Axial-flow blood pump with magnetically suspended, radially and axially stabilized impeller

A blood pump, comprising:

• a stator having a cavity extending therethrough;
• an impeller, rotatably disposed and magnetically suspended within the cavity of the stator, the impeller defining an axis of rotation, and the stator and impeller defining a fluid passage therebetween;
• a plurality of magnetic bearings, including permanent and electromagnet bearings, suspending the impeller within the cavity of the stator, including an axial bearing to support the impeller axially in the cavity;
• the axial bearing including an array of adjacent bearing sets arrayed axially with respect to the axis of rotation, each bearing set including an impeller magnet on the impeller and a stator magnet on the stator, the impeller and stator magnets being radially aligned across the fluid passage from one another;
• adjacent impeller magnets and adjacent stator magnets having axially aligned polarities and reverse polarities with respect to adjacent magnets;
• a motor including impeller magnets on the impeller and coils/magnetic poles associated with the stator;
• and
• all of the magnetic bearings and the motor having stator magnets or coils/magnetic poles disposed radially across the fluid passage from corresponding impeller magnets to define an annular gap positioned radially between the impeller and the stator, and positioned radially between all of the plurality of magnetic bearings.

A blood pump, comprising:

• a stator with a cavity extending therethrough;
• an impeller, rotatably disposed and magnetically suspended within the cavity of the stator, and defining an axis of rotation;
• a fluid passage, defined between the stator and the impeller, configured to receive a flow of blood;
• and
• a plurality of magnetic bearings, including permanent and electromagnetic bearings, suspending the impeller within the cavity of the stator, including an axial magnetic bearing to support the impeller axially in the cavity, the axial magnetic bearing including:
• a plurality of adjacent impeller magnets disposed axially on the impeller;
• and
• a plurality of adjacent stator magnets disposed axially on the stator;
• and
• the impeller magnets and the plurality of stator magnets being radially aligned across the fluid passage from one another;
• the plurality of impeller magnets and the plurality of stator magnets having axially aligned poles with respect to the axis of rotation;
• each of the plurality of impeller magnets having sequentially alternating polarity with respect to adjacent impeller magnets with adjacent impeller magnets having opposite axially aligned polarity, each of the plurality of stator magnets having sequentially alternating polarity with respect to adjacent stator magnets with adjacent stator magnets having opposite axially aligned polarity;
• and
• a motor including impeller magnets on the impeller and coils/magnetic poles associated with the stator.

A blood pump, comprising:

• a) a stator having a cavity extending therethrough;
• b) an impeller, rotatably disposed and magnetically suspended within the cavity of the stator, the impeller defining an axis of rotation, and the stator and impeller defining a fluid passage therebetween;
• c) a radial, active, electromagnet bearing, disposed nearer an inlet to the fluid passage, to radially support the impeller in the cavity, including:
• i) an impeller magnet, disposed nearer a leading end on the impeller;
• and
• ii) a plurality of poles and coils, disposed on the stator radially across the fluid passage from the impeller magnet;
• d) an axial, passive, permanent magnet bearing, disposed intermediate along the fluid passage, to axially support the impeller in the cavity, including:
• i) a plurality of impeller magnets, disposed intermediate along the impeller, the impeller magnets having axially oriented polarities with sequentially altering polarity;
• and
• ii) a plurality of stator magnets, disposed on the stator radially across the fluid passage from the impeller magnets, the stator magnets having axially oriented polarity with sequentially alternating polarity;
• and
• iii) the impeller and stator magnets being radially aligned across the fluid passage from one another with the polarity of the impeller and stator magnets oppositely aligned with opposite polarities radially aligned across the fluid passage;
• e) a radial, passive, permanent magnet bearing, disposed nearer an outlet of the fluid passage, to radially support the impeller in the cavity, including:
• i) a plurality of impeller magnets, disposed near a trailing end of the impeller, the impeller magnets having axially oriented polarities with sequentially alternating polarity;
• and
• ii) a plurality of stator magnets, disposed on the stator radially across the fluid passage from the impeller magnets, the stator magnets having axially oriented polarities with sequentially alternating polarity;
• and
• iii) the impeller and stator magnets being radially aligned across the fluid passage from one another with the polarities of the impeller and stator magnets commonly aligned with common polarities radially aligned across the fluid passage;
• and
• f) a motor including impeller magnets on the impeller and coils/magnetic poles associated with the stator.