The oil seal is generally composed of three basic components: sealing element, metal shell and clamping spring.Types of oil seals include single and double lips, rubber or polymer, metal housing, spring loaded, and internal, external and axial guides.
5 Types of Oil Seals
NBR, also known as nitrile rubber or nitrile, is the most popular material for an oil seal because of its good resistance to many oils and greases, such as mineral grease and hydraulic oil. Depending on their composition, synthetic oils and greases, such as those based on glycol, can damage NBR rubber materials. Depending on the amount of glycol, a PTFE lip seal may be the best choice. NBR is also unable to cope with contact with acids and solvents. The rubber is suitable for oil and grease at temperatures from -35 °C to 100 °C.
Iridium spark plugs are becoming increasingly popular among car owners due to their superior performance and longevity compared to traditional copper spark plugs. These advanced spark plugs are made with a small center electrode made of iridium, a rare metal known for its strength and high melting point. This allows the spark plug to create a more consistent and powerful spark, resulting in better ignition of the air-fuel mixture in the engine.
The temperature range of the mechanism in which the seal is installed must not exceed the temperature range of the seal elastomer.
An overview of the different standard types of oil seals and their main characteristics is shown below.
Viton Oil Seals - A synthetic rubber and fluoropolymer elastomer, Viton is used to make oil seals that provide resistance in both high temperature, up to 250°C and low compression set components. They also offer a high resistance to chemicals and abrasions, so they can be used in elements that regularly interact with petroleum and solvents.
The range of uses of peroxydically cross-linked EPDM includes in hot water and steam seals. EPDM is also very resistant to ageing and ozone. Compared with the usual types of synthesis natural rubber it has good resistance to cold temperatures. EPDM is not resistant to aliphatic or aromatic hydrocarbons or mineral oil products. Resistance to chemicals, and also to oxidising agents, is very good. Temperature range from -50 °C to +140 °C depending on type.
Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.
The primary advantage of using a double oil seal is its ability to protect against both external and internal leaks. External leaks can lead to loss of lubricant,, and potential safety hazards. Internal leaks, on the other hand, can compromise the integrity of the system by allowing contaminants into the lubricant, potentially causing damage to sensitive components.Duplex Oil Seals
JTEKT provides special seals for use in a wide variety of machines and applications.
Table 5 lists the major special seals, their shapes, and their features.