| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a back pressure during swiveling power running to suppress power loss of a hydraulic pump. <P>SOLUTION: A swiveling-type work machine is provided, in which communicating valves 25 and 26 are provided between a tank T and conduits 14 and 15 on both sides of a hydraulic motor 11 as a swivel drive source. The communicating valve 25 or 26 on the side opposite to that where the valve is operated during swiveling power running is opened to connect the conduit on the meter-out side to the tank T, and oil discharged from the hydraulic motor 11 is returned directly to the tank T without passing through a control valve 13, thereby eliminating a back pressure caused by a closing actin of the control valve 13, to reduce pump pressure. Furthermore, during deceleration, braking is applied by a regenerative action of a swiveling electric motor 20 to cause deceleration while storing generated power in a capacitor 30. <P>COPYRIGHT: (C)2013,JPO&INPIT |
