A magnetic bearing control apparatus includes a plurality of output elements configured to generate electromagnetic force, a magnetic bearing configured to float a rotation shaft from a surface of the magnetic bearing based on the electromagnetic force generated by the plurality of output elements, at least one displacement sensor configured to sense a displacement of the rotation shaft, and a controller. The controller is configured to control a current supplied to the plurality of output elements, to control a position of the rotation shaft based on the current supplied to the plurality of output elements according to the displacement of the rotation shaft, and to determine a failure of the displacement sensor.

A radial magnetic bearing includes an axis, a stator and a rotor, where the stator includes at least two stator assemblies axially spaced from one another, where each of the stator assemblies includes a magnetically soft core, where at least one of the stator assemblies comprises one said magnetically soft core with several radially projecting teeth arranged distributed in the circumferential direction, and several coils likewise arranged distributed in the circumferential direction, and where two respective teeth of the magnetically soft core that are successive in the circumferential direction are connected to each other by way of a connecting section of the core. The magnetic bearing includes a permanent magnet assembly disposed axially between the two magnetically soft cores. At least one said stator arrangement with several coils arranged distributed in the circumferential direction, the magnetically soft core of which includes several radially projecting teeth arranged distributed in the circumferential direction, is embodied such that one of the respective connecting sections is wound with one of the respective coils.

Described is a bearingless motor based upon a homopolar flux-biased magnetic bearing for force generation and a hysteresis motor for torque generation. The bearingless slice motor levitates and rotates a ring-shaped rotor made of a semi-hard magnetic material. The rotor is biased with a homopolar permanent-magnetic flux, on which 2-pole flux can be superimposed to generate suspension forces. Torque is generated by a hysteretic coupling between the rotor and a rotating multi-pole stator field.

An electromagnet unit in which influence of a noise on a displacement sensor is suppressed and which can be installed in a space-saving manner and a vacuum pump including the electromagnet unit are provided. An electromagnet unit includes a radial electromagnet which controls a shaft to a predetermined position, a radial sensor which detects a position of the shaft, and a printed board interposed between the radial electromagnet and the radial sensor and on which a wiring pattern for sensor connecting coils of the corresponding two radial sensors to each other and a wiring pattern connecting coils of the corresponding two radial electromagnets to each other are provided. The wiring pattern for sensor and the wiring pattern for electromagnet are disposed so as not to overlap when seen from the axial direction.

A control apparatus includes a constant storage portion that stores constant values of an electromagnet coil including a resistance value Rm, an inductance Lm, a sampling time Ts, etc. A current storage portion stores previous current command values Ir having been regularly sampled by a microcomputer inside a current control circuit. A low-frequency feedback circuit generates a signal for suppressing an error between DC components and low-frequency components of an input current command value Ir and a detected current value IL and outputs the signal. An output voltage computing circuit calculates, based on the input current command value Ir[n+1], a stored value Ir[n] of the current storage portion, a stored value of a constant storage portion, and the signal of the low-frequency feedback circuit, a voltage for suppling the electromagnet coil with a current in accordance with a command, and outputs the calculated voltage.

A magnetic bearing (20) comprises: a rotor (22) to be supported for rotation about an axis (502); a stator (24) extending from a first end (30) to a second end (32) and comprising: one or more first permanent magnets (110); one or more second permanent magnets (112) of polarity substantially opposite to a polarity of the one or more first permanent magnets; at least three radial windings (40, 42, 44, 46); a first axial winding (34); a second axial winding (36); a first end pole (120); and a second end pole (122).

A magnetic bearing, comprising: a magnetic base; at least three actuator bobbins mounted on the magnetic base; and magnetic sensors associated with the actuator bobbins. At least one magnetic system amidst the magnetic actuators and the magnetic sensors comprises together: a coil holder; a coil wound up around the coil holder; and a connector device integrated to the coil holder and designed for plugging at least one wire. Additionally disclosed is an apparatus comprising such a magnetic bearing and a method for manufacturing such a magnetic bearing.

A magnetic bearing, adapted to equip a rotary apparatus. The magnetic bearing comprises: an actuator sub-assembly provided with a magnetic base and at least three actuator bobbins mounted on the magnetic base, and a sensor sub-assembly provided with at least three magnetic sensors associated with the actuator bobbins. At least one sub-assembly amidst the actuator sub-assembly and the sensor sub-assembly comprises at least three sectors mounted together. Each sector includes at least one actuator bobbin when the sector belongs to the actuator sub-assembly, or at least one magnetic sensor when the sector belongs to the sensor sub-assembly. The invention also concerns a rotary apparatus comprising such a magnetic bearing and a method for manufacturing such a magnetic bearing.

A magnetic bearing which would reduce a leakage magnetic flux to be generated between teeth is provided. A predetermined one of its teeth (24) is configured so that a pitch (P1) between the predetermined tooth (24) and one of two adjacent teeth (24) that are located on clockwise and counterclockwise sides thereof in the circumferential direction is broader than a pitch (P2) between the predetermined tooth (24) and the other tooth (24) and that a magnetic flux flows in the same radial direction through the predetermined tooth (24) and the tooth (24) spaced from the predetermined tooth (24) by the narrower pitch (P1) but flows in two different radial directions through the predetermined tooth (24) and the tooth (24) spaced from the predetermined tooth (24) by the broader pitch (P2).

A radial stator includes a stator core, and the stator core includes a stator outer ring. M magnetic poles are arranged on an inner circumferential wall of the stator outer ring, and are evenly distributed along the inner circumferential wall of the stator outer ring. The M magnetic poles include M.sub.1 magnetic poles arranged along the inner circumferential wall of the stator outer ring and M.sub.2 magnetic poles arranged along the inner circumferential wall of the stator outer ring; M2, M.sub.11, and M.sub.21; the M.sub.1 magnetic poles and the M.sub.2 magnetic poles are arranged on two sides of the stator outer ring with respect to a radial direction thereof, respectively; each of the M.sub.1 magnetic poles is provided with a first winding; and each of the M.sub.2 magnetic poles is provided with a second winding; and a coil turn N.sub.1 of the first winding is greater or less than a coil turn N.sub.2 of the second winding.