WE CLAIM:
[Claim 1] A permanent magnet motor, comprising:
a stator (70) comprising an armature winding (13) and a stator core (12) having slots (73) configured to accommodate the armature winding (13) therein; and
a rotor (34), which is provided on an inner side of the stator (70) with a gap therebetween and comprises a rotor core (22) formed by sequentially laminating a plurality of thin steel plates in an axial line direction of the rotor (34), a plurality of permanent magnets (23) bonded onto a plurality of bonding surfaces formed on a surface of the rotor core (22) at intervals in a circumferential direction of the rotor core (22), and a shaft (19) passing through the rotor core (22) along a center axis line of the rotor core (22),
the rotor (34) comprising a plurality of stages of rotor portions (78, 79) arranged along the axial line so as to be skewed in the circumferential direction,
the rotor core (22) comprising projections (74) in each stage of rotor portions (78, 79), the projections (74) being each formed between the bonding surfaces adjacent to each other so as to project in a radial direction of the rotor core (22) therefrom,
each of the projections (74) comprising a second projecting portion (81) to be brought into abutment against a side surface of corresponding one of the plurality of permanent magnets (23) in the circumferential direction and a first projecting portion (80) separated away from the side surface of the corresponding one of the plurality of permanent magnets (23),
wherein, when the first projecting portion (80) has a total length L1 in the axial line direction and a height t1 between an extended line from corresponding one of the plurality of bonding surfaces and a parallel line with the extended line, which intersects with a corner portion of the first projecting portion (80), and
when the second projecting portion (81) has a total length L2 in the axial line direction and a height t2 between the extended line and a parallel line with the
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extended line, which intersects with a corner portion of the second projecting portion (81),
(L1×t1)>(L2×t2) is satisfied,
wherein first projecting portions (80) of the plurality of stages of rotor portions (78, 79) adjacent to each other are held in abutment against each other in the axial line direction and
when a length in the circumferential direction, which is required until the first projecting portions (80) which are held in abutment against each other in the axial line direction overlap each other through rotation of the plurality of stages of rotor portions (78, 79) adjacent to each other, is defined as W, and
when a width of the second projecting portion (81) in the circumferential direction is defined as W3,
W3