Patent ID: 6703759
Filing Date: 2004-03-09
Classification: H02K

Abstract:
An alternator comprising:a rotor in which north-seeking (N) and south-seeking (S) poles are formed alternately in a direction of rotation; and a stator surrounding said rotor, said rotor including: a rotor coil for generating a magnetic flux on passage of an electric current; and a pair of pole core portions composed of: a cylindrical portion onto which said rotor coil is wound; disk portions extending radially outward from first and second end portions of said cylindrical portion; and a plurality of claw-shaped magnetic poles extending axially from said disk portions so as to cover said rotor coil, said claw-shaped magnetic poles being magnetized with said north-seeking (N) and south-seeking (S) poles by said magnetic flux, and said stator including: a stator core provided with a plurality of slots formed so as to extend axially and be spaced circumferentially; and a stator winding installed in said stator core by winding a conductor wire into said slots, wherein: a ratio (t1/t2) between a radial thickness (t1) of a tip of said claw-shaped magnetic poles and a radial thickness (t2) of a root portion of said claw-shaped magnetic poles is within a range equal to or greater than 0.10 and equal to or less than 0.25 (0.10&lE;t1/t2&lE;0.25), and a ratio (A/B) between a dimension (A) of overlap between said stator core and said disk portions when viewed from a radial direction and an axial dimension (B) of said disk portions is within a range equal to or greater than 0.2 and equal to or less than 1.0 (0.2&lE;A/B&lE;1.0).