Magnetic levitation bearing structure includes a cylinder body, a rotating shaft, a motor stator, a motor rotor, an axial bearing, a radial bearing and a displacement sensing device; the displacement sensing device, the axial bearing stator, and the radial bearing stator are directly fixed on an inner wall of the cylinder body.

A pumping device includes a single-use device and a reusable device. The single-use device is to be inserted into the reusable device and includes two pump units in series, one behind the other. Each pump unit includes a rotor for a bearingless motor, and can be magnetically levitated and driven without contact for rotation about an axial direction. The reusable device includes a stator for each rotor which form an electromagnetic rotary drive for rotating the rotor about the axial direction. Each stator is a bearing and drive stator with which the rotor can be magnetically driven and levitated without contact with respect to the stator. An independent control device is provided for each stator, and can independently activate a respective stator.

The present disclosure provides a stator core, a magnetic levitation bearing, and a motor. The stator core is used in the magnetic levitation bearing and includes an annual yoke. The annular yoke has an inner circumferential wall and an outer circumferential wall, a plurality of pole pillars are disposed on the inner circumferential wall, and each of the plurality of pole pillars extends towards an axis of the inner circumferential wall, there is a distance D between an axis of the outer circumferential wall and the axis of the inner circumferential wall, and D≠0 is satisfied. According to the stator core, the magnetic levitation bearing, and the motor of the present disclosure, the stator core has a non-centrosymmetric structure, so that a cross-sectional area of a magnetic path in some region of the stator core is increased, which is beneficial to an improvement of an output force of the magnetic levitation bearing.

An electromagnetic rotary drive includes a contactlessly magnetically drivable rotor that is coil-free and free of permanent magnets and that includes a magnetically effective core, and a stator by which the rotor is contactlessly magnetically drivable about a desired axis of rotation in the operating state. The stator has a plurality of coil cores of which each includes a bar-shaped longitudinal limb extending from a first end in a direction in parallel with the desired axis of rotation up to a second end, all the first ends being connected by a reflux of windings generate an electromagnetic rotational field of which each surrounds one of the longitudinal limbs. The coil cores include a plurality of permanent magnets by which a permanent magnetic pre-magnetization flux can be generated.

A thrust magnetic bearing includes a stator having a coil, and a rotor. The stator includes main and auxiliary stator magnetic-pole surfaces. The rotor includes main and auxiliary rotor magnetic-pole surfaces facing the main and auxiliary stator magnetic-pole surfaces. When an electric current flows in the coil, an electromagnetic force in an axial direction is generated between the main stator and rotor magnetic-pole surfaces, and an electromagnetic force in a radial direction is generated between the auxiliary stator and rotor magnetic-pole surfaces. When the rotor is displaced in the radial direction, a radial force that acts on the rotor between the auxiliary stator and rotor magnetic-pole surfaces is increased in a direction of the displacement, and a radial force that acts on the rotor between the main stator and rotor magnetic-pole surfaces is increased in a direction opposite to the direction of the displacement.

In an electric motor, a magnetic bearing generates an electromagnetic force between multiple permanent magnets and a coil and rotatably supports an other side of a rotation shaft in an axis line direction. The rotation shaft is configured to be capable of being inclined with a rotation center line using a bearing side of the rotation shaft as a fulcrum. An electronic control device controls a current that flows to the coil such that an axis line of the rotation shaft approaches the rotation center line due to a supporting force which is the electromagnetic force between the multiple permanent magnets and the coil. Accordingly, the rotation shaft is rotatably supported to be freely rotatable by a magnetic bearing and the bearing.

A rotation mechanism (20) of a vacuum pump (100) includes a magnetic bearing unit (21) having a first outer diameter (91), the magnetic bearing unit (21) being operable as a first radial magnetic bearing (40), and a motor unit (22) provided on a side of a second end (11b) of a rotary shaft (11) relative to the magnetic bearing unit, the motor unit (22) having a second outer diameter (92) larger than the first outer diameter, the motor unit (22) being operable as both a motor (30) and a second radial magnetic bearing (50).

An electric motor system includes a drive shaft, a first electric motor, a second electric motor, a first inverter, a second inverter and a control unit. The drive shaft is rotatable around an axis. The first electric motor and the second electric motor rotate the drive shaft. The first inverter supplies power in order to generate a torque to the first electric motor. The second inverter supplies power in order to generate a torque to the second electric motor. The control unit controls the first inverter and the second inverter. The controller is configured to be able to change a ratio between an output torque of the first electric motor and an output torque of the second electric motor.

An electromagnetic rotary drive includes a rotor, a stator and windings. The rotor includes a magnetically effective core. The rotor is contactlessly magnetically drivable about an axis of rotation and the rotor is contactlessly magnetically levitatable. The stator has coil cores, each with a longitudinal limb parallel with the axis and a transverse limb extending radially, the transverse limb being perpendicular to the axis. The windings generate an electromagnetic rotational field, each winding surrounding one longitudinal limb, such that the stator is free of permanent magnets. The rotor is ferromagnetic or ferrimagnetic with one preferential magnetic direction extending radially, and the core of the rotor has a magnetic resistance in the preferential magnetic direction, the magnetic resistance at most half as large as the magnetic resistance in a direction, which is perpendicular to the preferential magnetic direction and perpendicular to the axial direction.

A system for controlling an electric motor including a rotor supported by a lubricant upon a stator with a plurality of stator poles and stator windings includes monitoring a radial position and rotor angle of the rotor by a controller. The system includes generating adjustments by the controller to cause the stator poles to apply a net radial force to the rotor. This net radial force may be used, for example to cause the rotor to be centered upon a central axis of the electric motor and may be particularly advantageous for a lubricant supported rotor. A motor drive provides an AC current to the stator windings as well as phase current adjustments of the electrical current in one or more of the stator windings to apply the net radial force to the rotor in a direction perpendicular to the drive axis.