초록 ▼

A centrifugal blood pump apparatus includes an impeller provided in a blood chamber, a plurality of permanent magnets provided in the impeller, and a plurality of sets of magnetic materials and coils provided in a motor chamber for driving the impeller to rotate with a diaphragm interposed therebetw

A centrifugal blood pump apparatus includes an impeller provided in a blood chamber, a plurality of permanent magnets provided in the impeller, and a plurality of sets of magnetic materials and coils provided in a motor chamber for driving the impeller to rotate with a diaphragm interposed therebetween. The plurality of permanent magnets are aligned with a gap therebetween in a rotation direction of the impeller. Accordingly, if the weight of the permanent magnets is maintained at a constant value, a magnetic field can be strengthened even with a wide motor gap due to the diaphragm, as compared to an example where there is no gap between the permanent magnets.

대표청구항 ▼

1. A rotation drive device including a housing having first and second chambers partitioned from each other by a diaphragm, a rotor rotatably provided in said first chamber along said diaphragm, and a drive unit provided in said second chamber for driving said rotor to rotate with said diaphragm int

1. A rotation drive device including a housing having first and second chambers partitioned from each other by a diaphragm, a rotor rotatably provided in said first chamber along said diaphragm, and a drive unit provided in said second chamber for driving said rotor to rotate with said diaphragm interposed therebetween, said rotor comprising a plurality of first permanent magnets, the first permanent magnets having an angular spacing between each magnet, each of said first permanent magnets being magnetized in a direction orthogonal to said rotation direction of said rotor,every two adjacent ones of the first permanent magnets having magnetic polarities different from each other, said drive unit including:a plurality of first magnetic materials arranged to face said plurality of first permanent magnets,a plurality of coils wound around said plurality of first magnetic materials, respectively, for generating a rotating magnetic field;wherein a plurality of second permanent magnets is provided in said rotor and magnetically coupled to said plurality of first permanent magnets, wherein each of said second permanent magnets is provided correspondingly to a gap between every two adjacent ones of the first permanent magnets, and is magnetized in said rotation direction of said rotor,wherein each of said second permanent magnets is inserted in a corresponding gap, each of said second permanent magnets has a first magnetic polarity oriented to one of the two adjacent first permanent magnets having the first magnetic polarity oriented to the diaphragm, and each of said second permanent magnets has a second magnetic polarity oriented to the other of the two adjacent first permanent magnets having the second magnetic polarity oriented to the diaphragm; andwherein a ratio of a surface area of each of said second permanent magnets facing said diaphragm to a surface area of each of said first permanent magnets facing said diaphragm is set to be ½ or more and 2 or less. 2. The rotation drive device according to claim 1, further comprising a second magnetic material provided in said rotor, arranged on a side of said plurality of first permanent magnets opposite to a side closer to said diaphragm, and magnetically coupled to said plurality of first permanent magnets. 3. The rotation drive device according to claim 1, wherein each of said second permanent magnets is arranged to cover a corresponding gap from a side opposite to said diaphragm, and each magnetic polarity of each of said second permanent magnets is identical to an adjacent magnetic polarity of the second permanent magnet, and is different from a corresponding magnetic polarity of the first permanent magnet. 4. The rotation drive device according to claim 3, further comprising a plurality of second magnetic materials provided in said rotor and inserted in the plurality of gaps between said plurality of second permanent magnets, respectively. 5. The rotation drive device according to claim 1, wherein said diaphragm is formed in a cylindrical shape, and said rotor and said drive unit are arranged with a gap therebetween in a radial direction of said rotor. 6. The rotation drive device according to claim 1, wherein said diaphragm is formed in a plane shape, and said rotor and said drive unit are arranged with a gap therebetween in a direction in which a rotation central axis of said rotor extends. 7. A centrifugal pump apparatus comprising the rotation drive device according to claim 6, wherein said rotor is an impeller for delivering liquid by a centrifugal force during rotation. 8. The centrifugal pump apparatus according to claim 7, wherein said liquid is blood, and said centrifugal pump apparatus is used for circulating said blood. 9. A centrifugal pump apparatus including a housing having first and second chambers partitioned from each other by a diaphragm, an impeller rotatably provided in said first chamber along said diaphragm for delivering liquid by a centrifugal force during rotation, and a drive unit provided in said second chamber for driving said impeller to rotate with said diaphragm interposed therebetween, said centrifugal pump apparatus comprising: a first magnetic material provided in one surface of said impeller;a second magnetic material provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic material; anda plurality of first permanent magnets provided in the other surface of said impeller, the first permanent magnets having an angular spacing between each magnet,each of said first permanent magnets being magnetized in a direction in which a rotation central axis of said impeller extends,every two adjacent ones of the first permanent magnets having magnetic polarities different from each other,a plurality of second permanent magnets magnetically coupled to said plurality of first permanent magnets, wherein each of said second permanent magnets is provided correspondingly to a gap between every two adjacent ones of the first permanent magnets, and is magnetized in a rotation direction of said impeller,wherein each of said second permanent magnets is inserted in a corresponding gap, each of said second permanent magnets has a first magnetic polarity oriented to one of the two adjacent first permanent magnets having the first magnetic polarity oriented to the diaphragm, and each of said second permanent magnets has a second magnetic polarity oriented to the other of the two adjacent first permanent magnets having the second magnetic polarity oriented to the diaphragm,wherein a ratio of a surface area of each of said second permanent magnets facing said diaphragm to a surface area of each of said first permanent magnets facing said diaphragm is set to be ½ or more and 2 or less,said drive unit includinga plurality of third magnetic materials arranged to face said plurality of first permanent magnets, anda plurality of coils provided correspondingly to said plurality of third magnetic materials and wound around corresponding ones of the third magnetic materials, respectively, for generating a rotating magnetic field,during rotation of said impeller, a first attractive force between said first and second magnetic materials and a second attractive force between said plurality of first permanent magnets and said plurality of third magnetic materials being balanced with each other substantially in a center of a movable range of said impeller in said first chamber, andfirst grooves for hydrodynamic bearing being formed in the one surface of said impeller or in the inner wall of said first chamber facing the one surface, and second grooves for hydrodynamic bearing being formed in the other surface of said impeller or in said diaphragm facing the other surface. 10. The centrifugal pump apparatus according to claim 9, wherein said liquid is blood, and said centrifugal pump apparatus is used for circulating said blood.