| 摘要 |
<p>PURPOSE:To detect an overload state of motor in a short time by constituting the device so that a signal is generated when the value of root-means-square (RMS) for one cycle of torque which is calculated in accordance with each sampling value of the number of rotations and torque and with the cycle, exceeds a set value. CONSTITUTION:A transmission 3 to be tested is operated by a driving device 1 to detect 2, 3 the torque and the number of rotations of device 3 respectively, and the sampling 7 is made for them at constant time intervals for each. Then, the value of root-mean-square(RMS) for the torque is obtained in an overload deciding part 8 by calculating the sampling data from a specified formula. When the RMS value obtained by such a manner exceeds 50% overload rated torque, for instance, an overload signal is generated, and the next sampling is performed if it does not exceed. The overload detecting signal is supplied to a display part 9 to alarm and display that the driving device is overloaded, and at the same time supplied to a system protecting circuit as a digital signal, wherein the device 1 is protected from the overload.</p> |
