Patent ID: 6700296
Filing Date: 2004-03-02
Classification: H02K

Abstract:
An automotive alternator comprising:a field rotor provided with: a field coil; and a Lundell-type core having: a cylindrical portion on which said field coil is installed; yoke portions disposed so as to extend radially outward from axial end portions of said cylindrical portion; and claw-shaped magnetic pole portions disposed so as to extend axially from radial edge portions of said yoke portions so as to surround said field coil; and a stator composed of a laminated core and an armature coil disposed facing an outer circumference of said claw-shaped magnetic pole portions, wherein a ratio (R2/R1) between an outer radius R2 of said cylindrical portion and an outer radius R1 of said Lundell-type core is in a range from 0.50 to 0.54, and a ratio (Tr/Tp) between in axial overlap length Tr between said laminated core and said yoke portions and an axial length Tp of said yoke portions is in a range greater than or equal to 0.2.