Magnetically suspended type pump
AssigneeNtn Corporation
InventorsTsugito Nakazeki, Hiroyoshi Ito, Teruaki Akamatsu
Life of this patent
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Abstract
In a magnetically suspended type pump, an operating state of the pump can be obtained without using a pressure gauge and a flowmeter. In addition, in the case where the magnetically suspended type pump is applied to a blood pump, in order to reduce the number of connections in a flow path and to avoid thrombus formation, a correlation between current flowing in a motor and flow or a correlation between current flowing in the motor and pressure is obtained in advance, and the speed of rotation of motor is varied by a speed of rotation control circuit in response to an instruction from a CPU circuit, based on the obtained correlation between current and flow or between current and pressure, whereby flow or pressure is controlled.
Claims11
A magnetically suspended type pump in which an impeller is supported within a case by a magnetic bearing without contact and said impeller is rotated by a motor whose speed can be controlled by magnetic coupling through a partition therebetween, comprising:
- processing means for obtaining a correlation between current flowing in said motor and fluid flow or between current flowing in said motor and outlet pressure;
- control means for changing a speed of rotation of said motor based on the correlation between current and flow or between current and pressure obtained by said processing means, thereby controlling flow or pressure;
- and
- correction means for correcting flow or pressure obtained from blood viscosity which is obtained from disturbance response of said impeller supported by said magnetic bearing.
A magnetically suspended type pump in which an impeller is supported within a case by a magnetic bearing without contact and said impeller is rotated by a motor whose speed can be controlled by magnetic coupling through a partition therebetween, comprising:
- processing means for obtaining a correlation between current flowing in said motor and fluid flow or between current flowing in said motor and outlet pressure;
- and
- control means for changing a speed of rotation of said motor based on the correlation between current and flow or between current and pressure obtained by said processing means, thereby controlling flow or pressure,
- wherein said impeller includes two coaxial blades, and
- said case includes inlets, outlets and pump chambers which serve as flow paths for said two blades, respectively,
- said two blades are different in shape from each other so that said pump chambers have higher pressure or lower pressure at a fixed speed of rotation.
A magnetically suspended type pump in which an impeller is supported within a case by a magnetic bearing without contact and said impeller is rotated by a motor whose speed can be controlled by magnetic coupling through a partition therebetween, comprising:
- processing means for obtaining a correlation between current flowing in said motor and fluid flow or between current flowing in said motor and outlet pressure;
- and
- control means for changing a speed of rotation of said motor based on the correlation between current and flow or between current and pressure obtained by said processing means, thereby controlling flow or pressure,
- wherein said magnetic bearing includes:
- a first passive type magnetic bearing for radially supporting one side of said impeller, and
- a second passive type magnetic bearing having a pair of magnets located on another side of said impeller so as to radially repulsive to each other.
Dependencies are inferred from the claim text.