JP2002021763A - Magnetically levitating pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a rotary position of a rotary body so as to optimize detecting output of a position detecting part even after assembling. SOLUTION: A sine wave signal not more than 1 Hz is added to a driving signal of an electromagnet sensor 24, an impeller 31 is periodically moved in the shaft direction, a maximum value and a minimum value of sensor output at that time are detected, voltage set to 1/2 by adding the maximum value and the minimum value is added to the sensor output so that a levitating position of the impeller 31 is corrected, and gain of a sensor circuit 210 is corrected by the voltage by subtracting the minimum value from the maximum value so that the gain of the sensor circuit is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation type pump device, and more particularly to a magnetic levitation type pump device for magnetically levitating an impeller to discharge liquid such as blood.

[0002]

2. Description of the Related Art FIG. 7 is a vertical sectional view of a magnetic levitation pump device as an example of a conventional magnetic levitation device and a diagram showing a controller.

In FIG. 7, a magnetic levitation type pump device 10 is shown.
0 denotes an electromagnet section 12 in the casing 101 in the axial direction.
0, a pump unit 130, and a motor unit 140 are built therein. An electromagnet 121 and a magnetic bearing sensor 122 are built in the electromagnet section 120. Casing 1
An inlet 102 through which liquid flows is formed at the center of one side surface in the axial direction of 01, and at least three electromagnets 121 and at least three magnetic bearing sensors 122 are arranged around the inlet 102. The electromagnet 121 and the magnetic bearing sensor 122 are connected to the electromagnet section 120 and the pump section 13.
It is attached to a partition wall 103 that partitions 0 and 0 in the axial direction.

[0004] An impeller (impeller) is provided in the pump section 130.
The impeller 131 is accommodated rotatably in the circumferential direction. The electromagnet section 120 side (one side) of the impeller 131 is supported by the electromagnet 121 via the partition 103 in a non-contact manner. The distance to one side is detected. On the other axial side of the impeller 131, a permanent magnet 132 is embedded. Motor unit 1
40 houses a motor 141 and a rotor 142. On the surface of the rotor 142 facing the pump section 130, a permanent magnet 132 embedded in the impeller 131 is provided with a partition wall 104.
The permanent magnets 143 are embedded so as to face each other.

In the magnetic levitation pump device configured as described above, the sensor output of the magnetic bearing sensor 122 is
Sensor circuit (not shown) included in controller 150
And the distance between the impeller 131 and the magnetic bearing sensor 122 is detected by the sensor circuit. The output of the sensor circuit is supplied to a PID compensator (not shown),
Compensation is performed, and the output of the PID compensator is amplified by a power amplifier (not shown) and provided to the electromagnet 121. Therefore, the attractive force to the opposing surface of the impeller 131 is controlled by the electromagnet 121.

On the other hand, an attractive force composed of permanent magnets 132 and 143 acts on the motor section 140 side of the impeller 131, and the impeller 131 has a non-controllable bearing using the permanent magnets 132 and 143 and a control type bearing using the electromagnet 121. Magnetically levitated by the motor 141 and rotated by the driving force of the motor 141 controlled by the controller 150.
The liquid, such as blood, flowing into the pump section 130 is caused to flow out from a discharge port (not shown) formed in the pump section 130.

[0007]

In the magnetic levitation pump device shown in FIG. 7, it is necessary to adjust the distance between one side of the impeller 131 and the magnetic bearing sensor 122 to an appropriate value. In the conventional magnetic levitation pump device, the pump unit 130 of the casing 101 can be disassembled, a spacer having an appropriate thickness is inserted between the impeller 131 and the partition wall 103, and an appropriate signal is output from the magnetic bearing sensor 122. Has been adjusted so that is output.

On the other hand, the magnetic levitation pump device 100 shown in FIG. 7 is also used as a blood pump device for an artificial heart. However, when used as a pump for an artificial heart, the pump unit 130 has a casing 101 to maintain airtightness.
The parts are assembled by welding. For this reason, since it cannot be disassembled after assembling, there is a problem that the distance between the impeller 131 and the magnetic bearing sensor 122 cannot be adjusted after assembling.

[0009] Therefore, a main object of the present invention is to provide a magnetic levitation pump capable of adjusting the rotational position of a rotating body so that the sensor output becomes optimum even after assembly.

[0010]

According to the present invention, there is provided a pump for discharging a fluid by rotating a rotary body in a casing, and a rotary unit for rotating the rotary body in a non-contact manner with the rotary body by magnetic force. After assembling a magnetic levitation type pump device, it includes a drive unit, a position detecting unit for detecting a floating position of the rotating body, and a control type magnetic bearing unit for supporting the rotating body in a non-contact manner by an output of the position detecting unit. An adjusting means for adjusting the floating position of the body is provided.

Thus, the rotating body can be positioned in the casing such that an optimum detection output can be obtained from the position detecting section without disassembling the casing.

Further, the adjusting means moves the rotating body in the casing periodically in the axial direction.

The adjusting means generates a periodic signal of a low frequency and supplies the periodic signal to the circuit of the controllable magnetic bearing unit, and the rotating body is periodically moved by the periodic signal from the periodic signal generating means. And a correction unit that outputs a correction signal to the circuit unit of the controllable magnetic bearing unit such that the rotating body rotates at the axial center position of the casing based on the detection output of the position detection unit. I do.

Further, the periodic signal generating means generates a periodic signal of 1 Hz or less to periodically move the rotating body.

Furthermore, the magnetic levitation type pump device is characterized in that it is a blood pump device.

[0016]

FIG. 1 is a view showing a magnetic levitation type pump device according to an embodiment of the present invention. In particular, FIG.
1 shows a longitudinal sectional view, and FIG. 1B shows a line AA of FIG.
FIG. 2 is a sectional view taken along line BB in FIG. 1A, and FIG. 3 is a sectional view taken along CC in FIG. 1A. Here, the sensor is not shown in FIG.

In FIG. 1, a magnetic levitation type pump device comprises:
The cylindrical casing 1 is provided with partition walls 11, 12 and 13 in the axial direction.
And 14 and each region has a magnetic bearing portion 20.
, A pump unit 30 and a motor unit 40 are provided. The casing 1 is formed of plastic, ceramic, metal, or the like, and 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 of the casing 1 have magnetic properties. Since the material cannot be used, it is composed of a non-magnetic material.

A pump chamber 33 is provided in the casing 1 of the pump section 30. The impeller 31 rotates in the pump chamber 33, and the fluid flowing from the inlet 15 is supplied to the pump chamber 33 as shown in FIG.
The ink is discharged from the discharge port 16 shown in FIG. The impeller 31 has a plurality of blades 34, and the blades 34 are 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 in the circumferential direction are magnetized to magnetic poles in opposite directions.

By coating the entire pump chamber 33 with heparin, which is an anticoagulant, the formation of thrombus in these parts can be prevented and the pump can be used as a blood transport pump. In this case, the heparin coating has effects such as suppression of coagulation activation, protection of platelets, suppression of activation, suppression of inflammatory activity, and suppression of fibrinolytic activation.

In FIG. 1, the non-magnetic member 35 of the impeller 31 is indicated by oblique lines, the soft magnetic member 36 is indicated by spots, and the other portions are indicated by non-magnetic materials. When used for transporting corrosive fluids such as blood, the soft magnetic material is a high corrosion resistant ferritic stainless steel (SUS447J, SUS444, etc.), and the nonmagnetic material is a high corrosion resistant austenitic stainless steel (SUS316L, etc.). ), Or a titanium alloy, pure titanium or the like.

The motor portion 40 is formed with a cylindrical portion 48 extending in the axial direction from the center of the partition 13 to the partition 14 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 an outer peripheral surface of the cylindrical portion 48, and the motor rotor 46 is rotatably supported by the motor bearing 49, and is rotatably provided.
A motor stator 47 is attached to the tip of the column 48. The motor rotor 46 is driven and rotated by a motor stator 47. The motor rotor 46 has an impeller 3
The same number of permanent magnets 45 as the impeller 31 are provided so as to face one permanent magnet 32 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 and an asynchronous motor including an induction motor 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 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 reluctance sensors are 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. Wide 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 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 becomes 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, which facilitates coil winding work and, as a result, makes it easier to ensure 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 the yoke of each electromagnet 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 yoke of the electromagnet a cylinder or a prism, and to make the coil The winding work 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 an example of a controller for controlling the magnetic levitation pump device according to one embodiment of the present invention.

In FIG. 4, a controller 200 includes a sensor adjustment circuit 201, a sensor circuit 210, and an addition circuit 2
11 and 212, a PID compensator 213, and a power amplifier 214. The sensor adjustment circuit 201 includes a sine wave generation circuit 202 which generates a sine wave signal as a periodic signal of 1 Hz or less, for example, 0.5 Hz, and is provided in a stage preceding the PID compensator 213. To the adder circuit 212 which is in operation. The addition circuit 212 adds a 0.5 Hz sine wave to the sensor output and supplies the result to the PID compensator 213.

The sensor output is supplied to a maximum value detection circuit 203.
And the minimum value detection circuit 204. The maximum value detection circuit 203 detects the maximum value of the sensor output, and the minimum value detection circuit 204 detects the minimum value of the sensor output. The output of the maximum value detection circuit 203 and the output of the minimum value detection circuit 204 are provided to addition circuits 208 and 209, respectively. The adder circuit 208 adds the maximum value and the minimum value, and the adder circuit 209 subtracts the minimum value from the maximum value.
At the output of 8, an average value of the maximum value and the minimum value of the amplitude value of the sensor output is obtained, and at the output of the addition circuit 209, the difference between the maximum value and the minimum value, that is, the amplitude is obtained. Adder circuit 20
The added output of 8 is given to the hold circuit 205 via the switch element SW1. The output of the hold circuit 205 is 1
The signal is supplied to the / 2 circuit 206 and is multiplied by 1/2, and is supplied to the addition circuit 211. The amplitude output from the addition circuit 209 is applied to the hold circuit 20 via the switch element SW2.
7 given. The output of the hold circuit 207 is provided to the sensor circuit 210 as a correction signal for the sensor output gain.

The sensor circuit 210 includes a magnetic bearing sensor 2
4 is provided with the sensor output, and the hold circuit 20
By applying the output of 7, the gain of the sensor is adjusted. The output of the sensor circuit 210 is provided to the adding circuit 211, and the added output of the adding circuit 211 is provided to the adding circuit 212.

FIG. 5 is a waveform diagram of a sine wave output from the sine wave generator 202 shown in FIG. 4, and FIG. 6 is a diagram showing a relationship between sensor output and time.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS. Sine wave generation circuit 202
Generates a sine wave signal of 1 Hz or less, for example, 0.5 Hz as shown in FIG. This sine wave signal is added to the addition circuit 21
2 is added to the sensor output, and the added output is PI
After being given to the D compensator 213 to perform PID compensation, it is amplified by the power amplifier 214, and the drive signal drives the electromagnet 23 shown in FIG. The amplitude of the drive signal of the electromagnet 23 is changed by a 0.5 Hz sine wave signal in synchronization with the waveform shown in FIG.

For this reason, the attraction force of the electromagnet 23 to the impeller 31 increases or decreases in a cycle of 0.5 Hz, so that the impeller 31 is connected to the electromagnet section 2 shown in FIG.
In the pump chamber 33 between the partition wall 12 on the side of the motor 40 and the partition wall 13 on the side of the motor 40, the pump chamber slowly and repeatedly moves in the axial direction. At this time, the impeller 31 may come into contact with the inner wall of the pump chamber 33 depending on the level of the sine wave signal, but since the movement of the impeller 31 is caused by a sine wave of 0.5 Hz, the impeller 31 It does not hit the inner wall and damage the heparing coating on the wall.

When the impeller 31 is moved in the axial direction by the sine wave signal of 0.5 Hz, the sensor 2 for the magnetic bearing is moved.
4 also changes greatly, and the maximum value detection circuit 203
Detects the maximum value of the sensor output voltage, and detects the minimum value.
04 detects the minimum value of the sensor output voltage. The detected maximum value and minimum value are added by the addition circuit 208 and the addition circuit 209 subtracts the minimum value from the maximum value. The relationship between the maximum value and the minimum value is as shown in FIG. That is, from the sensor circuit 210, M shown in FIG.
A voltage having a waveform a having an amplitude of D between AX and MIN is output. On the other hand, the waveform b in FIG. 6 is setting data, the amplitude is C, and the neutral voltage is A in FIG. Here, MAX shown in FIG. 6 indicates that the impeller 31 is
Side and the MIN is the impeller 3
1 is closest to the motor unit 40.

The output of the addition circuit 208 is a switch element SW
1 to the hold circuit 205 to be held. Then, the output is given to the 回路 circuit 206 and １ ／ times, and then given to the adding circuit 211.
The input of the adding circuit 211 corresponds to the voltage B shown in FIG. The output of the addition circuit 209 is provided to the hold circuit 207 via the switch element SW2 and is held. Then, the hold voltage is given to the sensor circuit 210, and the gain of the sensor circuit 210 is corrected. That is,
The addition circuit 2 is set so that the floating position of the impeller 31 is set to the neutral position in the pump chamber 33 by the output of the 1/2 circuit 206.
11, the hold circuit 207
, The gain of the sensor output is corrected. As a result, the neutral position of the impeller 31 becomes a position corresponding to the voltage A in FIG. 6, and the gain of the sensor output voltage can be set to a desired value.

The above-described setting is to generate a sine wave from the sine wave generation circuit 202 with the impeller 31 magnetically levitated by driving the electromagnet 23 and the motor unit 40. Is stopped and the switching element S
This is performed by turning on W1 and SW2.

As a result, even when the impeller 31 is sealed in the pump chamber 33, the neutral position of the impeller 31 can be set so that the sensor output can be appropriately obtained.

In the above description, the sine wave generation circuit 20
Although a sine wave of 2 to 0.5 Hz is generated, the present invention is not limited to this, and a frequency of 1 Hz or less can be applied to the present invention.

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.

[0044]

As described above, according to the present invention, after assembling the magnetic levitation type pump device, the adjusting means for adjusting the levitation position of the rotating body is provided, so that the optimum position detection from the position detection unit is achieved. The rotating body can be positioned in the casing so as to obtain an output.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention;
(A) is a longitudinal sectional view, and (b) is a line A- in FIG.
It is sectional drawing which follows A.

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

FIG. 3 is a cross-sectional view taken along line CC of FIG.

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

5 is a waveform diagram of a sine wave generated from the sine wave generation circuit shown in FIG.

FIG. 6 is a diagram illustrating a relationship between a sensor voltage and time.

FIG. 7 is a sectional view of a conventional magnetic levitation pump device and a diagram showing a controller.

[Explanation of symbols]

1 casing, 11, 12, 13, 14 partition wall, 15
Inflow port, 16 discharge port, 20 electromagnet section, 23 electromagnet, 24 sensor for magnetic bearing, 30 pump section, 31
Impeller, 32, 45 permanent magnet, 33 pump room, 3
4 blades, 35 non-magnetic member, 36 soft magnetic member, 40
Motor part, 47 motor stator, 46 motor rotor, 48 cylinder part, 49 motor bearing, 200 controller, 201 sensor adjustment circuit, 202 sine wave generation circuit, 203 maximum value detection circuit, 204 minimum value detection circuit, 205, 207 hold circuit, 206 1/2 circuit, 208, 209, 211, 212 Adder circuit, 21
0 Sensor circuit, 213 PID compensator, 214 power amplifier, SW1, SW2 switching element.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // H02K 7/09 H02K 7/09 F term (reference) 3H022 AA01 BA04 CA06 CA16 CA50 DA08 DA09 3J102 AA01 BA03 BA19 CA16 CA17 DA02 DA09 DB05 DB10 DB11 DB24 DB32 DB37 GA06 5H607 AA12 BB01 BB07 BB09 BB14 BB17 CC05 DD07 DD19 FF06 GG07 GG19 GG21

Claims (5)

[Claims] A pump for discharging a fluid by rotating a rotating body in a casing; a rotation driving unit for rotating the rotating body in a non-contact manner with the rotating body by magnetic force; A magnetic levitation pump device including: a position detection unit that detects a levitation position of a body; and a control magnetic bearing unit that supports the rotating unit in a non-contact manner based on an output of the position detection unit. Assembling the magnetic levitation pump device A magnetic levitation type pump device, further comprising adjusting means for adjusting a levitation position of the rotating body. 2. The magnetically levitated pump device according to claim 1, wherein said adjusting means moves the rotating body in the casing periodically in an axial direction. 3. The adjusting unit includes: a periodic signal generating unit that generates a low-frequency periodic signal and supplies the periodic signal to a circuit unit of the controllable magnetic bearing unit; Correction means for outputting a correction signal to the circuit section of the control-type magnetic bearing so that the rotating body rotates at the axial center position of the casing based on a detection output of the position detection section when moving periodically. The magnetic levitation pump device according to claim 1, further comprising: 4. The magnetic levitation pump device according to claim 3, wherein the periodic signal generating means generates a periodic signal of 1 Hz or less to move the rotating body periodically. 5. The magnetically levitated pump device according to claim 1, wherein the magnetically levitated pump device is a blood pump device.