shaft inset

例句：

1. 1.The machine's shaft inset is perfectly aligned with the gears.
   这台机器的轴心与齿轮完美对齐。
2. 2.The scientist used a shaft inset to measure the distance between two points.
   科学家使用一个轴心来测量两点之间的距离。
3. 3.The new design incorporates a shaft inset that reduces friction and improves efficiency.
   新设计采用了一种轴心，以减少摩擦并提高效率。