An active magnetic bearing comprising a plurality of electromagnetic actuators, each actuator receiving for control thereof an input current and being able to exert a radial force on a shaft of a rotary machine, with respect to the rotation axis of said shaft, the shaft being able to be held without contact between the electromagnetic actuators and to undergo radial motion when it is in rotation, means for supplying input current of each actuator, the supply means comprising means for controlling the input current of each actuator, according to the position of the shaft with respect to the actuators. The supply means comprise means for damping the radial motion of the shaft.

A flywheel system includes a rotor and a fixture. The rotor forms an aperture. The fixture includes a bottom support, a top support, and a shaft connecting the bottom support to the top support. The shaft passes through the aperture. The bottom support and the top support are outside opposite ends of the aperture. The rotor is configured to rotate about the shaft. A method for operating a flywheel system includes converting between rotational energy of a rotor and electrical energy in windings of a generator stator that is implemented in a stationary shaft passing through an aperture of the rotor, while the rotor is rotating about the shaft.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic radial bearing, wherein the hybrid magnetic radial bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

An electric submersible pump (ESP) assembly. The ESP assembly comprises a centrifugal pump, an electric motor mechanically coupled by a drive shaft to the centrifugal pump, wherein the electric motor comprises a stator and a rotor, a bearing, wherein the bearing is disposed inside the electric motor, and a magnetic shield disposed in the electric motor between bearing and the rotor and stator.

A magnetic bearing device comprises a stator (30) and a rotor (10) supported in the stator for rotation around a rotation axis (R). The rotor comprises at least one permanent magnet (21, 22) that is magnetized along the rotation axis. The stator comprises at least one closed magnetic core (31) that surrounds the rotor (10) and at least one radial bearing winding (32) arranged on the closed magnetic core (31) in a toroidal configuration. The at least one radial bearing winding is arranged to interact with a permanent magnetic field generated by the at least one permanent magnet to obtain a radial bearing force when current is supplied to the at least one radial bearing winding.

An electric submersible pump (ESP) assembly. The ESP assembly comprises a centrifugal pump, an electric motor mechanically coupled by a drive shaft to the centrifugal pump, wherein the electric motor comprises a stator and a rotor, a bearing, wherein the bearing is disposed inside the electric motor, and a magnetic shield disposed in the electric motor between bearing and the rotor and stator.

A magnetic bearing having a colocated eddy-current displacement sensor, comprising an electromagnet unit including a circular casing having a hollow portion therein, and a plurality of electromagnets disposed along an inner periphery of the casing, an amplifier unit coupled to one side of the electromagnet unit, a coil wiring unit coupled to the other side of the electromagnet unit, and a plurality of sensor units disposed along an inner periphery of the electromagnet unit and each having two opposite ends respectively coupled to the coil wiring unit and the amplifier unit, the plurality of sensor units being provided between the coil wiring unit and the amplifier unit, in which the sensor unit is disposed colocatedly with a suspended body supported by the electromagnet unit and configured to measure a displacement of the suspended body.

An advanced substrate rotation device is provided. A substrate rotation device is disclosed. The substrate rotation device includes an outer cylinder, an inner cylinder positioned inside the outer cylinder, a motor for rotating the inner cylinder, a magnetic bearing for magnetically levitating the inner cylinder, and a substrate holder disposed on the inner cylinder. The motor is a radial motor including a motor stator mounted on the outer cylinder, and a motor rotor mounted on the inner cylinder. The magnetic bearing is a radial magnetic bearing including a magnetic bearing stator mounted on the outer cylinder, and a magnetic bearing rotor mounted on the inner cylinder. The magnetic bearing is configured to magnetically levitate the inner cylinder with an attractive force between the magnetic bearing stator and the magnetic bearing rotor.

A magnetic bearing controller for controlling a magnetic levitation motor, the magnetic levitation motor including: a rotor; a pair of electromagnets that causes the rotor to levitate by electromagnetic force; an auxiliary bearing that supports a rotating shaft of the rotor when the rotor is stopped; and a rotor position detector that detects the rotor's position in a levitation direction. The magnetic bearing controller includes an operation current generator that generates an operation current value corresponding to a deviation between a position command value and the rotor's position detected by the rotor position detector. The operation current generator is configured to give a predetermined initial value greater than 0 to the operation current value at a start of levitation for causing the rotor in a state where the rotating shaft of the rotor is supported by the auxiliary bearing to levitate and be positioned at a predetermined target position.

An electric motor system includes a rotary shaft having an axis line displaceable relative to a rotation center, a magnetic bearing for supporting the rotary shaft, a permanent magnet mounted on the rotary shaft and having a plurality of magnetic poles arranged in a circumferential direction around the axis line of the rotary shaft, three detection elements arranged in the circumferential direction around the rotation center for detecting a magnetic flux generated from the permanent magnet, and a coordinate detection section for determining coordinates of the axis line of the rotary shaft based on output values of two detection elements selected out of the three detection elements in accordance with a rotation angle of the rotary shaft.