Centrifugal pump apparatus

摘要

This centrifugal blood pump apparatus includes an impeller provided in a blood chamber, a first permanent magnet provided in one surface of the impeller, and a second permanent magnet provided in an inner wall of the blood chamber, for attracting the first permanent magnet. The attractive force between the first permanent magnet and the second permanent magnet on the opening side of a sidewall of the blood chamber is set to be smaller than the attractive force between the first permanent magnet and the second permanent magnet on the opposite side of the opening. As a result, inclination of the impeller with respect to a dividing wall during pump operation can be prevented.

主权项

1. A centrifugal pump apparatus including a housing having first and second chambers partitioned from each other by a dividing wall, an impeller rotatably 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 being interposed, the centrifugal pump apparatus comprising:
a first magnetic element provided in one surface of said impeller; a second magnetic element provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic element a third magnetic element provided in the other surface of said impeller and attracted by said drive unit and a fluid outlet port for allowing said fluid to flow to the outside of said housing from an opening provided in a sidewall of said first chamber, wherein during rotation of said impeller, a first attractive force acting between said first and second magnetic elements and a second attractive force acting between said third magnetic element and said drive unit are balanced with each other substantially in a center of a movable range of said impeller in said first chamber, a first groove for hydrodynamic bearing is formed in the 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, at least one of said first and second magnetic elements is formed annularly around a rotation centerline of said impeller, and the first attractive force on an opening side of said sidewall is set to be different from the first attractive on an opposite side from said opening side of said sidewall such that said impeller becomes parallel to said dividing wall during rotation of said impeller.