Active magnetic rotor-bearing assembly having an even number of electromagnetic units with a salient connected to inter-yoke portions separated from each other by a permanent magnet structure spacer of defined magnetic permeability

A fluid pump comprising a housing having an inlet opening for receiving the fluid and an outlet opening for discharging the fluid, an active magnetic rotor-bearing assembly for conveying a fluid comprising a rotor assembly driven by a motor assembly and a bearing assembly for contactless bearing the rotor assembly to pump the fluid from an inlet opening through a rotor assembly to an outlet opening, wherein the bearing assembly comprises an even number of electromagnetic units arranged around a central structure of the bearing assembly, which provides a fluid channel towards the rotor assembly, each comprising a first salient established by a magnetic material and a permanent magnet at least magnetically connected to the magnetic material providing a first magnetic pole facing towards the rotor assembly and a coil wound around the first salient, where the bearing assembly further comprises an inter yoke comprising inter yoke portions connected to the first salient of each electromagnetic unit, where the permanent magnets of adjacent electromagnetic units, where the permanent magnets of the adjacent electromagnetic units are suitably arranged to provide a closed first magnetic flux via the first salient and the yoke portions of the both adjacent electromagnetic units and the rotor assembly applying a first attractive force acting on the rotor-assembly for compensating at least present motor and fluid-caused forces at a levitation position of the rotor assembly further comprising means for a position stabilizing portion perpendicular to the first attractive force on the rotor-assembly, and the coils providing an electromagnetic flux between each first salient and the rotor assembly for applying adaptable axial force and/or tilting torque to the rotor assembly keeping the rotor within a levitation range during rotation and compensating the current motor force and fluid-caused forces during any fluctuation and-any additional forces in order to adjust the bearing provided by the first magnetic flux with rotor the rotor assembly to pump the fluid from the inlet opening through the rotor assembly to the outlet opening and the bearing assembly to enable a contactless rotating the rotor assembly inside the housing, and the motor assembly to drive the rotor assembly, where the rotor assembly has an open central structure connected to the outlet opening for discharging the fluid, wherein adjacent inter-yoke portions are separated from each other by a structure spacer with a magnetic permeability lower than a magnetic permeability of the inter-yoke portions, wherein the structure spacer is a permanent magnet with an orientation adding an extra magnetic flux to the first magnetic flux.

A method to operate an active magnetic rotor-bearing assembly for conveying a fluid comprising a rotor assembly driven by a motor assembly and a bearing assembly comprising an even number of electromagnetic units arranged around a central structure of the bearing assembly, which provides a fluid channel towards the rotor assembly, each comprising a first salient established by a magnetic material and a permanent magnet at least magnetically connected to the magnetic material providing a first pole facing towards the rotor assembly and a coil wound around the first salient, where the bearing assembly further comprises an inter-yoke comprising inter-yoke portions connected to the first salient of each electromagnetic unit, the method comprising the steps of:

• contactless bearing the rotor assembly to pump the fluid from an inlet opening through the rotor assembly to an outlet opening by providing a closed first magnetic flux via the first salient and the inter-yoke portions of the both adjacent electromagnetic units and the rotor assembly applying a first attractive force acting on the rotor-assembly for compensating at least present motor and fluid-caused forces at a levitation position of the rotor assembly further comprising a position stabilizing portion perpendicular to the first attractive force on the rotor-assembly using suitably arranged permanent magnets of the first salient;
• and
• balancing the bearing provided by the first magnetic flux by an electromagnetic flux between each first salient and the rotor assembly to apply an adaptable axial force and/or tilting torque to the rotor assembly keeping the rotor within a levitation range during rotation and compensating the current motor force and fluid caused force during any fluctuation and any additional forces, wherein adjacent inter-yoke portions are separated from each other by a structure spacer with a magnetic permeability lower than a magnetic permeability of the inter-yoke portions, wherein the structure spacer is a permanent magnet with an orientation adding an extra magnetic flux to the first magnetic flux.