JP2001329988A - Liquid pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small, lightweight liquid pump device capable of efficiently radiating heat. SOLUTION: An electromagnet 23 and a magnetic bearing sensor 24 are fixed to partition wall 12 for a pump part 30, a motor stator 47 is fixed to a partition wall 23 for the motor part through a column part 48, and heat generating in the electromagnet 23 and the motor stator 47 is cooled with liquid within the pump part 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid pump device, and more particularly, to a liquid pump device that discharges a liquid such as blood by magnetically levitating an impeller.

[0002]

2. Description of the Related Art FIG. 6 is a longitudinal sectional view of a conventional liquid pump device. In FIG. 6, a housing 1 includes partition walls 11, 1.
The interior is partitioned by 2, 13, and 14, and an electromagnet section 20, a pump section 30, and a motor section 40 are formed. The electromagnet section 20 has an electromagnet 21 and a magnetic bearing sensor 22 built therein. An inlet 15 through which a liquid such as blood flows is formed in the center of one side surface of the casing 1. At least three electromagnets 21 and at least three magnetic bearing sensors 22 are arranged around the inlet 15. I have. These electromagnets 21 and magnetic bearing sensors 22
Is attached to the inner wall surface of the partition wall 11 that separates the outside from the electromagnet section 20.

An impeller (impeller) 3 is provided in a pump section 30.
1 is rotatably housed, the electromagnet section 20 side (one side) of the impeller 31 is supported by the electromagnet section 21 through the partition wall 12 in a non-contact manner, and the impeller 31 is in contact with one side of the impeller 31 by the magnetic bearing sensor 22. The distance between them is detected. A permanent magnet 32 is embedded in the other side of the impeller 31. The motor portion 40 houses a motor stator 41 and a motor rotor 42. The outer periphery of a cylindrical member 43 formed so as to extend cylindrically from the inner wall surface of the partition wall 14 that separates the motor portion 40 from the outside. The rotating shaft of the motor rotor 42 is supported on the inner peripheral surface of the cylindrical member 43 via a motor bearing 44 formed of a rolling bearing. The motor rotor 42 is a motor stator 41
, And is rotated by the motor bearing 44 by the magnetic force. A permanent magnet 32 embedded in an impeller 31 has a partition 13
The permanent magnet 45 is embedded so as to oppose via the.

In the liquid pump device configured as described above, based on the sensor output of the magnetic bearing sensor 22,
The control circuit (not shown) controls the current flowing through the electromagnet 21, and controls the attractive force of the electromagnet 21 on the opposing surface of the impeller 31.

On the other hand, an attractive force composed of permanent magnets 32 and 45 acts on the motor section 40 side of the impeller 31, and the impeller 31 has a non-controllable bearing by the permanent magnets 32 and 45 and a controllable bearing by the electromagnet 21. And impeller 3 by
1 is magnetically levitated, the impeller 31 is rotated by the driving force of the motor unit 40, and liquid such as blood flowing into the inflow port 15 flows out of a discharge port (not shown) formed in the pump unit 30.

[0006]

In the liquid pump device shown in FIG. 6, the electromagnet 21 generates heat by the current flowing to magnetically levitate the impeller 31, and the motor stator 41 generates the current by the current flowing to rotate the motor rotor 42. Fever. Further, as the motor bearing 44, for example, a rolling bearing is used, and frictional heat is generated as the motor rotor 42 rotates. Moreover, in order to dissipate the heat generated by the electromagnet 21 to the outside, the casing 1
An electromagnet 21 and a magnetic bearing sensor 22 are fixed to the inner wall surface of the partition 11 in contact with the outside of the motor stator 41.
The cylindrical member 43 is also provided on the inner wall surface of the partition wall 14 that is in contact with the outside of the casing 1.
For this reason, the temperature of the casing 1 increases due to heat generated by the electromagnet 21 and the motor stator 41.

When the temperature rises due to the heat, a drift is generated by the magnetic bearing sensor 22 and there is a problem that the sensing becomes unstable.

Further, since the liquid pump device shown in FIG. 6 constitutes a part of an artificial heart as, for example, a blood pump, and when implanted in a human body, there is a concern that the above-mentioned heat may adversely affect human body tissues. , Additional measures are needed. However, if these measures are taken, the size of the blood pump becomes large, and the size and weight reduction required for the blood pump used for the artificial heart cannot be achieved.

SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a liquid pump device which is small and lightweight, and can efficiently radiate heat.

[0010]

SUMMARY OF THE INVENTION The present invention has a rotating part in a casing and couples a pump part for discharging a fluid by rotating the rotating part with one side of the rotating part in a non-contact manner by magnetic force. A rotation drive unit that magnetically levitates and rotationally drives one side of the rotation unit, a position detection unit that detects the floating position of the rotation unit, and non-contacts the other side of the rotation unit based on the output of the position detection unit. In a liquid pump device including a controllable magnetic bearing unit to be supported, at least one of a rotating unit, a position detection unit, and a controllable magnetic bearing unit is radiated with heat through a liquid flowing through the pump unit. Features. Thereby, sensing is stabilized without increasing the temperature of the liquid pump device. Further, the temperature of the outer surface of the casing does not increase, and the influence of the peripheral portion can be eliminated.

Preferably, the casing includes a first partition partitioning between the pump section and the rotary drive section, and a second partition partitioning between the pump section and the controllable magnetic bearing section. Is mounted on the first partition and the controlled magnetic bearing is mounted on the second partition. Thus, since a heating element such as a rotation drive unit or a control type magnetic bearing unit is provided with the fluid of the pump unit and one partition wall interposed therebetween, heat can be efficiently radiated to the fluid.

[0012] More preferably, the position detecting section is attached to the second partition.

[0013] More preferably, the rotary drive section includes a motor stator and a motor rotor that is rotated by the magnetic force of the motor stator, and the motor stator is mounted on the second partition.

[0014]

FIG. 1 is a view showing a liquid pump apparatus according to an embodiment of the present invention. In particular, FIG. 1 (a) is a longitudinal sectional view, and FIG. 2) is a sectional view taken along line AA. FIG. 2 is a sectional view taken along line BB of FIG. 1, and FIG. 3 is a sectional view taken along line CC of FIG.

In the conventional example shown in FIG.
1 is mounted on the inner wall surface of the partition wall 11 contacting the outside of the casing 1, and the motor stator 31 is also mounted on the inner wall surface of the partition wall 14 contacting the outside of the casing 1. In the embodiment shown in FIG. It is attached to the inner wall surfaces of the partition walls 12 and 13 partitioning from 30, and heat is cooled by a liquid such as blood.

More specifically, in the liquid pump device, the casing 1 is divided by partitions 11, 12, 13, and 14, and a magnetic bearing section 20 and a pump section 3 are provided in each section.
0 and a motor section 40 are provided. The casing 1 is made of plastic, ceramic, metal, etc.
The partition wall 12 between the magnetic bearing unit 20 and the pump unit 30 and the partition wall 13 between the pump unit 30 and the motor unit 40 in the casing 1 are made of a non-magnetic material because magnetic materials cannot be used. .

A pump chamber 33 is provided in the casing 1 of the pump section 30, and the impeller 31 rotates in the pump chamber 33 to discharge fluid from the discharge port 16 (FIG. 1).
(B). The impeller 31 has a plurality of blades 34,
The blade 34 is formed in a spiral shape as shown in FIG. The impeller 31 includes a non-magnetic member 35 having a permanent magnet 32 constituting a non-control type magnetic bearing, and a soft magnetic member 36 corresponding to a rotor of the control type magnetic bearing. The permanent magnet 32 is divided in the circumferential direction of the impeller 31, and magnets adjacent to each other are magnetized with magnetic poles in opposite directions.

By coating the entire inside of the pump chamber 33 with heparin, which is an anticoagulant, it is possible to prevent thrombus formation in these parts and use it as a pump for transporting blood. In this case, the heparin coating has effects such as coagulation activation inhibition, platelet protection, activation inhibition, inflammatory activation inhibition, fibrinolysis activation inhibition, and infection inhibition.

In FIG. 1, the non-magnetic member 35 and the soft magnetic member 36 are indicated by hatched portions, and the other portions are indicated by non-magnetic materials. When used for transporting corrosive fluids such as blood, high corrosion resistant ferritic stainless steel (SUS447J, SU) may be used as the soft magnetic material.
S444), as the non-magnetic material, high corrosion-resistant austenitic stainless steel (SUS316L or the like), a titanium alloy, pure titanium, or the like is preferable.

A column portion 48 extending from the center of the partition 13 to the partition 14 is formed in the motor portion 40 so as to face the side of the impeller 31 having the permanent magnet 32. A motor bearing 49 made of a rolling bearing is provided on the outer peripheral surface of the cylindrical portion 48, and a motor rotor 46 is rotatably supported by the motor bearing 49, and a motor stator 47 is provided at the tip of the cylindrical portion 48. Is attached.
The motor rotor 46 is driven and rotated by a motor stator 47. The motor rotor 46 is provided with the same number of permanent magnets 45 as the side of the impeller 31 so as to oppose the permanent magnets 32 of the impeller 31 and to apply an attractive force. As for the permanent magnet 45, magnets adjacent to each other are magnetized to magnetic poles in opposite directions.

As the motor, a synchronous motor including a DC brushless motor, an asynchronous motor including an induction motor, and the like are used, but the type of the motor is not limited.

The electromagnet section 20 is provided with an electromagnet 23 and a magnetic bearing sensor 24 such that the inner wall of the partition wall 12 separating the electromagnet section 20 and the pump section 30 faces the side of the impeller 31 having the soft magnetic member 36. Is attached. The impeller 31 can be held at the center of the pump chamber 33 by the electromagnet 23 and the magnetic bearing sensor 24 in proportion to the attraction of the permanent magnets 32 and 45 in the pump chamber 33.

With this configuration, the heat generated by the electromagnet 23 can be transmitted to the partition wall 12 and cooled by the liquid in the pump section 30. Similarly, the heat generated in the motor stator 47 is also transmitted from the column 48 to the partition 13 and is cooled by the liquid in the motor 30.
As a result, the transfer of heat to the outside of the casing 1 can be reduced. Further, heat transmitted to the magnetic bearing sensor 24 can be reduced, and sensing can be stabilized. Furthermore, if the thickness of the partition walls 12 and 13 is increased to some extent so that the electromagnet 23, the magnetic bearing sensor 24, and the motor stator 47 have sufficient strength to attach, the thickness of the outer diameter portion of the housing 1 can be reduced. .

The electromagnet 23 and the magnetic bearing sensor 24 are shown in FIG.
And are arranged as shown in FIG. That is, the sensor 24 is provided between the magnetic poles 51 and 52 of each pair of the electromagnets 23.
1 is disposed, and a sensor 242 is provided between the magnetic poles 53 and 54.
Are arranged, and a sensor 243 is arranged between the magnetic poles 55 and 56. As these sensors 241 to 243, magnetic sensors such as an eddy current sensor and a reluctance sensor are generally used.

Further, as shown in FIG.
The 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.

Thus, by arranging the magnetic poles 51 to 56 in the circumferential direction, the storage space of the electromagnet coils 81 to 86 that can be stored in the magnetic bearing portion 40 can be increased, and the coil size can be increased without increasing the pump size. Can secure a wide winding space. By expanding the coil storage space in this way, it is possible to increase the number of turns of the electromagnet coil and to increase the wire diameter of the coil, and as a result, power saving of the electromagnet can be achieved.

Further, by making the shapes of the electromagnet yokes 71 to 76 cylindrical, it is easy to wind the electromagnet coils 81 to 86 around the electromagnet yokes 71 to 76. Further, since the shapes of the electromagnet yokes 71 to 76 are simple, insulation from the electromagnet coils 81 to 86 is ensured. Although the electromagnet yokes 71 to 76 are columnar, they may be prismatic, thereby facilitating the winding operation of the coil, and as a result, it is easy to ensure the dielectric strength between the coil and the yoke. .

Further, in FIG. 2 and FIG. 3, all the electromagnet yokes 71 to 76 and the electromagnet coils 81 to 86 are arranged on the same circumference. To 76 and the electromagnet coils 81 to 86 may not be on the same circumference.

By arranging the magnetic poles and yokes of the respective electromagnets of the magnetic bearing in the circumferential direction, it is possible to increase the space of the magnetic bearing portion, that is, to make the yokes of the electromagnets cylindrical or prismatic. The coil winding operation becomes easy, and as a result, it becomes easy to secure the dielectric strength between the coil and the yoke.

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 includes an impeller position control function, an impeller rotation torque control function, an impeller floating position control function of changing the floating position of the impeller 31 in the pump chamber 33 using the impeller position control function, and a motor unit. Fluid viscosity calculation function for calculating the viscosity of the fluid using the current change amount of the motor unit 40 obtained by changing the floating position of the impeller 31 using the current measurement function of the motor 40 and the floating position control function of the impeller 31. It has.

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,
This is a driver for rotating the motor unit 40. Further, the impeller position control controller 103 controls the current or voltage or the current and the voltage flowing through the electromagnet 23 in order to maintain the impeller floating position output from the controller main body 101.

The detection output from the magnetic bearing sensor 24 is input to the impeller position control controller 103, where the impeller 31 is translated in the direction of the central axis (z axis) and the x axis and y are orthogonal to the central axis (z axis). The current flowing through the electromagnet 23 is controlled so as to control the rotation about the axis. The detection output from the magnetic bearing sensor 24 is input to the controller main body 101 and the controller main body 1
A voltage value or a current value to be given to the electromagnet 23 may be output from 01.

The controller main unit 101 has a storage unit (RO)
M) 104, a CPU 105, a display unit 110, and an input unit 107. The display unit 110 includes a set discharge flow holding unit 111, an effective discharge flow display unit 112, a set discharge output display unit 113, and an effective discharge pressure display unit 114.
, A fluid temperature display section 115 and a fluid viscosity display section 116
And an impeller rotation speed display section 117. The input unit 107 includes a set discharge flow rate input unit 108,
A set discharge pressure input unit 109 is provided.

The controller main body 101 calculates the relationship between the fluid viscosity and the motor current change amount (motor drive current change amount) due to the change in the impeller flying position, or calculates the fluid viscosity-motor current change amount-related data or the related data. And a data storage unit that stores the obtained relational expression (for example, correlation expression data or viscosity calculation expression data). The fluid viscosity calculation function stores the data of the data storage unit and the floating position of the impeller 31 using the impeller floating position control function. The liquid viscosity is calculated using the amount of change in the current of the motor unit 40 obtained by the change.

In other words, in the storage section of the controller main body 101, the relation between the fluid viscosity and the motor current change amount due to the change in the impeller floating position is measured in advance, or the fluid viscosity-motor current change amount related data or the related data. The calculated correlation data (which is also viscosity calculation formula data) is stored.

FIG. 5 is a longitudinal sectional view of another embodiment of the present invention. This embodiment differs from the embodiment of FIG. 1 only in the motor unit 50, and the electromagnet unit 20 and the pump unit 30 are the same as those in FIG.

In the embodiment shown in FIG.
Is provided with a coil on the motor stator 47, and the motor rotor 4
6, a permanent magnet is provided, and the motor rotor 46 is connected to the pump unit 30.
Whereas in the embodiment shown in FIG. 5,
A coil is provided on the motor stator 51, and the impeller 31 is driven by a magnetic force with a permanent magnet 32 disposed on the impeller 31.
Is a method of rotating.

Also in this embodiment, the motor stator 51 that generates heat is attached to the partition 13 so that
The heat generated in the motor stator 51 can be cooled by the liquid in the pump unit 30.

The embodiments disclosed this time are to be considered in all respects as illustrative 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.

[0040]

As described above, according to the present invention, the rotation drive unit for driving the rotation unit in a non-contact manner with the rotation unit and the magnetic unit and the position detection unit for detecting the floating position of the rotation unit. And a structure in which heat generated by at least one of the control-type magnetic bearing portions that support the other side of the rotating portion in a non-contact manner is radiated through a fluid flowing through the pump portion, so that the casing is small and light in weight. Heat can be reduced.

Further, since the transfer of heat to the position detecting section sensitive to the environmental temperature can be reduced, the drift can be suppressed.

Further, if the rotary drive unit and the control magnetic bearing unit are attached to the partition wall with the pump unit, and if the partition wall is strengthened, the casing can be made of a thin material, and the size and weight can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention;
(A) is a longitudinal cross-sectional view, (b) is a cross-sectional view along line AA of FIG.

FIG. 2 is a sectional view taken along line BB in FIG.

FIG. 3 is a sectional view taken along line CC of FIG. 1;

FIG. 4 is a schematic block diagram of a controller that controls the liquid pump device of the present invention.

FIG. 5 is a longitudinal sectional view of another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a conventional liquid pump device.

[Explanation of symbols]

1 casing, 11, 12, 13, 14 partition wall, 15
Inlet 16 Outlet 20 Electromagnet part 23 Electromagnet 24 Sensor for magnetic bearing 30 Pump part 31
Impeller, 32, 45 permanent magnet, 33 pump room, 3
4 blades, 35 non-magnetic member, 36 soft magnetic member, 4
0,50 motor part, 47,51 motor stator, 4
6,52 motor rotor, 48 cylinder, 49 motor bearing, 100 controller.

Continued on the front page (72) Inventor Minoru Suzuki 1578 Higashikaizuka, Iwata-shi, Shizuoka F-term (reference) 3N020 BA01 BA06 BA11 BA22 CA00 CA08 DA00 DA04 EA10 EA12 EA16 3H035 AA01 AA06

Claims (4)

[Claims] 1. A pump having a rotating part in a casing and discharging a fluid by rotating the rotating part, and a pump connected to one side of the rotating part by magnetic force in a non-contact manner. A rotation drive unit that floats and rotates one side, a position detection unit that detects a floating position of the rotation unit, and supports the other side of the rotation unit in a non-contact manner based on an output of the position detection unit. In a liquid pump device including a control type magnetic bearing unit, heat generated by at least one of the rotating unit, the position detection unit, and the control type magnetic bearing unit is radiated through a liquid flowing through the pump unit. A liquid pump device having a structure. 2. The casing includes a first partition partitioning between the pump unit and the rotary drive unit, and a second partition partitioning between the pump unit and the controllable magnetic bearing unit. The liquid pump device according to claim 1, wherein the rotation drive unit is attached to the first partition, and the controlled magnetic bearing unit is attached to the second partition. 3. The liquid pump device according to claim 2, wherein the position detector is attached to the second partition. 4. The apparatus according to claim 2, wherein the rotation drive unit includes a motor stator and a motor rotor that is rotated by a magnetic force of the motor stator, and the motor stator is attached to the second partition. Liquid pumping equipment.