Abstract: An induction motor rotor comprises a rotor shaft, a rotor core, which may be solid or may include a plurality of rotor laminations, having rotor bar slots, a plurality of rotor bars extending through the rotor bar slots, and two rotor end rings brazed to the rotor bars and extending to the rotor shaft, the rotor bars and rotor end rings pre-stressing the rotor core.

Abstract: An induction motor rotor comprises a rotor shaft, a rotor core, which may be solid or may include a plurality of rotor laminations, having rotor bar slots, a plurality of rotor bars extending through the rotor bar slots, and two rotor end rings brazed to the rotor bars and extending to the rotor shaft, the rotor bars and rotor end rings pre-stressing the rotor core.

Abstract: An induction motor rotor comprises a rotor shaft, a rotor core, which may be solid or may include a plurality of rotor laminations, having rotor bar slots, a plurality of rotor bars extending through the rotor bar slots, and two rotor end rings brazed to the rotor bars and extending to the rotor shaft, the rotor bars and rotor end rings pre-stressing the rotor core.

Abstract: A compact bearingless machine drive system includes: a first rotor segment; a first stator segment with the first stator segment including a drive winding and a first control winding; a second rotor segment; a second stator segment with the second stator segment including the drive winding and a second control winding; and a rotor shaft. The first and second rotor segments are attached to the rotor shaft. A common end ring is coupled between the first and second rotor segments. A drive inverter controls the drive winding to generate torque, and first and second control inverters control the first and second control windings to generate radial forces on the first and second rotor segments.

Abstract: An induction motor rotor comprises a rotor shaft (12), a rotor core (14), which may be solid (114) or may include a plurality of rotor laminations (13), having rotor bar slots (15), a plurality of rotor bars (16) extending through the rotor bar slots, and two rotor end rings (18) brazed to the rotor bars and extending to the rotor shaft, the rotor bars and rotor end rings pre-stressing the rotor core.

Abstract: A rotor includes a shaft; a permanent magnet layer; and a retainer comprising a conductive, low magnetic permeability material bound to the rotor shaft. The permanent magnet layer is semi-restricted between the shaft and the retainer. In one embodiment, the magnet layer includes a molded ring magnet. In another embodiment, the magnet layer includes a plurality of magnet segments which can be situated on the rotor in rotor pockets or in a rotor cage. The bond between the retainer and the rotor can be enabled by a cap or by support elements. A high conductivity material can be situated over the retainer with the combination of the retainer and the high conductivity material having a resistivity high enough to minimize space harmonic losses and low enough to minimize time harmonic losses. The high conductivity material can also be applied to induction rotors for excluding high frequency components while permitting penetration of low frequency torque producing fields.

Abstract: A compact bearingless machine drive system includes: a first rotor segment; a first stator segment with the first stator segment including a drive winding and a first control winding; a second rotor segment; a second stator segment with the second stator segment including the drive winding and a second control winding; and a rotor shaft. The first and second rotor segments are attached to the rotor shaft. A common end ring is coupled between the first and second rotor segments. A drive inverter controls the drive winding to generate torque, and first and second control inverters control the first and second control windings to generate radial forces on the first and second rotor segments.

Abstract: A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage.

Abstract: A rotor includes a shaft; a permanent magnet layer; and a retainer comprising a conductive, low magnetic permeability material bound to the rotor shaft. The permanent magnet layer is semi-restricted between the shaft and the retainer. In one embodiment, the magnet layer includes a molded ring magnet. In another embodiment, the magnet layer includes a plurality of magnet segments which can be situated on the rotor in rotor pockets or in a rotor cage. The bond between the retainer and the rotor can be enabled by a cap or by support elements. A high conductivity material can be situated over the retainer with the combination of the retainer and the high conductivity material having a resistivity high enough to minimize space harmonic losses and low enough to minimize time harmonic losses. The high conductivity material can also be applied to induction rotors for excluding high frequency components while permitting penetration of low frequency torque producing fields.

Abstract: A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage.

Abstract: A motor with positive torque parking positions. The motor includes a rotor which is rotatable about an axis of rotation and a stator in magnetic coupling relation with the rotor. The stator includes a plurality of teeth each having a radially extending shaft and an axially extending face. The faces of the stator teeth define an aperture for receiving the rotor and the faces of the stator teeth and the rotor define an air gap therebetween. Each stator tooth has a notch in its face that is approximately at least as wide as the shaft of the stator tooth so that the stator has a magnetic configuration relative to the rotor for parking the rotor in a rest position corresponding to a positive torque starting position. The motor also includes a winding on the shafts of the stator teeth and a control circuit for controlling current in the winding whereby an electromagnetic field is produced for rotating the rotor at a desired speed or torque during operation of the motor.

Abstract: In a five-axis magnetic bearing, each of two combined radial and axial magnetic bearing structures includes a radial magnetic stator and a radial magnetic rotor. A shaft supports the rotors of the bearing structures. Each rotor and stator have an asymmetrical orientation such that the bearing structure is capable of creating a force in an axial direction when the bearing structure is excited. A creatable axial force of a first one of the bearing structures is capable of being in sufficient opposition to a creatable force of a second one of the bearing structures so as to maintain the shaft assembly in a desired axial position. The asymmetrical orientation may include, for example, a rotor being physically offset from a stator or a spatial distinction between a surface region of a respective rotor and a surface region of a respective stator. Examples of spatial distinctions include material extensions, notches, and holes.

Abstract: A motor with positive torque parking positions. The motor includes a rotor which is rotatable about an axis of rotation and a stator in magnetic coupling relation with the rotor. The stator includes a plurality of teeth each having a radially extending shaft and an axially extending face. The faces of the stator teeth define an aperture for receiving the rotor and the faces of the stator teeth and the rotor define a air gap therebetween. Each stator tooth has a notch in its face that is approximately at least as wide as the shaft of the stator tooth so that the stator has a magnetic configuration relative to the rotor for parking the rotor in a rest position corresponding to a positive torque starting position. The motor also includes a winding on the shafts of the stator teeth and a control circuit for controlling current in the winding whereby an electromagnetic field is produced for rotating the rotor at a desired speed or torque during the operation of the motor.