The marine crane is mainly composed of a rotating tower body, a boom, a fixed pillar welded to the deck, lifting, pitching and turning mechanisms, hydraulic power and piping systems, and electrical control systems. The marine crane is installed on the bottom of the crane tower with a slewing ring. The lower end of the inner ring is connected with the fixed pillar welded on the deck of the ship by bolts. The upper end of the outer ring is connected with the tower by bolts. When the ship crane is working, the rotary pinion gear driven by the rotary mechanism meshes with the ring gear of the slewing bearing to realize the rotation of the outer ring so as to realize the normal rotation of the ship crane.
The role of the slewing bearing is to support the ship's crane and transmit torque, mainly to withstand the axial force and the overturning moment. In order to make the mainframe structure compact, the bearing diameter and height are much smaller than the normal products, and no counterweight is provided. The overturning moment can reach 18 times of the axial force. The ratio of the two is basically 14.9-l8. between. The most commonly used structures at present are double-row reducer ball slewing bearings and three-row cylindrical roller combination slewing bearings.
