求翻译：车钩是用来实现机车和车辆或车辆和车辆之间的连挂，传递牵引力及冲击力，并使车辆之间保持一定距离的车辆部件。车钩作为火车、地铁、轻轨等轨道车辆一种不可缺少的装置，研究各种车钩问题的原因与对策就显得极为重要。车钩结构要随着列车重量和速度的提高而不断更新，车钩零件的疲劳和磨损问题日益突出，成为车钩失效的主要形式。本文阐述了车辆车钩的组成、基本原理与类型，对目前我国使用的车钩进行了介绍，并针对几种车钩问题的原因及措施进行了分析概述。是什么意思？

The coupler is used to achieve the coupling between the locomotives and rolling stock or vehicles and vehicle pass traction and impact, keeping a certain distance between the vehicle components and vehicle. Coupler as a train, subway, light rail vehicles an indispensable device, research the causes

The hook is used to fulfill locomotives and vehicles or vehicles and between vehicles and the Company passed to traction and shock, and allow the vehicle maintain a certain distance between the vehicle parts. As a car-train, subway, light rail vehicles, such as orbit an indispensable unit to the stu