Abstract: To positively prevent a pressure medium sealed into an outer tube from leaking out from a clearance relative to an oil damper, there is provided a seal construction of a shock absorber 1 with leveling function wherein a seal mechanism 3 is disposed in an outer tube 2 to slidably insert a shock absorber 4 thereinto, a piston rod 5 extending from the shock absorber 4 is connected on the outer tube 2 side, a pressure medium sealed into the outer tube 2 is heated by a heating means 7 and leveling is carried out while controlling the support force exerting on the shock absorber 4, the seal construction being constituted that a free piston 15 is interposed opposite to the seal mechanism 3 between the outer tube 2 and the shock absorber 4, and the seal mechanism 3 and the free piston 15 compart and form a lubricating oil chamber 16 therebetween whereas the free piston 15 is always biased toward the lubricating oil chamber 16.
Abstract: The oil seal of the present invention for a valve stem includes a triple seal lip having a cam chamber side lip, a first combustion chamber side lip and a second combustion chamber side lip. Notches are provided on the second combustion chamber side lip and other notches are provided on the first combustion chamber side lip. These notches permit flow communication from the cam chamber side with the combustion chamber side. The notches provided on the combustion chamber side lip and the notches provided on the second combustion chamber side lip are placed circumferentially shifted from each other so that the notches are not axially aligned relative to the notches. Preferably, the non-notched portion is axially aligned and spaced apart relative to the notched portion.