| 摘要 |
Inorder to educe the magnetic flux leak through the gap between the magnetic pole teeth of the armature so as to reduce the magnetic attraction force generated between the armature and the needle, an armature unit, comprising an armature core 5 to be wound with an armature coil 4 and two magnetic poles 1 and 2, is constructed on the top of which there are provided magnetic pole teeth 11a, 12b, 21b, and 22a protruding toward the opposing magnetic pole, where the magnetic pole teeth of the magnetic pole 1 are arranged in two heights, upper and lower, so that the (2n-1)-th tooth (n=1, 2, 3, ...) protrudes as the upper one and the (2n)-th tooth (n=1, 2, 3, ...) protrudes as the lower one and the magnetic pole teeth of the opposing magnetic pole 2 are arranged in two heights, upper and lower, so that the (2n-1)-th tooth (n=1, 2, 3, ...) protrudes as the lower one and the (2n)-th tooth (n=1, 2, 3, ...) protrudes as the upper one, and the magnetic flux flows upward and downward alternately between the upper and lower magnetic pole teeth; wherein the needle 6 equipped with permanent magnets moves relatively in the gap 8 between the upper and lower magnetic pole surfaces of the armature unit. <IMAGE> |
