They are divided into two main classes: one class with handwheels but no gearing, and the other class with cranking actuators and worm gearing or worm and spur gearing combined.

• 这些地轴架分为两大类:一类配置手轮,没有齿轮执行机构;另一类配置转动曲轴执行机构和蜗轮或蜗轮和凸轮组合执行机构。