Rolling Bearing Seals
A rolling bearing is a device used to reduce friction and enable smooth rotation between two components of a machine, such as an axle, a wheel, or a shaft. In order to ensure that all parts are adequately sealed, manufacturers use a number of different types of seals designed to prevent ingress and egress of lubricants, dirt, dust, and other contaminants.
The most common type of seal used in rolling bearings is known as a contact or labyrinth seal, which uses very thin gaps between circular grooves to create a tortuous path, making it difficult for contaminants to enter. This type of seal generally consists of two rings with teeth, which form the channels that guide the lubricant around the bearing, while also allowing some leakage past the internal and external edges of the housing. The gaps between the teeth of the two rings are made to tolerances of a few microns, providing an effective seal against ingress and egress of contamination.
Another popular type of seal used on rolling bearings is the non-contact seal, which uses a non-metallic elastomeric material as the main seal. This material, typically made from nitrile rubber, has very low friction properties, making it ideal for seals used in rolling bearings. This type of seal wipes contaminants away from the bearing rather than keeping them out, which makes it effective at preventing wear and extending the life of the bearing. It is also quite inexpensive to manufacture, and can be used in a variety of applications, ranging from automotive to industrial.
The final type of seal used with rolling bearings is the double-lip seal, which is designed to contain both lubricant and debris within the bearing assembly. This seal consists of two lips, one facing inwards and the other outward, and is typically made of a metal such as stainless steel. One lip forms a barrier against debris, while the other helps seal the lubricant in and prevent it from escaping. Double-lip seals are generally used in high-speed and high-temperature applications where the addition of a metal seal can help improve performance and longevity.
Rolling bearing seals are an essential component of any bearing assembly, and manufacturers must take great care in selecting the most appropriate seals for specific applications. Contact seals, non-contact seals, and double-lip seals are the three most common types used, each offering its own unique benefits. The choice of seal will ultimately depend on the application and the environment in which the bearing must operate.
