Sealing of the piston shafts of hydraulic frame-saw tensioners against dirt accumulation

摘要

Hydraulic frame-saw tensioners having two sealing mats surrounding the pistons, in which the inner sealing mat surrounds the pistons with a cylindrically formed-on sealing lip, the axial height of said sealing lip being at least twice as great as the thickness of said inner sealing mat in its remaining regions, and in which a second, outer sealing mat surrounds the pistons and protects against coarse impurities and damage. The outer sealing mat is made of harder material than the inner sealing mat.