Permanent magnet synchronous motors (PMSMs) may utilize various permanent magnet (PM) materials, including those that do not contain rare earth (RE) elements. RE-free PMs show some potential in permanent magnet synchronous motors (PMSMs) compared to RE PMs, but some PMs show an increased risk of irreversible demagnetization at lower temperatures. In some cases, as in Manganese bismuth (MnBi) surface permanent magnet synchronous motors (SPMSM), the low temperature demagnetization risk significantly impacts the torque and power density. Due to this, somewhat unconventional stator tooth geometries are used to achieve competitive torque and power densities in SPMSMs. Because conventional approaches to machine design do not consider these factors, a set of guidelines are provided for stator teeth configurations that reduce the risk of irreversible demagnetization in slotted motors.

Permanent magnet synchronous motors (PMSMs) may utilize various permanent magnet (PM) materials, including those that do not contain rare earth (RE) elements. RE-free PMs show some potential in permanent magnet synchronous motors (PMSMs) compared to RE PMs, but some PMs show an increased risk of irreversible demagnetization at lower temperatures. In some cases, as in Manganese bismuth (MnBi) surface permanent magnet synchronous motors (SPMSM), the low temperature demagnetization risk significantly impacts the torque and power density. Due to this, somewhat unconventional stator tooth geometries are used to achieve competitive torque and power densities in SPMSMs. Because conventional approaches to machine design do not consider these factors, a set of guidelines are provided for stator teeth configurations that reduce the risk of irreversible demagnetization in slotted motors.

In a brushless motor, a coil cap is formed with a cap-side first positioner in which a coil-side positioner is to be fitted and a cap-side second positioner for positioning Hall elements of a plurality of phases about an axis with respect to the coil cap. A circuit board is formed with a board-side positioner in which the cap-side second positioner is to be fitted. A relative positional relationship about the axis between the cap-side first positioner and the cap-side second positioner is such a positional relationship that the Hall elements of the plurality of phases are positioned at preset positions about the axis relative to stator coils of a plurality of phases.

In a brushless motor, a coil cap is formed with a cap-side first positioner in which a coil-side positioner is to be fitted and a cap-side second positioner for positioning Hall elements of a plurality of phases about an axis with respect to the coil cap. A circuit board is formed with a board-side positioner in which the cap-side second positioner is to be fitted. A relative positional relationship about the axis between the cap-side first positioner and the cap-side second positioner is such a positional relationship that the Hall elements of the plurality of phases are positioned at preset positions about the axis relative to stator coils of a plurality of phases.