rotation center的用法和样例：
例句
- It is defined as the perpendicular distance between the follower's axis of motion and the center of the cam.
从凸轮的转动中心到直动推杆的导路之间的垂直距离。 - But some caution is needed in choosing the center of rotation to be employed in evaluating the torques and calculating the motion.
但是，在选择用来求力矩和计算运动的转动中心时，需要注意几个问题。
