JP3742777B2 - Magnetic levitation type magnet pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetically levitated magnet pump, and more particularly, a rotary shaft for transmitting rotation to an impeller is a sealless structure that does not penetrate the rear wall of the pump chamber, and is suitable for handling corrosive fluids. The present invention relates to a magnetic levitation type magnet pump.
[0002]
[Prior art]
Conventionally, as a magnet pump, a front casing is attached to the front part of a bracket constituting the pump to form a pump chamber, and a main shaft is provided in a bowl-shaped partition wall attached to the bracket at the rear of the pump chamber. In addition, a rotor unit having an impeller that rotates in the pump chamber is rotatably supported via a slide bearing, and an inner magnet is disposed on the rotor provided at the rear of the rotor unit, and an outer partition wall corresponding to the inner magnet is provided. to arrange outer magnet, which is attached to a magnetic coupling coupled to an output shaft of the prime mover such as a motor over to form a magnetic coupling by combining the rotor and the magnetic coupling magnetically, rotor unit by the rotation of the prime mover There has been proposed a magnet pump that is configured to be rotated synchronously.
[0003]
In the transfer of the chemical solution by the magnet pump of this configuration, the chemical solution is sucked from the suction port on the front surface of the impeller toward the impeller center, and is pressurized in the radial direction by the impeller, and the discharge port provided in the pump chamber corresponding to the impeller outer periphery. It is discharged from. At this time, the rotor unit moves forward due to the thrust force generated by the chemical pressure discharged from the impeller to the pump chamber acting on the back surface of the impeller, and this thrust force is applied to the thrust bearing provided on the main shaft on the back surface of the impeller. The front end face of the bearing is brought into contact with the bearing, and the load of the rotor unit is supported by the main shaft via the sliding bearing.
[0004]
In this type of magnet pump, the driven inner magnet that drives the impeller in the pump chamber and the outer magnet on the drive side outside the pump chamber are separated by a partition, and the main shaft is in the pump chamber and does not penetrate the partition. Since a shaft seal device that seals the portion where the shaft passes through the partition wall is unnecessary, it is frequently used as a no-maintenance pump with no liquid leakage for transferring highly corrosive chemicals.
[0005]
As another magnet pump, the applicant of the present application previously described that in the rotor unit, the rotor forming the magnetic coupling is a cylindrical rotor made of a non-magnetic material made of a highly conductive material. Is inserted into a gap formed in a double-structured inner and outer cylindrical can provided on the rear wall of the pump chamber, and permanent magnet cylinders are arranged oppositely on the outer and inner sides of the inner and outer cylindrical cans corresponding to this rotor. Has proposed a magnet pump having a configuration in which a permanent magnet cylinder is coupled to a magnetic coupling connected to an output shaft of a motor such as a motor (see Japanese Patent Application No. 2001-214772).
[0006]
This magnet pump has a cylindrical rotor in a magnetic field formed by permanent magnet cylinders arranged opposite to the inside and outside of the inner and outer cylindrical cans, and both permanent magnet cylinders rotate integrally by a prime mover to generate a rotating magnetic field. In this rotating magnetic field, an eddy current flows through the rotor under a voltage induced in the rotor, and an electromagnetic force acts between this current and the rotating magnetic flux, so that the rotor moves in the same direction as the permanent magnet cylinder. Asynchronously rotates and exhibits pump action. Here, when the rotor rotates within the gap between the inner and outer cylindrical cans, the chemical liquid filling the gap flows, and a wedge effect appears between the rotor and the inner and outer cylindrical cans, causing the rotor to rise into the gap and the rotor unit. On the other hand, the thrust force generated in the forward direction is generated by engaging the support protrusion provided on the support body on the suction port side of the pump chamber with the support recess provided in the center of the front surface of the impeller to hold the impeller in a fixed position. When the rotor unit is moved backwards, for example, by shaking the rotor unit due to vibration of the pump itself or pressure change of the chemical flowing in the pump, etc. The support protrusion provided on the wall is locked to hold the impeller temporarily to continue the rotation.
[0007]
[Problems to be solved by the invention]
As described above, as the internal structure of the pump, the bearing portion in the case of the magnet pump having a structure in which the rotor unit is supported via a slide bearing on a fixed main shaft having a straight diameter supports the load of the rotor unit. In addition, it has a complicated structure that receives the thrust force generated on the rotor unit, has a large friction loss, is not only difficult to maintain, but also hinders downsizing of the pump.
[0008]
In addition, in the case of a magnet pump having a structure in which a support recess and a support protrusion are provided on the front and rear center portions of the rotor unit and the corresponding fixed side as the internal structure of the pump, and both are engaged, the normal operation of the pump Sometimes it functions as a thrust bearing that receives the thrust generated in the axial direction with respect to the rotating part when the support protrusion engages with the support recess, but when the pump is stopped, the rotor unit is in a state where the support recess and the support protrusion are engaged. In order to apply a pressure load as a radial bearing that supports the load, the support recesses and the support protrusions are required to have a strong structure with high load resistance in terms of strength.
[0009]
Accordingly, an object of the present invention is to maintain the rotor unit having an impeller in a state where it is always levitated at the center of rotation in the pump chamber by a magnetic force of a permanent magnet without being influenced by the weight of the rotor unit. It is an object of the present invention to provide a high-performance magnetic levitation type magnet pump that does not require a radial bearing that supports the load of the rotor unit, simplifies the support structure of the rotor unit, and has excellent maintainability.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a magnetically levitated magnet pump according to the present invention includes a rotor unit having an impeller at a front portion disposed in a pump chamber, and a rotor provided at a rear portion of the rotor unit separated by a partition wall. In a magnet pump that is magnetically coupled to a prime mover and a magnet coupling, a rotating magnet is mounted in the middle of the rotor unit, and stationary magnets are arranged around the pump chamber in correspondence with the rotating magnet. The magnetic force generated by the magnetic field of the magnet acting on the magnetic field of the rotating magnet always directs the magnetic poles of the rotating magnet and stationary magnet so that the rotor unit is floated and held at the center of rotation . In addition to the magnetic force that floats to the center of rotation, the same magnetic force generates a thrust force that moves the rotor unit backward. To, to set the HaiSo location of the stationary magnets around the outer pump chamber, the rear portion of the partition wall of the pump chamber, characterized in that a brake cone which abuts the rear face center of the rotor.
[0011]
Here, the rotating magnet and the stationary magnet are both high-performance permanent magnets with strong magnetic poles. The form and the like are not particularly limited, and the stationary magnet may be a plurality of stationary magnets surrounding the rotating magnet, or may be a single ring-shaped stationary magnet. In short, overall, it is possible to maintain the state in which the rotor unit is levitated at the center of rotation by the magnetic force generated by the magnetic field of the stationary magnet acting on the magnetic field of the rotating magnet. The number and arrangement of magnets are set experimentally. In addition, in order to restrict the rotor unit from moving forward due to the thrust force generated by the chemical pressure discharged to the pump chamber acting on the back of the impeller during pump operation, the bearing on the suction port side of the pump chamber In addition, a conical braking cone that is in contact with the front center of the impeller is mounted.
[0012]
According to the magnet pump of the present invention configured as described above, the rotor unit is configured by the magnetic force generated by acting on the magnetic field of the plurality of stationary magnets arranged around the outside of the pump chamber and the magnetic field of the rotating magnet mounted on the rotor unit. Since the rotor is floated and held at the center of rotation, the rotor unit rotates in the floated state with the rotation of the prime mover during pump operation, and exhibits the pump action. During the operation of the pump, the thrust force generated by the chemical pressure discharged into the pump chamber acting on the impeller back surface causes the rotor unit to move forward. It rotates at a fixed position and exerts a pump action. In a normal state, that is, when the pump is in a stopped state, the rotor unit that tends to move backward due to the magnetic force stabilizes in a fixed position with the braking cone in contact with the center of the rear end surface. On the other hand, the rotor unit is moved forward, so that during the pump operation, the pressure load received by the braking cone that abuts against the center of the front surface of the impeller is reduced, thereby realizing efficient rotation.
[0013]
Therefore, the magnet pump according to the present invention does not require a radial bearing that supports the rotor unit in the pump as the pump internal structure, so the pump structure is simplified, there is no friction loss of the bearing portion, and excellent maintainability is achieved. A high-performance pump can be provided.
[0014]
In the present invention, a rotating magnet is mounted on the main shaft disposed in the middle part of the rotor unit so as to be separated from the front and rear, and stationary magnets are respectively disposed at two locations around the outside of the pump chamber corresponding to both rotating magnets. By setting the levitation force at the two locations to levitate the rotor unit to the levitation force commensurate with the weight of the impeller side and the rotor side, the rotor unit can float in a balanced manner regardless of its length, etc. The stability of the rotor unit can be improved.
[0015]
In addition, as described above, if the rotor unit is allowed to move slightly back and forth, and the brake cones are provided oppositely before and after the rotor unit, when the pump is idling or when air is sucked in, or cavitation occurs. When the thrust force is generated in the opposite direction, the rotor unit may move temporarily with the brake cone in contact with the center of its rear end, even if the rotor unit temporarily moves backward. Since it is regulated, the operation of the pump is not affected by the occurrence of a minor abnormality that occurs during operation of the pump.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a cross-sectional view of a magnetic levitation type magnet pump showing an embodiment of the present invention.
[0018]
In the figure, a front casing 2 is attached to the front part of the bracket 1 to form a pump chamber 3, a rear casing 4 is attached to the rear part of the bracket 1, and the rear casing 4 is squeezed toward the rear casing 4 side. A rear casing cover 5 having a cylindrical wall portion 5a is attached thereto, and the cylindrical wall portion 5a is concentrically inserted into the rear portion of the rear casing 4 to form a double structure inner / outer cylindrical can portion 6.
[0019]
A cylindrical rotor 9 made of a non-magnetic material made of a highly conductive material is connected to the rear part of the impeller 7 through the main shaft 8 in the pump chamber 3 to form a rotor unit 10. The rotor 9 is connected to the inner and outer cylindrical can parts 6. It is loosely inserted into the gap 6a.
[0020]
Permanent magnet cylinders 11 and 12 are arranged oppositely on the outer and inner sides of the inner and outer cylindrical can parts 6, both the magnet cylinders 11 and 10 are coupled to a magnetic coupling 13, and this magnetic coupling 13 is output from a motor 14 such as a motor. A magnet coupling is constituted by the permanent magnet cylinders 11 and 12 connected to the shaft 15 and the rotor 9 in the magnetic field. That is, when both the permanent magnet cylinders 11 and 12 are integrally rotated by the prime mover 14 and a rotating magnetic field passing through the inner and outer cylindrical can portions 6 is generated, an eddy current flows in the rotor 9 under a voltage induced in the rotor 9. The electromagnetic force acts between the current and the rotating magnetic flux so that the rotor 9 rotates asynchronously in the same direction as the rotation of the permanent magnet cylinders 11 and 12.
[0021]
A rotating magnet 16 is mounted on the main shaft 8 of the rotor unit 10, and a plurality of stationary magnets 17 (1 around the outside of the pump chamber 3 corresponding to the rotating magnet 16, that is, around the outside of the bracket 1 in FIG. 1. It may be a ring-shaped stationary magnet). The stationary magnet 17 is fixed to a magnet holder 18 and attached to the bracket 1 integrally with the magnet holder 18.
[0022]
Both the rotating magnet 16 and the stationary magnet 17 are high-performance permanent magnets having strong magnetic poles, and the magnetic force F1 generated by the magnetic field of the stationary magnet 17 acting on the magnetic field of the rotating magnet 16 through the bracket 1 (see FIG. 2). ), The rotor unit 10 is always kept in a state of being floated to the center of rotation. For this purpose, the magnetic poles of the rotating magnet 16 and the stationary magnet 17 are oriented, and the number and arrangement of the stationary magnets 17 are set experimentally.
[0023]
The suction of the pump chamber 3 corresponding to the center of the front surface of the impeller 7 in order to restrict the rotor unit 10 in the pump chamber 3 and floating in the center of rotation from moving forward (to the impeller 7 side). A conical braking cone 20 is provided on the support member 19 on the side of the mouth 3a, and the rear casing cover 4 is provided corresponding to the center of the rear surface of the rotor 9 in order to restrict the rotor unit 10 from moving backward. A braking cone 21 is provided on the inner end surface.
[0024]
In setting the positions of the rotating magnets 16 attached to the main shaft 8 and the corresponding stationary magnets 17 arranged around the outside of the bracket 1, in the embodiment, in addition to the magnetic force that causes the rotor unit 10 to float at the center of rotation. The position of the stationary magnet 17 is shifted forward with respect to the rotating magnet 16 so as to generate a thrust force that causes the rotor unit 10 to move rearward by the same magnetic force.
[0025]
As shown in FIG. 3, by setting the position of the stationary magnet 17 as described above, the magnetic force F2 that generates a thrust force that moves the rotor unit 10 rearward is a thrust that moves the rotor unit 10 forward when the pump is operated. Since the force is against the force, the pressure load applied to the braking cone 20 in contact with the center of the front surface of the impeller 7 is reduced.
[0026]
In the above-described configuration, in the magnetic levitation magnet pump according to the present invention, the rotating magnets 16 attached to the rotor unit 10 are surrounded by a plurality of stationary magnets 17 arranged around the outside of the bracket 1, and the magnetic field of the stationary magnets 17 is increased. With the magnetic force generated by acting on the magnetic field of the rotating magnet 16, the rotor unit 10 is constantly levitated and held at the center of rotation.
[0027]
During the pump operation, if the permanent magnet cylinders 11 and 12 rotate around the inner and outer cylindrical can portions 6 by the start of the prime mover 14 and a rotating magnetic field is generated, an eddy current flows through the rotor 9 in the rotating magnetic field and electromagnetic force acts. The rotor unit 10 rotates in the same direction as the rotating magnetic field while floating at the center of rotation. When the impeller 7 is rotated by the rotation of the rotor unit 10, the chemical liquid sucked into the impeller 7 from the suction port 3 a is pressurized in the radial direction by the impeller 7 and discharged from the outer periphery of the impeller 7 into the pump chamber 3. It is discharged out of the pump from the discharge port 3b.
[0028]
Thus, during the pump operation, the rotor unit 10 moves forward by the thrust force generated by the chemical pressure discharged to the pump chamber 3 acting on the back surface of the impeller 7. This movement is caused by the braking provided on the support member 19. The cone 20 abuts against the center of the front surface of the impeller 7 and is regulated, and the impeller 7 rotates at a fixed position and exhibits a stable pumping action.
[0029]
Further, when the rotor unit 10 is moved rearward by a reverse thrust force generated in the impeller 7 due to vibration or the like generated during pump operation, the braking cone 21 provided on the inner end surface of the rear casing cover 5 is moved to the rotor. 9 abuts against the center of the rear surface to restrict the backward movement of the rotor unit 10. Therefore, even if temporarily, the rotor unit 10 does not rub against the fixed portion and continues to rotate smoothly.
[0030]
FIG. 4 shows an embodiment in which the main shaft is applied to a relatively long rotor unit having a long configuration. In this embodiment, a rear casing 4 a extending rearward is coaxially provided in the bracket 1. And a cylindrical rotor 9 made of a non-magnetic material made of a highly conductive material is coupled to the rear portion of the impeller 7 through a long main shaft 8a to form a rotor unit 10a. In order to balance the rotor unit 10a when it floats, the rotating magnets 16a and 16b to be mounted on the main shaft 8a are mounted near both ends of the main shaft 8a at a predetermined interval, and correspond to both the rotating magnets 16a and 16b. A plurality of stationary magnets 17a and 17b (may be two ring-shaped stationary magnets) are arranged around the outside of the rear casing 4a. In this case, the front and rear stationary magnets 17a and 17b are located between the bracket 1 and the rear casing 4a, and both are fixed to the magnet holders 18a and 18b, and the interval between the front and rear stationary magnets 17a and 17b is held by the spacer 22. The rear magnet holder 18 b is fixed to the bracket 1 by using a holder presser 23.
[0031]
In this way, in the case of a configuration in which a levitation force is generated at two locations with a gap on the main shaft 8a, the levitation force at the two locations is set to a levitation force commensurate with the weight of the impeller 7 side and the rotor 9 side. Thus, the rotor unit 10a can be floated to the center of rotation in a balanced manner regardless of the length of the rotor unit 10a.
[0032]
Further, in the configuration in which the rotating magnets 16a and 16b are mounted at two locations on the main shaft 8a, depending on the position setting of the stationary magnets 17a and 17b corresponding to both the rotating magnets 16a and 16b, as shown in FIG. It is possible to freely direct the magnetic forces F3 and F4 or to direct the magnetic forces F3 and F4 in the same direction. Therefore, the magnitude and direction of the thrust force generated by the magnetic forces F3 and F4 are set with comprehensive consideration in accordance with the operating conditions of the pump.
[0033]
【The invention's effect】
The present invention is implemented in the form described above. According to the present invention, the rotor unit having the impeller is always centered on the rotation center in the pump chamber by the magnetic force of the permanent magnet without being influenced by its weight. Since it was kept floating and rotated by a prime mover via a magnet coupling to exert its pumping action, a radial bearing mechanism for supporting the rotor unit in the pump is not required, and the rotor unit This simplifies the support structure, provides excellent maintainability, and enables high performance and miniaturization of the pump.
[Brief description of the drawings]
FIG. 1 is a sectional view of a magnetic levitation magnet pump showing an embodiment of the present invention.
FIG. 2 is a schematic longitudinal sectional view of a rotor unit for explaining a state in which the rotor unit floats to the center of rotation by magnetic force.
FIG. 3 is a schematic side view of a rotor unit for explaining a magnetic force that generates a thrust force in the rearward direction with respect to the rotor unit.
FIG. 4 is a cross-sectional view of a magnetic levitation magnet pump showing an embodiment of the present invention applied to a relatively long rotor unit.
FIG. 5 is a schematic side view of a rotor unit for explaining magnetic force that generates thrust force in two directions with respect to the rotor unit shown in FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bracket 2 Front casing 3 Pump chamber 3a Suction port 3b Discharge port 4, 4a Rear casing 5 Rear casing cover 5a Cylindrical wall part 6 Inner / outer cylindrical can part 6a Gap 7 Impeller 8, 8a Main shaft 9 Rotor 10, 10a Rotor unit 11, 12 permanent magnet cylinder 13 magnetic coupling 14 prime mover 15 output shaft 16, 16a, 16b rotating magnet 17, 17a, 17b stationary magnet 18, 18a, 18b magnet holder 19 bearing member 20, 21 braking cone 22 spacer 23 retainer presser

Claims (2)

In a magnet pump in which a rotor unit having an impeller at the front is disposed in a pump chamber, and a rotor provided at the rear of the rotor unit is magnetically coupled to an external prime mover separated by a partition wall via a magnet coupling, the rotor A rotating magnet is attached to the middle part of the unit, stationary magnets are arranged around the pump chamber corresponding to the rotating magnets, and the magnetic force generated by the magnetic field of these stationary magnets acting on the magnetic field of the rotating magnet, Orient the magnetic poles of the rotating and stationary magnets so that the rotor unit floats to the center of rotation , and in addition to the magnetic force that causes the rotor unit to levitate to the center of rotation, the same magnetic force causes the rotor unit to move backward. Set the position of the stationary magnet around the outside of the pump chamber so that a thrust force that moves toward the In the partition wall, the magnetic floating type magnetic drive pump, characterized in that a brake cone which abuts the rear face center of the rotor.   It is characterized in that a rotating magnet is mounted on the main shaft arranged in the middle part of the rotor unit so as to be separated from the front and rear, and stationary magnets are arranged at two locations around the outside of the pump chamber corresponding to both rotating magnets. The magnetic levitation type magnet pump according to claim 1.

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