Radially embedded permanent magnet rotor and methods thereof

An electric machine comprising:

• a machine housing;
• a stator disposed at least partially within said machine housing, said stator comprising at least one tooth and an aluminum winding wound around said at least one tooth;
• and
• a rotor disposed at least partially within said machine housing, said rotor configured to rotate with respect to said stator, wherein said rotor is a radially embedded permanent magnet rotor configured to generate an amount of flux to reduce efficiency loss due to said aluminum winding said rotor comprising:
• at least one permanent magnet;
• a substantially cylindrical rotor core comprising an outer edge and an inner edge defining a central opening, said rotor core having a radius R, said rotor further comprising at least one pole and at least one radial aperture extending radially into said rotor core from said outer edge to a predetermined depth less than said radius, said at least one radial aperture configured to receive said at least one permanent magnet;
• and
• at least one protrusion extending into said at least one radial aperture, said at least one protrusion positioned substantially along a bottom of said at least one radial aperture and configured to facilitate retention of said at least one permanent magnet within said at least one radial aperture,
• wherein said predetermined depth of each of said plurality of radial apertures is between a minimum depth defined by the equation
• D
• min
• =
• (
• π
• *
• R
• )
• n
• ,
• and a maximum depth defined by the equation
• D
• max
• =
• R
• -
• 0.5
• 
• t
• tan
• (
• 180
• n
• )
• ,
• wherein n is the number of poles of the rotor core and t is the thickness of said at least one permanent magnet.

A method of manufacturing an electric machine, the method comprising:

• positioning a stator at least partially within a housing, the stator comprising a plurality of teeth and an aluminum winding wound around at least one tooth of the plurality of teeth;
• positioning a radially embedded permanent magnet rotor at least partially within the housing, the rotor including at least one pole, an outer edge, and an inner edge defining a central opening, the rotor having a radius R;
• forming at least one radial aperture radially into the rotor from the outer edge to a predetermined depth less than the radius;
• forming at least one protrusion extending into the at least one radial aperture, the at least one protrusion positioned substantially at a bottom of the at least one radial aperture and configured to facilitate retention of the at least one permanent magnet within the at least one radial aperture;
• and
• inserting, in a radial direction, a permanent magnet into the at least one radial aperture, wherein the radially embedded permanent magnet rotor is configured to generate an amount of flux to reduce efficiency loss due to said aluminum winding.