From heat, to water, chemicals and extremely abrasive contamination, the steel industry offers some of the toughest environments that can threaten bearing life. The question is, “How can we reduce the effects of these factors?” Simply put, with proper bearing seals.
Rex and Link-Belt roller bearings offer an all-metal clearance seal, which is ideal for combatting excessive heat, but not as effective when it comes to moisture, chemical attack and the highly abrasive contamination associated with steel making and coating processes.
For temperatures below 225oF, a Buna rubber spring-loaded lip seal works well, but as we all know, you’re often dealing with temperatures approaching 400oF. To handle these extreme temperatures, our Rex roller bearing line features a Viton rubber spring loaded lip seal as a standard option.
Viton can run up to 400oF and is excellent at resisting chemical attack associated with steel pickling and coating. The pickling and coating processes often use acidic solutions to clean the steel, which can overflow or splash onto the bearings and dramatically limit bearing life. So why not choose a bearing that offers a Viton Seal (Rex roller bearing or Link-Belt ball bearing) to increase the overall performance of your application?
Now, a Viton seal is a great solution, but what if the seal alone doesn’t provide enough protection? The answer is Rex auxiliary caps. These cast iron components are bolted to the bearing housing faces to provide a five-part sealing system to maximize bearing life (see Section View below).
The first barrier (#1) is a V-ring which can be offered in Viton or Buna, depending on the application. Next up (#2) is a Labyrinth seal, and (#3) a large grease cavity which when filled offers an effective seal. The cast iron caps are bolted with a gasket (#4) to the housing. Finally, we reach the primary bearing seal (#5).
The bottom line? More barriers mean a better, longer lasting seal for the toughest environments. And that means using Rex auxiliary caps.
If temperatures are running above the 200oF, please call the Rexnord Bearing Application Engineering Department because bearing clearance, retainer material and grease may need to be changed to meet the application requirements.
If you have questions about Rex auxiliary caps or would like to talk to one of our application engineers, call (317)273-5781 or email [email protected]. For videos and other demos, visit our YouTube channel.
Mark Czubak is a Principal Engineer with the Rexnord Bearing business. He has spent nearly 40 years with Rexnord where he has managed all facets of engineering, including application, design and manufacturing, giving him a cradle to grave knowledge of mounted roller bearings. With this experience, Mark shares his passion and knowledge through bearing training, application assistance and installation. “Bearings are overlooked for the more expensive components of the system, but a bearing failure can cause just as much downtime as any other component so choose your bearings wisely, and save time and money.”