Mainshaft Face Type Seal
Face type seals used on large engine mainshafts are similar in construction to conventional our compact mechanical seals, but have additional characteristics to handle the surface speeds, temperatures and pressure typically required of such applications. The carbon seal ring stator is housed into a metal carrier and is spring loaded against the mating ring by a series of coil springs. Due to the temperature requirements, elastomers are not used. Instead, the secondary seal is one or two piston rings comprised of metal carbon graphite, or Teflon jacketed spring seal. At high speeds and pressures, some seals are configured to introduce oil lubrication directly at the interface, and is achieved by a flow of oil introduced through lubrication at the interface.
A mating ring is usually located next to bearing.
In the case of the seal for high-speed application, since there is also much higher heat generation from a mating ring, this heat generated by friction must be efficiently removed. Then, a good heat conductivity and also a good wear resistance material is used. In order to acquire a good seal performance, the roughness of the surface of a mating ring, and a surface deflection must be controlled minimum.
For this reason, a design must be surveyed from the point of minimizing deflection in various conditions.