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 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 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: 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 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: 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 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: 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: An electric centrifugal compressor for a heat ventilation air conditioning system for vehicles comprises a motor portion (20) and a centrifugal compressor portion (10) driven by the motor portion (20) through a shaft (15). It comprises an electromagnetic device for levitating the shaft (15) during functional operation of the electric compressor and auxiliary landing bearings (8). The electromagnetic device may comprise in particular an axial bearingless motor.

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: 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 compact electric centrifugal compressor particularly suitable for a heat ventilation air conditioning system for vehicles provides a motor portion (20) and a centrifugal compressor portion (10) driven by the motor portion (20) through a shaft (15). The motor portion includes first and second radial bearingless motors (140, 150). An active axial magnetic bearing or an axial bearingless motor (130) is located between the first and second radial bearingless motors (140, 150). The motor portion is further equipped with auxiliary landing bearings (8).