Axial air gap brushless alternator

An alternator current generator comprising:

• an alternator outer housing;
• a rotatable shaft having a longitudinal axis, said shaft extending longitudinally within said housing and rotatable with respect to said housing about said axis;
• a stator assembly having a magnetic stator core with a stator coil wound thereon defining an effective axial stator coil length along said shaft axis, said stator core being located within and fixed with respect to said housing;
• a field assembly having a magnetic field core with a field coil wound thereon defining an effective axial field coil length along said shaft axis, said field core being located within and fixed with respect to said housing;
• said stator coil and core radially spaced apart from said field coil and core with respect to said shaft axis thereby defining a cylindrical radial air gap therebetween;
• at least one of said stator and field magnetic cores having a core end portion axially extending beyond the effective length of the coil wound thereon;
• a rotor assembly fixed to and rotatable with said shaft and including at least a first magnetic claw pole member fixed to said shaft and having magnetic fingers extending into said cylindrical radial gap and forming a low reluctance radial flux air gap between said claw pole member fingers and at least one of said stator and field magnetic cores;
• wherein the improvement comprises,
• said first magnetic claw pole member having magnetic portions that radially extend with respect to said shaft axis and form a low reluctance axial flux air gap with a radially extending end surface of said axially extending core end portion at a position axially beyond the effective axial length of the coil wound on the core having said axially extending core end portion, wherein said axial flux air gap provides a low reluctance magnetic path for conducting a substnatial portion of flux created by said field coil in said field core, and
• wherein said rotor assembly includes pole extension magnetic fingers axially extending and circumferentially interweaved with, but spaced apart from, said first claw pole member magnetic fingers and being secured thereto by a non-magnetic coupling apparatus, said pole extension magnetic fingers being support solely by virtue of their connection to said first claw pole member magnetic fingers by said non-magnetic coupling apparatus, wherein said field coil and field magnetic core are radially spaced apart from said shaft with said stator coil and stator magnetic core being further radially spaced apart from said shaft, and wherein said field coil has two opposite effective ends with said effective axial length of said coil defined therebetween, and wherein said field core is generally cylindrical in shape and is positioned about said rotatable shaft with said shaft being substantially non-flux conductive with respect to field coil flux and being positioned direct adjacent to said field core along a majority of the effective axial length of said field coil, said one core having an end, which includes said core end portion, that extends radially with respect to said shaft axis and forms one entire radially extending end surface of said one core which is positioned directly adjacent to radial extension portions of said first magnetic claw pole member which extend from said shaft to form a low reluctance axial flux air gap along substantially all of said entire radially extending end surface.