion is It is suitable that the radius of the circle inscribed in the square shape is larger and the holder rotation preventing means is the square non-circular portion.

Further, in the disk type magnet pump of the present invention, the holder accommodating recess is cylindrical, the holder also serves as a thrust bearing plate, and the holder rotation preventing means is provided on the protrusion and the holder formed in the holder accommodating recess. It is characterized in that it is a fitted portion.

In the disk type magnet pump of the present invention, it is suitable that the holder is outsert-molded with resin.

The disc type magnet pump of the present invention is characterized in that the holder detent means is a detent member provided on the separation plate and a notch formed in the holder.

The disk type magnet pump of the present invention is characterized in that the fixed shaft is made of ceramic.

Further, in the disk type magnet pump of the present invention, the holder is fitted with the non-circular end portion of the fixed shaft having the non-circular hole to prevent rotation, and the size of the non-circular hole can be selected. It is characterized by that.

[0023]

The present invention is provided with the holder accommodating recess formed by drawing the center of the separating plate, the holder accommodated in the holder accommodating recess for supporting the fixed shaft, and the holder rotation preventing means. The rotation stop can be reliably performed. There is no risk of water leakage and there is no run-out. Further, it is possible to perform drawing without paying attention to the size of the holder accommodating recess.

Further, since the holder accommodating concave portion has a square shape having arcuate portions at four corners, and the radius of curvature of the arcuate portion is larger than the radius of the circle inscribed in the square shape, the separating plate is made of stainless steel. Even if the sheet metal is made of metal, the dimensional accuracy is ensured, stress cracking does not occur, and reliable detent can be achieved.

Since the holder also serves as a thrust bearing plate, the number of parts can be reduced.

Since the holder is outsert-molded with resin, the holder can be easily molded. It is possible to prevent the rotation more reliably by using the notch formed in the rotation stopper metal fitting and the holder.

Further, since the fixed shaft is made of ceramic, it has excellent wear resistance and corrosion resistance. Since the size of the non-circular hole of the holder can be selected, the size of the fixed shaft can be changed, and the diameter of the pump suction port can be changed by this. Can be selected.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a main part of a shaft fixing structure of a disk type magnet pump according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the separation plate and holder of the disk type magnet pump shown in FIG. 3 and 4 are cross-sectional views of a main part of a shaft fixing structure of a disk type magnet pump which also serves as a holder and a second thrust bearing plate according to another embodiment of the present invention. FIG. 4 is a sectional view of a main part of a shaft fixing structure of a disk type magnet pump in which a holder is formed of resin according to still another embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view of a main part of a shaft fixing structure of a disk type magnet pump using a stopper.

In FIG. 1 and FIG. 2, the separating plate 7 is a metal plate made of stainless steel, and there is no through hole as in the prior art at the center, and a holder housing recess A is formed by drawing. The holder accommodating recess A has a square shape having arcuate portions at four corners, and the radius of curvature of the arcuate portion is larger than the radius of a circle inscribed in the square shape. Since this square shape is such a shape, it is possible to achieve a high level of inner diameter dimensional accuracy and to prevent problems such as stress cracking. Moreover, since the size is larger than the outer diameter of the fixed shaft 9, it is easy to draw and the processing can be performed very easily. Reference numeral 17 denotes a holder fitted in the holder accommodating recess A, and has a non-circular hole into which the end of the fixed shaft 9 can be inserted and which serves as a rotation stopper, at the center. In this example, this is a D-shaped hole. As a matter of course, the shaft end of the fixed shaft 9 fitted into this hole is
It must have a pair of non-circular ends. That is, it has the same D shape as the holder storage recess A side. By the way, the holder accommodating recess A has a square shape having arcuate portions at four corners. Therefore, this outer shape includes a non-circular portion, which serves as a holder rotation preventing means for preventing rotation between the holder 17 and the separation plate 7. Since the holder rotation preventing means is present, the fixed shaft 9 does not rotate even if a rotational torque is generated on the fixed shaft 9 as the impeller 10 rotates. Moreover, with these configurations, the separation plate 7, the holder 17, and the centering of the fixed shaft 9 can be secured at the same time.

By the way, the size of the D-shaped hole formed in the center of the holder 17 can be made as small as the strength of the fixed shaft 9 allows. Therefore, pay attention to the size of the shaft end of the fixed shaft 9. Instead, the shaft support 6a on the pump casing side can be made smaller. If the pump casing side shaft support 6a is large, there is a tendency that the diameter of the suction port of the pump casing 6 will inevitably increase because the pump casing side shaft support 6a can be made small in this way. It is possible to reduce the diameter of the suction port of the pump casing 6. In that case, conventionally, it was often inconvenient to select the connecting pipe, but it is not necessary to consider the restriction on the diameter of the connecting pipe. Further, in order to fix the fixed shaft 9, it is not necessary to cut a screw on the shaft end of the fixed shaft 9 as in the conventional case.
Since it is only necessary to fit it to, there is no concern that the strength will be insufficient even if the material is ceramic, and the fixed shaft 9 made of ceramic can be realized. As a result, the wear characteristics with the carbon bearing 12 due to the rotary sliding of the impeller 10 are improved, the problems such as the reduction of the wear amount and the seizure that is likely to occur during sliding of stainless steel and carbon are solved, and the reliability is improved. A high pump can be obtained. As a matter of course, since the disk type magnet pump of this embodiment has a completely sealed structure, water leakage does not occur and the concentric core is secured, so that a low vibration pump can be realized.

FIGS. 3, 4, 5, and 6 each show another embodiment of the present invention. Explaining the embodiment of FIG. 3, reference numeral 7 is a separating plate, and 18 is a holder for both the holder 17 and the second thrust bearing plate 14 for both purposes. The material of the dual-purpose holder 18 is ceramic, which is cylindrical and has a D-cut portion as a non-circular hole in the center to prevent the fixed shaft 9 from rotating. The combined holder 18 is loosely fitted to the separating plate 7, and is inserted into the cylindrical holder accommodating recess A provided in the center of the separating plate 7. In order to prevent the holder 18 that also serves as the separation plate 7 from rotating, a fitting portion 18a is provided at the bottom of the holder 18 that also serves as holder rotation preventing means, and also at the bottom of the holder housing recess A facing the fitting portion 18a. Protrusions 7a are provided. Any number of the protrusion 7a and the fitting portion 18a may be provided. According to this embodiment, since the holder also serves as the second thrust bearing plate 14, the number of parts can be reduced as compared with the embodiment of FIG. Further, it is desirable that the fixed shaft 9 is made of ceramic so that the size of the D cut portion can be selected.

The embodiment shown in FIG. 4 will be described. Separation plate 7
The holder accommodating recess A at the center is formed by being squeezed into a cylindrical shape having a size larger than the fixed shaft 9. Reference numeral 20 denotes a resin holder, which also functions as the second thrust bearing plate 14. Therefore, a resin material suitable for sliding is used, and the separation plate 7 is formed by injection molding by outsert molding. Resin holder 2
A non-circular D cut is applied to the center of 0 to prevent the fixed shaft 9 from rotating. Similar to the embodiment shown in FIG.
Since the holder also serves as the second thrust bearing plate 14, the number of parts can be reduced and the manufacturing is easy. The fixed shaft 9 is made of ceramic, and the size of the D cut portion can be selected.

Explaining the embodiment of FIG. 5, the holder accommodating recess A at the center of the separating plate 7 is a cylindrical perfect circular diaphragm. This is much easier to draw than the drawing of the embodiment of FIG. Further, the center of the holder 17 has a D-shaped hole to prevent the fixed shaft 9 from rotating, and several cutout grooves are provided on the outer periphery along the axial direction. The separation plate 7 is welded with a ring-shaped detent metal fitting 21 having a protrusion protruding from the inner circumference. Then, by engaging this protrusion in the notch groove of the holder 17, it is possible to prevent the separation plate 7 from rotating. According to this embodiment, it is possible to surely prevent the rotation by a simpler method. The fixed shaft 9 is made of ceramic, and the size of the D-shaped hole can be selected. As a result, the combination of the materials of the fixed shaft 9 and the bearing 12 can be optimized in terms of wear resistance and corrosion resistance, and can be selected without worrying about the diameter of the connecting pipe.

[0035]

As described above, according to the present invention, water leakage does not occur even if the disk type magnet pump has been used for many years. The disk-type magnet pump of the present invention is excellent in wear resistance and corrosion resistance, and at the same time, secures dimensional accuracy, does not cause stress cracking, and can perform a reliable detent. Further, since the size of the fixed shaft can be changed, the diameter of the pump suction port can be changed, and the diameter of the connection pipe can be variously selected. Since the material of the fixed shaft can be made of ceramic, the material of the fixed shaft and the bearing can be optimally combined. In addition, it is easy to center the fixed shaft and the separation plate, and it is possible to minimize vibration during pump operation.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a shaft fixing structure of a disk type magnet pump according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the separation plate and the holder of FIG. 1 of the disk type magnet pump in one embodiment of the present invention.

FIG. 3 is a sectional view of an essential part of a shaft fixing structure of a disk type magnet pump which also serves as a holder and a second thrust bearing plate according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part of a shaft fixing structure of a disk type magnet pump in which a holder is formed of resin according to still another embodiment of the present invention.

FIG. 5 (a) is a view showing a main part of a shaft fixing structure of a disc type magnet pump using a rotation stopper according to still another embodiment of the present invention. (B) A rotation stopper according to still another embodiment of the present invention. Cross-sectional view of the main part of the shaft fixing structure of the disk type magnet pump using metal fittings

FIG. 6 is a structural diagram of a conventional disc type magnet pump.

FIG. 7 is a sectional view of an essential part of a conventional shaft fixing structure of a disk type magnet pump.

FIG. 8 is a cross-sectional view of a main part of a conventional disc type magnet pump when a separator is made of resin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 2 Shaft 3 Housing 4 Driving magnet 5 Bracket 6 Pump casing 6a Shaft support 7 Separation plate 7a Non-rotating protrusion 8 First O-ring 9 Fixed shaft 9a Screw portion 10 Impeller 11 Driven magnet 12 Bearing 13 First Thrust bearing plate 14 second thrust bearing plate 15 nut 16 second O-ring 17 holder 18 holder 18 that also serves as 18a fitting part 19 guide 20 resin holder 21 non-rotating metal fitting A holder recess

Claims (7)

[Claims] 1. A separation plate for partitioning a pump chamber and an electric motor part, a fixed shaft provided in the pump chamber, an impeller rotatably supported by the fixed shaft, and an electric motor side of the impeller. A flat plate-shaped driven magnet and a flat plate-shaped driving magnet that is provided on the electric motor and forms a pair with the driven magnet. A holder housing recess formed by drawing the center of the separation plate and the holder. A disk-type magnet pump, comprising a holder housed in a housing recess for supporting the fixed shaft, and a holder rotation preventing means. 2. The separating plate is made of stainless steel, and the holder accommodating recess has a square shape having arcuate portions at four corners, and the radius of curvature of the arcuate portion is a circle inscribed in the square shape. 2. The disk-type magnet pump according to claim 1, wherein the holder rotation preventing means is a square non-circular portion having a radius larger than the radius of. 3. The holder accommodating recess is cylindrical, the holder is also a thrust bearing plate, and the holder rotation preventing means is provided on the protrusion formed in the holder accommodating recess and the holder. The disc type magnet pump according to claim 1, wherein the disc type magnet pump is a fitting portion. 4. The disk type according to claim 1, wherein the holder accommodating recess is cylindrical, the holder is outsert-molded with resin, and the holder rotation preventing means is a fixing force of the resin. Magnet pump. 5. The holder accommodating concave portion is cylindrical, and the holder rotation preventing means is a rotation preventing metal member provided on the separation plate and a notch formed in the holder. Disk type magnet pump. 6. The disk type magnet pump according to claim 1, wherein the fixed shaft is made of ceramic. 7. A non-circular hole is provided in the holder to engage with a non-circular end portion of the fixed shaft to prevent the holder and the fixed shaft from rotating, and the size of the non-circular hole can be selected. The disk type magnet pump according to any one of claims 1 to 6, which is characterized in that.