| 摘要 |
PURPOSE:To prevent the overheating of a brake lining in a power device by connecting a motor through a mechanical brake to a load, providing a tachometer generator, and operating a blower for cooling the generator at the braking time of the brake. CONSTITUTION:When a system power source 7 is alive, a switch 12 is connected to a contact (b) by a voltage detector 10, and when a brake 3 is braked by releasing a contactor 5, a blower 14 is operated by a contactor 13, thereby cooling the brake 3. The switch 12 is connected to a contact (a) side by the detector 10 at the power interrupting time, and a blower 14 is operated through a cnstant- voltage unit in accordance with the output of a tachometer generator 8 during braking. Accordingly, the overheat of the brake lining of the brake 3 can be prevented even for the load 1 which needs the large braking capacity at the braking time such as a downward conveyor or the like, thereby substantially improving the braking capacity and performing the preferable braking operation. |
