초록 ▼

In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic po

In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic pole cores that are polarized by a rotor coil to alternately different polarities are circumferentially disposed on the outer periphery thereof at prescribed equi-angular intervals. A permanent magnet which is embedded within a resin-made retainer body is provided between the magnetic pole cores and has side faces, as viewed circumferentially, which are polarized respectively to the same polarities as those of adjacent respective magnetic pole cores to thereby vary the magnetic flux quantity directed toward stator coils so as to exhibit a circumferential gentle curve. A rectifier is constructed using SiC-MOS transistors so that it is conductive and operative to thereby charge a battery with the current developed in the stator coils only when the alternating current voltages generated in the stator coils have become higher than the battery voltage.

대표청구항 ▼

[ What is claimed is:] [1.] An alternator comprising:a stator having a stator coil;a rotor comprising:a rotor coil;Lundell type magnetic poles which are disposed on an outer periphery of said rotor and along a circumferential direction of said rotor, said Lundell type magnetic poles being polarized

[ What is claimed is:] [1.] An alternator comprising:a stator having a stator coil;a rotor comprising:a rotor coil;Lundell type magnetic poles which are disposed on an outer periphery of said rotor and along a circumferential direction of said rotor, said Lundell type magnetic poles being polarized by said rotor coil to alternately different polarities;permanent magnets disposed between said Lundell type magnetic poles, respectively, so that side faces of each of said permanent magnets in said circumferential direction are polarized to opposite polarities, and said Lundell type magnetic poles and side faces of said permanent magnets which are adjacent to each other have the same polarity to thereby exhibit smooth variations of magnetic flux directed toward said stator coil along said circumferential direction;wherein said Lundell type magnetic poles have flanges which project at least circumferentially from side edges thereof and abut on an outer peripheral surface of said permanent magnets, and a magnetic force intensity of each of said side faces of said permanent magnets is substantially equal to a magnetic force intensity developed in each of said Lundell type magnetic poles which is respectively adjacent thereto; anda rectifier constructed using a MOS type transistor that converts an alternating current generated by said stator coil to a direct current, wherein said MOS type transistor is formed using as a base material a monocrystalline SiC that is a compound of silicon (Si) and carbon (C) and is smaller in resistivity than Si.