JP2010041742A - Axially levitated rotating motor, and turbo-type pump using axially levitated rotating motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axially levitated rotating motor reduced in thickness and size. <P>SOLUTION: This axially levitated rotating motor 1 includes: a rotor position adjusting permanent magnet 16 at the center; a rotor 3 having a rotor rotating permanent magnet 12 at the outer periphery of the radial direction; a rotor position adjusting electromagnet 11 at the center; and a stator 5 having a driving electromagnet 9 at the outer periphery of the radial direction. The axially levitated motor controls a distance in the axial direction of the rotor position adjusting permanent magnet 16 by adjusting an output of the rotor position adjusting electromagnet 11, and can maintain the rotor 3 at a floating position. At this time, the rotor 3 is maintained in the prescribed floating position by adjusting the output of the rotor position adjusting electromagnet 11 according to stress applied to the axial direction of the rotor 3 calculated from an induction voltage supplied to the driving electromagnet 9 and the number of revolutions of the rotor 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an axial magnetic levitation rotary motor and a turbo pump, and more particularly, to a compact axial maglev rotary motor and a turbo pump using the axial magnetic levitation rotary motor.

  A magnetically levitated rotary motor that has a non-contact structure by using a bearing that uses electromagnetic force, such as a shaft support by a bearing, has a high durability because it is extremely less affected by mechanical friction and wear. Have. As one of these magnetic levitation rotary motors, an axial magnetic levitation rotary motor that levitates a rotor by applying an electromagnetic force in the axial direction of the rotor is known.

The axial magnetic levitation rotary motor is suitable for continuous use for a long period of time because the rotor is mechanically non-contact with the stator. In addition, when a turbo pump is configured by providing an impeller on the rotor side, it is relatively easy to ensure the flow rate and to reduce the size, so in recent years, a turbo pump constructed using this axial magnetic levitation rotary motor has been developed. The proposal example applied as a blood pump of an artificial heart has been introduced (see Patent Documents 1 and 2 and Non-Patent Document 1).
According to the techniques disclosed in Patent Literatures 1 and 2 and Non-Patent Literature 1, an example in which an axial magnetic levitation rotating motor is used and configured as a blood pump of a size that can be implanted in the body as an implantable artificial heart is provided. It has been disclosed, and its excellent properties are attracting attention.

Japanese Patent Laid-Open No. 08-284870 Japanese Patent No. 3808811 NTN Technical Review No. 68 (2000) p76-80

  However, in any of the above-mentioned Patent Documents 1 and 2 and Non-Patent Document 1, since the configuration is such that the floating state of the rotor is detected using a plurality of gap sensors, the number of parts is complicated. . In addition, since the electromagnet for controlling the flying of the rotor is arranged on the outer diameter side of the electromagnet for controlling the rotation of the rotor, the electromagnet for controlling the flying of the rotor has a large size, while A magnet is not arranged in the central portion, and has a hollow structure. Therefore, the blood pump configured using such an axial magnetic levitation rotating motor has a problem that the size is increased.

In view of the above problems, an object of the present invention is to provide an axial magnetic levitation rotary motor and a turbo pump that are further downsized and more efficient.
Another object of the present invention is to provide a turbo pump suitable for use as a blood pump.

  In an axial magnetic levitation rotary motor that includes a stator including a driving electromagnet that rotationally drives a magnetically levitated rotor and a rotor that can be maintained in a floating state, the rotor is disposed at the center of rotation facing the stator. A rotor position adjusting permanent magnet, and a rotor rotating permanent magnet disposed on the outer peripheral side in the radial direction so as to be opposed to the stator, and the stator has a rotor position at a central portion on the rotor side. A rotor position adjusting electromagnet disposed opposite to the adjustment permanent magnet, and a driving electromagnet disposed opposite to the rotor rotating permanent magnet on the radially outer side of the rotor side, This is solved by adjusting the output of the rotor position adjusting electromagnet to maintain the rotor at a predetermined position.

  With the above-described configuration, the driving electromagnet and the rotor position adjusting electromagnet can be formed on substantially the same plane along the radial direction, so that the thickness can be reduced and the rotor can be formed in a region that has conventionally been a hollow portion. Since the position adjusting electromagnet is provided, an axial magnetic levitation rotating motor with a reduced size can be obtained. In addition, by arranging the rotor position adjusting permanent magnet and the rotor position adjusting electromagnet on the rotation axis of the rotor, high-efficiency axial magnetic levitation has little effect on the rotor rotation when adjusting the rotor floating position. A rotary motor is obtained.

  According to another aspect of the present invention, the axial magnetic levitation rotary motor controls the rotation control device that controls the rotation of the rotor by controlling the driving electromagnet, and the power supplied to the rotor position adjusting electromagnet. A rotor position control device for controlling the position of the rotor, an induced voltage detection device capable of detecting an induced voltage supplied to the drive electromagnet, and a drive capable of detecting a drive current supplied to the drive electromagnet A current detection device and a rotation speed detection device capable of detecting the rotation speed of the rotor, and the induced voltage detection device, the drive current detection device, and the rotation speed detection device are all included in the rotor position control device. The rotor position control device is connected to the induced voltage detected by the induced voltage detection device, the drive current detected by the drive current detection device, and the circuit. The axial stress applied to the rotor is calculated from the rotational speed detected by the number detection device, and the electric power supplied to the rotor position adjusting electromagnet is controlled based on the calculated stress value. Preferably, the rotor is configured to be maintained at a predetermined position.

  With the above configuration, since the mechanism calculates the stress applied in the axial direction of the rotor from the induced voltage, drive current, and rotational speed, there is no need to use a gap sensor, and an axial magnetic levitation rotary motor with further miniaturization is obtained. be able to.

  According to a third aspect of the present invention, there is provided a turbo pump according to a third aspect of the present invention, wherein a cylindrical pump casing in which a suction port, a discharge port, and a fluid passage communicating both are formed, and a rotor that can be maintained in a floating state in the pump casing. And an impeller fixed to the rotor side and having fins, and a stator having a driving electromagnet disposed on the discharge port side in the axial direction of the rotor to rotationally drive the rotor. A turbo-type pump in which fluid sucked from the suction port is transferred to the discharge port by rotation of the impeller, wherein the rotor is positioned at a rotation center portion of the rotor facing the stator. A permanent magnet for adjustment, and a rotor rotating permanent magnet disposed on the outer peripheral side in the radial direction so as to face the stator, and the stator has a rotor at a central portion on the rotor side. A rotor position adjusting electromagnet disposed opposite to the position adjusting permanent magnet, and a driving electromagnet disposed opposite to the rotor rotating permanent magnet on the radially outer side of the rotor side. This is solved by adjusting the output of the rotor position adjusting electromagnet to maintain the rotor at a predetermined position.

  With the above-described configuration, the driving electromagnet and the rotor position adjusting electromagnet can be formed on substantially the same plane along the radial direction, so that the thickness can be reduced and the rotor can be formed in a region that has conventionally been a hollow portion. Since the position adjusting electromagnet is provided, a turbo pump with a reduced size can be obtained. In addition, by arranging the rotor position adjusting permanent magnet and the rotor position adjusting electromagnet on the rotation axis of the rotor, there is a highly efficient turbo pump that has little influence on the rotation of the rotor when adjusting the floating position of the rotor. can get.

  Furthermore, as in claim 4, the turbo pump controls the rotation of the rotor by controlling the drive electromagnet and the power supplied to the rotor position adjusting electromagnet. A rotor position control device for controlling the position of the rotor, an induced voltage detection device capable of detecting an induced voltage supplied to the drive electromagnet, and a drive current detection capable of detecting a drive current supplied to the drive electromagnet A rotation speed detection device capable of detecting the rotation speed of the rotor, and the induced voltage detection device, the drive current detection device, and the rotation speed detection device are all connected to the rotor position control device. The rotor position control device includes an induced voltage detected by the induced voltage detection device, a drive current detected by the drive current detection device, and the rotation speed detection device. Accordingly, the axial stress applied to the rotor is calculated from the detected rotational speed, and the electric power supplied to the rotor position adjusting electromagnet is controlled based on the calculated stress value. Suitably, the rotor is configured to be maintained in position.

  With the above configuration, since it is a mechanism for calculating the stress applied in the axial direction of the rotor from the induced voltage, the drive current, and the rotational speed, it is not necessary to use a gap sensor, so that a turbo pump with further miniaturization can be obtained. . In addition, since the rotor is mechanically non-contact, it does not generate dirt due to wear, and there is no fear of contaminating the fluid due to wear, so safety can be ensured and maintenance-free can be realized. Since it can be used for a long period of time, a turbo pump suitable for use as a blood pump can be obtained.

According to the present invention, when adjusting the floating position of the rotor, there is little influence on the rotation of the rotor, and a highly efficient rotation characteristic can be obtained. An axial magnetic levitation rotating motor and a turbo pump can be obtained by further reducing the size by forming the electromagnet and the rotor position adjusting electromagnet on substantially the same plane along the radial direction of the rotor. Furthermore, it is not necessary to use a gap sensor, and an axial magnetic levitation rotary motor and a turbo pump that can be further reduced in size can be obtained.
In addition, since there is no bearing that supports the rotor, the life can be extended and the inertia can be reduced due to the absence of bearing sliding loss. Turbo that is suitable for use as a blood pump that can be used continuously for a long period of time because it does not occur and there is no fear of contaminating the fluid due to wear, and safety can be ensured. A shaped pump is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the gist of the present invention.

  1 to 3 show an embodiment according to the present invention, FIG. 1 is a sectional view of an axial magnetic levitation rotary motor, FIG. 2 is a system configuration diagram of an axial magnetic levitation rotary motor, and FIG. 3 is an axial magnetic levitation rotary motor. This is an application example to a turbo pump (mixed flow pump).

First, based on FIG. 1, the structure of the axial magnetic levitation rotary motor 1 which concerns on embodiment of this invention is demonstrated.
The axial magnetic levitation rotating motor 1 according to the present embodiment includes a rotor 3, a stator 5, and a housing 4 that accommodates the rotor 3, and is a disc rotor type brushless motor that can be rotated in a state where the rotor 3 is levitated by electromagnetic force. It is configured.

  The rotor 3 includes a shaft 8 as an output shaft, a rotor back yoke 10 fixed to one end side of the shaft 8, a rotor rotating permanent magnet 12 attached to the rotor back yoke 10, and the center of the rotor back yoke 10. And a rotor position adjusting permanent magnet 16 attached to the part via a non-magnetic body 14.

The rotor back yoke 10 is a substantially disk-shaped member, and the one end portion side of the shaft 8 is fixed to the center portion as described above.
The rotor rotating permanent magnet 12 is fixed to the surface of the rotor back yoke 10 opposite to the surface on which the shaft 8 is fixed, and a plurality of permanent magnets having different polarities are formed in a ring shape on the outer peripheral side in the radial direction. They are fixed at regular intervals. The number of permanent magnets constituting the rotor rotating permanent magnet 12 is arbitrary, but it is desirable that the rotor 3 is composed of permanent magnets having four or more poles in order to eliminate the radial blur of the rotor 3.

  The rotor position adjusting permanent magnet 16 is a disk-shaped permanent magnet, and is fixed via a nonmagnetic material 14 to the center portion of the rotor back yoke 10 opposite to the surface on which the shaft 8 is fixed. . In this embodiment, it is composed of one permanent magnet that is magnetized only in one direction. The magnetic path formed in the rotor back yoke 10 is not adversely affected by being attached to the rotor back yoke 10 via a nonmagnetic material 14 made of austenitic stainless steel or the like.

The stator 5 includes a stator core 7, a driving electromagnet 9 wound around the stator core 7, and a rotor position adjusting electromagnet 11 wound around the center of the stator. In the present embodiment, the stator 5 is formed integrally with the housing 4.
The driving electromagnet 9 is formed by winding a conductive wire around each of the plurality of stator cores 7, and is disposed to face the rotor-rotating permanent magnet 12 on the rotor side. In the present embodiment, the driving electromagnet 9 is configured as two-phase eight poles, but the number of stator cores 7 constituting the driving electromagnet 9 is arbitrary.
The rotor position adjusting electromagnet 11 is formed by winding a conductive wire around a rotor position adjusting electromagnet core 13 formed at the center of the stator 5. The rotor position adjusting electromagnet 11 is fixed at the center of the rotor back yoke 10. The permanent magnet 16 is disposed so as to face the permanent magnet 16.

  Since the driving electromagnet 9 and the rotor position adjusting electromagnet 11 have the same magnetic flux generation direction, they can be formed on substantially the same plane along the radial direction. Therefore, it is possible to dispose the driving electromagnet 9 and the rotor position adjusting electromagnet 11 without any gap, and the axial magnetic levitation rotating motor 1 can be made thin and a compact structure.

  The axial magnetic levitation rotary motor 1 includes a rotation control device 21 that generates a continuous rotating magnetic field in the driving electromagnet 9, a rotor position control device 23 that controls a power value supplied to the rotor position adjustment electromagnet 11, and It is connected to the. The rotation control device 21 is connected to a detection device that detects the induced voltage and drive current supplied to the axial magnetic levitation rotary motor 1 and the rotation speed of the rotor 3. Further, a hall element 25 for detecting the magnetic pole position of the rotor 3 is attached to an arbitrary position on the stator 5 side.

Next, the control content of the axial magnetic levitation rotating motor 1 according to the embodiment of the present invention will be described with reference to FIG.
The control system of the axial magnetic levitation rotating motor 1 includes a Hall element 25 for detecting the magnetic pole position of the rotor 3, a rotation control device 21 that generates a continuous rotating magnetic field in the driving electromagnet 9, and the rotor 3 floating. And a rotor position control device 23 for generating a magnetic field.
The rotor position control device 23 detects the number of revolutions connected to the induced voltage detection device 27a and the drive current detection device 27b that detect the induced voltage and the drive current supplied to the drive electromagnet 9 and the Hall element 25, respectively. It is connected to the device 27c.

The rotation control device 21 is a control device that controls electric power (induced voltage and drive current) supplied to the drive electromagnet 9 to generate a continuous rotating magnetic field that rotates the rotor 3, and is detected by the Hall element 25. Further, a necessary rotational force is given while appropriately exciting an electromagnet at a position corresponding to the magnetic pole position of the rotor 3.
The induced voltage detection device 27a and the drive current detection device 27b are sensors that output the induced voltage and the drive current to the rotor position control device 23. In the present embodiment, the induced voltage detection device 27a and the drive current detection device 27b are connected to the rotation control device 21 and are driven electromagnets. The induced voltage and drive current supplied to 9 are read. Similarly, the rotation speed detection device 27 c is connected to the Hall element 25, and outputs the magnetic pole position of the rotor 3 detected by the Hall element to the rotor position control device 23. Based on the detection result of the magnetic pole position of the rotor 3, the rotational speed is calculated in the rotor position control device 23.

The rotor position control device 23 is a stress (buoyancy) applied in the axial direction of the rotor 3 based on the induced voltage, drive current, and rotation speed detected by the induced voltage detection device 27a, the drive current detection device 27b, and the rotation speed detection device 27c. The estimated value is calculated, and the power value supplied to the rotor position adjusting electromagnet 11 is controlled to adjust the rotor 3 to rotate at an appropriate floating position.
Here, the buoyancy of the rotor 3 is a value determined by the induced voltage, the drive current, and the rotational speed if the configuration and the mounting state of the axial magnetic levitation rotary motor 1 are determined. For this reason, a program for calculating the buoyancy of the rotor 3 from these values is prepared in advance, and stored in the rotor position control device 23 to enable real-time control of the power value supplied to the rotor position adjusting electromagnet 11.

  The rotation speed detection device 27 c may be configured to read the detection value of the Hall element 25 input to the rotation control device 21, and when the rotation control device 21 controls the rotation of the rotor 3, It is good also as a structure which reads rotation speed from the control signal to output. Furthermore, the rotation control device 21 and the rotor position control device 23 may be integrated, and sensors and circuits corresponding to the induced voltage detection device 27a, the drive current detection device 27b, and the rotation speed detection device 27c may be incorporated therein. In either case, the same effect can be exhibited.

The operation of the axial magnetic levitation rotary motor 1 having such a configuration will be described.
First, when not operating, the rotor 3 is attracted to the stator 5 side by the magnetic force of the rotor rotating permanent magnet 12 and the rotor position adjusting permanent magnet 16.
During operation, power is supplied to the rotor position adjusting electromagnet 11 to float the rotor 3 by a predetermined amount, and then the rotor 3 is rotated by supplying power to the driving electromagnet 9 by the rotary drive device 21. At this time, the buoyancy of the rotor 3 is calculated from the detected induced voltage, drive current, and rotation speed, and the power value supplied to the rotor position adjusting electromagnet 11 is controlled so that the rotor 3 becomes an appropriate floating position. Adjustments are made as appropriate.

The magnetic field generated from the driving electromagnet 9 for rotating the rotor 3 applies a rotational force to the rotor 3 and attracts the rotor position adjusting permanent magnet 16 to the driving electromagnet 9, so that the rotor 3 moves in the radial direction. Never move.
Of course, a control mechanism for more precisely controlling the floating position of the rotor 3 in the radial direction may be separately attached. For example, it can be considered that a magnet (positioning magnet) for continuously attracting a predetermined position of the rotor 3 to a predetermined position on the stator side is arranged.

According to the axial magnetic levitation rotating motor 1 according to the present embodiment, the rotor position adjusting permanent magnet 16 and the rotor position adjusting electromagnet 11 are arranged at the center (rotation center), so that these are the outer circumference in the stator radial direction. Compared with the case where the rotor 3 is arranged on the side, the magnetic field for levitating the rotor 3 does not adversely affect the magnetic field for rotation, the influence on the rotation of the rotor 3 can be reduced, and highly efficient and stable rotation characteristics. Is obtained. Further, since the driving electromagnet 9 and the rotor position adjusting electromagnet 11 can be formed on substantially the same plane along the radial direction, it is possible to reduce the thickness and conventionally, this is an area where no components are arranged. Since the rotor position adjusting electromagnet 11 made of an electromagnet is arranged at the center of the stator 5, windings and other parts can be arranged at a higher density than in the prior art, so that further miniaturization is possible. It is.
Furthermore, the mechanism that calculates the stress (buoyancy) applied in the axial direction of the rotor 3 from the induced voltage, the drive current, and the rotational speed makes it possible to make the structure relatively simple without using a gap sensor.

  According to the axial magnetic levitation rotating motor 1 according to the present embodiment, it is possible to achieve a long life due to the absence of a bearing that pivotally supports the rotor 3 and a low inertia due to the absence of a bearing sliding loss. Further, since the rotor 3 has a mechanical non-contact structure, mechanical wear and contamination due to wear do not occur, and maintenance free for a long period of time can be realized.

Next, an application example of the axial magnetic levitation rotating motor 1 according to the present embodiment will be shown. In the following examples, members, arrangements, and the like are assigned the same reference numerals as in the above-described embodiment, and detailed descriptions thereof are omitted.
FIG. 3 shows an example in which the axial magnetic levitation rotary motor 1 according to this embodiment is applied to the mixed flow pump 2. The mixed flow pump 2 is configured as an all-around flow in-line pump in which a suction port and a discharge port are arranged on the same line and a fluid communication path is formed on the outer peripheral surface of a cylindrical pump casing.

The mixed flow pump 2 includes a rotor 33 to which a plurality of fins constituting the impeller 32 are attached, a stator 35, and a case 34 that houses the rotor 3 and the stator 35.
The rotor 33 has an impeller 32 attached to one surface of a disk-like rotor back yoke 10, and the rotor (not shown) on the other surface (the surface on the stator 5 side) on the outer circumferential side of the rotor back yoke 10. A permanent magnet for rotation 12 is attached, and a permanent magnet 16 for adjusting the rotor position is attached to the center via a non-magnetic material 14.

  The impeller 32 is composed of a plurality of fins that are erected and fixed radially on the rotor back yoke 10 side, and pressurizes the fluid at the center of the impeller 33 in the centrifugal direction as the rotor 33 rotates. In the present embodiment, each fin constituting the impeller 32 is formed in a straight line, but may have a tilt angle and a curved shape with respect to the rotation direction.

The stator 35 includes a stator core 7, a driving electromagnet 9 wound around the stator core 7, and a rotor position adjusting electromagnet 11 wound around the center of the stator, like the axial magnetic levitation rotating motor 1 described above. Has been.
A fluid passage 39a is formed in the outer peripheral portion of the stator 35, and is connected to fluid passages 39b and 39b formed in a case 34 described later. By combining the outer peripheral portion of the stator 35 and the case 34, a substantially cylindrical pump casing constituting the outer shell of the mixed flow pump 2 is formed.

  Control devices such as the rotation control device 21 and the rotor position control device 23 are disposed in a circuit arrangement space 43 formed on the opposite side of the stator 35 from the rotor 33, and the control device is stored in the case 34. Possible configuration. The circuit arrangement space 43 is surrounded by the cover 41 and the stator 35 so that fluid does not enter the inside, and a cable 44 for supplying power is routed to the outside of the mixed flow pump 2. The driving electromagnet 9 and the position adjusting electromagnet 11 are also configured not to contact the fluid directly by a filler (not shown) made of resin or the like.

  The cases 34 and 34 are attached to both sides of the stator 35 to form a fluid passage, and are members that form part of a pump casing that houses the impeller 32 with the stator 35. Fluid between a suction port 36 through which fluid such as blood or blood flows, a discharge port 37 through which fluid is discharged, a centrifugal pressurization chamber 38 connected to the suction port 36, and the centrifugal pressurization chamber 38 and the discharge port 37. The fluid passages 39b and 39b are movable.

  The suction port 36 is an opening for allowing the fluid transferred by the mixed flow pump 2 to flow into the central portion of the impeller 32, and is formed in a tubular shape that protrudes outward from the case 34 to connect a pipe that guides the fluid. ing. In addition, in this embodiment, although it is set as the structure provided with the baffle plate 36a for aligning the fluid flow direction inside the suction inlet 36, it is good also as a structure without the baffle plate 36a. Further, the discharge port 37 is formed on the opposite side to the suction port 36 and is formed in a tubular shape protruding outward from the case 34 in order to connect a tubular body for guiding a fluid, like the suction port 36. Since the discharge port 37 and the suction port 36 are arranged on both sides of the case 34 with the stator 35 interposed therebetween, the mixed flow pump 2 can be disposed in a part of the fluid passage, and the usability is improved. Of course, the discharge port 37 can be changed according to the application, such as being formed in the side surface portion of the case 34.

The centrifugal pressurizing chamber 38 is connected to the suction port 36, and is a portion in which the impeller 32 formed integrally with the rotor 33 is stored. And in a floating state at a position (predetermined position) having a predetermined clearance. The fluid flowing in from the suction port 36 is guided to the central portion of the impeller 32 on the suction port 36 side, and is pressurized in the outer peripheral direction of the impeller 32 by applying a centrifugal force as the impeller 32 rotates.
The fluid passage 39 b is a passage formed so that fluid can be transferred between the side surface side of the centrifugal pressurizing chamber 38 and the discharge port 37 via a fluid passage 39 a formed in the stator 35. The fluid pressurized in the direction is transferred toward the discharge port 37 through the fluid passages 39b, 39a, 39b.

Note that a low friction member (not shown) formed so as to have low frictional resistance with the end surfaces of the fins constituting the impeller 32 is preferably disposed on a part of the inner wall surface of the centrifugal pressurizing chamber 38. It is. Since the low friction member is disposed, the fin 33 can rotate smoothly even when the end face of the fin is in contact with the low friction member. Therefore, even if vibration or impact is applied to the mixed flow pump 2, the rotation of the rotor 33 is prevented. It becomes difficult to influence. Moreover, the loss of the pressure energy given to the fluid from the impeller 32 can be reduced and the pump efficiency can be improved.
As the low friction member, it is preferable to use one or two or more kinds of materials selected from the group consisting of a fluororesin, diamond-like carbon (DLC), and a hydrophilic polymer. Further, the low friction member is not limited to the one using such a low friction material. For example, even if it is the same material as the inner wall surface, the frictional resistance of the surface is reduced by a polishing process or the like. There may be.

The operation of the mixed flow pump 2 having such a configuration will be described.
The fluid guided from the suction port 36 to the center of the impeller 32 moves in the centrifugal direction as the impeller 32 rotates. At the same time, since the central portion of the impeller 32 is depressurized, a new fluid is introduced from the suction port 36. The fluid that has moved in the outer circumferential direction of the centrifugal pressurizing chamber 38 due to the centrifugal force is discharged from the discharge port 37 through the fluid passage 39.

  In the mixed flow pump 2, the rotor 33 and the impeller 34 are integrally formed, so that the impeller 34 floats when the pump is operated (stress that is pulled toward the suction port 36) and the rotor 33 is pulled toward the stator 35 by the magnetic force. Even when the applied force acts on the impeller 32 and the rotor 33, no force in the radial direction or the tilt direction is applied to the rotor 33. Therefore, the movement of the rotor 33 is easily stabilized, and the floating position of the rotor 33 can be easily controlled by the electromagnetic force of the rotor position adjusting electromagnet 11.

  Here, in the mixed flow pump 2, the suction port 36 is depressurized in accordance with the amount of fluid transferred with the rotation of the impeller 34, so the rotor 33 formed integrally with the impeller 34 is connected to the suction port 36 (stator 5 side). In the direction of separating from each other). That is, the stress (buoyancy) applied in the axial direction of the rotor 33 in a state where electric power is not supplied to the rotor position adjusting electromagnet 11 can be calculated from the rotational speed and rotational torque of the rotor 33.

  The rotational speed of the rotor 33 can be calculated from the rotational speed detection device 27c, and the rotational torque can be calculated from the induced voltage and the drive current detected by the induced voltage detection device 27a and the drive current detection device 27b. Therefore, the rotor position control device 23 calculates the stress (buoyancy) applied in the axial direction of the rotor 33 from the induced voltage, the drive current, and the rotational speed, and the rotor position adjusting electromagnet 11 so that the rotor 33 stays at a predetermined position. Proper power is being supplied.

The mixed flow pump 2 is provided with the characteristics of the axial magnetic levitation rotary motor 1 in the following points by applying a motor having the same configuration as the axial magnetic levitation rotary motor 1 according to the present embodiment. Can do.
That is, by arranging the rotor position adjusting permanent magnet 16 and the rotor position adjusting electromagnet 11 at the rotation center portion (center portion), the rotor 33 can be rotated as compared with the case where it is formed on the outer peripheral side in the stator radial direction. Can reduce the effects of

  The drive electromagnet 9 and the rotor position adjusting electromagnet 11 can be formed on substantially the same plane along the radial direction, so that the thickness can be reduced and the conventional electromagnet is formed in the region that was a hollow portion. Since the rotor position adjusting electromagnet 11 is disposed, the mixed flow pump 2 can be downsized. Further, the control device such as the rotation control device 21 and the rotor position control device 23 is arranged in the circuit arrangement space 43 on the side opposite to the rotor 33 of the stator 35, thereby further reducing the size of the mixed flow pump 2. Can do.

Furthermore, since it is a mechanism for calculating the stress applied in the axial direction of the rotor 33 from the induced voltage, drive current, and rotation speed, it is not necessary to use a gap sensor, and the structure can be made relatively simple.
Further, since there is no bearing that supports the rotor 33, it is possible to extend the life and reduce the inertia due to the absence of bearing sliding loss.
Of course, even when the same configuration as the axial magnetic levitation rotary motor 1 according to the present embodiment is applied to another turbo pump such as a centrifugal pump, the above-described features of the axial magnetic levitation rotary motor 1 are provided. be able to.

In particular, when the mixed flow pump 2 according to the present invention is applied to an artificial heart, since the rotor 33 has a mechanical non-contact structure, contamination due to wear does not occur, and blood may be contaminated due to wear. Therefore, safety can be ensured and maintenance-free can be realized, which is suitable for long-term continuous use.
Of course, in addition to the blood pump, it can also be suitably used as a water pump for circulating the coolant of the radiator.
By disposing a low friction member on a part of the inner wall surface of the centrifugal pressurizing chamber 38, even if vibration or impact is applied to the mixed flow pump 2, it becomes difficult to affect the rotation of the rotor 33, and the impeller The loss of the pressure energy given to the fluid from 32 can be reduced and the pump efficiency can be improved.

It is a section explanatory view of the axial magnetic levitation rotation motor concerning one embodiment of the present invention. 1 is a system configuration of an axial magnetic levitation rotary motor according to an embodiment of the present invention. It is an application example to the turbo type pump of the axial magnetic levitation rotary motor which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial magnetic levitation rotary motor, 2 Diagonal flow pump, 3,33 Rotor, 4 Housing, 5,35 Stator, 7 Stator core, 8 Shaft, 9 Driving electromagnet, 10 Rotor back yoke, 11 Rotor position adjusting electromagnet, 12 Rotor Permanent magnet for rotation, 13 Electromagnetic core for rotor position adjustment, 14 Non-magnetic material, 16 Permanent magnet for rotor position adjustment, 21 Rotation control device, 23 Rotor position control device, 25 Hall element, 27a Induced voltage detection device, 27b Drive current Detecting device, 27c Rotational speed detecting device, 32 impeller, 36 Suction port, 36a Rectifier plate, 37 Discharge port, 38 Centrifugal pressure chamber, 39, 39a, 39b Fluid passage, 41 Cover, 43 Circuit arrangement space, 44 Cable

Claims (4)

In an axial magnetic levitation rotary motor including a stator including a driving electromagnet that rotationally drives a magnetically levitated rotor, and a rotor that can be maintained in a floating state,
The rotor includes a rotor position adjusting permanent magnet disposed at the center of rotation so as to face the stator, and a rotor rotating permanent magnet disposed on the radially outer side facing the stator. Prepared,
The stator has a rotor position adjusting electromagnet disposed in the central portion on the rotor side so as to face the rotor position adjusting permanent magnet, and a rotor rotating permanent magnet on the radially outer side of the rotor side. An electromagnet for driving disposed
An axial magnetic levitation rotating motor characterized in that the rotor is maintained at a predetermined position by adjusting an output of the rotor position adjusting electromagnet. A rotation control device for controlling the rotation of the rotor by controlling the driving electromagnet;
A rotor position control device for controlling the position of the rotor by controlling electric power supplied to the rotor position adjusting electromagnet;
An induced voltage detection device capable of detecting the induced voltage supplied to the driving electromagnet;
A drive current detector capable of detecting a drive current supplied to the drive electromagnet;
A rotational speed detection device capable of detecting the rotational speed of the rotor,
The induced voltage detection device, the drive current detection device, and the rotation speed detection device are all connected to the rotor position control device,
The rotor position control device is configured to cause the rotor to detect the induced voltage detected by the induced voltage detection device, the drive current detected by the drive current detection device, and the rotation speed detected by the rotation speed detection device. The applied axial stress is calculated, and the electric power supplied to the rotor position adjusting electromagnet is controlled based on the calculated stress value to maintain the rotor at a predetermined position. Item 2. The axial magnetic levitation rotary motor according to item 1. A cylindrical pump casing in which a suction passage, a discharge port, and a fluid passage communicating the both are formed;
A rotor capable of being maintained in a floating state in the pump casing;
An impeller fixed to the rotor side and having fins;
A stator having a driving electromagnet which is disposed on the discharge port side in the axial direction of the rotor and rotationally drives the rotor, and the impeller is rotated by the rotation of the rotor, and is sucked from the suction port A turbo-type pump using an axial magnetic levitation rotary motor in which fluid is transferred to the discharge port,
The rotor includes a rotor position adjusting permanent magnet disposed at the center of rotation so as to face the stator, and a rotor rotating permanent magnet disposed on the radially outer side facing the stator. Prepared,
The stator has a rotor position adjusting electromagnet disposed in the central portion on the rotor side so as to face the rotor position adjusting permanent magnet, and a rotor rotating permanent magnet on the radially outer side of the rotor side. An electromagnet for driving disposed
A turbo pump using an axial magnetic levitation rotating motor, wherein the rotor is maintained at a predetermined position by adjusting an output of the rotor position adjusting electromagnet. A rotation control device for controlling the rotation of the rotor by controlling the driving electromagnet;
A rotor position control device for controlling the position of the rotor by controlling electric power supplied to the rotor position adjusting electromagnet;
An induced voltage detection device capable of detecting the induced voltage supplied to the driving electromagnet;
A drive current detector capable of detecting a drive current supplied to the drive electromagnet;
A rotational speed detection device capable of detecting the rotational speed of the rotor,
The induced voltage detection device, the drive current detection device, and the rotation speed detection device are all connected to the rotor position control device,
The rotor position control device is configured to cause the rotor to detect the induced voltage detected by the induced voltage detection device, the drive current detected by the drive current detection device, and the rotation speed detected by the rotation speed detection device. The applied axial stress is calculated, and the electric power supplied to the rotor position adjusting electromagnet is controlled based on the calculated stress value to maintain the rotor at a predetermined position. A turbo pump using the axial magnetic levitation rotating motor according to claim 3.

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