传统的叉车门架系统多采用主滚轮与侧滚轮分体布置(独立安装)的结构形式,这种布置形式使整个门架系统的构造尺寸比较大,门架升降位移空间受到限制,安装维护不便。1976年全国叉车联合设计后开始应用组合滚轮,组合滚轮较分置滚轮具有更好的安全性和维修性,定位精度高以及结构紧凑等优点。 The traditional forklift gantry system mostly adopts the structure form that the main roller and the side roller are separately arranged (independent installation). This arrangement makes the construction of the whole gantry system relatively large, the space for lifting and displacing the mast is limited, and the installation and maintenance are inconvenient . After the joint design of the national forklift truck in 1976, the combination roller was started to be used. The combination roller has the advantages of better safety and maintainability, higher positioning accuracy and compact structure than the split roller.