ball spline

例句：

1. 1. The engineer used a ball spline to adjust the gearbox.
   工程师使用球面丝杠来调整齿轮箱。
2. 2.The ball spline is essential for smooth rotation of the machine parts.
   球面丝杠对于机器部件的平滑旋转至关重要。
3. 3.The ball spline was designed to reduce friction and improve efficiency in the manufacturing process.
   球面丝杠被设计用来减少摩擦，提高生产过程中的效率。