引言矿井井下进行的高效率的煤炭生产,几乎完全依靠可弯曲的动力电缆把电力传输给移动的设备。这些电缆应是相当大的,才能输送重型设备运行所需要的电流,但这些电缆又须轻而柔软,当设备从一个地方移到另一个地方时,电缆足以经得起连续的载运。载运电缆通常是用人力或用专门设计的电缆卷轴进行的,也可使用大功率设备来拖曳电 INTRODUCTION Efficient coal production in the mine shaft relies almost entirely on flexible power cables to deliver electricity to moving equipment. These cables should be fairly large to carry the current needed for the operation of heavy equipment. However, these cables, in turn, must be light and soft enough to withstand continuous transport when the equipment is moved from one place to another. Carrying cables are usually done manually or with specially designed cable reels, and high-power equipment can also be used to tow the electricity