在宽窄水平导轨上进行纯滚动双钢球碰撞实验，发现它与滑动运动中的双钢球碰撞实验明显不同; 其原因在于纯滚动双钢球的碰撞是在碰撞点的正碰和切向碰撞的复合碰撞，两类碰撞遵从不同的动力学规律;碰撞过后，两钢球的运动状态都不再是纯滚动，要恢复成纯滚动，每一个钢球都必须通过自身与导轨之间的相互作用，经历一次自调整阶段;而自调整阶段的能量损耗，与钢球的滚动半径和它的即时状态与纯滚动的偏离有关.

A pure rolling double steel ball collision experiment is carried out on a wide

and narrow horizontal rails，and it is found that it is significantly different from the double

steel ball collision experiment in sliding motion; the reason is that the collision of the pure

rolling double steel ball is the frontal and tangential collision at the colli- sion point. The

two types of collisions obey different dynamic laws; after a collision，the motion state of the two

steel balls is no longer pure rolling. To return to pure rolling，each steel ball must pass through

the interaction between it- self and the guide rail. The effect is to go through a self-adjusting

stage; the energy loss in the self-adjusting stage is related to the rolling radius of the steel

ball and the deviation of its immediate state from pure rolling.