JP2002130177A - Magnetically levitating pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetically levitating pump capable of improving support rigidity of an impeller by making the shaft directional length of the pump compact, and additionally arranging a radial directional impeller support part using attraction force of permanent magnets. SOLUTION: A soft magnetic member 126 is arranged on the inner diameter side on one surface of the impeller 123, an electromagnet 141 is arranged so as to be opposed to this member, the permanent magnet 124 is arranged on the outer diameter side of the impeller 123, the permanent magnet 114 is arranged on a rotor 112 so as to be opposed to this permanent magnet, a ferromagnetic substance 144 is arranged on the other surface of the impeller 123, the permanent magnet 148 is arranged in a casing 121 so as to be copposed to this ferromagnetic substance, the impeller 123 is magnetically levitated thereby, a motor rotor 152 is rotated by a motor stator 151, and the impeller 123 is rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation pump, and more particularly to a magnetic levitation pump using a magnetic bearing and used for medical equipment such as an artificial heart.

[0002]

2. Description of the Related Art FIG. 5 is a view showing a conventional magnetic levitation pump. In particular, FIG. 5A is a longitudinal sectional view, and FIG.
FIG. 5B is a sectional view taken along line AA of FIG.

First, a conventional magnetic levitation pump will be described with reference to FIG. As shown in FIG. 5A, the magnetic levitation pump 1 includes a motor unit 10, a pump unit 20, and a magnetic bearing unit 30. A pump chamber 22 is provided in a casing 21 of the pump section 20, and an impeller 23 rotates in the pump chamber 22. As shown in FIG. 5B, the impeller 23 has a plurality of blades 27 and is formed in a spiral shape.

[0004] The casing 21 is made of a non-magnetic member, and the impeller 23 is made of a permanent magnet 24 constituting an uncontrolled magnetic bearing.
And a soft magnetic member 26 corresponding to the rotor of the controlled magnetic bearing. The permanent magnet 24 is divided in the circumferential direction of the impeller 23, and magnets adjacent to each other are magnetized with magnetic poles in opposite directions. The rotor 12 supported by the bearing 17 is provided outside the pump chamber 22 so as to face the side of the impeller 23 having the permanent magnet 24. The rotor 12 is driven and rotated by a motor 13. The rotor 12 is provided with the same number of permanent magnets 14 as the impeller 23 so as to face the permanent magnets 24 of the impeller 23 and to apply an attractive force. In the permanent magnet 14, magnets adjacent to each other are magnetized to magnetic poles in opposite directions.

On the other hand, the impeller 23 is opposed to the side of the impeller 23 having the soft magnetic member 26 so as to be balanced with the attraction force of the permanent magnets 24 and 14 in the pump chamber 22.
Three or more electromagnets 31 and position sensors 32 are provided on the magnetic bearing 30 on the circumference so as to be able to be held at the center of the casing 21. The shape of the electromagnet 31 is C-shaped, and the position sensor 32 is a magnetic sensor.

In the magnetic levitation pump 1 configured as described above, the permanent magnet 14 embedded in the rotor 12
An axial absorbing force acts between the impeller 23 and the permanent magnet 24 provided on the impeller 23. The impeller 23 is rotationally driven by the magnetic coupling utilizing this attraction force, and a radial support rigidity is obtained. An electric current is applied to the coil of the C-shaped electromagnet 31 so as to balance this attractive force, and the impeller 23 floats. A motor 13 in which the rotor 12 includes a motor rotor 15 and a motor stator 16
, The permanent magnets 14 and 24 form a magnetic pole coupling, the impeller 23 rotates and fluid is sucked in from the inlet 60 and discharged from the outlet 70. The impeller 23 is connected to the rotor 12 by the casing 21.
The fluid (the blood when used as a blood pump) discharged from the magnetic levitation pump 1 is kept in a clean state because the fluid is isolated from the magnet and is not contaminated by the electromagnet 31.

[0007]

In the magnetic levitation pump 1 shown in FIG. 5, there is a problem that the axial length of the electromagnet 31 of the magnetic bearing portion 30 is long and the axial size of the entire pump becomes large. . In particular, when this pump is used for an implantable blood pump, it is required to be as small as possible.

Further, the magnetic levitation pump 1 shown in FIG.
Then, the impeller 23 is supported in the radial direction by an attractive force between the permanent magnet 14 embedded in the rotor 12 and the permanent magnet 24 provided on the impeller 23, and the magnetic coupling utilizing this attractive force is used. The bearings are configured with uncontrolled magnetic bearings, and their support stiffness is lower than that of the impeller rotation axis supported by the control of the attraction force of the electromagnet, and their support stiffness can be improved in consideration of disturbance resistance. desirable.

[0009] Therefore, a main object of the present invention is to reduce the axial length of the pump and at the same time, to additionally arrange a radial impeller support portion utilizing the attractive force of a permanent magnet. An object of the present invention is to provide a magnetic levitation pump capable of improving the support rigidity of an impeller.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a magnetic levitation pump in which a disk-shaped impeller for sending a liquid is magnetically levitated and rotated, and a first ferromagnetic material is provided on one surface of the impeller. A second ferromagnetic material is provided on the other surface in the circumferential direction. The second ferromagnetic material is disposed on one side of the impeller so as to face the first ferromagnetic material, and the impeller is attracted to one side. An electromagnet, a permanent magnet arranged on the other side of the impeller in the circumferential direction so as to face the second ferromagnetic body, and an electromagnet arranged on one side of the impeller, and rotating the driving force in a non-contact manner with the impeller. A rotating force transmitting means for transmitting the torque, controlling the current flowing through the electromagnet so that the attractive force of the permanent magnet to the second ferromagnetic material and the attractive force of the electromagnet to the first ferromagnetic material are balanced; Is magnetically levitated.

By arranging the electromagnet of the magnetic bearing on the side of the rotational force transmitting means in this way, the length in the pump axial direction can be shortened, and the size can be reduced. Also,
By adding an uncontrolled magnetic bearing using a permanent magnet, the radial rigidity of the impeller can be improved.

Also, a first permanent magnet is provided on one side of the impeller in the circumferential direction, and the rotational force transmitting means faces the second permanent magnet on the other side and faces the first permanent magnet of the impeller. It is characterized by including a rotor provided with a permanent magnet and having one surface serving as a motor rotor, and a motor stator provided facing one side of the motor rotor.

Thus, by arranging the electromagnet on the motor side, the axial length of the magnetic bearing can be reduced.

Further, the first ferromagnetic material of the impeller is provided on the inner diameter side of the first ferromagnetic material so as to face the electromagnet.
Is characterized in that the permanent magnet is provided on the outer diameter side in the circumferential direction, the electromagnet is provided on the inner diameter side, and the motor rotor is provided on the outer diameter side.

Further, the first permanent magnet of the impeller is provided on the inner diameter side in the circumferential direction, the first ferromagnetic material of the impeller is provided on the outer diameter side to face the electromagnet, and the motor rotor has the inner diameter. And the electromagnet is provided on the outer diameter side.

By arranging the electromagnet on the outer diameter side in this manner, the winding space of the electromagnet can be increased.

Further, the rotational force transmitting means includes a motor rotor provided on one side of the impeller and a motor stator arranged opposite to the motor rotor.

This eliminates the need for a rotor and a motor bearing for supporting the rotor.

[0019]

FIG. 1 is a longitudinal sectional view showing a magnetic levitation pump according to an embodiment of the present invention. Referring to FIG. 1, a magnetic levitation pump includes a motor unit 110 and a pump unit 12.
0 and the anti-motor unit 130. Pump section 12
A pump chamber 122 is provided in the casing 121 of the “0”, and the impeller 123 rotates in the pump chamber 122.

The casing 121 is made of plastic, ceramic, metal or the like.
The magnetic material cannot be used for the partition wall between the motor unit 110 and the impeller 123 and the partition wall between the anti-motor unit 130 and the impeller 123, and therefore, is made of a non-magnetic material. At one end (the left side in FIG. 1) of the impeller 123, a non-magnetic member 125 having a permanent magnet 124 constituting an uncontrolled magnetic bearing, and a soft magnetic member 126 corresponding to a rotor of the controlled magnetic bearing are provided. I have. The permanent magnet 124 is divided in the circumferential direction of the impeller 123, and magnets adjacent to each other are magnetized with magnetic poles in opposite directions. On the other end (the right side in FIG. 1) of the impeller 123, a ferromagnetic material (including a permanent magnet and a soft magnetic material) 144 having a ring shape and a soft magnetic material 14 serving as a sensor target constitute a non-controllable magnetic pole bearing.
5 is provided.

A rotor 112 supported by a motor bearing 111 such as a rolling bearing or a dynamic pressure bearing is provided outside the pump chamber 122 so as to face the side of the impeller 123 having the permanent magnet 124. The rotor 112 is rotated by being driven by an axial gap motor formed by the motor stator 151 and the motor rotor 152 facing each other in the axial direction. The rotor 112 is provided with the same number of permanent magnets 114 as the side of the impeller 123 so as to oppose the permanent magnets 124 of the impeller 123 and apply an attractive force. Adjacent magnets of the permanent magnet 114 are also magnetized to magnetic poles in opposite directions.

Motor rotor 152 and motor stator 15
A synchronous motor including a DC brushless motor, an asynchronous motor including an induction motor, and the like are used as the motor unit 150 including the motor unit 150, but the type of the motor is not limited.

An electromagnet 141 is provided so as to face the soft magnetic member 126 of the impeller 123. On the other hand, a position sensor 147 is arranged so as to face the soft magnetic material 145 of the impeller 123, and the ferromagnetic material 144
The ring-shaped permanent magnet 148 is disposed so as to face the.

In FIG. 1, the permanent magnet 148 opposed to the ferromagnetic body 144 is disposed on the inner diameter side of the impeller 123. This is for preventing pitching and yawing of the impeller 123 due to the attraction force acting between the two members. This is to reduce disturbance.

Further, the impeller 123 has a pump chamber 122.
Within the movable range, the attractive force acting between the permanent magnet 148 and the ferromagnetic material 144 is always larger than the attractive force acting between the permanent magnets 124 and 114 within this movable range. The material and shape of the permanent magnet 148 and the ferromagnetic body 144 and the position where the permanent magnet 148 is arranged are set in the table.

The impeller 123 is held at the center of the pump chamber 122 by the position sensor 147 and the electromagnet 141 in proportion to the attraction of the permanent magnets 124 and 114 and the attraction of the ferromagnetic material 144 and the permanent magnet 148 in the pump chamber 122. it can. Here, a ferromagnetic material (including a permanent magnet and a soft magnetic material) is arranged on the rotor side of the added uncontrolled magnetic bearing portion. However, when a permanent magnet is used for this ferromagnetic material, May use a soft magnetic material instead of the opposed permanent magnet 148.

As described above, in the embodiment shown in FIG. 1, the electromagnet 141 is arranged on the motor section 110 side, so that the conventional magnetic bearing section 30 shown in FIG. 5 or the anti-motor shown in FIG. The axial length of the portion 130 can be shortened, and the rigidity of the impeller 123 in the radial direction can be improved by adding an uncontrolled magnetic bearing composed of the ferromagnetic body 144 of the impeller 123 and the permanent magnet 148 opposed thereto. .

In FIG. 1, the position sensor 147 is arranged in the counter motor section 130. However, it may be arranged near the electromagnet as in the conventional example shown in FIG.

FIG. 2 is a longitudinal sectional view of a magnetic levitation pump according to another embodiment of the present invention. FIG. 2 is configured in the same manner as the magnetic levitation pump shown in FIG.
The method for driving the rotation of the motor 23 is different. In FIG. 1, the internal permanent magnet 114 is rotated by rotating the rotor 112.
Although the impeller 123 is rotated by magnetic coupling between the impeller 123 and the permanent magnet 124 on the side of the impeller 123, in the embodiment shown in FIG. 151, a rotating magnetic field is applied directly to the impeller 12
Rotate 3

In this case, the attractive force acting between the motor rotor 152 and the motor stator 151, the electromagnetic attractive force of the electromagnet 141, and the non-controllable magnetic bearing 14
By controlling the electromagnetic attraction force so as to balance the attraction force acting between the impeller 1 and the permanent magnet 148,
23 can be magnetically levitated without contact. That is, the attractive force acting between the ferromagnetic body 144, which is an uncontrolled magnetic bearing, and the permanent magnet 148 is smaller than the attractive force acting between the motor stator 151 and the motor rotor 152 within the operating range of the impeller in the pump chamber 122. Motor stator 151 and motor rotor 152 that vary with motor load.
The permanent magnet 148 is larger than the maximum value of the attractive force acting between
The material and shape of the permanent magnet 148 and the ferromagnetic body 144 and the position where the permanent magnet 148 is arranged are selected so that the attractive force acting between the permanent magnet 148 and the ferromagnetic body 144 always increases.

This eliminates the need for the rotor 121 and the motor bearing for supporting the rotor 121, and has the advantage that the structure can be simplified. Here, a ferromagnetic material (including a permanent magnet and a soft magnetic material) is arranged on the rotor side of the added uncontrolled magnetic bearing portion. However, when a permanent magnet is used for this ferromagnetic material, Opposing permanent magnet 148
Instead, a soft magnetic material may be used.

FIG. 3 is a longitudinal sectional view of a magnetic levitation pump according to still another embodiment of the present invention. The magnetic levitation pump shown in FIG. 3 is configured in substantially the same manner as in FIG. 1, except that the motor 150 is arranged on the inner diameter side and the electromagnet 141 is arranged on the outer diameter side. Therefore, the soft magnetic material 126 of the impeller 123 is also disposed on the outer diameter side, and the permanent magnet 124 is disposed on the inner diameter side. As shown in FIG. 3, by arranging the electromagnet 141 on the outer diameter side, the winding space of the electromagnet 141 can be increased, so that the consumption (movement loss) in the electromagnet coil portion can be reduced, and the electromagnet 141 can be used. The action radius of the action force (suction force) on the impeller 123 can be increased, and the pitching and yawing control of the impeller 123 can be performed.
This is advantageous for magnetic bearing control.

FIG. 4 is a block diagram showing a controller for driving the magnetic levitation pump according to one embodiment of the present invention. 4, the controller 100 has an impeller floating position control function of changing the floating position of the impeller 123 in the pump chamber 122 using the impeller position control function, the impeller rotation torque control function, and the impeller position control function.

More specifically, the controller 100 includes a controller main body 101, a motor driver 102, and an impeller position control controller 103. The motor driver 102 outputs a voltage corresponding to the number of rotations of the motor output from the controller main body 101, and
This is a driver for rotating 0. Further, the controller 103 for controlling the impeller position is the controller body 1.
In order to maintain the impeller floating position output from the control unit 01, the current or the voltage or the current and the voltage flowing through the electromagnet 141 are controlled. The detection output from the position sensor 147 is input to the impeller position control controller 103, and the impeller 123 translates in the direction of the central axis (z axis) and rotates about the x axis and the y axis orthogonal to the central axis (z axis). Is controlled so that the current flowing through the electromagnet 141 is controlled. The detection output from the position sensor 147 may be input to the controller main body 101, and the controller main body 101 may output a voltage value or a current value to be applied to the electromagnet 141.

The embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0036]

As described above, according to the present invention, by arranging the electromagnet of the magnetic bearing on the side of the rotational force transmitting means, the length in the axial direction of the pump can be shortened and the size can be reduced. Can be. As a result, when the magnetic levitation pump of the present invention is used for a blood pump for implanting in a body, implantation in the body becomes easy. Further, by adding the non-control type magnetic bearing, the rigidity in the radial direction of the impeller can be improved, and the allowable disturbance value of the pump can be increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a magnetic levitation pump according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a magnetic levitation pump according to another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a magnetic levitation pump according to still another embodiment of the present invention.

FIG. 4 is a schematic block diagram of a controller that drives the magnetic levitation pump according to the embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional magnetic levitation pump.

[Explanation of symbols]

100 controller, 101 controller body,
102 motor driver, 103 impeller position control controller, 110 motor unit, 111 motor bearing, 112 rotor, 114, 124, 148 permanent magnet, 120 motor unit, 121 casing, 122
Pump chamber, 123 impeller, 125 non-magnetic member, 1
26 soft magnetic member, 130 anti-motor part, 144 ferromagnetic material, 145 soft magnetic material, 146 non-magnetic member,
147 position sensor, 148 ring-shaped permanent magnet, 15
0 motor, 151 motor stator, 152 motor rotor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F04D 29/04 F04D 29/04 GR B

Claims (5)

[Claims] 1. A magnetic levitation type pump for magnetically levitation and rotating a disk-shaped impeller for sending a liquid, wherein a first ferromagnetic material is provided on one surface of the impeller, and A second ferromagnetic body is provided in a circumferential direction on the side, an electromagnet arranged on one side of the impeller to face the first ferromagnetic body, and attracting the impeller to one side; A permanent magnet that is arranged on the other side in the circumferential direction so as to face the second ferromagnetic body, and that attracts the impeller to the other side, and is arranged on one side of the impeller,
A rotational force transmitting unit that transmits a rotational driving force to the impeller in a non-contact manner, wherein the permanent magnet attracts the second ferromagnetic material to the impeller;
A magnetic levitation pump, wherein the impeller is magnetically levitated by controlling a current flowing through the electromagnet so that an attractive force of the electromagnet to the first ferromagnetic material is balanced. 2. A first circumferentially extending one side of the impeller.
The rotational force transmitting means is provided with a second permanent magnet on the other side in a circumferential direction facing the first permanent magnet of the impeller, and one surface becomes a motor rotor. The magnetic levitation pump according to claim 1, further comprising: a rotor; and a motor stator provided to face one side of the motor rotor. 3. The first ferromagnetic body of the impeller is provided so as to face the electromagnet, the first permanent magnet of the impeller is provided on an outer diameter side in a circumferential direction, and the electromagnet has an inner diameter. The magnetic levitation pump according to claim 2, wherein the motor rotor is provided on the outer diameter side. 4. A first permanent magnet of the impeller is provided in a circumferential direction on an inner diameter side thereof, and a first ferromagnetic body of the impeller is provided on an outer diameter side thereof so as to face the electromagnet, The magnetic levitation pump according to claim 2, wherein the motor rotor is provided on an inner diameter side, and the electromagnet is provided on an outer diameter side. 5. The magnetic levitation according to claim 1, wherein the rotational force transmitting means includes a motor rotor provided on one side of the impeller, and a motor stator arranged to face the motor rotor. Type pump.