A magnetic bearing may include an inner ring and an outer ring arranged concentrically. The inner ring and the outer ring may be mounted rotatably relative to each other by way of axial and radial magnets. The magnetic bearing may also include a back-up bearing, which is integrated into at least one of the outer ring or the inner ring both in an axial direction and in a radial direction. The outer ring may be multipiece and may include a recess that opens inwards and receives the inner ring. Further, the back-up bearing may be made of aluminum, austenitic steel, bronze, or ceramic, and the back-up bearing may operate as a shielding device that shields magnetic fields emitted by the axial and radial magnets from one another.

An active magnetic bearing system includes a radial actuator and an axial actuator. The radial actuator includes a radial stator coupled to a stationary component, and a radial rotor coupled to a rotatable impeller. The radial rotor extends circumferentially with respect to the radial stator and is configured to rotate about the radial stator. The axial actuator has first and second rotor rings and first and second stators. The first rotor ring is attached to a first axial end of the impeller, and the second rotor ring is attached to a second axial end of the impeller. The first and second stators are coupled to the shaft adjacent the first and second rotor rings, respectively. The radial actuator is positioned axially between the first and second rotor rings.

A stator is provided which exerts a combined electromagnetic force of a plurality of electromagnets on a drive shaft having a fluctuating load. A controller is provided which controls a current difference between a first coil current passed through a coil of the electromagnet generating an electromagnetic force in a direction opposite to that of the load and a second coil current passed through a coil of the electromagnet generating an electromagnetic force in the same direction as that of the load to perform a position control on the drive shaft. The controller adjusts the second coil current to reduce an average value of the second coil current.

The core inside a combined radial-axial magnetic bearing is stacked with coated laminations each equipped with at least one radial cut. These cuts prevent the inducement of circulating currents caused by varying axial control fluxes through the central hole of the stack. Magnetic symmetry is preserved by pivoting every lamination with respect to the previous one over a particular angle. This arrangement not only reduces the losses in the bearing, but improves the performance of the axial channel as well.

A magnetic levitation device includes a magnetically effective core and a stator including coil cores. Each coli core includes a longitudinal leg and a transverse leg at an end of the longitudinal leg. A concentrated winding surrounds each longitudinal leg. The stator has a cup-shaped recess to receive the rotor. The transverse legs are arranged around the cup-shaped recess. First and second holding device and a second holding device are connected to each other, The first holding device includes a bottom plate on which holding elements are provided, which extend in the axial direction and receive exactly one of the longitudinal legs. The second holding device receives the transverse legs.

Radial poles are placed around a radial actuator target mounted on a body. The poles are separated from a cylindrical surface of the target by radial gaps and adapted to communicate a magnetic flux with it. The radial poles are equipped with electrical control windings and magnetically coupled to form magnetic control circuits. A flux return pole is adjacent to the body, separated from it by an air gap and adapted to communicate a magnetic flux with the radial actuator target. A permanent magnet generates a magnetic bias flux in the magnetic bias circuit formed by the radial actuator target, the radial poles and the magnetic flux return pole. A radial force is exerted on the actuator when the control windings are energized with a current. A Hall effect sensor measures bias magnetic field in the air gap between the magnetic flux return pole and the body. A feature on a body is adapted to produce a circumferentially local discontinuity in the magnetic field measured by the Hall effect sensor as the body rotates.

An electromagnetic rotary drive includes a magnetically contactlessly drivable rotor free of coils, and a stator configured as a bearing and drive stator configured to drive the rotor magnetically and contactlessly about an axis of rotation. The rotor is capable of being supported magnetically contactlessly with respect to the stator in an operating state. The stator includes an upper stator part having a plurality of pronounced upper poles configured to carry upper windings and a lower stator part having a plurality of pronounced lower poles configured to carry lower windings. The upper stator part and the lower stator part are arranged spaced apart from one another with respect to an axial direction. A permanent magnet is disposed between the upper stator part and the lower stator part.

A diagnostic scanning apparatus includes a hollow rotor sized to receive a patient. First and second flanges are connected to and extend radially outward from the rotor in a spaced-apart relationship, each of the first and second flanges including, at least in part, a magnetically-permeable material. A radiation source is affixed to the first flange and/or the rotor. A first axial actuator generates a variable magnetic field, is fixedly disposed adjacent to the first flange and can magnetically pull the first flange in a first axial direction of the rotor. A second axial actuator generates a variable magnetic field, is fixedly disposed adjacent to the second flange and can magnetically pull the second flange in a second axial direction of the rotor that is opposite of the first axial direction. The first and second axial actuators are both at least substantially disposed between the first and second flanges.

A magnetic bearing, a compressor and an air conditioner. The magnetic bearing comprises: an axial iron core, permanent magnets, a magnetic conductive ring and a magnetic steel fixing frame; the permanent magnets comprise a first permanent magnet located on one axial side of the magnetic conductive ring and a second permanent magnet located on the other axial side of the magnetic conductive ring; the first permanent magnet is located between the magnetic conductive ring and the axial iron core and is connected to the magnetic conductive ring and the axial iron core; the second permanent magnet is located between the magnetic conductive ring and the axial iron core and is connected to the magnetic conductive ring and the axial iron core. The magnetic steel fixing frame can fix and support the radial inner sides of the permanent magnets.

An active magnetic bearing apparatus for supporting a rotor of a rotary machine comprises an axial magnetic bearing unit and a radial magnetic bearing unit mounted directly to one another. One of the axial magnetic bearing unit and the radial magnetic bearing unit is mounted to a support for attachment to a housing of the rotary machine.