What Is a Rubber Seal?
A rubber seal is a seal to protect equipment and maintain the functionality of the packing, preventing the intrusion of dust and other contaminants from the outside.
Rubber seals can be installed in an integrated groove, and double-lip rubber dust seals are also available to prevent oil from being scraped out.
Rubber seals are made of nitrile or fluoro rubber and can be used in a wide range of temperatures.
Uses of Rubber Seals
Rubber seals are used to seal a variety of locations to provide a proper seal.
Rubber seals are used to seal grease, dust, reciprocating dust, gaps, rolling bearing plummer blocks, automotive anti-vibration and wind noise, helmet box packing, and various box packings and various other box packings.
Principle of Rubber Seals
Among rubber seals, the contact type rubber seal (DDU or LLU) has high frictional torque and limited high-speed performance, but its grease sealing performance is slightly better than non-contact rubber seals, and it has the best dust-proofing and waterproofing properties.
In contrast, among rubber seals, the non-contacting rubber seal (VV or LLB) has lower frictional torque, better high-speed performance, better grease sealing performance than the Shield, and better dust resistance than the Shield, but is not waterproof.
On the other hand, shield (ZZ) has lower frictional torque, better high-speed performance, better grease sealing, and better dustproofing, but is not waterproof.
The contact type rubber seal has a rubber seal plate that is fitted into the outer ring. Since the rubber seal is in contact with the inner ring, the entry of dust from the outside is extremely small.
The seal material is mainly NBR, and the critical operating temperature range is about -40 to +120°C.
Types of Rubber Seals
There are several types of rubber seals that can be classified according to material. Since the characteristics of rubber seals vary depending on the material, it is important to select the most suitable one for your application.
1. Nitrile Rubber (NBR)
It is a sealing material with a good overall balance of mechanical strength and other physical properties, as well as cost. It is widely used for oil seals and O-rings.
2. Acrylic Rubber (ACM)
It has excellent resistance to oil, heat, and ozone, and is used in transmissions and other drive train equipment.
3. Fluoro Rubber (FKM)
It has superior heat resistance, oil resistance, and fuel oil resistance compared to other rubber materials, and its use as a sealing material for engines and drivelines is expanding.
4. Ethylene Propylene Rubber (EPDM)
Although it has excellent heat and ozone resistance, this material is weak against mineral oil-based lubricants, making it suitable for brake fluid and water-based liquid seals.
5. Styrene-Butadiene Rubber (SBR)
It is one of the general-purpose rubbers and has excellent abrasion resistance. It is a material with a good total balance, including cost, but it is not suitable for industrial oil and is used as a sealing material for brakes.
6. Urethane Rubber (AU)
It has excellent heat resistance, abrasion resistance, and ozone resistance. Known for its wide range of hardness adjustment, it is mainly used for construction machinery.