抄録
In servo-mechanisms, the vibration of the servomotor is an important problem in connection with the control quality. This paper concerns the torsional vibration of the 2 phase servomotor, especially the vibration at stall, such as in force servo-mechanisms.
In sinusoidal excitation, no torque variation occurs in stall torque, whereas, in non-sinusoidal excitation, torque variation occurs even in stall torque and the vibration is always induced. But even in the case of sinusoidal excitation, a parametric resonance with line frequency will be induced by the time-varying damping torque, because the stiffness of the gear train is so small that the mechanical resonance frequency is near the line frequency.
Further, the analysis of the peculiar torque hysteresis in gear train is also shown, which may affect on the vibration mode, control quality and controlling stability.
