Valve seal assembly with straight-walled retainer

摘要

A radially compliant valve stem seal assembly is adapted for installation over a valve guide of an internal combustion engine. The assembly includes a metallic cylindrical straight-walled retainer with an elastomeric sealing element chemically bonded to the interior surface of the retainer. The sealing element includes upper and lower portions; the upper portion includes a pair of sealing lips comprising an oil sealing lip and a gas sealing lip. The lips are adapted to meter oil through an interface between the seal assembly and the associated valve stem for assuring proper lubrication at the interface. The lower portion of the elastomeric sealing element provides one or more annular radially inwardly oriented gripping ribs adapted to engage the guide via an interference fit. The gripping ribs are adapted to balance forces of installation against those of securement of the valve stem seal assembly over a wide valve guide diameter tolerance range.