| 摘要 |
PURPOSE:To decrease the cost of an insulating material with heat resistance maintained, by forming an insulating resinous layer on all over the end surface of the electromagnetic coil comprising magnet wire, where the potential gradient is high. CONSTITUTION:The electromagnetic coil is formed in such a way magnet wire a is wound around in the order of numbers 1-30. Therefore, the pieces of the wire a, which have the highest potential gradient, are arranged in the close proximity together at the end surface of the electromagnetic coil, and the voltages between other portions of the winding are low. Hence, insulation is not required at the portion other than said end surface of the electromagnetic coil where the potential gradient is high. However, since disturbance will be caused in the electromagnetic coil in an insulation processing, the pieces of the wire are fixed together by the use of self-melting wire, and all over the end surface having high potential gradient is processed by an insulating resinous layer b. It is recommended that the heat resistance of the wire a has the constant thermo-gravimetric index TGI of 300 and more, and the insulating layer b has the constant TGI of 350 and more. |
