A pump unit includes a pump housing with an inlet and an outlet and a rotor arranged in the pump housing. The pump unit is designed for a non-contact magnetic levitation of the rotor and for a non-contact magnetic drive of the rotor by the stator. The vanes of the rotor are arranged around a central inlet area of the rotor, and the rotor includes a relief opening for generating a recirculation flow which is directed from a back side of the rotor facing away from the inlet in the direction of the central inlet area of the rotor, and a separating element arranged in the central inlet area, which redirects the recirculation flow in a radial direction perpendicular to the axial direction. The, the separating element and the relief opening of the rotor are a one-piece unit.

A device for changing a pump unit of a centrifugal pump is proposed. The centrifugal pump includes the pump unit and a stator extending in an axial direction. A cup-shaped recess is provided at the first axial end of the stator into which the pump unit is capable of being inserted. The device includes an actuating device with which a mechanical force is capable of being exerted on the pump unit. The mechanical force acts in the axial direction and is directed in such a way that it separates the pump unit from the stator in the axial direction.

A pump device includes a motor having a rotor and a stator, and an impeller which is disposed in a pump chamber and is integrally rotated with the rotor. The rotor includes a rotor member having a first cylindrical part and a drive magnet surrounding the first cylindrical part. A radial bearing is held on an inner side of the first cylindrical part. The drive magnet has a second cylindrical part surrounding an outer periphery of the first cylindrical part and a ring-shaped rib which protrudes from an end of the second cylindrical part to an inner side. The rotor member has a seat part, which protrudes from the first cylindrical part to an outer side and supports an end of the second cylindrical part, and a caulked part which is enlarged from the first cylindrical part to an outer side and is overlapped with the ring-shaped rib.

A fan module for cooling electronic devices comprises a first fan and a second fan detachably coupled together. The first fan includes a first housing having latching slots, a first engagement member defining a first engagement slot with a first opening oriented toward a corresponding latching slot, and a first fan blade disposed within the first housing. The second fan includes a second housing, a second engagement member detachably fitted in the first engagement slot of the first engagement member, and a second fan blade disposed within the second housing. A latching member is disposed in the corresponding latching slots and configured to prevent the second engagement member from disengaging from the first engagement member. When assembled, the rotational axes of the fan blades are aligned to direct airflow from the first fan into the airflow path of the second fan, providing enhanced cooling performance.