Rotary seals belong to a kind of dynamic seals. Rotary seals are composed of a slip ring filled with polytetrafluoroethylene and a rubber O-ring that provides elasticity. They are used to seal rods, shafts, pins, rotary joints, etc. with rotating or swinging movements. There are rotary hydraulic rotations in various industrial fields such as construction machinery, construction machinery, and automotive equipment.It is a two-way rotating sealing ring that can withstand pressure on both sides or alternating pressure.

Rotating sealing ring is often called oil seal, now let's analyze its sealing mechanism.

The sealing mechanism of the oil seal is: dry friction, boundary lubrication and fluid lubrication coexist on the contact surface between the lip of the oil seal and the shaft at the same time, and they are constantly alternating; dry friction produces wear, and fluid lubrication produces leakage.

Under boundary lubrication, a stable hydrodynamic oil film is formed between the lip of the oil seal and the interface of the shaft. In addition to being used for lubrication, this layer of oil film also plays a sealing role. If the oil film is too thick, the fluid will leak; if the oil film is too thin, the fluid lubricating oil film cannot be formed, and the lip will wear out.

In terms of installation and use：

Before installation, a little grease must be applied to the lip of the oil seal. Due to the interference of the lip of the oil seal relative to the shaft, care must be taken and prevented during installation, such as torsion and extrusion of the sealing lip. When the shaft end is not tapered, rounded and threaded, more attention should be paid, otherwise it is easy to scratch the lip and affect the sealing effect.