JP7303503B2 - magnetic levitation pump - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump that levitates a rotating body by magnetic force and supports it in a non-contact state.

As a blood pump installed in an extracorporeal circulation circuit to ensure blood flow during cardiac surgery, a mono-pivot bearing type in which an impeller as a rotating body accommodated in a housing is supported by a single bearing on the axis of rotation. of blood pumps are widespread. However, in the structure in which the impeller rotates while contacting the housing, it is not possible to completely eliminate the risk of causing problems such as the destruction of blood cells or the generation of thrombus due to friction at the contact portion. It is essential to take measures such as the combined use of As one attempt to solve such problems, a magnetic levitation type blood pump has been proposed in which an impeller is magnetically levitated and supported in a non-contact manner. For example, by connecting each of the plurality of electromagnetic coils provided on the housing side to an AC power supply via a capacitor to form a resonance circuit, and applying an AC voltage to the resonance circuit to excite the electromagnetic coil, A pump has been proposed in which an impeller is levitated by generating a magnetic attraction force in the axial direction between an electromagnetic coil and a magnetic body on the impeller side (see Patent Document 1). In this type of pump, the impeller rotates in a non-contact state with respect to the housing, so it is possible to eliminate the possibility of causing problems such as blood cell destruction or thrombus formation due to mechanical friction.

Japanese Patent Publication No. 2007-518464

When an alternating voltage is applied to the electromagnetic coil as in the pump of Patent Document 1 described above, the change in the magnetic gap between the electromagnetic coil and the magnetic body causes the magnetic gap to return to its original state. A self-equilibrium effect occurs. As a result, it is expected that the support rigidity of the rotating body such as the impeller is increased, and the process of controlling the voltage so as to cancel out the position change of the rotating body can be omitted. However, in the pump of Patent Document 1, among the plurality of electromagnetic coils arranged in the circumferential direction of the rotating body, two adjacent electromagnetic coils constitute a set of electromagnets. If the coil has the S pole, the electromagnetic coil on the other side has the N pole, and the magnetic flux passing through the rotor flows in its circumferential direction. will flow. Therefore, the magnetic fluxes flow in the opposite directions between the electromagnets, causing an interference effect, which may destabilize the magnetic force and make it difficult to rotate the rotating body smoothly.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a magnetically levitated pump that can stably levitate and smoothly rotate a rotating body using an AC power source.

A magnetically levitated pump according to one aspect of the present invention comprises a housing (10) having a suction port (11a) and a discharge port (12a), and housed in the housing in a rotatable state about an axis (AX). a rotating body (20) that rotates about the axis to generate a flow in the housing from the suction port to the discharge port; a magnetic body (32) provided on the rotating body; a plurality of electromagnetic coils (34) provided on the housing side so as to be aligned with each other, and each electromagnetic coil is connected to an alternating current power supply (AC) via a capacitor (55) to form a resonance circuit (54). a magnetic support means (3) for supporting the rotor in a non-contact manner with respect to the housing by applying an AC voltage from the AC power source to the resonance circuit to excite the electromagnetic coil; around the axis, and each of the plurality of electromagnetic coils is arranged such that the magnetic flux generated by each electromagnetic coil passes between the inner peripheral side and the outer peripheral side of the rotating body. It is provided so as to flow along the radial direction of the rotating body.

According to the above aspect, first, an alternating magnetic field is generated by applying an alternating voltage to the resonant circuit including the electromagnetic coil, and the resulting magnetic force levitates the rotating body including the magnetic material. Compared to the case where a magnetic field is generated by applying a DC voltage, it is possible to relatively widen the magnetic gap between the electromagnetic coil and the magnetic body, generate a larger magnetic force, and increase the support rigidity of the rotating body. can. Moreover, since the electromagnetic coils are provided so that the magnetic flux flows along the radial direction of the rotor between the inner and outer circumferences of the rotor, the direction of the magnetic flux is reversed between the electromagnetic coils adjacent in the circumferential direction. There is no risk of interference due to Therefore, variations in magnetic flux distribution in the circumferential direction of the rotor can be suppressed, and the rotor can be stably levitated and smoothly rotated.

In the magnetic levitation pump of the aspect described above, the magnetic body may include a plurality of segments (36) arranged in the circumferential direction of the rotor, and the segments may be separated so as not to contact each other. According to this, the direction of the magnetic flux flowing through each segment is generally restricted to the radial direction of the rotating body, and the interference of magnetic forces between the segments can be suppressed. Therefore, it is possible to support the rotating body more stably.

In the magnetically levitated pump of the above aspect, the magnetic support means applies an AC voltage having a frequency higher than the resonance frequency of the resonance circuit when the rotating body is at a predetermined position with respect to the direction of the axis to the resonance circuit. Voltage conversion means (52) may be provided for converting the AC voltage from the AC power source to be applied. According to this, a self-balancing action occurs between the electromagnetic coil and the magnetic body, and when the rotating body is displaced from a predetermined position in the axial direction, the magnetic force increases or increases so as to return the rotating body to its original position. Decrease. Therefore, the rotating body can be supported more stably. It is possible to omit the process of controlling the AC voltage applied to the electromagnetic coil according to the position of the rotating body. Accordingly, there is no need to provide sensors for position detection on the rotating body or to provide wiring for outputting the output signals of the sensors to the outside of the housing. As a result, the reliability of the pump can be improved, and the pump can be operated for a long period of time in a maintenance-free state.

Further, the plurality of electromagnetic coils may be divided into a plurality of groups (51A, 51B, 51C) and arranged, and each group may be provided with the voltage conversion means. According to this, the frequency of the voltage applied to each of the electromagnetic coils can be individually adjusted at least in group units. As a result, it is possible to suppress or eliminate variations in magnetic flux distribution due to individual differences of electromagnetic coils, etc., and to more stably support the rotating body.

The magnetic levitation pump of the above aspect may be configured as a blood pump for an extracorporeal circulation circuit. By applying the present invention to a blood pump, the function and effect of stably supporting the rotating body in a non-contact state and smoothly rotating it can be utilized to provide highly reliable blood without the risk of blood cell destruction or thrombus formation. A pump can be provided.

In the above description, the reference numerals of the attached drawings are added in parentheses for easy understanding of the present invention, but the present invention is not limited to the illustrated embodiments.

1 is a perspective view showing the appearance of a blood pump according to one embodiment of the present invention; FIG. FIG. 2 is a plan view of the blood pump shown in FIG. 1; FIG. 2 is a side view of the blood pump shown in FIG. 1; Sectional drawing along the IV-IV line of FIG. The perspective view of a coil module. The bottom view of a coil module. FIG. 4 is an axial cross-sectional view of the coil module; A perspective view of an impeller. A plan view of the impeller. An axial sectional view of an impeller. FIG. 4 is a diagram showing an example of the configuration of a drive circuit for the magnetic bearing unit; FIG. 4 is a diagram showing an example of a correspondence relationship between a magnetic gap between an electromagnetic coil and a target and a magnetic force acting therebetween;

A magnetic levitation pump according to one embodiment of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show the configuration of a blood pump 1 as an example of a magnetically levitated pump. A blood pump 1 is a pump incorporated in an extracorporeal circulation circuit to be connected to a patient undergoing heart surgery or the like, and includes a pump unit 2, a magnetic bearing unit 3, and a drive unit 4 (FIG. 4). . The magnetic bearing unit 3 corresponds to an example of magnetic support means, and the drive unit 4 corresponds to an example of drive means.

As shown in FIGS. 1-4, the pump unit 2 has a housing 10. As shown in FIG. The housing 10 is configured as a hollow container having a flat, generally disk-like appearance with a large diameter relative to its thickness. A suction pipe 11 is provided in the center of the upper surface of the housing 10 so as to extend upward, and a discharge pipe 12 is provided in the outer periphery of the housing 10 so as to extend in the tangential direction of the housing 10 . The opening at the upper end of suction tube 11 functions as suction port 11 a for taking blood into housing 10 , and the opening at the tip of discharge pipe 12 functions as discharge port 12 a for sending blood out of housing 10 . A coil module 31 is provided around the suction pipe 10 . The coil module 31 is a component of the magnetic bearing unit 3, and details thereof will be described later.

As shown in FIG. 4, an impeller 20 as an example of a rotating body is provided inside the housing 10 . The impeller 20 is housed in the housing 10 so as to be rotatable about its axis AX. Axis AX is coaxial with suction pipe 11 . The impeller 20 is provided with a plurality of blades 21 (only some of which are shown in the drawing) which are circumferentially spaced at regular intervals. Each blade 21 extends from the radial center side toward the outer peripheral side. Centrifugal force acts on the blood in housing 10 by rotating impeller 20 around axis AX, thereby forming a flow of blood in housing 10 from suction port 11a to discharge port 12a. In other words, the blood pump 1 is configured as a centrifugal pump, which is a type of non-displacement pump.

A target 32 is provided on the upper surface side of the impeller 20 . The target 32 is an example of a magnetic material included in the magnetic bearing unit 3, and details thereof will be described later. On the other hand, an annular portion 22 is formed on the lower surface side of the impeller 20 and on the outer peripheral side. A permanent magnet 40 is provided in the annular portion 22 . Permanent magnet 40 is a component of drive unit 4 .

The drive unit 4 includes a permanent magnet 40 in the impeller 20, a permanent magnet 42 embedded in a driving body 41 arranged below the housing 10, and an electric motor (not shown) that rotates the driving body 41 around the axis AX. including the motor. Permanent magnets 40 , 42 are arranged to attract each other to form a magnetic coupling 43 . When the driving body 41 is rotationally driven by the electric motor, the rotational torque is transmitted to the impeller 20 via the magnetic coupling 43, thereby rotationally driving the impeller 20 around the axis AX. A drive unit that rotates an impeller using a magnetic coupling is employed in various blood pumps. The illustrated drive unit 4 is an example, and its configuration may be changed as appropriate. For example, in the illustrated example, the permanent magnets 40 and 42 are arranged so as to attract each other in the direction of the axis AX (hereinafter sometimes referred to as the axial direction). Permanent magnets may be arranged so as to attract each other in a direction.

Next, details of the magnetic bearing unit 3 will be described with reference to FIGS. The magnetic bearing unit 3 generates an alternating magnetic field with the coil module 31 on the housing 10 side, and the magnetic force attracts the target 32 on the impeller 20 side in the axial direction to levitate the impeller 20 against gravity. are supported on the housing 10 in a non-contact state. 5 to 7 show details of the coil module 31. FIG. The coil module 31 includes a magnetic core 33 (only a portion of which appears in FIG. 5), a plurality of electromagnetic coils 34 wound around the magnetic core 33, and a holding plate 35 attached to the upper surface side of the magnetic core 33. there is The magnetic core 33 is made of a soft magnetic material. For example, the magnetic core 33 may be formed as a metal magnetic core made of silicon steel or the like, or may be formed as a powder magnetic core or a ferrite magnetic core. However, from the viewpoint of suppressing eddy-current loss and accompanying heat generation when an alternating magnetic field is applied, it is preferable to form the magnetic core 33 as a powder magnetic core or a ferrite magnetic core.

A plurality of winding cores 33a are provided in the magnetic core 33 at regular intervals in the circumferential direction. The winding core 33a has a prism shape extending linearly from the upper end of the magnetic core 33 to the lower end. An electromagnetic coil 34 is wound around each winding core 33a. As an example, the number of winding cores 33a is six. Therefore, the coil module 31 has a total of six electromagnetic coils 34, and the circumferential pitch between the electromagnetic coils 34 is 60°. The configurations of the electromagnetic coils 34 are identical to each other. That is, the electromagnetic coils 34 have the same material and wire diameter, and the same number of turns. Furthermore, the winding directions of the electromagnetic coils 34 are also the same. For example, all electromagnetic coils 34 are wound along the direction indicated by arrow WD in FIGS. Thereby, each electromagnetic coil 34 constitutes an electromagnet by itself. Therefore, in the coil module 31, six electromagnets with the same characteristics are symmetrically arranged around the axis AX. The magnetic flux generated by each electromagnetic coil 34 flows around the winding core 33a between the radially inner and outer peripheral sides of the magnetic core 33, as indicated by arrows MF in FIG. 7, for example. That is, at the target 32 on the impeller 20 facing the lower surface of the coil module 31, the magnetic flux generated by the electromagnetic coil 34 flows radially between the inner and outer peripheral sides of the impeller 20. Become. Since an alternating excitation current flows through the electromagnetic coil 34, the magnetic field generated by the electromagnetic coil 34 is an alternating magnetic field. Therefore, the direction of the magnetic flux alternates between the direction of the arrow MF in FIG. 7 and its opposite direction.

As described above, each of the electromagnetic coils 34 is provided so that the magnetic flux flows between the inner peripheral side and the outer peripheral side of the impeller 20 along the radial direction. Therefore, there is no possibility that magnetic flux interference will occur between the electromagnetic coils 34 adjacent in the circumferential direction and that the magnetic flux distribution in the circumferential direction will be disturbed. Therefore, the impeller 20 can be stably floated and rotated. It is possible to reduce the space in the circumferential direction required for providing one electromagnet, compared to the case where one electromagnet is configured by combining a pair of electromagnetic coils arranged in the circumferential direction. The arrangement of the electromagnetic coils 34 is such that the adjustment resolution of the magnetic flux distribution can be increased by arranging a large number of the electromagnetic coils 34 relatively densely in the circumferential direction, and a plurality of the electromagnetic coils 34 can be provided even in the impeller 20 with a relatively small diameter. There is also a high degree of freedom in design.

A holding plate 35 is provided as a structure for holding the magnetic core 33 and the electromagnetic coil 34 . By fixing the holding plate 35 to a support structure (not shown), the coil module 31 is supported at a fixed position on the upper surface side of the housing 10 . The magnetic core 33 and the holding plate 35 are formed with through holes 33b and 35a through which the suction pipe 11 of the housing 10 is passed.

8-10 show details of the impeller 20. FIG. As described above, the impeller 20 is provided with the target 32 of the magnetic bearing unit 3 . The target 32 is rotated around the axis AX by the drive unit 4 as part of the impeller 20 . On the target 32, segments 36 of the same shape and size (only some of them are denoted by reference numerals in the figure) are arranged in the circumferential direction at a constant pitch. In other words, the target 32 has a configuration in which the segments 36 are arranged symmetrically around the axis AX. The target 32 has a disk-like appearance as a whole. The segments 36 are separated so that they do not touch each other. As a result, the direction of the magnetic flux flowing through the target 32 can be substantially aligned in the radial direction, thereby suppressing the interference effect of the magnetic force. In addition, it is possible to prevent eddy currents from coming and going between the segments 36 when an alternating magnetic field is applied to the target 32, thereby suppressing heat generation of the target 32 due to eddy current loss.

Each segment 36 is made of a soft magnetic material like the magnetic core 33 . For example, the segments 36 may be formed using a material such as silicon steel, or the segments 36 may be formed using a dust core material or ferrite. As for the segments 36 as well, from the viewpoint of suppressing eddy current loss and accompanying heat generation, it is preferable to form the segments 36 with a dust core material or ferrite.

A through hole 32 a is formed in the center of the target 32 . The blood taken into the suction pipe 11 passes through the through hole 32a, flows into the impeller 20 from the central hole 20a of the impeller 20, and flows out from the opening 20b on the outer periphery of the impeller 20 toward the discharge pipe 12 of the housing 10. do.

In order to excite the electromagnetic coil 34 and levitate the impeller 20, the magnetic bearing unit 3 is further provided with a drive circuit 50 shown in FIG. The drive circuit 50 has three sets of drive units 51A, 51B, and 51C (hereinafter sometimes represented by reference numeral 51). Each drive unit 51 includes one function generator 52 that converts an AC voltage supplied from an AC power supply AC into an AC voltage having a predetermined frequency and a predetermined waveform and outputs the AC voltage, and amplifies the AC voltage output from the function generator 52. and one power amplifier 53 that The function generator 52 corresponds to an example of voltage conversion means. Two resonance circuits 54 are further connected to one power amplifier 53 . As a result, the electromagnetic coils 34 are divided into a plurality of drive units 51 , and each drive unit 51 constitutes one group including two resonance circuits 54 . Each resonance circuit 54 is formed by connecting one electromagnetic coil 34 and a capacitor 55 in series. That is, the resonance circuit 54 is configured as an LCR circuit including the electromagnetic coil 34 as a coil.

The correspondence relationship between the drive units 51A, 51B, 51C and the electromagnetic coils 34 is set so that the electromagnetic coils 34 arranged with a 60° shift in the circumferential direction form a pair and are included in the same drive unit 51 . In FIG. 6, the electromagnetic coil 34 included in the driving section 51A is denoted by G1, the electromagnetic coil 34 included in the driving section 51B is denoted by G2, and the electromagnetic coil 34 included in the driving section 51C is denoted by G3. be distinguished. One of the reasons why the electromagnetic coils 34 are separately arranged in the plurality of drive units 51 is that the magnetic field generated by each electromagnetic coil 34 can be adjusted separately for each drive unit 51, thereby To suppress or eliminate variations in magnetic flux distribution caused by individual differences of 34. The drive unit 51 may be provided in one-to-one correspondence with the resonance circuit 54 . That is, each of the electromagnetic coils 34 may be connected to different funk generators 52 and power amplifiers 53 . In short, the drive circuit 50 may be configured such that at least one pair of the electromagnetic coil 34 and the capacitor 55 are connected to one drive section 51 .

The frequency of the AC voltage output by the function generator 52 is set to a frequency somewhat higher than the resonance frequency of the resonance circuit 54 when the impeller 20 is at an appropriate position in the axial direction. When an alternating magnetic field is generated by applying an AC voltage to a resonant circuit containing a coil, the magnetic force obtained by the magnetic field reaches its maximum value when the resonant frequency of the resonant circuit and the frequency of the AC voltage applied to the coil match. , and decreases remarkably when the frequency of the AC voltage moves away from the vicinity of the resonance frequency. On the other hand, the resonance frequency of the resonance circuit changes according to the magnetic gap between the coil and the magnetic body. As the magnetic gap increases, the coil inductance decreases and the resonance frequency increases. inductance increases and the resonance frequency decreases. In the illustrated blood pump 1, the gap C between the electromagnetic coil 34 and the target 32 (specifically, the segment 36) shown in FIG. 7 corresponds to the magnetic gap. increases, and if the magnetic gap C decreases, the resonant frequency of the resonant circuit 54 decreases.

FIG. 12 shows the relationship between the magnetic gap C and the magnetic force with which the electromagnetic coil 34 attracts the target 32 . The solid line in FIG. 12 shows the relationship between the change in the magnetic gap C and the magnetic force, with the magnetic gap when the resonance frequency of the resonance circuit 54 coincides with the frequency of the AC voltage applied to the electromagnetic coil 34 as the reference gap Cr. there is The magnetic force has a maximum value Fmax at the reference gap Cr, and significantly decreases as the magnetic gap increases or decreases from the vicinity of the reference gap Cr. The reason is that the frequency of the alternating voltage applied to the electromagnetic coil 34 is constant and the resonance frequency of the resonance circuit 54 increases or decreases as the magnetic gap moves away from the reference gap Cr.

On the other hand, if the magnetic gap when the impeller 20 is at the proper position in the axial direction is defined as a proper gap Cs, the electromagnetic coil 34 has a frequency somewhat higher than the resonance frequency of the resonance circuit 54 corresponding to the proper gap Cs. Since the AC voltage is applied, in FIG. 12, the proper gap Cs is smaller than the reference gap Cr that gives the maximum magnetic force Fmax. Therefore, if the actual magnetic gap increases from the appropriate gap Cs, the magnetic force F also increases, and if the actual magnetic gap decreases from the appropriate gap Cs, the magnetic force F also decreases. Since the magnetic force acts as a force that pulls the target 32 upward in the axial direction, if the impeller 20 is displaced below the proper position that provides the proper gap Cs, the upward magnetic force increases so as to cancel it, and the impeller 20 moves toward the proper gap. If it is displaced above the appropriate position that gives Cs, the upward magnetic force will decrease so as to cancel it. In other words, a self-balancing effect acts between the electromagnetic coil 34 and the target 32 to suppress axial displacement of the impeller 20 from its proper position.

Therefore, a constant AC voltage is sufficient to be applied to the electromagnetic coil 34, and control to change the excitation voltage of the electromagnetic coil 34 according to the positional variation of the impeller 20 is unnecessary. Moreover, since there is no need to detect changes in the position of the impeller 20, there is no need to arrange sensors on the impeller 20, which is a rotating body, and extract signals out of the housing 10. FIG. As a result, the configuration inside the housing 10 can be simplified, and the risk of failure or disconnection of sensors does not occur, so the reliability of the blood pump 1 can be enhanced. The proper gap Cs may be determined according to the position at which the impeller 20 should be rotated in the axial direction. On the other hand, the reference gap Cr may be set according to the degree of self-balancing effect acting between the electromagnetic coil 34 and the target 32, and the output frequency of the function generator 52 may be set according to the reference gap Cr. FIG. 12 shows the relationship between the magnetic gap and the magnetic force when a DC voltage is applied. It can be understood that there are many inconveniences compared to the magnetic bearing unit 3 of this embodiment, such as the need to set it as small as possible.

The AC voltage output from the function generator 52 may be sinusoidal or rectangular. Using the square-wave AC voltage as the excitation voltage has the advantage that the configuration of the drive circuit 50 can be significantly reduced in size. Note that the phases of the AC voltages output from the function generator 52 are set to match between all the electromagnetic coils 34 . As a result, it is possible to uniformly change the alternating magnetic field over the entire circumference of the impeller 20 and further suppress variations in the magnetic flux distribution in the circumferential direction. However, by shifting the phase of the AC voltage by 120° for each of the drive units 51 described above, a rotational force may be applied to the impeller 20 in addition to the supporting force of the impeller 20 . The drive unit 4 may be omitted if sufficient rotational force can be obtained by such a configuration. Alternatively, a rotating magnetic field may be generated by the electromagnetic coil 34 so as to assist the rotating force applied by the drive unit 4 .

As described above, according to the blood pump 1 of this embodiment, the resonance circuit 54 is formed by connecting the capacitor 55 to the electromagnetic coil 34 of the magnetic bearing unit 3, so that an AC voltage near the resonance frequency is applied. The impeller 20 can be supported with sufficient rigidity by utilizing the effect of the remarkable increase in magnetic force seen when this occurs. Moreover, by setting the frequency of the AC voltage applied to the electromagnetic coils 34 as described above, the self-balancing property is generated and the direction of the magnetic flux is set so as not to cause interference between the electromagnetic coils 34. , the impeller 20 can be stably supported, and it is also possible to omit the process of detecting the position of the impeller 20 and controlling the excitation voltage in order to ensure its stability. As a result, it is possible to provide a highly reliable blood pump that can maintain smooth operation over a long period of time by taking full advantage of the magnetic levitation type using an alternating magnetic field.

The present invention is not limited to the embodiments described above, and may be implemented in various modified or modified forms. For example, in the above embodiment, the plurality of electromagnetic coils 34 are divided into the plurality of drive units 51, and the frequency and waveform of the excitation voltage are set for each drive unit 51. However, the AC voltage output from the same function generator 52 may be supplied to all the electromagnetic coils 34. The number of electromagnetic coils 34 may be appropriately changed according to the configuration of the pump. By arranging the target 32 also on the lower surface side of the impeller 20 and arranging the coil module 31 also on the lower part of the capacitor 55 so as to face the target 32, the impeller 20 is attracted by magnetic force from both sides in the axial direction and is kept in a non-contact state. You can support it.

When the magnetic levitation pump of the present invention is used as a blood pump for an extracorporeal circulation circuit, it can stably support a rotating body in a non-contact state and smoothly rotate it. A highly reliable blood pump with no risk of occurrence can be realized. However, the application of the magnetically levitated pump of the present invention is not limited to the extracorporeal circulation circuit, and may be configured as a pump for various applications.

1 Blood pump (magnetic levitation pump)
3 Magnetic bearing unit (magnetic support means)
4 drive unit (driving means)
REFERENCE SIGNS LIST 10 housing 11a suction port 12a discharge port 20 impeller (rotating body)
31 coil module 32 target (magnetic material)
33 magnetic core 34 electromagnetic coil 36 segment 50 drive circuit 51A, 51B, 51C drive unit (group)
52 function generator (voltage conversion means)
54 resonance circuit 55 capacitor

Claims (1)

a housing having an inlet and an outlet;
a rotating body that is housed in the housing in a rotatable state about an axis and that rotates about the axis to generate a flow in the housing from the suction port toward the discharge port;
A resonance circuit including a magnetic body provided on the rotating body side and a plurality of electromagnetic coils provided on the housing side so as to be aligned around the axis, each electromagnetic coil being connected to an AC power supply via a capacitor. is formed, and an AC voltage is applied from the AC power supply to the resonance circuit to excite the electromagnetic coil, thereby supporting the rotating body in a non-contact manner with respect to the housing;
driving means for rotating the rotating body around the axis,
each of the plurality of electromagnetic coils is provided so that the magnetic flux generated by each electromagnetic coil flows along the radial direction of the rotating body between the inner peripheral side and the outer peripheral side of the rotating body;
The magnetic levitation pump, wherein the magnetic body includes a plurality of segments arranged in a circumferential direction of the rotor, and the segments are separated so as not to contact each other.

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