| 摘要 |
PURPOSE:To produce a revolving magnetic field through simple and economical constitution by providing a short-circuiting ring to two opposite magnetic poles of a yoke which has four magnetic poles. CONSTITUTION:The yoke 19 made of ferrite has four magnetic poles and a magnetic thin plate 6 is arranged at its center part. The short-circuiting ring 18 made of copper, etc., is provided to two opposite poles of the yoke 19. A voltage Vm is applied to an exciting coil 17 and then a current which is 90 deg. delayed behind Vm flows through the exciting coil 17, which produces magnetic flux phim. The magnetic flux phim passes over the magnetic thin plate 6 and part of it passes by the poles provided with the short-circuiting ring 18 and reduced to magnetic flux phi'm. The magnetic flux phi'm induces a voltage Vs at the short- circuit ring 18 to flow a short-circuit current Is to the ring 18 and then produce magnetic flux phi's, and consequently the composite magnetic flux phis of phi'm and phi's is produced at the poles of the yoke 19. The magnetic flux phis is some phase delayed from phim, so the magnetic flux on the magnetic thin plate 6 goes to revolving magnetic flux in cooperation with a shift in production place. |
