Testing for max heat. 1

[Elroyjet]

What is the max heat a bearing can take without failure. If the pack grease has a drop temp of 520F and the seal is manufactured (rubber/ synthetic) at 475. There are no specs on the max temp... and this is not a field failure issue. This is a process issue.
Also how would you test this issue to ensure no field failures.?

 

[Tmoose]

Are you talking about a ball or roller bearing?
I'd start checking with the bearing manufacturer, and get some more specific failure analysis done, but here are some general things I'd think about.
- Problems develop with some cage materials way under 200 F.
- The steel parts must be processed differently to assure dimensional stability over 150F.
- Many Greases by themselves go to hell quickly as low as 180 F. In a high speed bearing the grease can be mechanically destroyed very quickly even it the bearing housing temp never exceeds 120F. Once the grease is dead a healthy bearing will follow sooner or later.

We have made some product test spindles that survive test environments over 400 F.

 

[Metalguy]

Tmoose,

Did you use something like Dow-C FS3451 white grease, or a dry lube for 400 deg?