| 摘要 |
PROBLEM TO BE SOLVED: To provide a prestressing device of on-load tap changer in which the elastic force can be adjusted easily, and the prestressing torque can be increased during initial prestressing release motion if it is insufficient.SOLUTION: A prestressing spring 140 includes a coil spring 143 and coil springs 146, 147 which are prestressed at the time of prestressing by a hoist prestressing case. The movement period of a prestressing case, by the prestressing force of the prestressing spring 140, includes a first movement period by release of both prestressing forces of the coil spring 143 and coil springs 146, 147, and a second movement period following to the first movement period by release only of the coil spring 143. Consequently, the prestressing torque required at the end of prestressing release is driven by a single coil spring as in the conventional, and the prestressing torque can be increased during initial prestressing release motion if it is insufficient. |
