Patent ID: 6037694
Filing Date: 2000-03-14
Classification: H02K

Abstract:
A rotor for an automotive alternator, comprising:a pair of field cores each having a cylindrical base portion and a plurality of claw-shaped magnetic poles projecting from outer circumferential edges of said base portions, said field cores being secured to a rotating shaft facing each other such that end surfaces of said base portions are in close contact with each other and said claw-shaped magnetic poles intermesh with each other;a cylindrical bobbin fitted over said base portions of said pair of field cores, said bobbin having a cylindrical portion, a pair of first and second annular flange portions projecting perpendicularly from both ends of said cylindrical portion, a recessed groove disposed at an angle to a radial direction in an inner wall of said first flange portion, and an anchor portion disposed on an outer circumferential portion of said first flange portion, in close proximity to an outer circumferential end of said recessed groove; anda field winding having a circular cross-section, a starting portion which is wound around said anchor portion and housed in said recessed groove, then drawn from an inner circumferential end of said recessed groove onto an outer circumferential surface of said cylindrical portion of said bobbin, and additionally wound a predetermined number of turns into multiple layers on said cylindrical portion of the bobbin,wherein at least one portion of said field winding excluding a prewind portion and a postwind portion is formed with a rectangular cross-section; andwherein the portion of said field winding housed in said recessed groove is formed with a rectangular cross-section, and said recessed groove is formed with a rectangular internal cross-section approximately matching an external shape of said portion of said field winding housed therein.