电动螺旋起重机组
power-driven screw-jack set
二自由度起重机机架模型
two-degree-of-freedom crane system
起重机起升机构
hoisting mechanism of crane
crane lifting mechanism
手动单轨起重机
hand-operated singletrack crane
手动单梁起重机
hand-handle single-beam crane
手动单双梁桥式起重机
hand-operated single-and-double beam bridge crane