JPH0716074Y2 - Magnet pump cooling device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is designed so that a direct current can be sequentially switched around each iron core, which is divided into a fan shape and arranged in plural in the circumferential direction, through a hall element or the like. A rotor including a stator around which a coil is energized to form a rotating magnetic field, and a plurality of permanent magnets axially opposed to the stator and having N and S poles alternately arranged in the circumferential direction. And a magnet for directly burying the motor rotor in the pump impeller or attaching a pump driving magnet to the motor rotor to rotate a driven magnet embedded in the pump impeller by magnetic force with the pump driving magnet. It is suitable for use as a circulation pump or the like for a pump, particularly a cooling device.

[Conventional technology]

In a conventional magnet pump, as shown in FIG. 3, an impeller 2 arranged in a pump casing 1 made of a non-magnetic material has a plurality of fan-shaped permanent magnets 3 (for example, 8 pieces). ), N poles and S poles are alternately arranged so as to be located in the circumferential direction, and the impeller 2 is mounted on a fixed bearing 5 mounted on a casing cover 4 with a cylindrical sliding surface and a radial sliding surface. The casing 1 is rotatably supported via a rotary bearing 6 having a moving surface, and a rotary bearing 7 is attached to the end face of the suction port of the impeller 2 in a direction perpendicular to the shaft.
The axial thrust toward the suction side is supported by abutting against the fixed bearing 8 on the side.

On the other hand, on the back side (right side in the figure) of the casing cover 4, a stator 9 is held by a core cover 10 so as to abut the casing cover 4, and the stator 9
Is a plurality (for example, 6) so that each has a fan shape.
A coil 11 is wound around each of the iron cores that are divided into and arranged in the circumferential direction, and a direct current is passed through the coil 11 to form a rotating magnetic field on the end surface of the stator 9, and the permanent magnet 3 on the rotor side is formed. Is designed to rotate. The number of iron cores of the permanent magnet 3 and the stator 9 is an even number, and the numbers are changed to reduce the attraction force that acts on each other.

When the pump is in operation, by applying a direct current to the coil 11 of the stator 9, a rotating magnetic field is formed along the end surface of the stator 9, and the rotating magnetic field rotates the impeller 2 in which the permanent magnet 3 is embedded. As indicated by a thick arrow C, liquid (water) is sucked through the casing suction port 12 and discharged through the discharge port 13.

[Problems to be solved by the device]

In the conventional magnet pump described above, when the pump is in operation, the thrust load direction in the arrow A direction applied to the impeller 2 by the attractive force acting between the stator 9 made of an iron core and the permanent magnet 3 embedded in the impeller 2, and The direction of the hydraulic thrust load in the arrow B direction applied to the back surface (right side in the figure) of the impeller 2 when pumping water is opposite. Therefore, if the discharge pressure of the pump becomes low and the hydraulic thrust in the arrow B direction becomes weaker than the magnetic attraction force in the arrow A direction due to a change in the pump operating pressure, the bearing of the suction port of the impeller 2 When the amount of return (leakage) from the gap of 7 and 8 to the suction side increases, then the discharge pressure of the pump increases, and the hydraulic thrust in the above arrow B direction becomes larger than the magnetic attraction force in the arrow A direction. , The return pressure (leakage) from the gap between the suction side bearings 7 and 8 disappears, and the discharge pressure of the pump rises again, but the performance curve of the pump at this time does not return to the original trajectory, and the pump pressure − A hysteresis phenomenon occurs in the flow rate performance.

As described above, when the gap between the bearings 7 and 8 on the impeller suction port side is eliminated, an impact load is applied to the bearings, and the bearings are damaged.

In order to address the above-mentioned problems, the present applicant has previously arranged the rotor made of the permanent magnets in a buried manner on the suction port side of the pump impeller, while facing the rotor and placing the stator in the pump casing. We applied for a magnet pump that was placed in the non-wetted part on the suction port side and made the axial thrust load acting on the impeller in one direction.

However, the magnet pump driven by the DC motor as described above is usually manufactured only by a small output of about 300 W, and the amount of heat generated by the motor is small, so that the magnet pump is naturally cooled. Therefore, there is a problem that the motor output cannot be increased.

It is an object of the present invention to provide a magnet pump having a large output by allowing the DC motor unit to be forcibly cooled.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a stator configured to form a rotating magnetic field by winding a coil around each iron core, each of which is divided into a fan shape and arranged in the circumferential direction. A DC motor is constituted by the stator and a rotor formed of a plurality of permanent magnets which are arranged axially opposite to each other and in which N poles and S poles are alternately arranged in the circumferential direction, and the motor rotor is embedded in a pump impeller. In the magnet pump described above, a fan provided with a driven magnet rotated by the stator is provided at a position opposite to the motor rotor with respect to the stator.

Further, in a magnet pump in which a pump driving magnet is attached to a motor rotor which constitutes the DC motor, and a driven magnet which is axially opposed to the pump driving magnet and is embedded in the pump impeller is rotated by magnetic force. On the other hand, a fan provided with a driven magnet rotated by the stator is provided at a position opposite to the motor rotor.

[Action]

Since the present invention is configured as described above, when a direct current is applied to a coil wound around each iron core forming a stator during pump operation, a rotating magnetic field is formed in the stator, and the rotating magnetic field causes When the motor rotor composed of a permanent magnet rotates and the motor rotor is embedded in the impeller, the impeller is directly rotated, and a pump driving magnet is attached to the motor rotor, and the driven rotor is embedded in the impeller by the pump driving magnet. In the case where the magnet is rotated, the impeller is rotated through both the pump driving and driven magnets to suck in the liquid, pressurize the liquid with the impeller, and discharge the liquid from the casing discharge port to the outside.

As described above, when a coil of the stator is energized, a rotating magnetic field is generated on both sides of the stator, and a fan driven magnet provided on the opposite side of the stator from the motor rotor also rotates. The fan is rotated by the rotation of the fan driven magnet,
Cooling air is forced to flow along the outer wall of the motor to cool the motor.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a magnet pump according to a first embodiment of the present invention, in which the same reference numerals as those shown in FIG. 3 denote the same or like parts.

In the figure, the suction casing 21 made of a non-magnetic material
And the casing cover 24, the impeller 22 is arranged in the pump chamber, and the suction port side of the impeller 22 has N
A plurality of poles and south poles arranged alternately in the circumferential direction (for example, 8
Rotors (motor rotors) 23 made of permanent magnets (not shown) are embedded, and the impeller 22 includes a rotary bearing 26 and a fixed bearing 25 attached to the center of the suction casing 21.
These bearings each have a cylindrical sliding surface 25a and a radial sliding surface 25b, and the radial load and the axial load are supported by these sliding surfaces orthogonal to each other. I support you.

On the other hand, on the suction side of the suction casing 21, a stator 9 is held by a suction cover 20 made of a non-magnetic material so as to come into contact with the back surface (left side in the figure) of the suction casing 21. The stator 9 is formed by winding a coil 11 around each iron core, which is divided into a fan shape and arranged in a plurality (for example, six) in the circumferential direction, and a direct current is applied to the coil 11 to form a rotating magnetic field. However, the permanent magnet on the rotor 23 side is rotated.

Suction cover on the side opposite to the rotor 23 with respect to the stator 9
A fan 32 is rotatably supported on the back side (left side in the figure) of 20 via a ball bearing 31 on a suction pipe portion (nozzle) 21a that is integral with the suction casing 21. A fan driven magnet 33 composed of a permanent magnet is integrally mounted so as to face 9.

Further, outside the fan 32 and the suction cover 20, a cooling air passage is formed, and the suction port 34a in the axial direction is formed.
And a fan cover 34 having a radial outlet 34b is attached.

Next, the operation will be described. When a direct current is applied to the coil 11 of the stator 9 during pump operation, a rotating magnetic field is formed along the end surface of the stator 9 on the impeller side, and the rotating magnetic field forms a rotor made of a permanent magnet. Impeller 22 with embedded 23
Rotate in the same direction to suck the liquid from the suction port 12, pressurize the impeller 22 and discharge the liquid to the outside from the casing discharge port 13 as indicated by arrow C.

At this time, the thrust load applied to the impeller 22 by the attractive force between the stator 9 and the permanent magnets of the rotor 23 is applied to the pump suction side as indicated by arrow a, while it is discharged from the outlet of the impeller during pump pumping. The hydraulic thrust load based on the pressure difference caused by the pressure water acting on both side plates of the impeller,
As shown by the arrow B, it is applied to the pump suction side, and the biaxial thrust load acting on the pump impeller 22 becomes unidirectional.

Then, the axial thrust load in the one direction is applied to the pump impeller 22
Is supported by a rotary bearing 26 and a fixed bearing 25, which are attached to the center of the suction port side and the center of the pump suction casing 21, respectively. Also, the radial load of the impeller 22 is
It is supported by both bearings 25 and 26 described above, and holds the central axis of the pump.

On the other hand, since the suction cover 20 supporting the back side of the stator 9 is made of a non-magnetic material, the magnetic force lines generated by energizing the coil 11 of the stator 9 are generated on both the rotor 23 (impeller) side and the fan 32 side. Since the strength is the same, the stator 9
A similar rotating magnetic field is generated on the opposite side (left side in the drawing), and the fan driven magnet 33 and the fan 32 integrally attached with the magnet 33 are rotated in the same direction.

By the rotation of the fan 32, the cooling air sucked from the axial suction port 34a flows through the passage inside the fan cover 34 as shown by the arrow D and is forced out of the motor section while being discharged from the air outlet 34b. Cooling.

According to this embodiment, the following effects are achieved.

(I) By providing the fan 32 to which the driven magnet 33 rotated by the stator 9 is attached at the position opposite to the motor rotor 23 with respect to the stator 9, the rotation of the fan 32 forcibly cools the motor section. The output of the pump and the motor can be increased under the completely leak-free structure.

(Ii) The thrust load applied to the impeller 22 by the attractive force between the stator 9 and the permanent magnets forming the rotor 23, and the thrust load applied to the impeller due to a hydraulic pressure difference during pump pumping are both pump suction ports. Therefore, since the axial movement of the impeller 22 can be eliminated,
Impact load is not applied to the bearings 25 and 26, and damage to the bearings can be prevented.

(Iii) Further, since the thrust bearing sliding surface 25b also slides at a constant sliding clearance without being affected by changes in the pump operating pressure, the hysteresis phenomenon of pump pressure-flow rate performance does not occur.

(Iv) Since the bearing is provided at the suction port side of the pump impeller 22 and at one position of the pump suction casing 21 that faces the suction port side, partial contact of the bearing can be eliminated and cost can be reduced. it can.

FIG. 2 is a longitudinal sectional view of a magnet pump showing a second embodiment of the present invention, in which the same reference numerals as those shown in FIG. 1 denote the same or like parts.

In this embodiment, a motor rotor 41 composed of a permanent magnet rotated by the stator 9 and N and S poles having the same number of poles as the driven magnet (motor rotor) 23 embedded in the impeller 22 are arranged in the circumferential direction. The drive magnet 42 and the drive magnet 42 are attached to the bracket 43 at symmetrical positions on both end faces of a drive magnet ring 45 rotatably supported by a ball bearing 44.
Is different from the first embodiment (FIG. 1) in that it is provided so as to face the driven magnet 23 embedded in the impeller 22 via the suction casing 21, and the back side of the stator 9 ( On the left side in the figure, a fan 32 having a driven magnet 33 attached is rotatably supported in a pump suction passage 21a via a bearing 31 with a suction cover 20 made of a non-magnetic material interposed therebetween. There is no change in that it is covered.

According to this embodiment, when the coil 11 of the stator 9 is energized during pump operation, a rotating magnetic field is formed along both end faces of the stator 9, and the rotating magnetic field on the end face on the impeller side causes the motor rotor 41 to drive the magnet ring. Pump drive magnet through 45
Along with 42, the impeller 22 in which the driven magnet 23 is embedded also rotates in the same direction, and the fluid is sent out as shown by the arrow C. At this time, the thrust load and hydraulic thrust load applied to the impeller 22 by the attraction between the pump drive magnet 42 and the driven magnet 23 are in one direction as shown by the arrow.

On the other hand, the rotating magnetic field on the fan side of the stator 9 causes the fan 32, which is integrated with the driven magnet 33, to rotate in the same direction, and sucks cooling air from the axial suction port 34a, so that the internal passage of the fan cover 34 is shown by an arrow D. While flowing, it cools the motor part and is discharged from the air outlet 34b.

In the above-described first embodiment (FIG. 1), the rotary bearing 26 attached to the suction port side of the impeller 22 and the suction casing 21.
The fixed bearing 25 has been described as having a structure having a cylindrical sliding surface 25a and a radial sliding surface 25b in order to support both radial and axial loads. It is also possible to replace it with an inclined conical surface.

[Effect of device]

As described above, according to the present invention, a DC motor is constituted by a stator and a rotor composed of a permanent magnet, and the motor rotor rotates the impeller directly or via a pump driving magnet. In the magnet pump, a cooling fan having a driven magnet rotated by the stator is provided on the opposite side of the stator from the motor rotor, so that power transmission for rotating the fan is directly connected to the motor output side rotor. Since the motor section can be forcibly air-cooled, the motor output can be increased while the pump and the motor are completely leak-free.

Further, a driven magnet (motor rotor) embedded in the impeller is provided on the suction side of the impeller, and the impeller is rotated by the stator also provided on the suction side, so that various kinds of pump impellers are generated. Unstable movement of the impeller can be eliminated by setting the axial load direction to one direction.

[Brief description of drawings]

1 and 2 are longitudinal sectional views of a magnet pump showing first and second embodiments of the present invention, and FIG. 3 is a longitudinal sectional view of a magnet pump showing a conventional example. 9 ... Stator, 11 ... Coil, 20 ... Suction cover, 21
...... Suction casing, 22 ...... impeller, 23 ...... motor rotor (driven magnet), 24 ...... casing cover, 25 ...... fixed bearing, 26 ...... rotary bearing, 32 ...... fan, 33 ...... fan driven magnet, 34 …… Fan cover, 41 …… Motor rotor, 42
...... Pump drive magnet, 43 …… bracket, 45 …… drive magnet wheel.

Claims (2)

[Scope of utility model registration request] 1. A stator in which a coil is wound around a plurality of iron cores each divided into a fan shape and arranged in the circumferential direction to form a rotating magnetic field, and the stator is axially opposed to the stator. In a magnet pump in which a DC motor is constituted by a rotor composed of a plurality of permanent magnets provided in an alternating manner with N poles and S poles arranged in a circumferential direction, and the motor rotor is embedded in a pump impeller, On the other hand, a cooling device for a magnet pump, characterized in that a fan having a driven magnet rotated by the stator is provided at a position opposite to the motor rotor. 2. A stator in which a coil is wound around a plurality of iron cores, each of which is divided into a fan shape and arranged in the circumferential direction, to form a rotating magnetic field, and the stator is axially opposed to the stator. And a rotor composed of a plurality of permanent magnets having N poles and S poles alternately arranged in the circumferential direction, a DC motor is formed, and a pump drive magnet is attached to the motor rotor, and an axis is attached to the pump drive magnet. In a magnet pump in which a driven magnet embedded in a pump impeller facing each other in a direction is rotated by magnetic force, a fan having a driven magnet rotated by the stator at a position opposite to the motor rotor with respect to the stator A cooling device for a magnet pump, wherein the cooling device is provided.