活塞机构 meaning in English

piston mechanism

The simulation for the structure of y4100q crank piston
柴油机曲柄活塞机构的仿真实现
Modeling and simulation analysis on internal combustion engine piston mechanism
内燃机活塞机构的建模及仿真分析
The hydraulic oil pressurizes the large - surface contact areas , which are equipped with special brake lining , onto the guide rail via a piston mechanism
液压油（配备了专用制动闸衬）通过活塞机构将大表面接触区域压至导轨上？