The screw ship unloader is a continuous ship unloader, which is composed of the following parts: the gantry and traveling trolley moving along the track along the shore; Platform supported on the gantry and rotating around the center; The luffing oil cylinder drives the horizontal boom that can pitch up and down and the horizontal screw conveyor fixed on it; The swing oil cylinder drives the vertical arm that can swing back and forth around the end of the horizontal extension arm and the vertical screw conveyor fixed on it; Loose material screw and reclaiming device installed at the lower end of vertical screw; Horizontal screw conveyor located under the rotating tower on the portal; Belt conveyor behind the wharf, etc.

The machine is mainly composed of metal structure, conveying system, auxiliary working mechanism, operation control system, etc. The metal structure includes gantry and supporting cylinder, cylinder upper turntable, horizontal support arm, vertical support arm, etc. The gantry adopts a box-shaped structure, and the gantry legs often use a rigid and flexible leg to avoid the phenomenon of wheel gnawing due to the gantry deformation. The slewing bearing device adopts rolling bearing slewing bearing, and the horizontal arm and vertical arm can adopt tubular structure or box structure. For horizontal arm with long horizontal conveying distance, auxiliary truss shall be added to enhance its rigidity. The tail end of the horizontal arm is equipped with a live counterweight to balance the self-gravity of the vertical arm and the vertical screw conveyor. The conveying system of the screw ship unloader consists of a vertical arm screw conveyor, a relatively rotating reclaimer, a horizontal arm screw conveyor and a gantry screw conveyor. The belt conveyor system is generally used behind the wharf. The auxiliary working mechanism of the ship unloader includes the walking mechanism of the ship unloader, the rotating mechanism of the rotating part, the pitching hydraulic cylinder of the horizontal arm and its upper horizontal arm screw conveyor, the vertical arm and its upper vertical arm screw conveyor, and the swing hydraulic cylinder of the reclaiming device.