| 摘要 |
<p>PURPOSE:To obtain a coil for rotary transformer to restore surely to a circle according to the forming method by a method wherein a shape memory alloy is utilized as a wire. CONSTITUTION:A Cu-Zn-Al alloy is used as the shape memory alloy of a conductor, and the wire is formed in a coil shape at a temperature whereat the crystal construction of the shape memory alloy shows a high temperature phase (an austenite phase). External force is applied to the coil 9 cooled to the martensite phase transition finishing temperature Mf or less to deform the coil into a form smaller than the inside diameter of a core 7. Then when the temperature of the coil is risen to the austenite phase transition finishing temperature Af point or more by applying heat to the coil 9, the conductor returns to the austenite phase to return to the shape of before deformation, and the coil 9 is accommodated in grooves 8 for windings provided inside of the core 7. For the shape memory alloy, the alloy having electric resistance of the grade usable as a conductor, and having the martensite phase transition starting temperature Ms point of sufficiently higher temperature than the upper limit of the range of the working temperature of a rotary transformer.</p> |
