Abstract: A device for detecting the axial position of a rotor shaft of a rotary machine having a stator and a rotor is provided. The detecting device includes a sensor stator ring, secured to the stator, made from ferromagnetic material, facing the shoulder of one end of the hollow or not hollow rotor shaft and arranged so as to leave an axial airgap with the one end of the rotor shaft. The sensor stator ring having at least one annular slot receiving an annular induction coil. The rotor shaft is made from solid magnetic steel, an outer end of the rotor shaft acts as a target surface whose axial position is to be measured by the sensor stator ring.

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 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 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 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: 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: A hybrid magnetic suspension of a rotor (1) having compressor wheels (2, 3) having permanent magnets (104, 114) integral to shrunk fit rings (8, 18) arranged on the rotor (1) in the vicinity of the compressor wheels (2, 3), permanent magnets (124, 134) integral to stationary rings (23, 33) coaxially arranged with the rotor (1) and associated with a resilient material (5, 15) to define a passive radial magnetic bearing, coils (6, 16) associated with magnetic armatures (10, 20) and facing rotor parts (7, 17) being located perpendicularly to the rotor (1), and axial sensors (60, 160) configured for sensing the axial position of the rotor (1) and control means (200) configured for feeding the coils (6, 16) as a function of the outputs of the axial sensors (60, 160) for generating both axial bearing forces and a motor torque and thereby being adapted for defining an axial bearingless motor.

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: A radial magnetic bearing having an inner rotor including a central shaft having a ferromagnetic armature mounted on the shaft and an outer stator providing a plurality of electromagnets including poles made of ferromagnetic material which project radially inwardly towards the rotor is provided. As such, air-gaps (e) are left between end faces of the poles and the ferromagnetic armature, and coils wound around the poles. The poles are extended through outer portions attached to a supporting member. Each pole and the corresponding outer portion are included in an angularly segmented module providing a stack of laminations made of ferromagnetic material. The outer portion defines shoulders with respect to the corresponding pole, the outer portion contacting outer portions of neighboring segmented modules and the outer portions of all segmented modules being assembled by clamping rings, wherein the coils located in free spaces around the poles are mounted in a string.

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 permanent magnet rotor shaft assembly for a high speed electrical machine provides a permanent magnet cylindrical core having a longitudinal axis, the cylindrical core being axially compressed by first and second end shafts and being radially compressed by a sleeve made of a non-magnetic high strength metal. At least one of the first and second end shafts includes, facing the cylindrical core, a central shoulder head that cooperates with a mating central recess made in a central portion of a front face of the cylindrical core. An easy concentric alignment of the first and second end shafts with the permanent magnet cylindrical core is allowed while inserting the sleeve and the stiffness of the assembled set is enhanced.

Abstract: An electrical device comprising a housing having cooling fins located in a central portion along an exterior surface of the housing and a laminated magnetic stack disposed within the housing and interfacing with an interior surface of the housing at the central portion. The cooling fins are configured alternatively higher and smaller on an inlet manifold and in opposition on an outlet manifold.

Abstract: An assembly includes a rotating shaft supported with respect to a stationary housing by at least one active magnetic bearing presenting a mean radial air gap and at least one auxiliary bearing having first and second coaxially arranged annular surfaces is provided. One of the first and second coaxially arranged annular surfaces defines a clearance (E2) with one of the stationary housing and the rotating shaft, the clearance (E2) being less than the mean radial air gap and the other of the first and second coaxially arranged annular surfaces being integral with the other one of the stationary housing and the rotating shaft. The auxiliary bearing provides a first ball bearing and a second ball bearing having a misalignment with respect to each other in order to increase the starting torque.

Abstract: An assembly that includes a rotating shaft supported with respect to a stationary housing by at least one active magnetic bearing presenting a mean radial air gap and at least one auxiliary bearing having a bushing fixed to the housing and a sleeve fixed on the rotating shaft. The bushing and the sleeve have opposite surfaces that define a clearance (E2) which is less than the mean radial air gap (E1). The bushing and the sleeve each exhibit symmetry around a longitudinal axis of the shaft and have different profiles in a longitudinal cross-section including the longitudinal axis to optimize the contact pressure distribution when the rotating shaft lands on the auxiliary bearing.

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: A rotary machine provides a stator having a stator casing, and a rotor shaft having a rotational axis and supported in the stator casing by at least one radial magnetic bearing. The rotary machine further provides an axial mechanical thrust bearing being disposed proximate a radial surface of one end of the rotor shaft, the axial mechanical thrust bearing, including a rolling element located on the rotational axis of the rotor shaft.

Abstract: A permanent magnet rotor assembly includes 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 includes 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 defined by the following formula IF2=?ØY+?{square root over (((ØY+IF1)^2+ØY^2?ØX^2))}, where ?Y is an external diameter of the plurality of permanent magnets, ?X 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.

Abstract: This radial position sensor measures the radial position of a rotor within a stator. The sensor provides measuring means for measuring the position of the rotor along a first axis radial to a rotation axis of the rotor and along a second axis perpendicular to the first axis. The measuring means includes four magnetic poles, among which two poles are diametrically opposed along the first axis and two other poles are diametrically opposed along the second axis, the magnetic poles distributed, on the inner surface of the stator, with alternating magnetic polarities around the circumference of the stator. Alternatively, the measuring means includes eight magnetic poles distributed, on the inner surface of the stator, with alternating magnetic polarities around the circumference of the stator and are arranged so that each pole deviates by an angle of approximately 30° from the nearest axis among the first axis and the second axis.

Abstract: The invention concerns an electrical installation providing an apparatus, a three-phase inverter and a control device, the inverter being adapted for generating a three-phase current presenting a first frequency for operating the apparatus and an undesired frequency component presenting a second frequency. The control device is adapted for measuring a parameter of each phase of the current, the measured parameters forming a measurement vector, and for calculating a Clarke transform, providing a first vector represented in a first basis of a two-dimensional vector space, of the measurement vector. The control device is adapted for generating a representation of the first vector in a second basis of the vector space, the second basis rotating at the second frequency with respect to the first basis.

Abstract: This rotary machine includes a shaft and a housing. The shaft is rotatable with respect to the housing thanks to at least one axial magnetic bearing including a magnetic thrust disc coupled in rotation to the shaft (3) and magnetic actuators fixed to the housing and located axially around the magnetic thrust disc. This rotary machine includes a magnetically insulating insert mounted between the magnetic thrust disc and the shaft so that there is no contact between the magnetic thrust disc and the shaft.