| 摘要 |
Provided is a slewing-type working machine including a lower travel body, an upper slewing body, a hydraulic motor, a slewing electric motor, a hydraulic pump, a slewing operation device, a control valve, a brake valve, a communication valve switched between an open position for bringing a motor outlet-side line into direct communication with a tank or a motor inlet-side line, bypassing the control valve, and a close position for blocking the communication, and a control device outputting a communication-valve-switching command and a torque command for the slewing electric motor. The control device performs (i) determining, as a target value, a pressure generated in the hydraulic motor without the communication valve, or a torque obtained from the pressure, based on an operation state of the slewing operation device and a slewing state of the upper slewing body, (ii) determining, as an actual value, a pressure actually generated in the hydraulic motor or a torque obtained from the pressure, and (iii) outputting the torque command based on a value obtained by subtracting the actual value from the target value. |
