The sealing ring is small but effective!

Sealing materials are divided into elastic and plastic. Elastic materials are generally made of rubber, while plastic materials are generally made of leather; In addition, some soft metal materials are also used as sealing materials, while the end faces of rotating components (such as axial piston pumps) often use carbon as the surface material.

The material of the sealing rubber ring is different, and the corresponding resistance is also different: for example, nitrile rubber, which is resistant to petroleum but not acid, synthetic rubber; Neoprene rubber, petroleum resistant, abrasion resistant, acid resistant, acetylene based; Isoprene rubber, resistant to acid and hydraulic oil; Teflon is resistant to high temperatures, suitable for various media, and has low expansion characteristics; PTFE, on the other hand, has good lubricity, corrosion resistance, wear resistance, and toughness.

There are also classifications for sealing rings, which can be divided into O-shaped sealing rings, star shaped sealing rings, X-shaped sealing rings, hollow tube sealing rings, V-shaped sealing rings, L-shaped sealing rings, U-shaped sealing rings, Y-shaped sealing rings, and special-shaped sealing rings according to their cross-section. If classified by material, it can be divided into nitrile rubber sealing rings, natural rubber sealing rings, chloroprene rubber sealing rings, EPDM rubber sealing rings, hydrogenated nitrile rubber sealing rings, silicone sealing rings, fluorine rubber sealing rings, and silicon fluorine rubber sealing rings.

The O-Ring has a dual function of preventing internal and external leakage, so it can be installed in areas that require sealing in both directions, making it the most widely used. The V-shaped Sealing ring is a one-way Seal, and the V-port should be facing the pressure side during installation. The U-shaped sealing ring is also a one-way seal, with the U-port facing the pressure side during installation. The cross-section of the Y-shaped sealing ring is Y-shaped, which is a typical lip shaped sealing ring. The applicable working pressure of the Y-shaped sealing ring is not more than 40MPa, and the working temperature is -30-80 ℃.

In summary, sealing rings are the most important and effective means to solve the leakage problem of hydraulic systems. If the sealing ring of the hydraulic system is poor, the sealing ring may experience impermissible leakage, and the leaked oil will pollute the environment; It may also cause air to enter the oil suction chamber, affecting the working performance of the hydraulic pump and the smoothness of the hydraulic actuator movement. Therefore, the rational selection of sealing ring materials and the design of sealing ring shapes are crucial throughout the entire process of aircraft operation.

When selecting sealing rings, certain requirements must also be met. When we find leakage due to damaged sealing rings in our work, we will definitely search for sealing rings with the same part number based on IPC, and rarely consider their characteristics. At the same time, corresponding replacement part numbers will also be found, indicating that the materials and functions of these two different part numbers of sealing rings are the same. When designing and manufacturing sealing rings, manufacturers will consider the following requirements: they should have good sealing performance and can automatically improve sealing performance with the increase of pressure and temperature; The friction force between the sealing ring and the moving parts should be small and the friction coefficient should be stable; The sealing ring has strong corrosion resistance, is not prone to aging, has a long working life, good wear resistance, and can automatically compensate for wear to a certain extent. The structure is simple, easy to use and maintain, and can prolong the service life of the sealing ring.
Don't look at the small sealing ring, it's actually too powerful! On airplanes, there are actually many systems that use fluid transmission