how to recognize tower crane slewing structure

We take different tower crane factories's slewing structure to compare with each other, to regognize the difference to tower crane slewing structure. we take Liebherr tower crane, Potain tower crane, Zoomlion tower crane, Yongmao tower crane, Jianglu tower crane, Dahan tower crane, and another three Shandong tower crane brands for comparison. Could you find which one they are?

The slewing mechanism of tower cranes is very important in tower crane structure. The difference of welding, thickness, height,length, design, and the slewing motor assembling, all of these will effect tower crane working, such as shaking, breaking, striking. The good tower crane slewing structure could make tower crane stable while working, and bring the comfortable feeling when tower crane operator are in the cabin.