Rotor for synchronous motor

Claim 1

A rotor for a synchronous motor, comprising: a rotating shaft; a plurality of permanent magnets radially arranged around said rotating shaft, with a gap between each permanent magnet and said shaft, and extending in an axial direction; a plurality of laminated core members formed by axially stacking magnetic thin-plate cores, and arranged around said rotating shaft while holding each permanent magnet therebetween so as to constitute magnetic poles; a pair of end plates arranged at both axial ends of said permanent magnets and said laminated core members, and fixed to said rotating shaft; a plurality of rod members passing through each of said laminated core members in the axial direction, and connected to said end plates at both ends of the rod members; and a fastening means for fastening said permanent magnets between adjacent laminated core members at predetermined positions in a radial direction; wherein said fastening means includes at least one non-magnetic circular-plate member arranged at a predetermined position in a laminated construction of said laminated core members; said circular-plate member being provided with a shaft hole into which said rotating shaft is substantially close fitted, rod-supporting holes arranged around said shaft hole, into which said rod members are inserted, and magnet-fastening holes arranged around said shaft hole separate from said shaft hole and said rod-supporting holes, into which said permanent magnets are inserted; said magnet-fastening holes being formed in and passing through said circular-plate member while having peripheral edge portions adapted to abut on at least radial outer and inner surfaces of said permanent magnets at positions substantially corresponding to said permanent magnets.