JP3360393B2 - Disk type magnet 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 disk type magnet pump for sending a liquid by using a magnetic coupling force of a flat magnet as a power transmission means.

[0002]

2. Description of the Related Art There are two types of magnet pumps: 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 an axially opposed magnet is arranged. Among them, the disk type magnet pump is difficult to cope with step-out or poor start-up due to the magnet coupling coming off,
At present, cylinder type magnet pumps are more popular. This is because, in the case of a disk type magnet pump, minute and precise magnet gap control is required to deal with the above-mentioned problems because variations in each part and assembling greatly affect the coupling torque. This is because the magnet pump has a fixed magnet gap and is essentially large, so that it is not necessary to consider such a thing. However, the wave of space saving is also rushing in pumps, and there is growing expectation from large cylinder type magnet pumps to smaller disk type magnet pumps.

[0003] First, the configuration 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 flat driving magnet 4 is fixed to a shaft 2 of the electric motor 1 via a housing 3. A pump casing 6 and a separation plate 7 are fixed to the bracket 5, and the separation plate 7 and the pump casing 6 are sealed by a first O-ring 8. That is, the separation plate 7 partitions the pump chamber including the electric motor unit on the electric motor 1 side and the pump casing 6 and the like. The fixed shaft 9 has a screw portion 9a
And a nut 15, the other end of which extends from the pump casing 6 to form a shaft support 6 formed in the pump suction port.
a. An impeller 10 is rotatably supported on the fixed shaft 9 via a bearing 12.
On the separation plate 7 side of the impeller 10, a flat driven magnet 11 opposed to the drive magnet 4 and opposed thereto is provided.
Are fixed, and the two magnets are magnetically coupled via the separation plate 7. A boss formed at 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 rotates and 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 bearing 6a, and between the bearing 12 and the separation plate 7. These are thrust bearing plates that receive the magnetic coupling force between the driving magnet 4 and the driven magnet 11 and the axial thrust caused by the rotation of the impeller 10 at the end face. Both are prevented from rotating by a D-cut structure provided on the fixed shaft 9, respectively.

Now, the operation of the above-described conventional structure will be described. The bearing 12 is slidably rotated on the fixed shaft 9 around the fixed shaft 9, and both end surfaces of the bearing 12 are the first thrust bearing plate 1.
3 and the second thrust bearing plate 14 rotates and slides in opposition to the surface thereof. By the way, the distance between the first thrust bearing plate 13 and the second thrust bearing plate 14 is formed slightly longer than the entire length of the bearing 12 fixed in the impeller 10, so that there is a slight distance between the two. A gap P exists. As a result, the distance 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 and the like, so that the bearing 12 is not seized. 10 does not lock. In the pump stop state, the impeller 10 holding the driven magnet 11 on the back side is drawn toward the separation plate 7 by the magnetic attraction of both magnets, and the gap P is shifted toward the pump chamber. ing. That is, the magnetic attraction between the two magnets makes the bearing 12 fixed at the center of the impeller 10 and the opposing surface of the second thrust bearing plate 14 come into contact with each other, and the state where all the magnetic attraction is applied to this contact portion. Become. Therefore, when the pump is started, the bearing 12 and the fixed shaft 9 start rotating and sliding around the fixed shaft 9, but
The end surface of the bearing 12 and the opposing surface of the second thrust bearing plate 14 also start sliding at the same time. However, when the impeller 10 reaches the steady rotation speed, an axial thrust 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. Try to move. That is, the axial thrust by the pump drive is larger than the magnetic attraction between the two magnets, and the impeller 10 moves toward the pump casing 6 by the gap P. Therefore, the bearing 12 and the second thrust bearing plate 14 slide at the time of startup, but the bearing 12 rotates and slides on the opposing surface of the first thrust bearing plate 13 due to the movement of the impeller 10 during operation. .

Next, a fixing structure of the fixed shaft 9 and the separation 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 end of the fixed shaft 9 on the separation plate 7 side. Also, the second thrust bearing plate 14
A D-cut is made on the fixed shaft 9 which is a non-circular portion to stop the rotation of the shaft. The screw portion 9 a is inserted into a through hole located at the center of the separation plate 7 with the second thrust bearing plate 14 interposed therebetween, and is fastened and fixed by a nut 15. This prevents the fixed shaft 9 and the second thrust bearing plate 14 from rotating with the rotation of the impeller 10. Also, the second O-ring 16 is used to prevent water from leaking through the penetrated hole.
Sealed by

[0006]

However, this conventional disk-type magnet pump has the following problems. This problem will be described as follows.

First, the advantage of the disk-type magnet pump is that there is no sliding wear of the mechanical part which occurs with the lapse of time as occurs with a widely used mechanical seal system, and water leakage occurs even at the end of life. However, in the conventional disk-type magnet pump, since a through hole for fixing the fixed shaft 9 is provided at the center of the separation plate 7, the time is lighter than that of the mechanical seal method, but the time is shorter. The second that seals after the passage
There was a risk that the O-ring 16 would deteriorate and cause water leakage. There is also a danger that water leakage will occur due to insufficient sealing due to defective parts.

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

The tip of the fixed shaft 9 on the opposite side is supported by the shaft support 6a of the pump casing 6 as described above. In addition to smooth flow, the pump casing 6 is often formed of resin, and the inner diameter of the suction port must be larger than the diameter of the outer periphery of the shaft support 6a due to the structure of the mold during manufacture. . Therefore, if the outer diameter of the fixed shaft 9 is φ10 and the thickness of the shaft support 6a is 1.
Assuming that the thickness of the outside diameter of the suction port is 2 mm on one side, the size of the connection pipe must be at least φ17 or more. That is, the lower limit of the diameter of the connection pipe is restricted.

Thirdly, in the conventional disk-type magnet pump, a screw portion 9a is formed on the fixed shaft 9 and inserted and fixed in the through hole of the separation 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 difficult to provide a guide for positioning the fixed shaft 9 with respect to the separation plate 7, and the center is misaligned. Occurred.

Fourth, 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 the best combination of materials for the bearing 12 and the fixed shaft 9 is a combination of carbon and ceramic from the viewpoint of wear resistance.
When the material of the fixed shaft 9 is ceramic, the ceramic screw may not be strong enough to cause a breakage 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 has been hesitant to realize it.

As a method of solving such a problem, it is often thought simply that the fixed shaft 9 may be fixed without providing a through hole in the separation plate 7.
In the past, it was considered difficult because of the circumstances that prevented this. To explain this situation, since the disk-type magnet pump is driven magnetically, the material of the separation plate 7 must be non-magnetic and have wear resistance and corrosion resistance. For this reason, the material of the separation plate 7 is substantially limited to resin and the like in addition to stainless steel. However, if the material of the separation plate 7 is made of stainless steel as described in the conventional example, a small D-shaped drawing is performed on the stainless steel separation plate 7 to fix the fixed shaft 9 and prevent rotation. However, since the shape of the draw forming is not cylindrical, it is difficult to draw in stainless steel, stress cracking often occurs, and it is difficult to secure dimensional accuracy. . Even if the size of the drawn portion is increased in order to facilitate the drawing, there is a limit to the upper limit in relation to the fixed shaft 9 in freely selecting the size of the drawn portion. Then, as shown in FIG. 8, if a resin should be used for the separation plate 7, a new problem in strength arises in this case. The problem is not limited to the strength of the pump itself, and the pump chamber is subjected to high internal pressure, so that the separation plate 7 is greatly deformed, and the pump may be damaged by contacting the tip of the shaft 2 or the housing 3. It even causes them to occur. In order to avoid this, the strength of the separating plate 7 made of resin may be increased. However, even if the separating plate 7 is provided with ribs or thickened to increase the strength, the driving magnet 4 and the driven magnet 4 are driven. It was necessary to reduce the gap r with the gap No. 11 and it was not possible to sufficiently reinforce it.

For these reasons, conventionally, it was 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. There is no danger of water leakage, excellent abrasion resistance and corrosion resistance, and stress cracking does not occur while ensuring dimensional accuracy. It is an object of the present invention to provide a disk-type magnet pump that can surely be prevented from rotating without running out.

Further, the present invention has no danger of water leakage, is excellent in wear resistance and corrosion resistance, does not cause stress cracking while ensuring dimensional accuracy, and can reliably prevent rotation without core runout, etc. It is another object of the present invention to provide a disk-type magnet pump having no restriction on the diameter of a connection pipe.

[0016]

In order to achieve the above object, a disk type magnet pump according to the present invention has a holder receiving recess formed by drawing the center of a separation plate, and a fixed shaft supported in the holder receiving recess. Technical measures are taken to provide a holder and holder detent means.

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

Further, in the disk type magnet pump of the present invention, the holder accommodating recess is cylindrical, the holder is also a thrust bearing plate, and the holder detent means is provided on the protrusion formed in the holder accommodating recess and the holder. It is a featured fitting part.

In the disk type magnet pump of the present invention, it is appropriate 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 formed on the holder and a detent member provided on the separation plate.

The disk type magnet pump according to 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 non-circular end of the fixed shaft provided with the non-circular hole in the holder is prevented from rotating, and the size of the non-circular hole can be selected. It is characterized by the following.

[0023]

DETAILED DESCRIPTION OF THE INVENTION The present invention, the center of the separation plate of the motor shaft
A holder housing recess formed by drawing to form a bottom on the housing side, a holder housed in the holder housing recess to support the fixed shaft, and a holder detent means are provided, so that the size of the fixed shaft can be reduced. Can be reliably stopped. There is no danger of water leakage and no run-out. Also, it can be drawn and formed without concern for the size of the holder storage recess.

Further, since the holder accommodating recess has a square shape having arc-shaped portions at four corners and the radius of curvature of the arc-shaped portion is larger than the radius of the circle inscribed in the square, the separating plate is made of stainless steel. Even if the sheet metal is made, it is possible to reliably prevent rotation without causing stress cracking while ensuring dimensional accuracy.

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. If rotation is stopped by the notch formed in the rotation stopper and the holder, the rotation can be more reliably stopped.

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 in the holder can be selected, the size of the fixed shaft can be changed, and further, the diameter of the pump suction port can be changed. Can be selected.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail 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 one embodiment of the present invention, and FIG. 2 is an enlarged view of a separation plate and a holder of FIG. 1 of the disk type magnet pump according to one embodiment of the present invention. FIG. 3 and FIG. 3 are cross-sectional views of a main part of a shaft fixing structure of a disk type magnet pump serving 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, and FIG. FIG. 2 is a sectional view of a main part of a shaft fixing structure of a disk type magnet pump using a stopper.

1 and 2, the separating plate 7 is a sheet metal made of stainless steel, has no through hole as in the prior art at the center, and has a bottom portion on the housing side of the motor shaft.
The holder accommodating recess A is formed by drawing and forming. The holder accommodating recess A is a square 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. And since this square shape is such a shape, a high level of inner diameter dimensional accuracy can be realized and problems such as stress cracking hardly occur. Moreover, since the size is larger than the outer diameter of the fixed shaft 9, it is easy to draw, and processing can be performed very easily. Reference numeral 17 denotes a holder to be fitted into the holder accommodating recess A. A non-circular hole is formed at the center of the holder so that the end of the fixed shaft 9 can be inserted therein and serves as a stopper. In this embodiment, this is a D-shaped hole. Naturally, the shaft end of the fixed shaft 9 fitted into this hole is
It must have a paired non-circular end. That is, it has the same D shape as the holder storage recess A side. Incidentally, the holder accommodating concave portion A is a square shape having arcuate portions at four corners. Therefore, the outer shape includes a non-circular portion, which serves as a holder detent means for detent between the holder 17 and the separation plate 7. The presence of the holder detent means prevents the fixed shaft 9 from rotating even if a rotation torque is applied to the fixed shaft 9 as the impeller 10 rotates. Moreover, with these configurations, the centering of the separation plate 7, the holder 17, and the fixed shaft 9 can be secured at the same time.

Since 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, care must be taken of the size of the shaft end of the fixed shaft 9. Also, the pump casing side shaft support 6a can be made smaller. If the pump casing-side shaft support 6a is large, it is necessary to allow the pump casing 6 to smoothly flow in. Therefore, there is a tendency that the diameter of the suction port of the pump casing 6 tends to be large. The diameter of the suction port of the pump casing 6 can be reduced. Then, in many cases, inconvenience was conventionally felt in selecting the connection pipe, but there is no need to consider the restriction on the diameter of the connection pipe. Further, it is not necessary to cut a screw on the shaft end of the fixed shaft 9 in order to fix the fixed shaft 9 as in the related art.
Therefore, there is no concern that the strength will be insufficient even if the material is ceramic, and the ceramic fixed shaft 9 can be realized. This improves the abrasion characteristics of the carbon bearing 12 due to the rotational sliding of the impeller 10, and solves problems such as a reduction in the amount of abrasion and seizure that is likely to occur when the stainless steel and the carbon slide. High pump can be obtained. And of course, the disk type magnet pump of this embodiment
Form a bottom on the housing side of the motor shaft
Because of the completely closed structure, there is no occurrence of water leakage , the size is small, and the concentricity is ensured, so that a low vibration pump can be realized.

FIGS. 3, 4, 5 and 6 each show another embodiment of the present invention. Referring to the embodiment shown in FIG. 3, reference numeral 7 denotes a separation plate, and reference numeral 18 denotes a dual-purpose holder which serves as both the holder 17 and the second thrust bearing plate 14. The dual-purpose holder 18 is made of ceramic, has a cylindrical shape, and is provided with a D-cut portion as a non-circular hole at the center to prevent the fixed shaft 9 from rotating. The dual-purpose holder 18 is loosely fitted with the separation plate 7 and is inserted into a cylindrical holder storage recess A provided at the center of the separation plate 7. In order to prevent rotation of the separation plate 7 and the dual-purpose holder 18, a fitting portion 18 a is provided at the bottom of the dual-purpose holder 18 as a holder rotation preventing means, and the bottom of the holder storage recess A opposed thereto is also provided. The projection 7a is provided. Any number of protrusions 7a and fitting portions 18a may be provided. According to this embodiment, since the holder is used as the second thrust bearing plate 14, the number of components can be reduced as compared with the embodiment of FIG. 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. Separating plate 7
The central part of the holder accommodating recess A is larger than the fixed shaft 9 and is narrowed down into a cylindrical shape. Reference numeral 20 denotes a resin holder, which also functions as the second thrust bearing plate 14. For this reason, a resin of a material suitable for sliding is used, and the separation plate 7 is formed by outsert molding by injection molding. Resin holder 2
The center of 0 is provided with a non-circular D-cut to prevent the fixed shaft 9 from rotating. As in the embodiment shown in FIG.
Since the holder and the second thrust bearing plate 14 are shared, the number of parts can be reduced and the manufacture is easy. Further, the fixed shaft 9 is made of ceramic, and the size of the D-cut portion can be selected.

Referring to the embodiment shown in FIG. 5, the holder accommodating recess A at the center of the separation plate 7 is a cylindrical perfect circular stop. This is easier to draw than the draw of the embodiment of FIG. The center of the holder 17 has a D-shaped hole to prevent the fixed shaft 9 from rotating, and the outer periphery is provided with several notches along the axial direction. A ring-shaped detent metal fitting 21 having a projection protruding from the inner periphery is welded to the separation plate 7. By engaging this projection in the notch groove of the holder 17, the rotation of the separation plate 7 can be prevented. According to this embodiment, the rotation can be reliably stopped by a simpler method. The fixed shaft 9 is made of ceramic, and the size of the D-shaped hole can be selected. This makes it possible to optimize the combination of the materials of the fixed shaft 9 and the bearing 12 in terms of wear resistance and corrosion resistance, and to select the combination without worrying about the diameter of the connection 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 abrasion resistance and corrosion resistance, and at the same time, is small in size, secures dimensional accuracy, does not cause stress cracking, and can reliably prevent rotation. . 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, the centering of the fixed shaft and the separation plate is easy, and the vibration during the operation of the pump can be extremely reduced.

[Brief description of the 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.

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

FIG. 3 is a sectional view of a main part of a shaft fixing structure of a disk type magnet pump serving 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 diagram showing a main part of a shaft fixing structure of a disk type magnet pump using a rotation stopper according to still another embodiment of the present invention. (B) Rotation stopper according to still another embodiment of the present invention. Sectional view of main part of shaft fixing structure of disk type magnet pump using metal fittings

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

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

FIG. 8 is a cross-sectional view of a main part of a conventional disk-type magnet pump when a separation plate is made of resin.

[Description of Signs] 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 Follower magnet REFERENCE SIGNS LIST 12 bearing 13 first thrust bearing plate 14 second thrust bearing plate 15 nut 16 second O-ring 17 holder 18 dual-purpose holder 18 a fitting portion 19 guide 20 resin holder 21 detent fitting A holder receiving recess

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04D 13/02

Claims (7)

(57) [Claims] 1. A separation plate for partitioning a pump chamber and a motor section, a fixed shaft provided in the pump chamber, an impeller rotatably supported by the fixed shaft, and a motor provided on the motor side of the impeller. a flat driven magnet has, of the motor Shi
And a flat plate-like drive magnet forming a pre <br/> SL driven magnet pair is fixed to a housing provided in Yafuto, the housing center of the separating plate
A disk-type magnet pump, comprising: a holder storage recess formed by drawing so as to form a bottom on the side; a holder stored in the holder storage recess to support the fixed shaft; and a holder detent means. 2. The method according to claim 1, wherein the separating plate is made of stainless steel sheet metal, and the holder accommodating recess has a square shape having arcuate portions at four corners, and a 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 radius of the holder is larger than a radius of the holder and the holder detent means is the square non-circular portion. Wherein the holder housing recess is cylindrical, the holder has a thrust bearing plate together, the holder detent means is provided on the holder and projections formed in the holder housing recess 2. The disk type magnet pump according to claim 1, wherein the disk type magnet pump is a fitting portion. 4. The disk type according to claim 1, wherein said holder accommodating recess has a cylindrical shape, said holder is formed by outsert molding with resin, and said holder detent means has a fixing force of said resin. Magnet pump. 5. A holder according to claim 1, wherein said holder accommodating recess has a cylindrical shape, and said holder detent means comprises a detent formed on said separation plate and a notch formed on said holder. Disk type magnet pump. 6. The disk-type magnet pump according to claim 1, wherein said fixed shaft is made of ceramic. 7. The holder is provided with a non-circular hole, and is fitted to a non-circular end of the fixed shaft to prevent rotation of the holder and the fixed shaft. The size of the non-circular hole is selectable. The disk type magnet pump according to any one of claims 1 to 6, wherein