The present invention relates to a check valve unit (1, 100, 200, 300, 400) having a shaft bearing body (10, 110, 210, 310, 410) with an at least substantially cylindrical mounting portion (11) extending along an axial direction (A) and an axially extending valve shaft (20, 120) mounted therein. The latter is displaceable along the axial direction (A). The check valve unit (1, 100, 200, 300, 400) further includes a valve head (25, 125) with a sealing surface (33, 133), wherein the valve head (25, 125) is disposed on a distal end (21) of the valve shaft (20, 120) in the axial direction (A), the distal end (21) facing away from the mounting portion (11). Further, a damping reservoir (50) is provided inside the shaft bearing body (10, 110, 210, 310, 410). A volume of the damping reservoir (50) is changed by axial movement of the valve shaft (20, 120). In order to obtain a well-defined times for opening and closing under given conditions and to make the check valve unit (1, 100, 200, 300, 400) less prone to making noise, at least two channels (46a, 46b) are provided in parallel, each of them constituting a fluid connection between the damping reservoir (50) and an outside (70). The damping reservoir (50) is, apart from the channels (46a, 46b), at least substantially enclosed. Each channel (46a, 46b) has a length being at least ten times a hydraulic diameter of the respective channel (46a, 46b).

A magnetic levitation centrifugal pump comprises: an internally hollow body, an inlet connector and an outlet connector for blood. The hollow body comprises a lower element and an upper element which are mutually coupled to each other; a rotor element housed inside the hollow body and provided with a portion made of magnetic material, the rotor element being magnetically commanded in rotation about a relative axis, without contact, by a stator element associable with the hollow body. The upper element has a perimeter flange for coupling and a substantially dome-shaped body projecting from the perimeter flange. The outlet connector is associated with the dome-shaped body and is spaced away from the perimeter flange, between the outlet connector and the perimeter flange being defined an air space inside which mutual tightening device/component can be inserted for the tightening of the upper element with the lower element.

A magnetic levitation centrifugal pump comprises: an internally hollow body, an inlet connector and an outlet connector for blood. The hollow body comprises a lower element and an upper element which are mutually coupled to each other; a rotor element housed inside the hollow body and provided with a portion made of magnetic material, the rotor element being magnetically commanded in rotation about a relative axis, without contact, by a stator element associable with the hollow body. The upper element has a perimeter flange for coupling and a substantially dome-shaped body projecting from the perimeter flange. The outlet connector is associated with the dome-shaped body and is spaced away from the perimeter flange, between the outlet connector and the perimeter flange being defined an air space inside which mutual tightening device/component can be inserted for the tightening of the upper element with the lower element.

A stator for a downhole-type motor includes a housing. The housing includes a sleeve. The sleeve includes a first layer, a second layer, and a third layer. The first layer is erosion-resistant. The second layer is corrosion-resistant. The third layer can provide structural support. The stator includes a motor stack. The stator can be used to drive a rotor disposed within an inner bore of the housing.

A bearing structure includes a drive shaft that extends in a horizontal direction, a touchdown bearing, and a bearing housing. The drive shaft is supported by a magnetic bearing. The touchdown bearing includes a rolling member interposed between an outer ring and an inner ring. The bearing housing supports the touchdown bearing from an outer periphery. At least one of an outer peripheral surface of the drive shaft, an inner peripheral surface of the inner ring, an outer peripheral surface of the outer ring, and an inner peripheral surface of the bearing housing includes a recess in a region overlapping the rolling member in a bearing radial direction.

A heart pump including: a housing forming a cavity including: at least one inlet aligned with an axis of the cavity; and, at least one outlet provided in a circumferential outer wall of the cavity; an impeller provided within the cavity, the impeller including vanes for urging fluid from the inlet to the outlet; and, a drive for rotating the impeller in the cavity and wherein a flow path through the pump has a minimal cross-sectional area of at least 50 mm.sup.2.

A heart pump including: a housing forming a cavity including: at least one inlet aligned with an axis of the cavity; and, at least one outlet provided in a circumferential outer wall of the cavity; an impeller provided within the cavity, the impeller including vanes for urging fluid from the inlet to the outlet; and, a drive for rotating the impeller in the cavity and wherein a flow path through the pump has a minimal cross-sectional area of at least 50 mm.sup.2.

A magnetic levitation centrifugal pump comprises: an internally hollow body, an inlet connector and an outlet connector for blood. The hollow body comprises a lower element and an upper element which are mutually coupled to each other; a rotor element housed inside the hollow body and provided with a portion made of magnetic material, the rotor element being magnetically commanded in rotation about a relative axis, without contact, by a stator element associable with the hollow body. The upper element has a perimeter flange for coupling and a substantially dome-shaped body projecting from the perimeter flange. The outlet connector is associated with the dome-shaped body and is spaced away from the perimeter flange, between the outlet connector and the perimeter flange being defined an air space inside which mutual tightening device/component can be inserted for the tightening of the upper element with the lower element.

A magnetic levitation centrifugal pump comprises: an internally hollow body, an inlet connector and an outlet connector for blood. The hollow body comprises a lower element and an upper element which are mutually coupled to each other; a rotor element housed inside the hollow body and provided with a portion made of magnetic material, the rotor element being magnetically commanded in rotation about a relative axis, without contact, by a stator element associable with the hollow body. The upper element has a perimeter flange for coupling and a substantially dome-shaped body projecting from the perimeter flange. The outlet connector is associated with the dome-shaped body and is spaced away from the perimeter flange, between the outlet connector and the perimeter flange being defined an air space inside which mutual tightening device/component can be inserted for the tightening of the upper element with the lower element.

A magnetic levitation centrifugal pump, comprises: one hollow body provided with at least one inlet connector and with at least one outlet connector for blood; one rotor element, housed inside the hollow body and comprising at least one magnetic portion, where the rotor element can be commanded in rotation about an axis of rotation, without contact, by a stator element associable with the hollow body, the rotor element comprising at least one revolving body, which defines an upper surface supporting a plurality of blades which are adapted to convey blood towards the outlet connector; where the upper surface has a substantially concave shape and where the revolving body comprises at least one through hole which is positioned along the axis of rotation.