| 摘要 |
PURPOSE:To increase the even distribution width of the magnetic field intensity within a coil without increasing the driving electric power or the heat loss, by increasing the winding density of a rotary magnetic field generating solenoid coil from the center toward both ends of the coil. CONSTITUTION:For a solenoid coil c, the winding density is set coarse at the part t1 near the center of the highest layer in the direction of coil length l3 and dense at the end part t2 of the highest layer respectively. At the same time, the winding density is varied within the region t1 with a certain factor. For such coil c, a region length R1 where the rotary magnetic field HR is >=95% the maximum value can be increased by about 1.5 times as much as a similar region length R2 of a conventional coil d. |
