摘要 |
PCT No. PCT/JP93/00760 Sec. 371 Date Feb. 7, 1994 Sec. 102(e) Date Feb. 7, 1994 PCT Filed Jun. 7, 1993 PCT Pub. No. WO93/26076 PCT Pub. Date Dec. 23, 1993.A rotor (10) for a synchronous motor includes a plurality of permanent magnets (14) arranged at generally equal intervals around a shaft (12), and a plurality of core members (16) arranged around the shaft (12) while holding each permanent magnet (14) therebetween in a circumferential direction, so as to constitute magnetic poles. Each core member (16) has a symmetrical plane (S) involving a center axis (0) of the shaft (12), and is provided with a rod insertion hole (20) axially passing through the core member so as to involve the symmetrical plane (S) at the generally center of the core member. A rod member (22) is inserted into each rod insertion hole (20). Each core member (16) is further provided with a first through hole (24) formed at a portion defined from the neighborhood of a radial inner surface (16a) to the neighborhood of the rod insertion hole (20); the first through hole axially passing through the core member so as to involve the symmetrical plane (S), and a second through hole (28) formed at a portion defined from the neighborhood of the rod insertion hole (20) to the neighborhood of the radial outer surface (16b); the second through hole axially passing through the core member so as to involve the symmetrical plane (S). The first through hole (24) and the second through hole (28) can maintain the distribution of the main magnetic flux passing through the core member (16) in generally symmetrical state relative to the symmetrical plane (S).
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