| 摘要 |
Provided is a rotation-type working machine configured so that back pressure generated during the drive of rotation can be reduced. This rotation-type construction machine is provided with: a lower travel body; an upper rotation body; a hydraulic motor (11) having first and second ports (11a, 11b) and rotationally driving the upper rotation body; a hydraulic pump (10); a rotation operation device (12) including an operation member (12a); a control valve (13) for controlling the hydraulic motor (11) on the basis of an operation signal from the rotation operation device (12); first and second conduits (14, 15) connecting the control valve and the first and second ports (11a, 11b) of the hydraulic motor (11); communication switching devices (25, 26) capable of switching between the connection between a tank (T) and both conduits (14, 15) and the interruption of the connection; and a switching commanding section (27) which, when rotationally driving the upper rotation body, operates the communication switching devices (25, 26) so that, among both conduits (14, 15), only the conduit corresponding to the conduit on the discharge side of the hydraulic motor (11) is connected to the tank (T) without passing through the control valve (13). |
