Centrifugal pump apparatus
AssigneesTerumo Kabushiki Kaisha, Ntn Corporation
InventorsTakayoshi Ozaki, Hiroyuki Yamada, Ken Sugiura
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Abstract
A centrifugal blood pump apparatus includes a plurality of permanent magnets (17) in an impeller (10) in a blood chamber (7), a plurality of coils (20) in a motor chamber (8), and a magnetic element (18) in each of the coils (20). The magnetic elements (18) are made shorter than the coils (20) to lower attractive force between the magnetic elements (18) and the permanent magnets (17) in the impeller (10), to set a large gap between the magnetic elements (18) and the permanent magnets (17). As a result, axial attractive force and negative rigidity can be lowered while required torque is satisfied.
Claims19
A centrifugal pump apparatus including a housing (2) having first and second chambers (7, 8) partitioned from each other by a dividing wall (6), an impeller (10) rotatably provided in said first chamber (7) along said dividing wall (6), for delivering fluid by centrifugal force during rotation, and a drive unit (18 to 20) provided in said second chamber (8) for driving said impeller (10) to rotate with said dividing wall (6) being interposed, comprising:
- a first magnetic element (15) provided in one surface of said impeller (10);
- a second magnetic element (16) provided in an inner wall of said first chamber (7) facing the one surface of said impeller (10), for attracting said first magnetic element (15);
- and
- a plurality of third magnetic elements (17) provided in the other surface of said impeller (10), arranged in a direction of rotation of said impeller (10), and attracted by said drive unit (18 to 20), wherein
- said drive unit (18 to 20) includes
- a plurality of coils (20) provided to face said plurality of third magnetic elements (17), for generating rotating magnetic field, and
- a plurality of fourth magnetic elements (18) provided in correspondence with said plurality of coils (20) respectively and each inserted in the corresponding coil (20),
- each said fourth magnetic element (18) is shorter than the corresponding coil (20) in a direction of a central axis of said impeller (10),
- during rotation of said impeller (10), first attractive force between said first and second magnetic elements (15, 16) and second attractive force between said plurality of third magnetic elements (17) and said plurality of fourth magnetic elements (18) are balanced with each other substantially in a center of a movable range of said impeller (10) in said first chamber (7), and
- a first groove for hydrodynamic bearing (22) is formed in one surface of said impeller (10) or in the inner wall of said first chamber (7) facing the one surface, and a second groove for hydrodynamic bearing (21) is formed in the other surface of said impeller (10) or in said dividing wall (6) facing the other surface.
A centrifugal pump apparatus including a housing (2) having first and second chambers (7, 8) partitioned from each other by a dividing wall (6), an impeller (10) rotatably provided in said first chamber (7) along said dividing wall (6), for delivering fluid by centrifugal force during rotation, and a drive unit (18 to 20) provided in said second chamber (8) for driving said impeller (10) to rotate with said dividing wall (6) being interposed, comprising
- a plurality of first magnetic elements (17) provided in said impeller (10), arranged in a direction of rotation of said impeller (10), and attracted by said drive unit (18 to 20), wherein
- said drive unit (18 to 20) includes
- a plurality of coils (20) provided to face said plurality of first magnetic elements (17), for generating rotating magnetic field, and
- a plurality of second magnetic elements (18) provided in correspondence with said plurality of coils (20) respectively and each inserted in the corresponding coil (20),
- each said second magnetic element (18) is shorter than the corresponding coil (20) in a direction of a central axis of said impeller (10),
- a first groove for hydrodynamic bearing (22) is formed in one surface of said impeller (10) or in an inner wall of said first chamber (7) facing the one surface, and a second groove for hydrodynamic bearing (21) is formed in the other surface of said impeller (10) or in said dividing wall (6) facing the other surface, and
- during rotation of said impeller (10), force which is the sum of hydrodynamic force during rated rotation generated by said first groove for hydrodynamic bearing (22) and attractive force between said plurality of first magnetic elements (17) and said plurality of second magnetic elements (18), and hydrodynamic force during rated rotation generated by said second groove for hydrodynamic bearing (21) are balanced with each other substantially in a center of a movable range of said impeller (10) in said first chamber (7).
A centrifugal pump apparatus including a housing (2) having first and second dividing walls (6, 6A) and a fluid chamber (7) therebetween, an impeller (10) rotatably provided in said fluid chamber (7) along said first and second dividing walls (6, 6A), for delivering fluid by centrifugal force during rotation, and first and second drive units (18 to 20, 18A to 20A) provided outside said fluid chamber (7), for driving said impeller (10) to rotate with said first and second dividing walls (6, 6A) being interposed, respectively, comprising
- a plurality of first magnetic elements (17, 17A) provided in said impeller (10), arranged in a direction of rotation of said impeller (10), and attracted by said first and second drive units (18 to 20, 18A to 20A), wherein
- each of said first and second drive units (18 to 20, 18A to 20A) includes
- a plurality of coils (20, 20A) provided to face said plurality of first magnetic elements (17, 17A), for generating rotating magnetic field, and
- a plurality of second magnetic elements (18, 18A) provided in correspondence with said plurality of coils (20, 20A) respectively and each inserted in the corresponding coil (20, 20A),
- each said second magnetic element (18, 18A) is shorter than the corresponding coil (20, 20A) in a direction of a central axis of said impeller (10),
- during rotation of said impeller (10), first attractive force between said plurality of first magnetic elements (17) and said plurality of second magnetic elements (18) of said first drive unit (18 to 20) and second attractive force between said plurality of first magnetic elements (17A) and said plurality of second magnetic elements (18A) of said second drive unit (18A to 20A) are balanced with each other substantially in a center of a movable range of said impeller (10) in said fluid chamber (7), and
- a first groove for hydrodynamic bearing (21) is formed in one surface of said impeller (10) or in said first dividing wall (6) facing the one surface, and a second groove for hydrodynamic bearing (22) is formed in the other surface of said impeller (10) or in said second dividing wall (6A) facing the other surface.
Dependencies are inferred from the claim text.