往返运动 meaning in English

back and forth movement
back-and-forth movement

The piston is playing within the cylinder at a moderate speed
活塞在汽缸中以中等速度往返运动。
The special design of double taper mill barrel can make mill bead do auto back - and ? forth movement and stay in a dynamic balance state , thereby ensure the mill bead distribute more even and get a better distribution effect
双锥型研磨腔特殊设计，可使研磨珠自动往返运动，处于一个动态的平衡状态，确保研磨珠分布更加均匀，分散效果更佳。
It was found that the decay of levitation force is dependent on both the maximum lateral displacement and the movement cycle times , while the guidance force hysteresis curve does not change after the first cycle
研究发现运动过程中的悬浮力衰减与最大横向偏移量和往返运动次数有关；但导向力在第一次往返运动之后的往返运动中迟滞曲线基本不变。