Patent ID: 6037695
Filing Date: 2000-03-14
Classification: H02K

Abstract:
A vehicle alternator, comprising:a rotatable shaft;a yoke, including a first series and a second series of hook-shaped magnetic poles, each hook-shaped magnetic pole including a hook portion having an outer end, each of said first series and said second series being made as a unitary body with said first series and said second series arranged facing each other and mounted concentrically on said rotatable shaft for rotation therewith, with a part of each hook portion of said first series intermediate parts of two hook portions of said second series and with a part of each hook portion of said second series intermediate parts of two hook portions of said first series, and with first spaces defined between each two adjacent hook portions of said first series and adjacent the outer end of a hook portion of said second series intermediate said two adjacent hook portions of said first series, and second spaces defined between each two adjacent hook portions of said second series and adjacent the outer end of a hook portion of said first series intermediate said two adjacent hook portions of said second series;a field winding for generating a magnetic field in said first series and said second series of hook-shaped magnetic poles, the magnetic field having a first polarity in said first series and a second, opposite polarity in said second series;stator magnetic poles arranged around the periphery of said yoke and spaced therefrom by a preset gap;a plurality of leakage magnetic flux decreasing members fitted in the defined spaces, each leakage magnetic flux decreasing member having the same polarity as its two adjacent hook portions of the same series and directly contacting side walls of said two adjacent hook portions of the same series, the radially outer width of each leakage magnetic flux decreasing member being greater than the radially inner width of such leakage magnetic flux decreasing member; anda plurality of non-magnetic metal cover plates, each plate being disposed over the radially outer surface of an associated one of said leakage magnetic flux decreasing members and welded to said two adjacent hook portions of the same series to cause the outer periphery of said cover plates to be substantially even with the outer periphery of said hook portions.