What Is a Rubber Seal?
Rubber seals are seals that protect equipment and maintain the function of the packing, preventing the ingress of dust and other substances from the outside.
It can be fitted in an integral groove, and there is also a double-lip rubber seal to prevent oil from being scraped off the dust seal. Rubber seals are available in a wide range of temperatures, as nitrile and fluoro rubbers are used as materials.
Uses of Rubber Seals
Rubber seals are used to seal a variety of areas and provide an adequate seal. Examples of rubber seal applications include
Grease in Various Machines
Sealing of dust
Dust seals for reciprocating movements
for sealing gaps
Grease seals on plummer blocks for rolling bearings
Anti-vibration and wind noise protection for motor vehicles
Gaskets for helmet boxes
Principles of rubber seals
Of the rubber seals, contact rubber seals (DDU or LLU) have a high frictional torque. They have limited high-speed performance, but their grease sealing properties are slightly better than non-contact rubber seals, and they have the best dust protection and good waterproofing properties.
In contrast, non-contacting rubber seals (VV or LLB) have lower frictional torque and better high-speed performance. They provide a better grease seal than Shields and better dust protection than Shields, but are not watertight.
On the other hand, the Shield (ZZ) has lower frictional torque and better high-speed performance. They also have better grease sealing and dust protection, but are not watertight. Contact rubber seals consist of a rubber seal plate fitted into the outer ring.
As the rubber seal is in contact with the inner ring, the ingress of dirt from the outside is extremely low. The seal material is mainly NBR, with a limit operating temperature range of -40 to +120°C.
Types of Rubber Seals
1. O-Ring Seals
O-ring seals are annular rubber seals with a circular cross-section. They are generally used to prevent leakage of liquids and gases due to the durability and compressibility of rubber.
They have a simple construction that can be adapted to tight spaces, such as pipes and joints. The pressure of the liquid or gas compresses the rubber and fills the gap between it and the surrounding components, thereby providing a sealing effect.
2. Flat Rubber Sheets
Flat rubber sheets are rubber seals in sheet form, available in various thicknesses and sizes. These rubber seals can be cut and processed to specific shapes and dimensions, making them suitable sealing materials for special applications.
It is used in various fields, including construction, vehicles and industrial machinery, and has excellent waterproofing and vibration-absorbing properties. It may also be used as an electrical insulator.
3. Expansion Joints
Expansion joints are rubber seals with elasticity. They are used in buildings, bridges, pipelines and other structures to absorb displacements caused by temperature changes and vibrations.
It responds to expansion and contraction caused by changes in temperature, preventing cracking and damage to structures. As a sealing material that requires durability and weather resistance, it is effective in extending service life and ensuring safety.
4. Diaphragm Seals
Diaphragm seals are thin, flexible rubber membrane seals. They deform in response to external pressure changes and are used in devices such as liquid and gas control valves, pumps and instruments.
They have high flexibility and durability and are used where high precision control is required. The thin and lightweight construction of these products also improves the efficiency and performance of equipment.
5. Sponge Rubber Seals
Sponge rubber seals are soft sealing materials made from foamed rubber material. It easily adheres to uneven surfaces and has excellent waterproofing and dustproofing properties.
It is used in the assembly of electronic equipment, vehicles and furniture, and is widely used in situations where vibration absorption is required and as a packing material to fill gaps. Sponge rubber seals are flexible and can be used freely according to shape, making them suitable sealing materials for a wide range of industrial product designs.