Seals

Most bearing failures occur due to lubrication failures. Among the most common problems is the entry of contaminants into the bearing housing, causing a breakdown of the lubricant or causing particulate damage to the raceways or rolling elements. Critical to the prevention of contamination is making sure that an effective seal exists between the rotating shaft and the housing.

The most common sealing device is the oil seal. Typical construction includes a metal case (sometimes rubber coated), a rubber piece bonded to the metal case having one or more sealing "lips", and a spring to provide compression of the rubber to the rotating shaft. Dimensions can be either inch or metric for the inside diameter (ID), outside diameter (OD) and width.

The lip material can be made of a variety of compounds including nitrile (also know as Buna N), flouroelastomer (also known as Viton, a trademark of the Dupont Corporation), silicone, and polyacrylate. Each compound has different temperature and chemical resistance properties, with most industrial applications using the standard nitrile lip seals.

Some common devices which are provided through seal manufacturers include:

  • V-Rings - all rubber rings which rotate with the shaft and run against a seal face or housing, providing additional sealing to the application
  • Redi-sleeves - thin wall sleeves used to cover damaged shafts
  • Wear sleeves - thicker wall sleeves commonly used in truck seal applications
  • Installation tools - used to allow for easy installation of new seals

In addition to oil seals and the other devices above, Bearing Service stocks a complete line of O-Rings, which are used in static sealing applications. Other products that we are able to source include various packings, u-cups, and mechanical seals.

Here is a list of Manufacturers / Brands that we represent: