| 摘要 |
<p>PURPOSE:To obtain good cooling performance in both the time of running and the time of stopping in self-cooling by providing ventilating ports at the front, rear, upper and bottom parts of a protective cover and by attaching shutter plates formed of shape memory alloy closing at low temperature and opening upwardly at high temperature on the upper ventilating ports. CONSTITUTION:A protective cover 3 is provided so as to cover winding end parts 2a of a primary winding 2 mounted on a slot 1a of a primary iron core 1. The protective cover 3 provides in a running direction front part ventilating ports 4 and rear part ventilating ports 5, and upper part ventilating ports 6 and bottom part ventilating ports 7 as well. Further in the upper part ventilating ports 6 shutter plates 20 formed of shape memory alloy are attached which curves upwardly when the plate comes into contact with high temperature air, and returns downwardly at low temperature. Thus at both the time of running and the time of stopping in self-cooling, a temperature rise of the primary winding can be lowly suppressed.</p> |
