A reciprocating piston, the inhalation and from a liquid, known as a working cycle; this pump known as the single-action pump.

活塞往复一次，各吸入和排出一次液体，称为一个工作循环；这种泵称为单动泵。

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Working principle: piston moves from left to right, form a negative pressure pump cylinder, the liquid tank into the pump by the inhalation valve cylinder.

工作原理：活塞自左向右移动时，泵缸内形成负压，则贮槽内液体经吸入阀进入泵缸内。

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A new working mode of directly using the reciprocating motion of piston for outputting liquid power was put forward.

提出了一种直接利用内燃机活塞的直线往复运动实现流体压力能输出的新工作模式。

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EcoMotors and Achates are developing two-stroke, opposed piston diesel engines while Pinnacle is working on a four-stroke opposed piston gasoline engine.

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The main difference between the thermoacoustic system and Stirling's original idea is that, instead of using thermal expansion of the working fluid to push the piston, it uses powerful pulses of sound.

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