AS and SA Standard Bearing Seals

Radial Bearing Shaft Seals – AS and SA

AS and SA are radial oil seals for stainless steel bearing housings. They seal bearing housings against contaminants with long-lasting efficiency. There are two versions available, AS and SA. Each version has a specific design for specific applications.

The seals are made of nitrile rubber (NBR) which provides good resistance against mineral oils and greases, making them suitable for a wide range of standard industrial applications.

AS Seal

AS oil seals are designed with asymmetric lip angles. The angle α between the shaft and lip on the air side is larger than the angle β on the lubricant side. This geometry is designed to prevent contamination from entering the bearing housing while retaining lubricant inside. Normally, seals are designed with a small angle β on the lubricant side and a large angle α on the air side. This prevents lubricant from leaking out of the system. However, when grease is used, the difference in angles is less important and often reversed to provide better sealing against contaminants from outside. This is what we call the AS version.

The AS seal provides reliable sealing for bearing housings in standard to moderately contaminated environments, especially suitable for use in closed bearing assemblies such as AS / AS-VK assembly. Used on places with none abrasive surrounding. Just to close and become a maintenance free bearing unit sealed against contaminants.

SA Seal

SA oil seals are designed with asymmetric lip angles as shown in the illustration. The angle α between the shaft and lip on the air side is smaller than the angle β on the lubricant side to prevent lubricant from leaking out of the system. When grease is used, the difference in angles is less important and often reversed to provide better sealing against contaminants from outside. We call this seal version SA. Leakage is less of a concern here due to the consistency of grease, which prevents excessive loss of lubricant. Therefore the main purpose of the grease seal is to keep contaminants out.

To improve bearing life by the correct use of bearing shaft seals, it is recommended to use an automatic lubricator or lubricate regularly. Only a small quantity of grease is necessary when slowly flushed into the bearing cavity to force dust and moisture away from the seal lips.

Grease Is a Great Help to Sealing Bearing Housings Against Contaminants

Grease can be a great help to sealing bearing housings against contaminants. The gaps between the lips of the centrifugal seal and the stator must be sealed to keep out dust and water. To improve bearing life for centrifugal bearing shaft seals, it is recommended to use an automatic lubricator or to lubricate regularly. Only a small quantity of grease is necessary when slowly flushed into the bearing cavity to force dust and moisture away from the working parts.