| 摘要 |
PROBLEM TO BE SOLVED: To improve an output by forming an inside of a section of each permanent magnet in an arcuate shape convex toward the rotating center, and forming its outside linear in a semicylindrical state, thereby reducing in size. SOLUTION: A sectional area of each permanent magnet 18 is increased in size as compared with a conventional one. Accordingly, since a value of an interlinkage magnetic fluxϕa on a d-q conversion axis is increased, its magnetic torque is also increased. Further, a magnetic flux at a q axis as a center is decreased at a part passing a rotor core 6, while a part passing the permanent magnet is increased. Since the permeability of the magnet 18 is substantially equal to that of the air, the part of the magnetic flux passing the magnet 18 becomes a magnetic reluctance. Since the d-axis inductance Ld is reduced and the difference between the q-axis inductance and the d-axis inductance Ld is increased, its reluctance torque is also increased. As a result, a rotary torque of a permanent magnet type motor is increased. If the torque T is the same, a current necessary to drive the permanent magnet type motor is decreased, and hence its copper loss is reduced, and its efficiency is improved.
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