Motor having reduced cogging torque
AssigneeNidec Motor Corporation
InventorRyan M. Bastien
Life of this patent
Estimating the term…
Abstract
An electric motor comprising a rotor rotatable about a rotor axis and a stator at least substantially circumscribing the rotor is provided. The stator includes a generally toroidal core including a plurality of arcuately spaced apart, radially inwardly extending teeth. Each of the teeth presents a radially innermost face that extends along a curved contour. A portion of the contour has a radius of curvature that corresponds to a circle having a center. The center is radially offset from the rotor axis. Furthermore, each of the teeth includes a radially extending arm having an end and a crown extending relative to the end. The crown presents a pair of arcuately spaced apart endmost tips, each of which has a rotor-facing side. The rotor-facing side includes a tapered portion that turns away from the rotor.
Claims33
An electric motor for use in a machine, said motor comprising:
- a rotor rotatable about a rotor axis;
- and
- a stator at least substantially circumscribing the rotor,
- said stator including a generally toroidal core including a plurality of arcuately spaced apart, radially inwardly extending teeth,
- each of said teeth defining a pair of arcuately outermost margins,
- each of said teeth presenting a radially innermost face that extends along a curved contour at least substantially arcuately centered between the outermost margins,
- a portion of said contour having a radius of curvature that corresponds to a circle having a center,
- said center being radially offset from the rotor axis,
- said portion being at least substantially arcuately centered between the outermost margins,
- said contour having arcuately spaced apart first and second endpoints,
- said contour spanning an angle bounded by the first and second endpoints,
- said portion spanning at least 25% of the angle.
An electric motor for use in a machine, said motor comprising:
- a rotor rotatable about a rotor axis;
- and
- a stator at least substantially circumscribing the rotor,
- said stator including a generally toroidal core including a plurality of arcuately spaced apart, radially inwardly extending teeth,
- each of said teeth defining a pair of arcuately outermost margins,
- each of said teeth presenting a radially innermost face that extends along a curved contour,
- said radially innermost face defining a face center at least substantially centered between said margins,
- said contour extending along said face center,
- a portion of said contour having a radius of curvature that corresponds to a circle having a circle center,
- said circle center being radially offset from the rotor axis,
- said portion extending along said face center,
- said contour having arcuately spaced apart first and second endpoints,
- said contour spanning an angle bounded by the first and second endpoints,
- said portion spanning at least 25% of the angle.
Dependencies are inferred from the claim text.