axle center的用法和样例：
例句
- In this cavern are three massive stone wheels, each with a huge pole through its centre as an axle.
洞里有三个巨大的砂轮，每个砂轮的中心穿过一个巨大的杆作为轮的轴心。 - This short-arc coupled with the low pendulum effect achieved by pivoting the disc through a point near its center of gravity assures rapid closure.
绕轴旋转的阀瓣的重力中心距轴心较短，因此这种短弧的钟摆效应也比较小，从而确保能够迅速关闭。
