JP4612926B2 - Magnetic levitation pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic levitation type pump capable of miniaturizing a magnetic bearing part. SOLUTION: This magnetic levitation type pump 1 is composed of a motor part 10, a pump part 20 and a magnetic bearing part 40; the magnetic bearing part is constituted of plural electromagnets composed of magnetic poles 51 through 56, electromagnet yokes 71 through 76 and electromagnet coils 81 through 86; and is constituted by circumferentially arranging at least the electromagnet yokes 71 through 76 and the electromagnet coils 81 through 86 of S, N magnetic poles of the respective electromagnets.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic levitation pump, and more particularly, to a clean pump using a magnetic bearing, for example, a magnetic levitation pump used in a medical device such as an artificial heart.
[0002]
[Prior art]
FIG. 7 is a view showing a conventional magnetic levitation type pump. In particular, FIG. 7 (a) is a longitudinal sectional view, and FIG. 7 (b) is a sectional view taken along line AA in FIG. 7 (a). . 8 is a cross-sectional view taken along line BB in FIG. 7, and FIG. 9 is a cross-sectional view taken along line CC in FIG.
[0003]
First, a conventional magnetic levitation pump will be described with reference to FIGS. As shown in FIG. 7A, 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 the casing 21 of the pump unit 20, and the impeller 23 rotates in the pump chamber 22. The casing 21 is made of a non-magnetic member, and the impeller 23 includes a non-magnetic member 25 having a permanent magnet 24 constituting a non-control type magnetic bearing, and a soft magnetic member 26 corresponding to a rotor of the control type magnetic bearing. The permanent magnet 24 is divided in the circumferential direction of the impeller 23, and adjacent magnets are magnetized by magnetic poles in opposite directions.
[0004]
The rotor 12 supported by the shaft 11 is provided outside the pump chamber so as to face the side of the impeller 23 having the permanent magnet 24. The rotor 12 is driven by a motor 13 to rotate. The rotor 12 is provided with the same number of permanent magnets 14 as the impeller 23 side so as to oppose the permanent magnets 24 of the impeller 23 and to exert an attractive force. The permanent magnets 14 are also magnetized adjacent to each other in opposite magnetic poles.
[0005]
On the other hand, an electromagnet 31 and a position sensor (not shown) are provided on the magnetic bearing portion 30 so as to face the side of the impeller 23 having the soft magnetic member 26. The electromagnet 31 and the position sensor allow the impeller 23 to be held at the center of the pump chamber 22 in balance with the attractive force of the permanent magnets 24 and 14 in the pump chamber 22.
[0006]
In the magnetic levitation pump 1 configured as described above, an axial attractive force acts between the permanent magnet 14 embedded in the rotor 12 and the permanent magnet 24 provided on the impeller 23. The impeller 23 is rotationally driven by the magnetic coupling using this attractive force, and the support rigidity in the radial direction is obtained. A current is passed through the coil of the C-type electromagnet 31 so as to balance this attractive force, and the impeller 23 rises. When the rotor 12 is rotated by the driving force of the motor 13, the permanent magnets 14 and 24 constitute a magnetic coupling, the impeller 23 rotates, the fluid is sucked from the suction port 60, and the outlet 70 (FIG. 7 ( discharged from b). Since the impeller 23 is isolated from the rotor 12 by the casing 21 and does not receive contamination from the electromagnet 31, the fluid discharged from the magnetic levitation pump 1 (blood when used as a blood pump) is clean. Keep state.
[0007]
8 and 9, in the conventional magnetic levitation blood pump, the shape of the yoke 41 of the electromagnet 31 is a straw shape and the magnetic pole pairs 42, 43, 44, 45, 46 47 are arranged in the radial direction.
[0008]
[Problems to be solved by the invention]
By the way, when the magnetic levitation pump 1 as shown in FIG. 7 is used as a blood pump for an artificial heart, it is used by being implanted in the body or used close to the body, so that it always supplies energy from an external power source. Can not be done. Normally, energy obtained from a portable battery or an in-body battery installed in the body is supplied, so it is necessary to suppress the amount of energy used as much as possible for long-term use. In addition, maximum attention is required for small size and reliability for use on the human body.
[0009]
However, in the conventional magnetic levitation pump 1, as shown in FIGS. 8 and 9, the magnetic poles of the electromagnets are arranged in the radial direction, so that a space for accommodating the coil is effectively used. There is a problem that the power consumption of the electromagnet cannot be reduced unless the size of the magnetic bearing portion is increased and the coil space is newly increased.
[0010]
That is, in order to save labor with the electromagnet, a method of increasing the number of turns of the electromagnet coil or increasing the coil wire diameter is employed. In either method, the size of the magnetic bearing portion 30 is secured in order to ensure a large coil storage space. It was necessary to enlarge. Furthermore, in the conventional magnetic levitation pump 1, the shape of the yokes of the electromagnets 31 and 32 has a straw shape, so that it is difficult to wind the coil, and at the same time, it is difficult to ensure the insulation resistance between the coil and the yoke.
[0011]
Therefore, a main object of the present invention is to provide a magnetic levitation pump capable of reducing the size of a magnetic bearing portion.
[0012]
[Means for Solving the Problems]
The magnetic levitation pump according to the present invention includes a casing which is arranged in parallel and includes first and second partition walls made of a nonmagnetic material, and a pump chamber formed between them . The second partition is formed in an annular shape. The magnetically levitated pump is further provided in the pump chamber so as to be rotatable along the first and second partition walls. The rotation center line penetrates the first partition wall and penetrates the inner diameter side portion of the second partition wall. An impeller that is provided outside the pump chamber adjacent to the first partition, is coupled to the impeller in a non-contact manner by a magnetic force, rotates the impeller, and discharges fluid, and a second partition A magnetic bearing portion is provided adjacent to the outside of the pump chamber and coupled to the impeller in a non-contact manner by a magnetic force so as to float the impeller between the first and second partition walls. Here, the magnetic bearing portion includes a plurality of electromagnets arranged in the rotation direction of the impeller along the second partition. Each electromagnet is provided opposite to the impeller and arranged in the rotation direction of the impeller, and is arranged in the rotation direction of the impeller, the first and second magnetic poles, one of which is an N pole and the other is an S pole. First and second yokes joined to the first and second magnetic poles, and first and second coils wound around the first and second yokes, respectively.
[0013]
In addition, another magnetic levitation pump according to the present invention includes a casing that is arranged in parallel and includes first and second partition walls made of a nonmagnetic material, and a pump chamber formed between them . Is. The second partition is formed in an annular shape. The magnetically levitated pump is further provided in the pump chamber so as to be rotatable along the first and second partition walls. The rotation center line penetrates the first partition wall and penetrates the inner diameter side portion of the second partition wall. An impeller that is provided outside the pump chamber adjacent to the first partition, is coupled to the impeller in a non-contact manner by a magnetic force, rotates the impeller, and discharges fluid, and a second partition A magnetic bearing portion is provided adjacent to the outside of the pump chamber and coupled to the impeller in a non-contact manner by a magnetic force so as to float the impeller between the first and second partition walls. Here, the magnetic bearing portion includes a plurality of electromagnets arranged in the rotation direction of the impeller along the second partition. The electromagnets are arranged opposite to the impeller and arranged in the radial direction of the impeller, and are arranged in the rotation direction of the impeller, the first and second magnetic poles, one of which is N pole and the other is the S pole. First and second yokes joined to the first and second magnetic poles, and first and second coils wound around the first and second yokes, respectively.
[0014]
Preferably, the impeller is formed in the shape of a disk-shaped, a plurality of permanent magnets and array in the rotational direction of the impeller on the surface facing a rotational drive section of the impeller, the non-contact manner by magnetic coupling and the impeller and the rotary drive unit Connect with.
[0015]
Preferably, three electromagnets are provided.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a magnetic levitation pump according to an embodiment of the present invention. In particular, FIG. 1 (a) shows a longitudinal sectional view, and FIG. 1 (b) shows a line AA in FIG. 1 (a). FIG. 2 is a cross-sectional view taken along line BB shown in FIG. 1A, and FIG. 3 is a cross-sectional view taken along CC shown in FIG.
[0017]
A magnetic levitation pump according to an embodiment of the present invention will be described with reference to FIGS. The magnetic levitation pump includes a motor unit 10, a pump unit 20, and a magnetic bearing unit 40. A pump chamber 22 is provided in the casing 21 of the pump unit 20, and the impeller 23 rotates in the pump chamber 22. The impeller 23 has a plurality of blades 27, and the blades 27 are formed in a spiral shape as shown in FIG.
[0018]
The casing 21 is made of plastic, ceramic, metal, etc., and magnetic material is used for the partition part between the pump part 20 and the motor part 10 and the partition part between the pump part 20 and the magnetic bearing part 40 in the casing 21. Because it cannot be made, it is made of a non-magnetic material. The impeller 23 includes a nonmagnetic member 25 having a permanent magnet 24 constituting a non-control type magnetic bearing, and a soft magnetic member 26 corresponding to a rotor of the control type magnetic bearing. The permanent magnet 24 is divided in the circumferential direction of the impeller 23, and adjacent magnets are magnetized by magnetic poles in opposite directions.
[0019]
The rotor 12 supported by the shaft 11 is provided outside the pump chamber so as to face the side of the impeller 23 having the permanent magnet 24. The rotor 12 is driven by a motor 13 to rotate. The rotor 12 is provided with the same number of permanent magnets 14 as the impeller 23 side so as to oppose the permanent magnets 24 of the impeller 23 and to exert an attractive force. The permanent magnets 14 are also magnetized adjacent to each other in opposite magnetic poles. As the motor unit 10, a synchronous motor including a DC brushless motor, an asynchronous motor including an induction motor, or the like is used, but the type of the motor is not limited.
[0020]
On the other hand, the electromagnet 41 and the position sensor 62 are provided in the magnetic bearing portion 40 so as to face the side of the impeller 23 having the soft magnetic member 26. The electromagnet 41 and the position sensor 62 balance the attraction force of the permanent magnets 24 and 14 in the pump chamber so that the impeller 23 can be held at the center of the pump chamber. For the soft magnetic member 26 corresponding to the rotor of the control type magnetic bearing, for example, a material such as low carbon steel, ferritic stainless steel or permalloy is used.
[0021]
FIG. 1A shows only one electromagnet 41 composed of a magnetic pole 51, an electromagnet yoke 71, an electromagnet coil 81, and an electromagnet back plate 91, but three electromagnets are circular in the magnetic bearing portion 40. It is arranged in the circumferential direction. As shown in FIG. 2, a sensor 61 is disposed between the magnetic poles 51 and 52 forming a pair, a sensor 62 is disposed between the magnetic poles 53 and 54, and the magnetic poles 55 and 56 are disposed between the magnetic poles 55 and 56. The sensor 63 is arranged. As these sensors 61 to 63, magnetic sensors such as eddy current sensors and reluctance sensors are generally used.
[0022]
Further, as shown in FIG. 3, the electromagnet yokes 71 to 76 are formed in a cylindrical shape, and electromagnet coils 81 to 86 are wound around the electromagnet yokes 71 to 76, respectively.
[0023]
Thus, by arranging the magnetic poles 51 to 56 in the circumferential direction, the storage space for the electromagnet coils 81 to 86 that can be housed in the magnetic bearing portion 40 can be increased, and the shape of the electromagnet yokes 71 to 76 is made cylindrical. By doing this, the winding work of the electromagnet coils 81-86 to each electromagnet yoke 71-76 becomes easy. Furthermore, since the shapes of the electromagnet yokes 71 to 76 are simple, insulation from the electromagnet coils 81 to 86 is ensured. In addition, although the electromagnet yokes 71-76 are made into the cylinder, this may be a prism. Further, in FIG. 2 and FIG. 3, all the electromagnetic yokes 71 to 76 and the electromagnetic coils 81 to 86 are arranged on the same circumference, but in order to effectively secure a storage space, each of the electromagnetic yokes 71 to 76 and The electromagnet coils 81 to 86 may not be on the same circumference.
[0024]
4 and 5 are views showing another embodiment of the present invention. FIG. 4 shows an arrangement example of magnetic poles and coils. FIG. 5 is a cross-sectional view taken along the line CC shown in FIG.
[0025]
The electromagnet coils 81 to 86 and the electromagnet yoke (not shown) shown in FIG. 4 are arranged in the circumferential direction in the same manner as in FIG. 3, but the magnetic pole pairs 101, 102, 103, 104, 105, and 106 are arranged in the radial direction. Is arranged. As shown in FIG. 5, the magnetic pole 105, the electromagnet yoke 75, the electromagnet back plate 92, the electromagnet yoke 76, and the magnetic pole 106 constitute one C-type electromagnet. 4 and 5, the electromagnet yoke is formed in a cylindrical shape to facilitate the winding work of the electromagnet coils 81 to 86. However, this is not limited to a cylinder, and may be a prism. .
[0026]
Also in this embodiment, the same effect as the embodiment of FIGS. 1 to 3 can be obtained.
[0027]
FIG. 6 is a block diagram showing a controller for driving the magnetic levitation pump according to one embodiment of the present invention. In FIG. 6, the controller 100 includes an impeller floating position control function, an impeller rotational torque control function, an impeller floating position control function that changes the floating position of the impeller 23 in the pump chamber 22 using the impeller position control function, and the motor 13. A fluid viscosity calculation function for calculating a fluid viscosity using a current change amount of the motor 13 obtained by changing the flying position of the impeller 23 using the impeller flying position control function. ing.
[0028]
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 is a driver for outputting a voltage corresponding to the number of rotations of the motor output from the controller main body 101 and rotating the motor 13. The impeller position control control unit 103 controls the current or voltage flowing in the electromagnet 41 or the current and voltage to maintain the impeller flying position output from the controller main body 101. The detection output from the position sensor 42 is input to the impeller position control control unit 103, and the impeller 23 translates in the direction of the central axis (z axis) and rotates about the x and y axes orthogonal to the central axis (z axis). The current flowing through the electromagnet 41 is controlled so as to control the movement. Note that a detection output from the position sensor 42 may be input to the controller main body 101 and a voltage value or a current value applied to the electromagnet 41 from the controller main body 101 may be output.
[0029]
The controller body 101 includes a storage unit (ROM) 104, a CPU 105, a display unit 110, and an input unit 107. The display unit 110 includes a set discharge flow rate holding unit 111, an effective discharge flow rate display unit 112, a set discharge output display unit 113, an effective discharge pressure display unit 114, a fluid temperature display unit 115, and a fluid viscosity display unit 116. And an impeller rotational speed display section 117 is provided. The input unit 107 is provided with a set discharge flow rate input unit 108 and a set discharge pressure input unit 109.
[0030]
The controller main body 101 is a fluid viscosity-motor current change related data obtained by measuring in advance a relationship between a fluid viscosity and a motor current change amount (motor drive current change amount) due to a change in impeller flying position, or a relationship calculated from this related data. Including a data storage unit storing formulas (for example, correlation formula data or viscosity calculation formula data), and the fluid viscosity calculation function has changed the data storage unit data and the flying position of the impeller 23 using the impeller flying position control function The liquid viscosity is calculated using the current change amount of the motor 13 obtained as described above.
[0031]
In other words, in the storage unit of the controller main body 101, the relationship between the fluid viscosity and the motor current change amount due to the change in the impeller flying position is calculated from the fluid viscosity-motor current change related data or the related data measured in advance. Correlation data (also viscosity calculation formula data) is stored.
[0032]
The embodiment 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.
[0033]
【The invention's effect】
As described above, according to this invention, by sequence the two yokes of the electromagnets of the magnetic bearing portion in the rotational direction of the impeller, without increasing the space of the magnetic bearing unit, i.e. to increase the pump size In addition, a large coil winding space can be secured. By expanding the coil storage space in this way, it is possible to increase the number of turns of the electromagnet coil and increase the wire diameter of the coil. As a result, power saving of the electromagnet can be achieved. Furthermore, the yoke of the electromagnet can be a cylinder or a prism, and the coil winding operation is facilitated. As a result, it is easy to ensure the withstand voltage between the coil and the yoke.
[Brief description of the drawings]
FIG. 1 is a diagram showing a magnetic levitation pump according to an embodiment of the present invention.
FIG. 2 is a cross-sectional arrow view taken along line BB in FIG.
FIG. 3 is a cross-sectional view taken along the line CC shown in FIG.
FIG. 4 is a diagram showing another embodiment of the present invention, showing an arrangement example of magnetic poles and coils.
FIG. 5 is a cross-sectional view taken along line CC shown in FIG.
FIG. 6 is a block diagram of a controller for driving the magnetic levitation pump of the present invention.
FIG. 7 is a view showing a conventional magnetic levitation pump.
8 is a cross-sectional arrow view taken along line BB in FIG.
FIG. 9 is a cross-sectional view taken along line CC in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Motor part, 11 axis | shaft, 12 Rotor, 13 Motor, 14, 24 Permanent magnet, 20 Pump part, 21 Casing, 22 Pump chamber, 23 Impeller, 25 Nonmagnetic member, 26 Soft magnetic member, 40 Magnetic bearing part 51- 56, 101-106 magnetic pole, 61-63 sensor, 71-76 electromagnet yoke, 81-86 electromagnet coil, 91,92 electromagnet backplate, 60 inlet, 70 outlet, 100 controller.

Claims (4)

The first and second partition walls, which are arranged in parallel and include a first partition wall and a pump chamber formed between the first and second partition walls, are formed in an annular shape .
Further, the impeller is rotatably provided along the first and second partition walls in the pump chamber and has a rotation center line that penetrates the first partition wall and penetrates the inner diameter side portion of the second partition wall. When,
A rotation drive unit that is provided outside the pump chamber adjacent to the first partition, is coupled to the impeller in a non-contact manner by magnetic force, and rotates the impeller to discharge fluid;
A magnetic bearing portion provided outside the pump chamber adjacent to the second partition wall, coupled to the impeller in a non-contact manner by magnetic force, and levitating the impeller between the first and second partition walls; In the magnetic levitation pump,
The magnetic bearing portion includes a plurality of electromagnets arranged in the rotation direction of the impeller along the second partition wall,
Each electromagnet
First and second magnetic poles provided opposite to the impeller and arranged in the rotation direction of the impeller, wherein one is an N pole and the other is an S pole;
First and second yokes arranged in the rotation direction of the impeller and joined to the first and second magnetic poles, respectively;
A magnetic levitation pump comprising: first and second coils wound around the first and second yokes, respectively. The first and second partition walls, which are arranged in parallel and include a first partition wall and a pump chamber formed between the first and second partition walls, are formed in an annular shape .
Further, the impeller is rotatably provided along the first and second partition walls in the pump chamber and has a rotation center line that penetrates the first partition wall and penetrates the inner diameter side portion of the second partition wall. When,
A rotation drive unit that is provided outside the pump chamber adjacent to the first partition, is coupled to the impeller in a non-contact manner by magnetic force, and rotates the impeller to discharge fluid;
A magnetic bearing portion provided outside the pump chamber adjacent to the second partition wall, coupled to the impeller in a non-contact manner by magnetic force, and levitating the impeller between the first and second partition walls; In the magnetic levitation pump,
The magnetic bearing portion includes a plurality of electromagnets arranged in the rotation direction of the impeller along the second partition wall,
Each electromagnet
First and second magnetic poles provided opposite to the impeller and arranged in the radial direction of the impeller, wherein one is an N pole and the other is an S pole;
First and second yokes arranged in the rotation direction of the impeller and joined to the first and second magnetic poles, respectively;
A magnetic levitation pump comprising: first and second coils wound around the first and second yokes, respectively.   The impeller is formed in a disk shape, and a plurality of permanent magnets are arranged in a direction of rotation of the impeller on a surface of the impeller facing the rotation driving unit, and the impeller and the rotation driving unit are magnetically coupled. 3. The magnetic levitation pump according to claim 1 or 2, wherein the magnetic levitation pump is coupled in a non-contact manner.   The magnetic levitation pump according to any one of claims 1 to 3, wherein three electromagnets are provided.

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