Featuring a spring piston firing mechanism, the sniper rifle is almost silent when fired.
采用弹簧活塞式发射装置，狙击步枪射击时几乎无声。
2
Reciprocating compressors is using the piston, the crank, link mechanism or the piston, the crank, sliding tube institutions, rotary compressor rotor is the use of crankshaft institutions.
往复式压缩机使用的是活塞、曲柄、连杆机构或活塞、曲柄、滑管机构，旋转式压缩机使用的是转轴曲轴机构。
3
This article designed a displacement setting mechanism by the fixed quantity of valve model radial column piston as base pump.