Rotation drive device and centrifugal pump apparatus employing same

1. A rotation drive device comprising:

a rotor in a first chamber, wherein said rotor is an impeller for delivering fluid by centrifugal force during rotation; and

said drive unit including:

a plurality of first magnetic elements provided facing said rotor,

a plurality of coils wound around said plurality of first magnetic elements, respectively, for generating a rotating magnetic field,

a connector for externally receiving a driving voltage, and

a flexible substrate connected to said plurality of coils and said connector, wherein:

said flexible substrate comprises a wiring pattern for supplying said driving voltage externally provided via said connector to said plurality of coils,

said flexible substrate comprises a strip which has a length at least partially arranged to surround the outer circumferences of said plurality of coils, and

said flexible substrate comprises a plurality of electrodes connected with said plurality of coils, wherein said plurality of electrodes are arranged in pairs which are located along said length, each pair comprising two electrodes located side-by-side in an axial direction of the drive unit at a common distance along said length, and each pair of electrodes connected with two leads from one of the plurality of coils.

2. The rotation drive device according to claim 1 , wherein

said rotor includes a plurality of first permanent magnets,

each first permanent magnet is magnetized in a direction orthogonal to a rotation direction of said rotor,

the magnetic polarities of adjacent ones of said first permanent magnets oppose each other, and

said plurality of first magnetic elements are arranged to face said plurality of first permanent magnets.

3. The rotation drive device according to claim 2 , wherein

said rotor further includes a plurality of second permanent magnets,

said plurality of second permanent magnets are interposed between said plurality of first permanent magnets, respectively,

each second permanent magnet is magnetized in the rotation direction of said rotor,

each second permanent magnet has a first magnetic polarity at a first end toward one of two first permanent magnets adjacent thereto having a first magnetic polarity toward said rotor, and

each second permanent magnet has a second magnetic polarity at a second end toward one of two first permanent magnets adjacent thereto having a second magnetic polarity toward said rotor.

4. The rotation drive device according to claim 1 , wherein

said rotor and said drive unit are spaced apart from each other in a direction in which a rotation central axis of said rotor extends, and

said plurality of first magnetic elements are aligned in a rotation direction of said rotor.

5. The rotation drive device according to claim 4 , wherein

said flexible substrate is at least partially arranged cylindrically to surround the outer circumferences of said plurality of coils, with a plurality of clearances formed between an inner circumferential surface of said flexible substrate and outer circumferential surfaces of said plurality of coils, and

said plurality of electrodes are arranged in a dispersed manner in said flexible substrate so as to be positioned in said plurality of clearances.

6. The rotation drive device according to claim 5 , wherein

said flexible substrate in the shape of a strip includes a plurality of bent portions on one side or both sides in a width direction of said flexible substrate,

said plurality of bent portions are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of clearances, each bent portion being bent into the corresponding clearance, and

said plurality of electrodes are formed in said plurality of bent portions.

7. The rotation drive device according to claim 4 , wherein

said plurality of electrodes are aligned in a length direction of said flexible substrate, and

each electrode is provided in a substantially central portion in a width direction of said flexible substrate.

8. The rotation drive device according to claim 4 , wherein

said flexible substrate is at least partially arranged in a corrugated shape along the outer circumferences of said plurality of coils, with a plurality of recesses formed on an outer side of said flexible substrate,

said flexible substrate in the shape of a strip includes a plurality of bent portions on one side or both sides in a width direction of said flexible substrate,

said plurality of bent portions are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of recesses, each bent portion being bent into the corresponding recess, and

said plurality of electrodes are arranged in a dispersed manner in said plurality of bent portions.

9. The rotation drive device according to claim 4 , wherein

said flexible substrate is at least partially arranged in a corrugated shape along the outer circumferences of said plurality of coils, with a plurality of recesses formed on an outer side of said flexible substrate, and

said plurality of electrodes are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of recesses.

10. The rotation drive device according to claim 4 , wherein

said flexible substrate has a length at least 1.25 times the length of an outer circumference of said drive unit.

11. The rotation drive device according to claim 4 , wherein

said drive unit further includes a second magnetic element in the shape of a disc, said second magnetic element being provided to face said rotor with said plurality of first magnetic elements interposed therebetween, and being coupled to said plurality of first magnetic elements, and

said plurality of coils are arranged on a surface of said second magnetic element along an outer circumference of said second magnetic element.

12. The rotation drive device according to claim 1 , wherein

said rotor and said drive unit are spaced apart from each other in a radial direction of said rotor, and

said plurality of first magnetic elements are aligned in a rotation direction of said rotor.

13. The rotation drive device according to claim 12 , wherein

said drive unit further includes a second magnetic element in a cylindrical shape, said second magnetic element being provided to face said rotor with said plurality of first magnetic elements interposed therebetween, and being coupled to said plurality of first magnetic elements.

14. The rotation drive device according to claim 1 , comprising a housing having the first chamber and a second chamber partitioned from each other by a dividing wall, wherein

said rotor is provided in said first chamber along said dividing wall, and said drive unit is provided in said second chamber for driving said rotor to rotate with said dividing wall interposed there between.

15. The rotation drive device according to claim 1 , wherein

each of said plurality of coils comprises two terminals located side-by-side at a common angular position about an axis of the coil.

16. A centrifugal pump apparatus including a housing having first and second chambers partitioned from each other by a dividing wall, an impeller provided in said first chamber along said dividing wall, for delivering fluid by centrifugal force during rotation, and a drive unit provided in said second chamber for driving said impeller to rotate with said dividing wall interposed therebetween, said centrifugal pump apparatus comprising:

a plurality of first permanent magnets provided in said impeller and attracted by said drive unit, wherein

said drive unit includes

a plurality of magnetic elements arranged to face said plurality of first permanent magnets,

a plurality of coils provided correspondingly to said plurality of magnetic elements respectively and each wound around the corresponding magnetic element, for generating a rotating magnetic field,

a connector fixed to said housing and externally receiving a driving voltage, and

a flexible substrate connected to said plurality of coils and said connector, wherein

said flexible substrate comprises a strip which has a length at least partially arranged to surround the outer circumferences of said plurality of coils, and

said flexible substrate comprises a plurality of electrodes connected with said plurality of coils, wherein said plurality of electrodes are arranged in pairs which are located along said length, each pair comprising two electrodes located side-by-side in an axial direction of the drive unit at a common distance along said length, and each pair of electrodes connected with two leads from one of the plurality of coils.

17. The centrifugal pump apparatus according to claim 16 , wherein

said fluid is blood, and

said centrifugal pump apparatus is used for circulating said blood.

18. The centrifugal pump apparatus according to claim 16 further comprising:

a second permanent magnet provided in one surface of said impeller; and

a third permanent magnet provided in an inner wall of said first chamber facing said impeller, for attracting said second permanent magnet;

wherein during rotation of said impeller, a first attractive force between said second and third permanent magnets and a second attractive force between said plurality of first permanent magnets and said plurality of magnetic elements are balanced with each other in a substantially central portion of a movable range of said impeller in said first chamber.

19. The centrifugal pump apparatus according to claim 18 , wherein a first groove for hydrodynamic bearing is formed in one surface of said impeller or in the inner wall of said first chamber facing the one surface, and a second groove for hydrodynamic bearing is formed in the other surface of said impeller or in said dividing wall facing the other surface.

20. The centrifugal pump apparatus according to claim 19 , wherein

said flexible substrate is at least partially arranged cylindrically to surround the outer circumferences of said plurality of coils, with a plurality of clearances formed between an inner circumferential surface of said flexible substrate and outer circumferential surfaces of said plurality of coils, and

said plurality of electrodes are arranged in a dispersed manner in said flexible substrate so as to be positioned in said plurality of clearances.

21. The centrifugal pump apparatus according to claim 20 , wherein

said flexible substrate in the shape of a strip includes a plurality of bent portions on one side or both sides in a width direction of said flexible substrate,

said plurality of bent portions are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of clearances, each bent portion being bent into the corresponding clearance, and

said plurality of electrodes are formed in said plurality of bent portions.

22. The centrifugal pump apparatus according to claim 19 , wherein

said plurality of electrodes are aligned in a length direction of said flexible substrate, and

each electrode is provided in a substantially central portion in a width direction of said flexible substrate.

23. The centrifugal pump apparatus according to claim 19 , wherein

said flexible substrate is at least partially arranged in a corrugated shape along the outer circumferences of said plurality of coils, with a plurality of recesses formed on an outer side of said flexible substrate,

said flexible substrate in the shape of a strip includes a plurality of bent portions on one side or both sides in a width direction of said flexible substrate,

said plurality of bent portions are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of recesses, each bent portion being bent into the corresponding recess, and

said plurality of electrodes are arranged in a dispersed manner in said plurality of bent portions.

24. The centrifugal pump apparatus according to claim 19 , wherein

said flexible substrate is at least partially arranged in a corrugated shape along the outer circumferences of said plurality of coils, with a plurality of recesses formed on an outer side of said flexible substrate, and

said plurality of electrodes are arranged in a dispersed manner in a length direction of said flexible substrate so as to be positioned in said plurality of recesses.

25. The centrifugal pump apparatus according to claim 19 , wherein

said flexible substrate has a length at least 1.25 times the length of an outer circumference of said drive unit.

26. he centrifugal pump apparatus according to claim 16 , wherein

each of said plurality of coils comprises two terminals located side-by-side at a common angular position about an axis of the coil.