Engine Valve Stem Seal II, Improved Lip with PTFE Layer for Oil Leakage Control

970548

02/24/1997

Event
SAE International Congress and Exposition
Authors Abstract
Content
It was presented in the previous paper (1) that oil leakage from valve stem seal (VSS) can be controlled by design and the characteristics of the newly designed composite VSS with a filled polyetrafluoroethylene (PTFE) layer lip are:
  • a constant lower limit of oil leakage,
  • minimal loss of power at low speed due to low friction,
  • extended life over 300,000 km of vehicle traveled distance.
It was also reported that oil leakage for lubrication can be determined by the stress distribution across the seal lip contact width touching the valve stem under a certain interference. However, the variable pressure inside Intake and Exhaust ports of an engine will affect the stress distribution of the seal lip causing the change in oil leakage.
This report presents the design evaluation method and results of the improved VSS with filled PTFE layer lip which keeps the oil leakage constant even though the inside pressure of the engine port changes.
Meta TagsDetails
DOI
https://doi.org/10.4271/970548
Pages
8
Citation
Silan, M., Seki, S., Goichi, M., Ohishi, T. et al., "Engine Valve Stem Seal II, Improved Lip with PTFE Layer for Oil Leakage Control," SAE Technical Paper 970548, 1997, https://doi.org/10.4271/970548.
Additional Details
Publisher
Published
Feb 24, 1997
Product Code
970548
Content Type
Technical Paper
Language
English