| 摘要 |
PURPOSE:To unify a surfacial pressure applied on an insulation key and improve strength reliability by providing a cross-section area on the internal periphery larger than that of the external periphery of an insulation key connected, with a prearranged surfacial pressure, to a coil conductor through the intermediary of an insulation key. CONSTITUTION:An insulation key 1d fixing the winding start end of a coil conductor 1a, the winding finish end and the adjoining coil conductor 1a with a required surfacial pressure is formed with a step in such manner that the relationship betwen the thickness h1 of an insulation key on the internal dia. side and the thickness h2 of an insulation key on the external dia. side may be h1>h2. In addition, in the peripheral direction of the insulation key 1d, the length of its internal dia. side will be larger than that of the external dia. side so as to form a step in the diametrical direction. Thus the cross-section area on the internal periphery of the insulation key 1d is constituted larger than that of the external periphery. Under this constitution, it is possible to equalize a surfacial pressure on the internal dia. side and a surfacial pressure on the external dia, side which act between the coil conductor 1a and the insulation key 1d by a tension in the peripheral direction due to an electromagnetic force brought to bear on a troidal coil and therefore, eliminate an unnecessary force. |
