| 摘要 |
PURPOSE:To prevent a loss of synchronism surely while securing satisfactory response properties, even if the variation of a working environment temperature covers a wide range, by detecting the temperature of oil filling up a housing and by changing the upper limits of the rotational speed and roll acceleration of a stepping motor on the basis of the detected temperature. CONSTITUTION:Detection signals N2, N3 taken out from the connecting wire of resistances 72a, 72b and stator coils 32b, 32c immersed in oil are inputted and the values of resistance of respective stator coils 32b, 32c are operated on the basis of the detection signals N2, N3. Then, the temperature of respective stator coils 32b, 32c, i.e., the temperature T of the oil packed around the stator coils 32b, 32c is estimated. The upper limits of the driving speed and driving acceleration of a stepping motor are set from the estimated temperature T. Thus, a loss of synchronism can be prevented surely while satisfactory response properties are secured. |
