When they are subjected to hot & pressured oil, or hot & pressured gas, they will compress. These seals reduce in size and become more compact. Afterward, they store the mechanical energy generated by the heat and pressure, which is why they can maintain a leak-proof mating surface.
* Oil contamination in the coolant If you notice oil in your coolant reservoir, it could be a sign that the cylinder head gasket has failed and is allowing oil to leak into the cooling system.Polytetrafluoroethylene
Chemical resistant
Low coefficient of friction poor elastic properties not wear resistant if used by dynamic applications
Foam inhibitors: This additive does exactly what it sounds like. Foam inhibitors keep motor oil from forming foam and bubbles. If foam and bubbles were to form, the oil would be unable to coat the important parts of the engine and keep it cool.
Figure 4.4. Scanning electron microscope (SEM) image of the surface quenched for (A) uncured rubber and (B) transmission electron microscope (TEM) image for cured rubber [64].
Lever the seal out with a screwdriver, working carefully to avoid scoring the seal housing.
Cylinder Head Gaskets The Heart of Your Engine's Performance
Minor lip The minor lip prevents the entry of dust and contaminants from outside.
Lubricant can be retained in the space between the main lip and the minor lip.
Vulcanizates of several fluoroelastomers, listed in Table 14.1, were exposed to a standard 5W-30 engine oil, ASTM Service Fluid 105, for up to 6 weeks at 150°C (302°F).5 The oil was changed weekly, but was not aerated. Retained elongation was measured after exposure for 1, 2, 3, and 6 weeks; data are shown in Fig. 14.3. The results indicate that bisphenol-cured FKM-A500 VDF/HFP copolymer, FKM-B600 VDF/HFP/TFE terpolymer, and peroxide-cured FEPM-7456 TFE/P/VDF terpolymer lost most of their original elongation over the course of the test exposure, indicating considerable additional cross-linking occurred by reaction with amine- and phenol-containing oil additives. The other fluoroelastomers showed better retention of elongation, being much less susceptible to additional crosslinking. Note that FEPM-7456 contains a high level of VDF (about 30%), while FEPM-7506 contains a relatively low VDF level (10–15%) to serve as cure site for bisphenol curing. The other FEPM types contain no VDF.
The material used in oil seals is also important, as it affects the seal's durability and resistance to chemicals and heatPolyacrylate
Better heat, oil and chemical resistance than NBR
It is recommended for use in oil which contains load bearing additives such as EP gear oils
Oil seals are widely used as sealing devices for machines.
JTEKT's oil seals are described in our catalog, Oil Seals & O-Rings.
However, the catalog uses a large number of technical terms and is very long, so many people seem to have trouble handling it.
Therefore, this series of columns will summarize the following in order:
• The structure, functions, and types of oil seals
• How to select the right oil seal
• Handling of seals, and causes and countermeasures for oil seal failure