The motor is provided with: a rotor core; permanent magnets disposed on the outer circumferential surface of the rotor core and magnetized in parallel orientation; and a salient pole saliently formed between the permanent magnets. The ratio of the number of magnetic poles of the permanent magnets to the number of teeth is 2:3. Sloped surfaces are formed on the side surfaces of the permanent magnets in the circumferential direction. The angle θ2 between lines L3 and lines L2 is an electrical angle of 13° or more, said lines L3 connecting outer circumferential corner portions where the sloped surfaces and the outer circumferential surface are connected to each other and the shaft center, said lines L2 connecting the radial direction outermost side of the circumferential side surface of the salient pole and the shaft center.

Provided is a method of estimating a rotor operational parameter of an electrical machine including multiple winding sets wound to have a phase-shift between winding sets, the rotor operational parameter including rotor position and/or rotor speed, the method including: deriving, for each winding set, a preliminary rotor operational parameter based on a current and a voltage of the respective winding set; calculating for at least two winding sets and for at least one predefined harmonic, a rotor operational parameter harmonic correction term based on the preliminary rotor operational parameter of at least two winding sets; calculating for at least one winding set, a corrected rotor operational parameter based on the preliminary operational parameter of this winding set and the rotor operational parameter harmonic correction term of this winding set, wherein in particular the corrected rotor operational parameter has at least one predefined harmonic removed or at least attenuated.

Provided is a method of estimating a rotor operational parameter of an electrical machine including multiple winding sets wound to have a phase-shift between winding sets, the rotor operational parameter including rotor position and/or rotor speed, the method including: deriving, for each winding set, a preliminary rotor operational parameter based on a current and a voltage of the respective winding set; calculating for at least two winding sets and for at least one predefined harmonic, a rotor operational parameter harmonic correction term based on the preliminary rotor operational parameter of at least two winding sets; calculating for at least one winding set, a corrected rotor operational parameter based on the preliminary operational parameter of this winding set and the rotor operational parameter harmonic correction term of this winding set, wherein in particular the corrected rotor operational parameter has at least one predefined harmonic removed or at least attenuated.

An electric motor with a rotor and a stator, where the rotor and/or the stator can comprise two or more sections, and a torque ripple caused by the magnetic field(s) associated with a section of the rotor (or stator) can at least partially counters torque ripple caused by the magnetic field(s) associated with other section(s) of the rotor (or stator).

An electric motor with a rotor and a stator, where the rotor and/or the stator can comprise two or more sections, and a torque ripple caused by the magnetic field(s) associated with a section of the rotor (or stator) can at least partially counters torque ripple caused by the magnetic field(s) associated with other section(s) of the rotor (or stator).

An electric machine includes a stator and a rotor. The stator defines a central orifice and has an inner diameter. The rotor has an outer diameter and is disposed within the stator. An airgap is defined between inner diameter and the outer diameter. The rotor defines a plurality of cavities. The rotor has magnets disposed within each of the cavities. The magnets define a plurality of pole arc angles. Each pole arc angle is centered about a D-axis. The rotor has an outer periphery. The outer periphery forms smooth spline curves positioned within each pole arc angle. The smooth spline curves deviate radially inward relative to the outer diameter.

Aspects described herein relate generally to rotary compressors that incorporate a flywheel within to significantly reduce the compressor vibration and drive torque ripples as well as to achieve a higher overall electro-mechanical efficiency and potentially lower combined costs of BLDC rotary compressors and their drive electronics.

Aspects described herein relate generally to rotary compressors that incorporate a flywheel within to significantly reduce the compressor vibration and drive torque ripples as well as to achieve a higher overall electro-mechanical efficiency and potentially lower combined costs of BLDC rotary compressors and their drive electronics.

A single phase permanent magnet motor includes a stator and a rotor. The stator includes a stator corer and windings. The stator corer includes a yoke portion and stator teeth. Each stator tooth includes a winding portion and a pole shoe connected to an end of the winding portion. Each pole shoe includes a pole face. The pole face defines a first positioning notch at a middle thereof. Each of the pole faces further defines at least one second positioning notch. Said at least one second positioning notches in one of pole shoe are located at the same side of the first positioning notch of the corresponding one pole shoe. The first and second positioning notches are configured such that an initial position of the rotor received in the space of the stator is offset from a dead point position.

A vehicle steering system comprises: a motor assembly operably coupled to a steering rack, the motor assembly comprising a motor having a rotor and a motor position sensor configured to sense a rotor angle of the motor in a single-turn range; and a rotary-to-linear conversion mechanism operably coupled between the motor assembly and the steering rack, the rotary-to-linear conversion mechanism comprising a rotor operably coupled to the rotor of the motor. A processor calculates an absolute angular position of the pinion in a full-turn range of rotation of the pinion based on the sensed rotor angle of the motor and a pinion angle sensed by a pinion angle sensor in a single-turn range, or based on the sensed rotor angle of the motor and an angle of the rotor of the rotary-to-linear conversion mechanism sensed by an angular position sensor in the single-turn range.