spline shaft

例句：

1. 1. The machine has a spline shaft that can be adjusted to fit different parts of the machine.
   这台机器有一个可以调整以适应机器不同部分的花键轴。
2. 2. The spline shaft is used to connect two pieces of machinery together.
   花键轴用于将两台机械连接在一起。
3. 3. The spline shaft was designed to reduce friction and improve efficiency in the machine.
   花键轴的设计旨在减少摩擦并提高机器的效率。