double drum air driven hoist

The causes analysis of the welding seam cracking about the main winch drum of Zhongmacun Coal Mine;

中马村矿主井绞车滚筒开焊的原因分析

Narrow-gap submerged arc welding for drawworks drums of drilling rigs;

钻机绞车滚筒体的窄间隙埋弧焊