Abstract: A stator assembly having a housing and a stator that are concentric, the stator being mounted radially inside the housing is provided. This stator assembly includes fastening elements that are mounted between a radial inner surface of the housing and a radial outer surface of the stator and exert a radial fastening force on the housing and the stator.

Abstract: A stator assembly that provides a concentric housing and stator, the stator radially positioned inside the housing, the housing having an inner surface, the stator having an outer surface radially facing the inner surface. One of the outer surface of the stator and the inner surface of the housing has recessed shapes and the other one of the outer and inner surface has protruding shapes. When the two shapes are arranged in a first relative position, the protruding shapes are inserted in the recessed shapes so that the stator can be mounted radially inside the housing along a central axis of the assembly, and in a second relative position that is angularly shifted relative to the first position around the central axis, the protruding shapes exert, against the one of the housing and the stator that bears the recessed shapes, a radial force that angularly and axially locks the stator.

Abstract: A method of protecting ferromagnetic lamination stacks of a component of an electric machine, comprises the following steps: creating a component module by arranging a laminations stack of ferromagnetic sheets into a housing, (b) protecting locations of the component module where coating is unwanted, (c) inserting the component module into a hermetic chamber receiving an ionized gas, (d) polarizing the component module to submit a fixed electric potential to the component module, (e) depositing a thin layer of protective coating on the laminations stack of ferromagnetic sheets through a method of Plasma Enhanced Chemical Vapor Deposition (PECVD) at a temperature lower than 150° C., (f) monitoring the deposition homogeneity and deposition thickness of the thin layer of protective coating until desired thickness, and (g) rectifying the surface of the thin layer of protective coating to have a uniform protective layer.

Abstract: 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.

Abstract: A digital nonlinear corrector of an active magnetic bearing receiving an input signal x(t) and outputting an output control signal u(t) for controlling the position of said active magnetic bearing, the input signal being digitalized by a ADC circuit and provided to an adder, the digital nonlinear corrector comprising a closed control loop delivering an intermediary sequence of numbers y[kT] and having a direct branch comprising a first proportional gain circuit and a feedback branch comprising a series connection of a low-pass filter and a dead zone circuit, such that said low-pass filter is activated when determined upper and lower values of said output control signal are reached, the output control signal reproducing the input signal when these determined upper and lower values are not reached.

Abstract: 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.

Abstract: A method and system for determining core losses in a permanent magnet synchronous motor, comprising a measurement of the losses of the motor with the motor not connected to a load, and a deduction of the core losses of the motor from the losses of the motor. The motor is placed in an over-fluxing state during the measurement of the losses.

Abstract: A control device for controlling the position of a rotor supported by active magnetic bearings is provided. The control device includes a trajectory planning module for generating a requested position, speed and acceleration; a feedback unit for generating a position feedback value and a speed feedback value; a first correction circuit for generating a first command signal according to the difference between the requested position and speed and the position and speed feedback value respectively; a feed-forward controller for generating a second command signal; an adder for adding first and second command signals and delivering a third command signal for a non-linear inversion circuit connected to the adder for generating flux command signals for the electromagnets, and a second correction circuit for generating voltage command signals for the power amplifiers which control the current flowing in the electromagnet coils of the active magnetic bearings.

Abstract: A position detection device of active magnetic bearings (AMB's) maintaining the position of a rotating shaft and comprising two sensing inductance coils, the position detection device comprising a programmable digital component for generating a 25 KHz square waveform signal, a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and, depending on the displacement of the rotating shaft, an analog to digital (A/D) converter for delivering a position value from the voltage difference.

Abstract: An axial magnetic bearing comprising a rotor stop disc which is mounted perpendicularly and integral with a rotating shaft and a coaxially stator assembly and comprising at least one stator element of magnetic material having an inner face parallel to a side of the rotor stop disc and separated from it by an air gap, the at least one stator element comprising two annular coils and housed in two annular notches formed continuously in the magnetic material of the at least one stator element and opening to the side of the rotor stop disc, the two annular notches being separated by an annular tooth, rolled in series and are formed by a single continuous wire, a bridging recess being cut in the annular tooth for receiving a massive insert part that extends the annular tooth without locally modifying the air gap with the rotor stop disc.

Abstract: An electronic magnetic bearing controller for controlling the position of a rotor of an electrical machine supported by an active magnetic bearing the position of which being measured by at least one inductive position sensor having an inductive coil, comprising an automatic reactive power compensation device for automatically compensating the reactive power consumed by the inductive position sensor.

Abstract: An electrical machine (20) coupled to a compressor (12) having a rotatable shaft (16), comprising: a rotor forming part of the rotatable shaft and having at least two magnetic portions (22A, 22B) separated by an inclined non-magnetic portion (24) and two elements (26A, 26B) of non-magnetic material at each end of the rotatable shaft, a stator comprising a laminated magnetic iron stack (28) surrounded by a winding (30) and disposed along a periphery of the rotor to define a first annular gap (32), a ring (34) of non-magnetic material disposed around the stator, and a casing (40) of magnetic material comprising permanent magnets (36), disposed around the non magnetic ring and having radial walls (40A, 40B) that project inwardly towards the rotor by defining a second annular gap (42) therebetween.

Abstract: A rotary machine, comprising: a stator assembly and a rotor assembly centered on a central axis; a magnetic bearing; and an auxiliary bearing including a first ring held in the stator assembly and a second ring delimiting a gap radially to the central axis relative to the rotor. The second ring is not rotating around the central axis in a primary operation mode and is dragged in rotation around the central axis in a secondary operation mode. The rotary machine includes a monitoring system for detecting a transition from the primary operation mode to the secondary operation mode. The monitoring system comprises a target formed on the second ring and a sensor unit fixed relative to the stator assembly. A bearing and a method for manufacturing a rotary machine are additionally disclosed.

Abstract: An electrical machine (20) coupled to a compressor (12) having a rotatable shaft (16), comprising: a rotor forming part of the rotatable shaft and having at least two magnetic portions (22A, 22B) separated by an inclined non-magnetic portion (24) shaft, a stator comprising a laminated magnetic iron stack (28) surrounded by a winding (30) and disposed along a periphery of the rotor to define a first annular gap (32), a ring (34) of non-magnetic material disposed around the stator, a DC coil (38) disposed around the non-magnetic ring, and a casing (40) of magnetic material disposed around the DC coil and having radial walls (40A, 40B) that project inwardly towards the rotor by defining a second annular gap (42) therebetween.

Abstract: A modular motor and magnetic bearing assembly comprising a positioning casing having a plane reference surface, an outer cylindrical reference surface, a central portion provided on an outer face with cooling liquid flow channels, and intermediate portions provided with openings for gaseous fluid entry and exit; a rotor presenting an inner cylindrical reference surface and a plane reference surface; an electric motor; radial magnetic bearings; an axial abutment; and auxiliary mechanical bearings. The modular assembly can then be incorporated in a main casing simply by sliding and it can be connected directly to a functional unit without reworking adjustments of the magnetic bearings.

Abstract: A high speed energy storage flywheel comprises a rotor which is located in a vacuum chamber provided in a stator housing and is supported by magnetic bearings with respect to the stator housing. A fluid tank used for releasing in a controlled manner, a fluid inside the vacuum chamber and therefore create a braking effect on the rotor by friction.

Abstract: A rotor sensor target for magnetic bearings, the rotor sensor target comprising a ring-shaped assembly of magnetic material mounted on a generally ring-shaped assembly of non-magnetic material. The magnetic and non-magnetic ring shaped assemblies are coaxially arranged and mounted on a shaft having a longitudinal axis of rotation X?-X. The generally ring-shaped assembly of non-magnetic material comprises at least one ring-shaped slit having the longitudinal axis X?-X and may be made of a cheaper material, such as aluminum. The ring-shaped slit provides flexibility which permits operation over a wide range of temperatures without risking of damaging the ring-shaped assembly of magnetic material.

Abstract: A digital nonlinear corrector of an active magnetic bearing receiving an input signal x(t) and outputting an output control signal u(t) for controlling the position of said active magnetic bearing, the input signal being digitalized by a ADC circuit and provided to an adder, the digital nonlinear corrector comprising a closed control loop delivering an intermediary sequence of numbers y[kT] and having a direct branch comprising a first proportional gain circuit and a feedback branch comprising a series connection of a low-pass filter and a dead zone circuit, such that said low-pass filter is activated when determined upper and lower values of said output control signal are reached, the output control signal reproducing the input signal when these determined upper and lower values are not reached.

Abstract: A thrust disc for a magnetic bearing, wherein the thrust disc comprises: a body, which is adapted to be mounted on a shaft and which has a first offset yield strength and a first magnetic permeability, and at least one flange which is fixed to the body in a position where it can interact with a thrust stator in order to form a magnetic bearing and which has a second offset yield strength and a second magnetic permeability; wherein the first offset yield strength is higher than the second offset yield strength; and wherein the first magnetic permeability is smaller than the second magnetic permeability. Additionally, the magnetic bearing can be equipped with such a thrust disc. An apparatus can be equipped with such a magnetic bearing.

Abstract: A permanent magnet rotor assembly comprises a cylindrically shaped shaft having an outer surface, a plurality of permanent magnets constituting portions of annular segments and an outer retaining cylindrical sleeve surrounding the plurality of permanent magnets. The assembly further comprises a cylindrical magnet housing mounted on the cylindrically shaped shaft for supporting the plurality of permanent magnets. The cylindrical magnet housing is formed of a magnetic material. The retaining cylindrical sleeve is preloaded by a resultant interference fit IF2 which is defined by the following formula: IF2=?ØY+?{square root over (((ØY+IF1)?2+ØY?2?ØX?2))}. where ØY is an external diameter of the plurality of permanent magnets, ØX is an internal diameter of the cylindrical magnet housing, and IF1 is a primary interference fit between an external diameter of the cylindrically shaped shaft and the internal diameter of the cylindrical magnet housing.