For basic hydraulic bucket lifter, if part of effective volume in inner oil chamber is occupied by air, the oil in inner and outer oil chamber will be separated, making oil in inner oil chamber insufficient to compensate the high pressure oil chamber where inevitably air is entered, causing decreased oil inflexibility and increased loss of valve lift, thereby causing vibration and noise.     

While for labyrinth hydraulic bucket lifter, there is one more outer ring in outer oil chamber. When the hydraulic lifter is in adjustment stage, the oil needs to cross over the outer ring first and then enter into the inner oil chamber. Therefore, when the engine stops, though there is air entering into the outer oil chamber due to oil cooling, the outer ring will prevent air press oil from outer oil chamber to the oil channel of cylinder head; there is another inner ring, the oil needs to be sucked by bottom of the inner ring.

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