WO2015137126A1 - Dispositif pompe de type à lévitation magnétique, méthode d'estimation de viscosité de fluide par dispositif pompe de type à lévitation magnétique, et méthode d'estimation de débit de fluide par dispositif pompe de type à lévitation magnétique - Google Patents

Dispositif pompe de type à lévitation magnétique, méthode d'estimation de viscosité de fluide par dispositif pompe de type à lévitation magnétique, et méthode d'estimation de débit de fluide par dispositif pompe de type à lévitation magnétique Download PDF

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Publication number
WO2015137126A1
WO2015137126A1 PCT/JP2015/055536 JP2015055536W WO2015137126A1 WO 2015137126 A1 WO2015137126 A1 WO 2015137126A1 JP 2015055536 W JP2015055536 W JP 2015055536W WO 2015137126 A1 WO2015137126 A1 WO 2015137126A1
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Prior art keywords
impeller
viscosity
fluid
magnetic levitation
pump device
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PCT/JP2015/055536
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English (en)
Japanese (ja)
Inventor
亘 土方
進士　忠彦
将大 阿部
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国立大学法人東京工業大学
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Publication of WO2015137126A1 publication Critical patent/WO2015137126A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/04—Shafts or bearings, or assemblies thereof
    • F04D29/046—Bearings
    • F04D29/048—Bearings magnetic; electromagnetic
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0088—Testing machines
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00—General characteristics of the apparatus
    • A61M2205/33—Controlling, regulating or measuring
    • A61M2205/3331—Pressure; Flow
    • A61M2205/3334—Measuring or controlling the flow rate
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10—Location thereof with respect to the patient's body
    • A61M60/104—Extracorporeal pumps, i.e. the blood being pumped outside the patient's body
    • A61M60/117—Extracorporeal pumps, i.e. the blood being pumped outside the patient's body for assisting the heart, e.g. transcutaneous or external ventricular assist devices
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10—Location thereof with respect to the patient's body
    • A61M60/122—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10—Location thereof with respect to the patient's body
    • A61M60/122—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body
    • A61M60/126—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable via, into, inside, in line, branching on, or around a blood vessel
    • A61M60/148—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable via, into, inside, in line, branching on, or around a blood vessel in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10—Location thereof with respect to the patient's body
    • A61M60/122—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body
    • A61M60/196—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body replacing the entire heart, e.g. total artificial hearts [TAH]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/20—Type thereof
    • A61M60/205—Non-positive displacement blood pumps
    • A61M60/216—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller
    • A61M60/221—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller the blood flow through the rotating member having both radial and axial components, e.g. mixed flow pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/20—Type thereof
    • A61M60/205—Non-positive displacement blood pumps
    • A61M60/216—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller
    • A61M60/226—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller the blood flow through the rotating member having mainly radial components
    • A61M60/232—Centrifugal pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/20—Type thereof
    • A61M60/205—Non-positive displacement blood pumps
    • A61M60/216—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller
    • A61M60/237—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/40—Details relating to driving
    • A61M60/403—Details relating to driving for non-positive displacement blood pumps
    • A61M60/419—Details relating to driving for non-positive displacement blood pumps the force acting on the blood contacting member being permanent magnetic, e.g. from a rotating magnetic coupling between driving and driven magnets
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/40—Details relating to driving
    • A61M60/403—Details relating to driving for non-positive displacement blood pumps
    • A61M60/422—Details relating to driving for non-positive displacement blood pumps the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/50—Details relating to control
    • A61M60/508—Electronic control means, e.g. for feedback regulation
    • A61M60/538—Regulation using real-time blood pump operational parameter data, e.g. motor current
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/50—Details relating to control
    • A61M60/508—Electronic control means, e.g. for feedback regulation
    • A61M60/538—Regulation using real-time blood pump operational parameter data, e.g. motor current
    • A61M60/546—Regulation using real-time blood pump operational parameter data, e.g. motor current of blood flow, e.g. by adapting rotor speed
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/80—Constructional details other than related to driving
    • A61M60/802—Constructional details other than related to driving of non-positive displacement blood pumps
    • A61M60/818—Bearings
    • A61M60/82—Magnetic bearings

Definitions

  • the present invention relates to a magnetic levitation pump device in which an impeller supported in a non-contact manner on a magnetic bearing portion is levitated and rotated by electromagnetic force, a fluid viscosity estimation method using a magnetic levitation pump device, and a fluid using a magnetic levitation pump device
  • the present invention relates to a flow rate estimation method.
  • Magnetic levitation type that moves various fluids such as gas and liquid by rotating an impeller that is supported in a non-contact manner by magnetic force in medical equipment such as blood pumps, semiconductors, and food manufacturing fields.
  • a pump device is used.
  • the viscosity affects the fluid transfer performance of the pump device. Therefore, in order to maintain the performance, it is necessary to estimate and grasp the viscosity. .
  • the torque increases as the viscosity increases, so that the viscosity is conventionally estimated from the motor torque for rotating the impeller.
  • the viscosity is estimated by indirectly measuring the torque from the current and power consumption of the motor.
  • Patent Document 1 discloses that the impeller is floated from the rotation axis center to the vicinity of the housing wall. A technique for estimating the viscosity from the amount of change in motor current at that time by shifting is disclosed.
  • the present invention has been made in view of the above problems, and a new and improved magnetic levitation pump device capable of estimating the viscosity of a fluid more easily and reliably without being restricted by the structure of the device, It is an object of the present invention to provide a fluid viscosity estimation method using a magnetic levitation pump device and a fluid flow rate estimation method using a magnetic levitation pump device.
  • One aspect of the present invention is a magnetically levitated pump device that transfers the fluid while magnetically levitating and rotating an impeller in a housing having a fluid inflow portion and an outflow portion, and is non-contact with the impeller by magnetic force
  • a rotary drive unit coupled to the impeller to rotate the impeller, a magnetic bearing unit supporting the impeller in a non-contact manner by the magnetic force, and a position facing the permanent magnet built in the rotor of the impeller of the magnetic bearing unit.
  • An applied current control unit that controls an applied current to the electromagnet provided, a current sensor that detects the magnitude of the applied current, a displacement sensor that detects displacement of the impeller, and the applied current control unit within a predetermined frequency range
  • a calculation unit that calculates at least one of a phase difference between the impeller displacement due to vibration and the alternating current or an amplitude ratio between the impeller displacement and the alternating current, and at least one of the phase difference or the amplitude ratio calculated by the calculation unit
  • a viscosity estimation unit that estimates the viscosity of the fluid.
  • the impeller is forcibly vibrated by applying an alternating current so as to be superimposed on the exciting current applied to the electromagnet of the magnetic bearing portion for a predetermined time. Based on the phase difference and amplitude ratio of the alternating current, the viscosity of the fluid can be estimated easily and accurately.
  • the applied current control unit is configured to apply a frequency at which the impeller can vibrate around a levitation target position when the alternating current is applied and superimposed on the excitation current, and the impeller Alternatively, an alternating current having an amplitude within a range where the housing does not contact may be applied.
  • the vibration of the impeller can be suppressed to a slight vibration, the viscosity of the fluid to be transferred can be reliably estimated while maintaining a stable operation state of the magnetic levitation pump device.
  • the frequency may be a value close to a value calculated by the following equation.
  • the impeller when an alternating current is applied, the impeller can be slightly vibrated in a range where the impeller and the housing do not contact each other, so that the viscosity of the fluid to be transferred is maintained while maintaining a stable operation state of the magnetic levitation pump device. Can be reliably estimated.
  • the viscosity estimation unit is based on prior experimental data relating to the relationship between the phase difference and the viscosity, or a relational expression between the phase difference and the viscosity obtained theoretically in advance.
  • the viscosity may be estimated.
  • the viscosity of the fluid can be accurately estimated based on the phase difference of the impeller displacement caused by the impeller vibration generated by applying the alternating current superimposed on the exciting current.
  • the impeller may have any shape of a centrifugal type, an axial flow type, or a diagonal flow type.
  • the flow rate of the fluid is estimated based on at least one of the torque, current value, power consumption, and rotation speed of the rotation drive unit and the viscosity estimated by the viscosity estimation unit. It is good also as providing the flow volume estimation part to perform.
  • a fluid viscosity estimation method using a magnetic levitation pump device that transfers a fluid while magnetically levitating and rotating an impeller in a housing having a fluid inflow portion and an outflow portion.
  • An alternating current application step of applying and superimposing an alternating current in a predetermined frequency range on an exciting current applied to an electromagnet provided at a position facing a permanent magnet built in the rotor of the impeller, and after applying the alternating current
  • An impeller displacement detecting step for detecting an impeller displacement due to the vibration of the impeller, a recording step for recording at least one of a phase or an amplitude of the impeller displacement due to the vibration, a phase difference or an amplitude ratio of the impeller displacement and the alternating current Based on at least one of the phase difference or the amplitude ratio, and a calculation step for calculating at least one of the phase difference and the amplitude ratio.
  • the impeller is intentionally slightly vibrated by applying an alternating current so as to be superimposed on the exciting current applied to the electromagnet of the magnetic bearing portion for a predetermined time, and the impeller displacement
  • the viscosity of the fluid can be estimated easily and accurately based on the phase difference and amplitude ratio of the alternating current.
  • Still another aspect of the present invention is a method for estimating a fluid flow rate by a magnetic levitation pump device that transfers a fluid while magnetically levitating and rotating an impeller in a housing having a fluid inflow portion and an outflow portion.
  • An impeller displacement detecting step for detecting an impeller displacement due to the vibration of the impeller, a recording step for recording at least one of a phase or an amplitude of the impeller displacement due to the vibration, a phase difference or an amplitude ratio between the impeller displacement and the alternating current
  • the fluid Based on the viscosity estimation step of estimating the viscosity, at least one of the torque, current value, power consumption, and rotation speed of the rotation drive unit that rotates the impeller, and the viscosity estimated in the viscosity estimation step, the fluid And a flow rate estimating step for estimating the flow rate of.
  • the accuracy in estimating the fluid flow rate is improved by utilizing the viscosity estimated by the magnetic levitation pump device.
  • the estimated flow rate obtained from the torque of the rotation drive unit and the rotation speed is compensated by the viscosity estimated in the viscosity estimation step. It is good also as estimating the said flow volume by.
  • the viscosity of the fluid can be estimated more easily and reliably with high accuracy without adding new hardware and without being restricted by the structure of the apparatus.
  • the flow rate of the fluid can be estimated more easily and reliably using the viscosity.
  • FIG. 1 is a block diagram showing a schematic configuration of a magnetic levitation pump apparatus according to an embodiment of the present invention.
  • FIG. 2 is a flowchart showing an outline of a fluid viscosity estimation method by the magnetic levitation pump device according to the embodiment of the present invention.
  • FIG. 3 is a flowchart showing an outline of another aspect of the fluid viscosity estimation method by the magnetic levitation pump device according to the embodiment of the present invention.
  • 4A to 4D are examples of waveform diagrams of alternating current applied when the viscosity of the fluid is estimated by the magnetic levitation pump device according to the embodiment of the present invention.
  • FIG. 5A to 5E are explanatory views showing a configuration example of an impeller provided in a magnetic levitation pump device according to an embodiment of the present invention.
  • FIG. 6 is a block diagram showing a schematic configuration of a magnetic levitation pump device according to another embodiment of the present invention.
  • FIG. 7 is a flowchart showing an outline of a method for estimating the viscosity and flow rate of a fluid by a magnetic levitation pump device according to another embodiment of the present invention.
  • FIG. 8 is a flowchart showing an outline of another aspect of the fluid viscosity and flow rate estimation method by the magnetic levitation pump device according to another embodiment of the present invention.
  • FIG. 9 is an explanatory diagram showing the phase and amplitude relationship between the waveform of the impeller displacement and the waveform of the applied current in an example of fluid viscosity estimation by the magnetic levitation pump device according to the embodiment of the present invention.
  • FIG. 10 is an explanatory diagram showing the relationship between the amplitude ratio and phase difference between the waveform of the impeller displacement and the waveform of the applied current and the frequency of the applied current in this example.
  • FIG. 11 is an explanatory diagram showing the relationship between the viscosity and the phase difference at a vibration frequency of 70 Hz in this example.
  • FIG. 12 is an explanatory diagram showing the relationship between the flow rate of the fluid and the phase difference at the vibration frequency of 70 Hz in this embodiment.
  • FIG. 10 is an explanatory diagram showing the relationship between the amplitude ratio and phase difference between the waveform of the impeller displacement and the waveform of the applied current and the frequency of the applied current in this example.
  • FIG. 11 is an explanatory diagram showing the relationship between the vis
  • FIG. 13 is an explanatory diagram showing the relationship between the estimated viscosity and the actually measured viscosity in this example.
  • FIG. 14 is an explanatory diagram showing the relationship between the actually measured flow rate and the estimated flow rate in an example of fluid flow rate estimation by the magnetic levitation pump device according to another embodiment of the present invention.
  • FIG. 1 is a block diagram showing a schematic configuration of a magnetic levitation pump apparatus according to an embodiment of the present invention.
  • the magnetic levitation pump apparatus 100 is configured to drive the motor 108 by coupling the drive shaft 113 of the motor 108 serving as a drive source (rotation drive unit) and the impeller 104 in a non-contact manner by magnetic coupling. It is a non-contact type magnetic levitation type continuous flow pump that transmits force.
  • the magnetic levitation pump apparatus 100 according to the present embodiment applies the excitation current to the electromagnet 116 of the magnetic bearing unit 101 so that the center of the magnetically levitated impeller 104 rotates when the impeller 104 rotates. Position control is performed so as to rotate at the flying target position that coincides with A1.
  • the impeller 104 is a centrifugal impeller that is magnetically levitated in the housing 102 and is coupled in a non-contact manner with the drive shaft 113 of the motor 108 by magnetic coupling and rotates while magnetically levitating in the housing 102.
  • the center of the bottom surface of the rotor 106 of the impeller 104 is a concave portion 106 b, and the concave portion 106 b is opposed to the convex portion 102 b 1 provided on the central side of the bottom surface 102 b of the housing 102. ing.
  • the fluid L inflow portion 102 c is provided on the top side of the housing 102 that houses the impeller 104, and the fluid L outflow portion 102 d is provided at any part of the side wall 102 a of the housing 102. For this reason, when the impeller 104 rotates in the housing 102 while magnetically levitating, the fluid L is transferred from the inflow portion 102c to the outflow portion 102d.
  • the magnetic bearing portion 101 supports the impeller 104 in a non-contact manner by a magnetic force.
  • an electromagnet 116 is provided at a position facing the permanent magnet 110 built in the outer peripheral surface 106 a side of the rotor 106 of the impeller 104.
  • an exciting current to the electromagnet 116, the center of the impeller 104 is adjusted so as to be arranged on the rotation center axis A1.
  • the position of the impeller 104 is controlled by applying an exciting current to the electromagnet 116.
  • the impeller 104 is passively maintained in the floating state by the restoring force acting in the vertical direction of the magnetic circuit constituting the magnetic coupling without being controlled in position.
  • a motor 108 serving as a drive source for the impeller 104 is provided in the casing 122 of the magnetic bearing portion 101, and a permanent magnet 114 is provided on the outer peripheral surface on the front end side of the drive shaft 113 of the motor 108. ing. And the permanent magnet 112 which acts on the said permanent magnet 114 and attractive force is provided in the internal peripheral surface 106b1 of the recessed part 106b of the rotor 106 of the impeller 104. As shown in FIG. When these permanent magnets 112 and 114 are coupled by magnetic coupling, the driving force of the motor 108 is transmitted to the impeller 104 in a non-contact manner.
  • the driving of the motor 108 is controlled by a motor control unit 164 provided in a control unit 150 that performs various controls of the magnetic levitation pump device 100.
  • the applied current to the electromagnet 116 of the magnetic bearing unit 101 is controlled by the applied current control unit 154.
  • the applied current control unit 154 feeds back a signal of the displacement sensor 120 that detects the displacement of the impeller 104 to the calculation unit 152 of the control unit 150 so that the impeller 104 floats on the rotation axis center A1.
  • An appropriate current value is calculated and controlled to be supplied to the electromagnet 116.
  • the applied current control unit 154 appropriately adjusts the magnitude of the excitation current so that the impeller 104 returns to the floating target position that can rotate about the rotation axis center A1. Control to do.
  • the displacement sensor 120 is a sensor that is provided, for example, between any of a plurality of electromagnets 116 arranged in an annular shape and detects the position of the impeller 104 by detecting the outer peripheral surface 106a of the rotor 106, and is an eddy current sensor. Etc.
  • the magnitude of the applied current is detected by a current sensor 118 provided between the electromagnet 116 and the applied current control unit 154.
  • the exciting current applied to the electromagnet 116 is adjusted by the applied current adjusting unit 162 such as an amplifier or an inverter under the control of the applied current control unit 154.
  • the present inventor has intentionally applied an alternating current to the electromagnet 116 provided in the magnetic bearing portion 101 of the magnetic levitation pump device 100 of the present embodiment. It has been found that the phase difference ⁇ between the impeller displacement generated when the impeller 104 is forcibly vibrated by application and the applied alternating current is correlated with the viscosity ⁇ of the working fluid. It was also found that there is a correlation between the amplitude ⁇ of the impeller displacement at that time and the amplitude ratio a / b of the amplitude b of the applied alternating current and the viscosity ⁇ .
  • the magnetic levitation pump device 100 of the present embodiment realized the estimation of the fluid viscosity ⁇ using the principle described above.
  • the CPU (arithmetic unit) 152 that controls the above-described control of the magnetic levitation pump device 100 of the present embodiment will be described.
  • the CPU 152 has a function of controlling the operation of each component included in the magnetic levitation pump device 100 in accordance with various programs stored in the storage unit 166 such as a ROM. In addition, the CPU 152 has a function of appropriately storing necessary data and the like in a RAM (not shown) that temporarily stores data when executing these various processes.
  • the CPU 152 includes an applied current control unit 154, an impeller displacement recording unit 156, a calculation unit 158, and a viscosity estimation unit 160, as shown in FIG.
  • the applied current control unit 154 has a function of controlling the applied current to the electromagnet 116 of the magnetic bearing unit 101 as described above.
  • the applied current control unit 154 estimates the viscosity ⁇ of the fluid L
  • the applied current control unit 154 superimposes an alternating current in a predetermined frequency range on an excitation current to the electromagnet 116 for a predetermined time (for example, several seconds). And has a function of controlling the applied current so as to be applied.
  • the applied current control unit 154 when the applied current control unit 154 applies an alternating current and superimposes the excitation current on the excitation current, the applied current control unit 154 has a frequency at which the impeller 104 can vibrate around the floating target position, and a range where the impeller 104 and the housing 102 do not contact each other. An alternating current having an amplitude within the range is applied.
  • the frequency f is preferably a value close to the value calculated by the following equation (1).
  • Kx described in the above formula (1) is “negative rigidity (N / m) expressed in the magnetic bearing portion 101”, and M is “additional mass due to the fluid L added to the mass of the impeller 104”. Value (kg) ".
  • the “additional mass” indicates a mass corresponding to an increase in the apparent weight when the impeller 104 is placed in the liquid, and is a value that varies depending on the liquid density. For example, when the liquid is blood, the additional mass is about ten times the mass of the impeller 104.
  • the vibration of the impeller 104 can be suppressed to a slight vibration in a range where the impeller 104 and the housing 102 do not contact each other. For this reason, it is possible to reliably estimate the viscosity ⁇ of the fluid L to be transferred while maintaining a stable operation state of the magnetic levitation pump device 100.
  • the impeller displacement recording unit 156 has a function of creating and recording a function curve while plotting the impeller displacement detected by the displacement sensor 120.
  • the recording data plotted by the impeller displacement recording unit 156 is used to calculate the phase difference ⁇ or the amplitude ratio a / b used for estimating the viscosity of the fluid L.
  • the calculation unit 158 has a function of calculating data necessary for control of each component of the magnetic levitation pump apparatus 100 based on detection data of the current sensor 118 and the displacement sensor 120 and the like.
  • the calculation unit 158 includes the phase difference ⁇ between the impeller displacement and the alternating current detected by the vibration of the impeller 104 detected by the displacement sensor 120, or the amplitude ratio a / b between the amplitude a of the impeller displacement and the amplitude b of the alternating current.
  • the calculating unit 158 has at least one of the phase difference ⁇ and the amplitude ratio a / b. It has a function to calculate.
  • the viscosity estimating unit 160 has a function of estimating the viscosity ⁇ of the fluid L based on at least one of the phase difference ⁇ and the amplitude ratio a / b calculated by the calculating unit 158.
  • the viscosity estimating unit 160 estimates the viscosity of the fluid L based on the phase difference ⁇ , for example, the phase difference stored in the storage unit 166 or the like is used to accurately estimate the viscosity.
  • the viscosity ⁇ is estimated based on prior experimental data relating to the relationship between ⁇ and the viscosity ⁇ of the fluid, or based on a relational expression between the phase difference ⁇ and the viscosity ⁇ that is theoretically obtained in advance.
  • the impeller 104 is forcibly microvibrated by applying an alternating current intentionally superimposed on the exciting current applied to the electromagnet 116 of the magnetic bearing portion 101 for a predetermined time.
  • the viscosity ⁇ of the fluid L can be easily and accurately estimated based on the phase difference ⁇ between the impeller displacement generated by the minute vibration and the alternating current and the amplitude ratio a / b.
  • the viscosity ⁇ of the fluid L can be estimated more easily and reliably without adding new hardware such as a torque meter as in the prior art and without being restricted by the structure of the apparatus.
  • FIG. 2 is a flowchart showing an outline of a fluid viscosity estimation method by a magnetic levitation pump apparatus according to an embodiment of the present invention
  • FIG. 3 is a magnetic levitation pump apparatus according to an embodiment of the present invention. It is a flowchart which shows the outline of the other aspect of the viscosity estimation method of the fluid by A. 2 shows a flow of a method for estimating the viscosity ⁇ based on the phase difference ⁇
  • FIG. 3 shows a flow of a method for estimating the viscosity ⁇ based on the amplitude ratio a / b.
  • an alternating current in a predetermined frequency range is applied to the excitation current applied to the electromagnet 116 provided in the magnetic bearing unit 101 for a predetermined time (for example, several seconds).
  • a predetermined time for example, several seconds.
  • AC current application step S11 superimposed on the excitation current.
  • the impeller 104 is forcibly vibrated by intentionally applying an alternating current for a predetermined time.
  • an alternating current having a frequency f at which the impeller can vibrate around the floating target position and an amplitude b within a range where the impeller 104 and the housing 102 do not contact each other is applied. That is, it is necessary to select an appropriate frequency f and amplitude b so that the vibration of the impeller 104 does not contact the impeller 104 and the housing 102 around the floating target position.
  • the impeller 104 does not respond and does not vibrate, so the viscosity estimation method according to this embodiment cannot be performed. For this reason, in the low frequency region (for example, 400 Hz or less) where the impeller 104 vibrates, the impeller 104 and the housing 102 are adjusted so as not to contact each other by appropriately adjusting the amplitude of the alternating current.
  • the frequency f of the alternating current to be applied is selected to be a frequency that is low enough to obtain the vibration amplitude a of the impeller 104,
  • the amplitude b of the alternating current needs to be adjusted within a range where the impeller 104 and the housing 102 do not contact each other.
  • the alternating current applied here may be an alternating current having a predetermined period in which the current value periodically fluctuates, and the waveform thereof is, for example, a sine wave shown in FIG. 4A or a rectangle shown in FIG. 4B.
  • a wave, a triangular wave shown in FIG. 4C, and a sawtooth wave shown in FIG. 4D are applicable.
  • the displacement of the impeller due to the vibration of the impeller 104 is detected by the displacement sensor 120 (impeller displacement detection step S12). Then, the phase of the impeller displacement caused by the vibration of the impeller 104 generated by the application of the alternating current is plotted and recorded (recording step S13). Thereafter, the phase difference ⁇ between the impeller displacement and the alternating current is calculated (calculation step S14), and the viscosity ⁇ of the fluid L is estimated based on the phase difference ⁇ (viscosity estimation step S15).
  • the viscosity ⁇ of the fluid L is estimated using the phase difference ⁇ or the amplitude ratio a / b. However, if at least one of them is used, the viscosity ⁇ can be estimated. Both may be used together to estimate the viscosity ⁇ of the fluid L with higher accuracy.
  • the excitation current to the electromagnet 116 is calculated so that the impeller 104 does not shake from the target position (center of rotation axis, etc.). .
  • the impeller 104 is forcibly vibrated by superimposing an alternating current having a constant frequency f on the excitation current for several seconds. Then, during the forced vibration of the impeller 104, the phase difference ⁇ or the amplitude ratio a / b between the alternating current I of the frequency f and the impeller displacement X is calculated.
  • the viscosity estimation method by the magnetic levitation pump apparatus 100 of the present embodiment can easily estimate the viscosity ⁇ of the fluid L without adding new hardware. Also, the viscosity estimation method by the magnetic levitation pump device 100 of the present embodiment is less dependent on the flow rate and does not need to cut off the flow rate, unlike the conventional method using the motor torque for viscosity estimation. Since there is no influence of loss, the fluid viscosity ⁇ can be accurately estimated. Furthermore, the viscosity estimation method using the magnetically levitated pump device 100 according to the present embodiment does not affect the measurement accuracy of the viscosity ⁇ even if the gap between the impeller 104 and the housing 102 is large in principle. Accurate viscosity estimation is possible without being restricted by the above.
  • FIG. 5E the magnetic levitation pump device 100 of this embodiment can be applied to a magnetic levitation type continuous flow pump regardless of whether it is a centrifugal type, an axial flow type, or a diagonal flow type.
  • the viscosity can be estimated in the same procedure as in the present embodiment even in the case of an axial flow type or mixed flow type impeller shape.
  • the viscosity estimation method by the magnetic levitation pump device 100 of the present embodiment described above can be applied to various fields.
  • a conventional circulation system such as an artificial artificial heart that is difficult to install a flow meter
  • the error greatly increases or decreases depending on the working fluid viscosity.
  • the estimated viscosity value obtained by the viscosity estimation method using the magnetic levitation pump device 100 of this embodiment can be used for error correction in flow rate estimation.
  • the state of the working fluid may be applied to online monitoring using the estimated viscosity value itself.
  • blood coagulation monitoring such as blood clot detection and prediction in blood pumps and artificial hearts, and quality control of ultrapure water in semiconductor and food manufacturing. That is, it can be applied as a magnetic levitation type continuous flow blood pump for extracorporeal circulation, a magnetic levitation type artificial heart for implantation in the body, and an ultra-clean magnetic levitation type pump for semiconductor manufacturing and food manufacturing.
  • FIG. 6 is a block diagram showing a schematic configuration of a magnetic levitation pump device according to another embodiment of the present invention.
  • a drive shaft 213 and an impeller 204 of a motor 208 serving as a drive source (rotation drive unit) are coupled in a non-contact manner by magnetic coupling. It is a non-contact type magnetic levitation type continuous flow pump that transmits the driving force of the motor.
  • the magnetic levitation pump device 200 of the present embodiment applies the excitation current to the electromagnet 216 of the magnetic bearing unit 201 to rotate the central axis of the magnetically levitated impeller 204 when the impeller 204 is driven to rotate.
  • Position control is performed so as to rotate at the flying target position that coincides with A2.
  • the impeller 204 is a centrifugal impeller that rotates while being magnetically levitated in the housing 202 while being magnetically levitated in the housing 202 and coupled in a non-contact manner with the drive shaft 213 of the motor 208 by magnetic coupling.
  • the center of the bottom surface of the rotor 206 of the impeller 204 is a concave portion 206 b, and is configured to face the convex portion 202 b 1 provided on the central side of the bottom surface 202 b of the housing 202. ing.
  • the fluid L inflow portion 202 c is provided on the top side of the housing 202 that houses the impeller 204, and the fluid L outflow portion 202 d is provided at any part of the side wall 202 a of the housing 202. For this reason, when the impeller 204 rotates in the housing 202 while magnetically levitating, the fluid L is transferred from the inflow portion 202c to the outflow portion 202d.
  • the magnetic bearing unit 201 supports the impeller 204 in a non-contact manner by a magnetic force.
  • the magnetic bearing portion 201 is provided with an electromagnet 216 at a position facing the permanent magnet 210 built in the outer peripheral surface 206 a side of the rotor 206 of the impeller 204.
  • an exciting current to the electromagnet 216, the center of the impeller 204 is adjusted so as to be arranged on the rotation center axis A2.
  • the position of the impeller 204 is controlled by applying an exciting current to the electromagnet 216 in the horizontal direction.
  • the impeller 204 is passively maintained in the floating state by the restoring force acting in the vertical direction of the magnetic circuit constituting the magnetic coupling without being controlled in position.
  • a motor 208 serving as a drive source for the impeller 204 is provided in the casing 222 of the magnetic bearing unit 201, and a permanent magnet 214 is provided on the outer peripheral surface on the front end side of the drive shaft 213 of the motor 208.
  • a permanent magnet 212 that acts an attractive force with the permanent magnet 214 is provided on the inner peripheral surface 206 b 1 of the recess 206 b of the rotor 206 of the impeller 204.
  • These permanent magnets 212 and 214 are coupled by a magnetic coupling, whereby the driving force of the motor 208 is transmitted to the impeller 204 in a non-contact manner.
  • Driving of the motor 208 is controlled by a motor control unit 264 provided in a control unit 250 that performs various controls of the magnetic levitation pump device 200.
  • the applied current to the electromagnet 216 of the magnetic bearing unit 201 is controlled by the applied current control unit 254.
  • the applied current control unit 254 feeds back a signal of the displacement sensor 220 that detects the displacement of the impeller 204 to the calculation unit 252 of the control unit 250 so that the impeller 204 floats to the rotation axis center A2.
  • An appropriate current value is calculated and controlled to be supplied to the electromagnet 216.
  • the applied current control unit 254 appropriately adjusts the magnitude of the excitation current so that the impeller 204 returns to the levitation target position that can rotate around the rotation axis A2. Control to do.
  • the displacement sensor 220 is a sensor that is provided, for example, between any of the plurality of electromagnets 216 arranged in an annular shape, and detects the position of the impeller 204 by detecting the outer peripheral surface 206a of the rotor 206, and is an eddy current sensor. Etc.
  • the magnitude of the applied current is detected by a current sensor 218 provided between the electromagnet 216 and the applied current control unit 254.
  • the exciting current applied to the electromagnet 216 is adjusted by the applied current adjusting unit 262 such as an amplifier or an inverter under the control of the applied current control unit 254.
  • the present inventor intentionally applied an alternating current to the electromagnet 216 provided in the magnetic bearing portion 201 of the magnetic levitation pump device 200 of the present embodiment. It has been found that the phase difference ⁇ between the impeller displacement generated when the impeller 204 is forcibly vibrated by application and the applied alternating current is correlated with the viscosity ⁇ of the working fluid. It was also found that there is a correlation between the amplitude ⁇ of the impeller displacement at that time and the amplitude ratio a / b of the amplitude b of the applied alternating current and the viscosity ⁇ . Furthermore, the present inventor has found that the flow rate can be estimated with higher accuracy by using the estimated viscosity value obtained by the viscosity estimation method by the magnetic levitation pump apparatus 200 of the present embodiment for error correction of the flow rate estimation.
  • the magnetic levitation pump device 200 of the present embodiment realized the estimation of the fluid viscosity ⁇ using the principle described above.
  • the CPU (arithmetic unit) 252 that controls the above-described control of the magnetic levitation pump device 200 of the present embodiment will be described.
  • the CPU 252 has a function of controlling the operation of each component provided in the magnetic levitation pump device 200 according to various programs stored in the storage unit 266 such as a ROM. Further, the CPU 252 has a function of appropriately storing necessary data and the like in a RAM (not shown) that temporarily stores data when executing these various processes.
  • the CPU 252 includes an applied current control unit 254, an impeller displacement recording unit 256, a calculation unit 258, a viscosity estimation unit 260, and a flow rate estimation unit 261, as shown in FIG.
  • the applied current control unit 254 has a function of controlling the applied current to the electromagnet 216 of the magnetic bearing unit 201 as described above.
  • the applied current control unit 254 estimates the viscosity ⁇ of the fluid L
  • the applied current control unit 254 superimposes an alternating current in a predetermined frequency range on an excitation current to the electromagnet 216 for a predetermined time (for example, several seconds). And has a function of controlling the applied current so as to be applied.
  • the applied current control unit 254 applies a frequency at which the impeller 204 can vibrate around the floating target position when applying an alternating current and superimposing it with the excitation current, and a range where the impeller 204 and the housing 202 do not contact each other.
  • An alternating current having an amplitude within the range is applied.
  • the frequency f is preferably a value close to the value calculated by the above-described equation (1), as in the first embodiment.
  • the vibration of the impeller 204 can be suppressed to a slight vibration in a range where the impeller 204 and the housing 202 do not contact each other. Therefore, it is possible to reliably estimate the viscosity ⁇ of the fluid L to be transferred while maintaining a stable operation state of the magnetic levitation pump device 200.
  • the impeller displacement recording unit 256 has a function of creating and recording a function curve while plotting the impeller displacement detected by the displacement sensor 220.
  • the recorded data plotted by the impeller displacement recording unit 256 is used to calculate the phase difference ⁇ or the amplitude ratio a / b used for estimating the viscosity of the fluid L.
  • the calculation unit 258 has a function of calculating data necessary for control of each component of the magnetic levitation pump device 200 based on detection data of the current sensor 218 and the displacement sensor 220 and the like.
  • the calculation unit 258 includes the phase difference ⁇ between the impeller displacement detected by the displacement sensor 220 due to the vibration of the impeller 204 and the alternating current, or the amplitude ratio a / b between the impeller displacement amplitude a and the alternating current amplitude b.
  • the calculation unit 258 controls at least one of the phase difference ⁇ and the amplitude ratio a / b when the applied current control unit 254 controls the applied current so that the alternating current is superimposed on the excitation current to the electromagnet 216. It has a function to calculate.
  • the viscosity estimation unit 260 has a function of estimating the viscosity ⁇ of the fluid L based on at least one of the phase difference ⁇ and the amplitude ratio a / b calculated by the calculation unit 258.
  • the viscosity estimating unit 260 estimates the viscosity of the fluid L based on the phase difference ⁇ , for example, the phase difference stored in the storage unit 266 or the like is used to accurately estimate the viscosity.
  • the viscosity ⁇ is estimated based on prior experimental data relating to the relationship between ⁇ and the viscosity ⁇ of the fluid, or based on a relational expression between the phase difference ⁇ and the viscosity ⁇ that is theoretically obtained in advance.
  • the flow rate estimation unit 261 has a function of estimating the flow rate of the fluid L based on at least one of the torque, current value, power consumption, and rotation speed of the motor 208 and the viscosity of the fluid L estimated by the viscosity estimation unit 260. Have.
  • the flow rate estimation unit 261 uses the torque of the motor 208 measured by a known torque meter 224 installed on the drive shaft 213 of the motor 208 and the estimated flow rate calculated based on the rotation speed of the motor 208. By compensating with the estimated viscosity of the fluid L estimated by the viscosity estimating unit 260, the accuracy of the estimated value of the flow rate of the fluid L is improved.
  • the flow rate of the fluid L is estimated based on the following formula (2).
  • a symbol Qe represents an estimated flow rate value of the fluid L
  • a symbol T represents a torque of the motor 208
  • a symbol N represents a rotational speed of the motor 208
  • symbols A, B, and C represents a coefficient.
  • Qe A (T / N) + B ⁇ + C (2)
  • the magnetic levitation type is corrected by correcting the estimated flow rate of the fluid L calculated based on the torque T and the rotation speed N of the motor 208 with the estimated viscosity value calculated by the viscosity estimating unit 260.
  • the flow rate of the fluid L fed by the pump device 200 is obtained with high accuracy.
  • the flow rate of the fluid L actually fed by the magnetic levitation pump device 200 is a value that can vary depending on the viscosity of the fluid L. For example, if the viscosity of the fluid L is low, it is easy to send the fluid L. Conversely, if the viscosity of the fluid L is high, it is difficult to send the fluid L. That is, the estimated flow rate value of the fluid L calculated based only on the torque T and the rotation speed N of the motor 208 varies depending on the magnitude of the viscosity value of the fluid L.
  • the estimated flow rate of the fluid L calculated based on the torque T and the rotation speed N of the motor 208 is corrected with the estimated viscosity value calculated by the viscosity estimation unit 260, and the viscosity of the fluid L is thereby corrected.
  • the flow rate of the fluid L can be accurately calculated. That is, the accuracy in estimating the flow rate of the fluid L by the compensation by the viscosity estimated by the viscosity estimating unit 260 is improved.
  • the flow rate of the fluid L is accurately adjusted by correcting the estimated flow rate of the fluid L calculated based on the torque T and the rotation speed N of the motor 208 with the viscosity estimated by the viscosity estimation unit 260.
  • the flow rate of the fluid L can also be obtained by correcting the estimated flow rate calculated based on the current value and power consumption of the motor 208 with the viscosity of the fluid L. That is, the flow rate estimation unit 261 estimates the flow rate of the fluid L based on at least one of the torque, current value, power consumption, and rotation speed of the motor 208 and the viscosity of the fluid L estimated by the viscosity estimation unit 260. .
  • the viscosity ⁇ of the fluid L may be estimated more accurately by using the torque, current value, and power consumption of the motor 208 together.
  • the impeller 204 is forcibly microvibrated by applying an excitation current intentionally superimposed on the excitation current applied to the electromagnet 216 of the magnetic bearing portion 201 for a predetermined time.
  • the viscosity ⁇ of the fluid L can be easily and accurately estimated based on the phase difference ⁇ between the impeller displacement generated by the minute vibration and the alternating current and the amplitude ratio a / b.
  • the viscosity ⁇ of the fluid L can be estimated more easily and reliably without being restricted by the structure of the apparatus.
  • the flow rate estimation accuracy is improved by reflecting the estimated viscosity value of the fluid L estimated by the viscosity estimating unit 260 in the flow rate estimation of the fluid L. For this reason, by applying the magnetic levitation pump device 200 of this embodiment to a medical device such as a blood pump or an artificial heart, the flow rate of the fluid L to be fed can be accurately adjusted without installing an extra flow meter or the like. Since it can be estimated well, the safety of the patient who uses the medical device can be secured.
  • FIG. 7 is a flow diagram showing an outline of a method for estimating the viscosity and flow rate of a fluid by a magnetic levitation pump device according to another embodiment of the present invention
  • FIG. 8 shows another embodiment of the present invention. It is a flowchart which shows the outline of the other aspect of the estimation method of the viscosity and flow volume of the fluid by the magnetic levitation type pump apparatus which concerns.
  • 7 shows a flow of a method for estimating the viscosity ⁇ based on the phase difference ⁇
  • FIG. 8 shows a flow of a method for estimating the viscosity ⁇ based on the amplitude ratio a / b.
  • an alternating current in a predetermined frequency range is applied to the excitation current applied to the electromagnet 216 provided in the magnetic bearing unit 201 for a predetermined time (for example, , Applied for several seconds and superposed on the excitation current (AC current application step S31).
  • a predetermined time for example, , Applied for several seconds and superposed on the excitation current (AC current application step S31).
  • the impeller 204 is forcibly vibrated by intentionally applying an alternating current for a predetermined time.
  • an alternating current having a frequency f at which the impeller can vibrate around the floating target position and an amplitude b within a range where the impeller 204 and the housing 202 do not contact each other is applied. That is, it is necessary to select an appropriate frequency f and amplitude b so that the impeller 204 does not come into contact with the housing 202 around the floating target position.
  • the impeller 204 does not respond and does not vibrate, so the viscosity estimation method according to this embodiment cannot be implemented. For this reason, in the low frequency range (for example, 400 Hz or less) where the impeller 204 vibrates, by adjusting the amplitude of the alternating current appropriately, the impeller 204 and the housing 202 are adjusted so as not to contact each other.
  • the low frequency range for example, 400 Hz or less
  • the frequency f of the alternating current to be applied is selected to be a frequency that is low enough to obtain the vibration amplitude a of the impeller 204,
  • the amplitude b of the alternating current needs to be adjusted within a range where the impeller 204 and the housing 202 do not contact each other.
  • the alternating current applied here may be an alternating current having a predetermined cycle such that the current value periodically fluctuates in the same manner as in the first embodiment described above.
  • the sine wave shown in FIG. 4A, the rectangular wave shown in FIG. 4B, the triangular wave shown in FIG. 4C, and the sawtooth wave shown in FIG. 4D are applicable.
  • the displacement of the impeller due to the vibration of the impeller 204 is detected by the displacement sensor 220 (impeller displacement detection step S32). Then, the phase of the impeller displacement caused by the vibration of the impeller 204 generated by the application of the alternating current is plotted and recorded (recording step S33). Thereafter, the phase difference ⁇ between the impeller displacement and the alternating current is calculated (calculation step S34), and the viscosity ⁇ of the fluid L is estimated based on the phase difference ⁇ (viscosity estimation step S35).
  • the viscosity ⁇ of the fluid L is estimated using the phase difference ⁇ or the amplitude ratio a / b. However, if at least one of them is used, the viscosity ⁇ can be estimated. Both may be used together to estimate the viscosity ⁇ of the fluid L with higher accuracy.
  • the torque and rotation speed of the motor 208 detected by the torque meter 224 and the fluid L estimated in the viscosity estimation step S45 is estimated.
  • the flow rate of the fluid L is estimated based on the viscosity ⁇ (flow rate estimation steps S37 and S47).
  • the flow rate of the fluid L is estimated by compensating the estimated flow rate obtained from the torque and the rotation speed of the motor 208 with the viscosity ⁇ of the fluid L estimated in the viscosity estimation steps S35 and S45. .
  • the excitation current to the electromagnet 216 is calculated so that the impeller 204 does not shake from the target position (center of rotation axis, etc.). .
  • the impeller 204 is forcibly vibrated by superimposing an alternating current having a constant frequency f on the excitation current for several seconds. Then, during the forced vibration of the impeller 204, the phase difference ⁇ or the amplitude ratio a / b between the alternating current I of the frequency f and the impeller displacement X is calculated.
  • the viscosity estimation method by the magnetic levitation pump apparatus 200 of the present embodiment can easily estimate the viscosity ⁇ of the fluid L without adding new hardware. Also, the viscosity estimation method by the magnetic levitation pump device 200 of the present embodiment is less dependent on the flow rate and does not need to block the flow rate, unlike the conventional method using the motor torque for viscosity estimation. Since there is no influence of loss, the fluid viscosity ⁇ can be accurately estimated. Furthermore, the viscosity estimation method using the magnetic levitation pump apparatus 200 according to the present embodiment does not affect the measurement accuracy of the viscosity ⁇ even if the gap between the impeller 204 and the housing 202 is large in principle. Accurate viscosity estimation is possible without being restricted by the above.
  • the accuracy in estimating the flow rate of the fluid L to be measured is improved by compensating with the viscosity estimated by the magnetic levitation pump device 200.
  • the viscosity estimation method and the flow rate estimation method by the magnetic levitation pump device 200 of this embodiment can be applied to various fields.
  • a conventional circulation system such as an artificial artificial heart that is difficult to install a flow meter
  • the error greatly increases or decreases depending on the working fluid viscosity.
  • the estimated viscosity value obtained by the viscosity estimation method by the magnetic levitation pump apparatus 200 of the present embodiment can be used for error correction of the flow rate estimation and applied to the flow rate estimation of the fluid L.
  • the state of the working fluid may be applied to online monitoring using the estimated viscosity value itself.
  • blood coagulation monitoring such as blood clot detection and prediction in blood pumps and artificial hearts, and quality control of ultrapure water in semiconductor and food manufacturing. That is, it can be applied as a magnetic levitation type continuous flow blood pump for extracorporeal circulation, a magnetic levitation type artificial heart for implantation in the body, and an ultra-clean magnetic levitation type pump for semiconductor manufacturing and food manufacturing.
  • the present invention is applied to a magnetic levitation pump device including a centrifugal impeller.
  • the present invention is also applicable to a magnetic levitation pump device including an axial flow type impeller 124 (see FIG. 5D) and a mixed flow type impeller 134 (see FIG. 5E). That is, the magnetic levitation pump device 200 of the present embodiment can be applied to a magnetic levitation type continuous flow pump regardless of whether it is a centrifugal type, an axial flow type, or a diagonal flow type, as in the first embodiment.
  • the present embodiment is a magnetic levitation pump apparatus 100 having the configuration shown in FIG. It was used. The configuration is omitted because it has been described above.
  • the impeller of the present embodiment is passively supported by a restoring force due to electromagnetic force in the axial direction (vertical direction), but in the radial direction (horizontal direction), the magnet of a permanent magnet built in the rotor of the impeller.
  • the suction force works and is attracted to the wall surface of the housing. Therefore, in this embodiment, the impeller is stably levitated by feeding back the impeller position information with a displacement sensor and adjusting the electromagnetic force in the radial direction with an electromagnet.
  • FIG. 9 is an explanatory diagram showing the relationship between the impeller displacement waveform and the phase and amplitude of the applied alternating current waveform in an example of fluid viscosity estimation by the magnetic levitation pump device according to one embodiment of the present invention.
  • the impeller levitation target position is changed to a sinusoidal shape by the applied current control unit in the CPU (calculation unit) in a state where the impeller is stably magnetically levitated around the rotation axis, as shown in the lower graph of FIG.
  • An electromagnet current which is an alternating current, is supplied from the control unit and superimposed on the exciting current to the electromagnet.
  • the impeller also vibrates in a sine wave like the applied alternating current, as shown in the graph on the upper end side of FIG.
  • the phase difference ⁇ between the alternating current (electromagnet current) I and the impeller displacement X applied at this time is obtained by the calculation unit.
  • an amplitude ratio a / b which is a ratio of the amplitude a of the impeller displacement and the amplitude b of the alternating current is also obtained by the calculation unit.
  • FIG. 10 is an explanatory diagram showing the relationship between the amplitude ratio and phase difference between the impeller displacement waveform and the applied current waveform and the frequency of the applied current in this example.
  • the relationship between the amplitude ratio a / b and the frequency of the impeller vibration generated by applying the applied AC current is shown in a graph on the upper side of FIG. 10, and the relationship between the phase difference ⁇ and the frequency of the vibration is shown on the lower side of FIG. Is shown in the graph.
  • both the amplitude ratio a / b and the phase difference ⁇ oscillate.
  • the frequency is low
  • the sensitivity to the viscosity ⁇ is low.
  • the sensitivity of the amplitude ratio a / b and the phase difference ⁇ with respect to the viscosity ⁇ is improved when the frequency of vibration becomes a large value of about 30 Hz or more.
  • FIG. 11 shows the relationship between the viscosity and the phase difference ⁇ at a vibration frequency of 70 Hz.
  • the impeller rotational speed was 2000 rpm
  • the flow rate was 5 L / min
  • ⁇ A 0 ⁇ + B 0 (3)
  • the constants A 0 and B 0 differ for each impeller rotational speed, the constants A 0 and B 0 are identified at each rotational speed, or the rotational speed is set to a specific value (this time, 2000 rpm).
  • the present example is a magnetic levitation pump configured as shown in FIG. 6 in order to demonstrate the operation and effect of the viscosity estimation method by the magnetic levitation pump apparatus 200 (see FIG. 6) according to another embodiment of the present invention.
  • An apparatus 200 was used. Specifically, a flow meter is attached to the outflow portion 202d of the magnetic levitation pump device 200, the working fluid discharged from the outflow portion 202d is supplied to a reservoir provided in the thermostatic bath, and the magnetic levitation pump is supplied from the reservoir. The relationship between the measured flow rate and the estimated flow rate was examined by returning the working fluid to the inflow portion 202c of the apparatus 200.
  • the configuration of the magnetic levitation pump device 200 has been described above, and will not be described.
  • glycerin aqueous solutions having different viscosities described in Table 1 below are used as working fluids for which the flow rate is to be estimated, and are fed by a magnetic levitation pump device 200 according to another embodiment of the present invention.
  • the flow rate of the working fluid was measured 8 times, 2 times each for the case of no viscosity compensation and 2 for the estimated viscosity.
  • the flow rate is estimated based on the equation (2) by compensating the viscosity ⁇ of the above-described equation (2) with the estimated viscosity ⁇ e calculated by the following equation (4). did.
  • FIG. 14 is an explanatory diagram showing the relationship between the measured flow rate and the estimated flow rate in an example of fluid flow rate estimation by the magnetic levitation pump device 200 according to another embodiment of the present invention.
  • the horizontal axis indicates the actual flow rate Q actually measured by the flow meter
  • the vertical axis indicates the estimated flow rate Qe.
  • Magnetic levitation pump device 101, 201 Magnetic bearing part, 102, 202 Housing, 102a, 202a Side wall part, 102b, 202b Bottom part, 102b1, 202b1 Convex part, 102c, 202c Inflow part, 102d, 202d Outflow part, 104, 204 (centrifugal type) impeller, 106, 206 rotor, 106a, 206a outer peripheral surface, 106b, 206b concave portion, 106b1, 206b1 inner peripheral surface, 108, 208 motor (rotation drive unit), 110, 112, 114, 210, 212, 214 Permanent magnet, 113, 213 Drive shaft, 116, 216 Electromagnet, 118, 218 Current sensor, 120, 220 Displacement sensor, 122, 222 Casing, 124 Axial flow type impeller, 134 Diagonal flow type impeller, 150, 2 0 control unit, 152, 252 CPU (calculation unit), 154

Abstract

La présente invention rend possible une estimation plus précise de la viscosité de fluide sans contraintes par rapport à la structure d'un dispositif. La présente invention concerne un dispositif pompe de type à lévitation magnétique (100) permettant de transférer un fluide (L) en faisant léviter et tourner magnétiquement un impulseur (104), le dispositif pompe de type à lévitation magnétique (100) comprenant : une unité palier magnétique (101) permettant de supporter l'impulseur sans contact par force magnétique ; une unité de régulation de courant appliqué (154) permettant de réguler un courant appliqué à des électroaimants (116) situés dans l'unité palier magnétique ; un capteur de déplacement (118) permettant de détecter le déplacement de l'impulseur ; une unité de calcul (158) permettant de calculer le déphasage entre le déplacement de l'impulseur et un courant alternatif, et/ou le rapport d'amplitude entre le déplacement de l'impulseur et le courant alternatif, le déplacement de l'impulseur étant causé par la vibration de l'impulseur et étant détecté par le capteur de déplacement, lorsque l'unité de régulation de courant appliqué régule le courant appliqué de façon à provoquer la superposition du courant alternatif dans une gamme de fréquences prédéterminée avec un courant d'excitation des électroaimants ; et une unité d'estimation de viscosité (160) permettant d'estimer la viscosité du fluide en fonction du déphasage et/ou du rapport d'amplitude calculé dans l'unité de calcul.
PCT/JP2015/055536 2014-03-11 2015-02-26 Dispositif pompe de type à lévitation magnétique, méthode d'estimation de viscosité de fluide par dispositif pompe de type à lévitation magnétique, et méthode d'estimation de débit de fluide par dispositif pompe de type à lévitation magnétique WO2015137126A1 (fr)

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Cited By (5)

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CN110947040A (zh) * 2019-12-18 2020-04-03 山东大学 一种体外循环血泵及方法
WO2021015034A1 (fr) * 2019-07-19 2021-01-28 株式会社イワキ Pompe
CN113323889A (zh) * 2021-06-09 2021-08-31 苏州心擎医疗技术有限公司 一种用于对无轴悬浮泵进行水力学测试的测力平台
CN115544430A (zh) * 2022-12-02 2022-12-30 深圳核心医疗科技有限公司 流体的流量估计方法及装置

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JP2019508124A (ja) * 2016-02-12 2019-03-28 スミス アンド ネフュー インコーポレイテッド 減圧療法の動作条件を検出するシステムおよび方法
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WO2021015034A1 (fr) * 2019-07-19 2021-01-28 株式会社イワキ Pompe
CN114072586A (zh) * 2019-07-19 2022-02-18 株式会社易威奇 泵
CN114072586B (zh) * 2019-07-19 2023-11-03 株式会社易威奇 泵
CN110947040A (zh) * 2019-12-18 2020-04-03 山东大学 一种体外循环血泵及方法
CN113323889A (zh) * 2021-06-09 2021-08-31 苏州心擎医疗技术有限公司 一种用于对无轴悬浮泵进行水力学测试的测力平台
CN115544430A (zh) * 2022-12-02 2022-12-30 深圳核心医疗科技有限公司 流体的流量估计方法及装置

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