Basic hydraulic bucket lifter consists of guiding parts and hydraulic parts, in which the guiding parts are composed of one inverted steel outer housing which can slide up and down in the guide hole of cylinder head and one inner housing, and the hydraulic parts consists of cylinder, plunger, return spring, and check valve.

When the cylinder contacts with cam base circle, the oil will enter in inner oil chamber from oil duct of cylinder head under pressure of engine oil pump. At the moment the pressure in inner oil chamber exceeds that in high pressure oil chamber, cause opening of the check valve, making oil flow into the high pressure oil chamber. The pressure of the return spring separately pushes plunger and cylinder up and down, then the valve assembly lash gets automatic compensation. When the pressure in high pressure oil chamber equals pressure in inner oil chamber minus the opening pressure,  the oil supplement is finished.

Basic hydraulic bucket lifter is applicable to direct drive valve mechanism with ability to automatically adjust valve lash, decreasing movement energy and improving economical efficiency.