Oil Seals, also known as fluid seals, grease seals, dirt seals, shaft seals, or lip seals, help to seal the gap between static and moving components in machinery and equipment. Oil Seals used in rotating applications are known as rotary seals.

These seals are more commonly used in pumps, motors both electric & hydraulic, gearboxes & occasionally dirt wipers in hydraulic cylinders. They help protect shafts and bearings from dirt and harmful contaminants entering the internals of the application that they are fitted to, as well as prevent any leaks of lubricant.

How are Oil Seals made?

Generally, an oil seal is made up of an outer circular metal part and a bonded inner flexible material (often nitrile rubber) that does the actual sealing.

The sealing effect is achieved by manufacturing a smaller inside diameter than the required shaft size, which preloads the sealing lip. A garter spring is often used to ensure a constant force on the shaft.

Nitrile rubber offers good durability for general use, while the flexibility of the spring behind the sealing lip keeps the oil seal firmly in place against the moving part.

Rotary Wheel Of Auto Parts

How to Choose the Right Oil Seal

There are several key factors to consider when selecting the right oil seal to best protect your application.

1. Pressure: Many oil seals are used in high-pressure applications, so understanding the working pressure of your components is very important.

2. Temperature: Just like pressure, it is very important to choose the right seal that can withstand extreme heat or cold temperatures, depending on the operating environment of your application.

3. Fluid types: Oil seals interact with oils, fuels, grease, water, and more. Choosing a seal material that is most compatible with your chosen medium can help to increase the durability of the seal and its internal components.