Hello,
do any one know houw many running houre is equivalent to one shutdown/startup.
this is to have an accurate idea about the bearing life of rolling bearing that is frequently stoped and stared-up.
Many thanks.
N.T
Original Post
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N.T.
As such I believe there is nothing like equivalent hours. For frequent shutdown/startup general recommendation from bearing manufacturers is the use of AW or EP additives. Use anti-wear for lightly loaded bearings, and EP for medium and heavily loaded bearings.
You could try to model the startup/shutdown conditions by using average speed/load and time during the startup/operation/shutdown conditions. For example:
If the bearing is running at 1500 rpm you could do something like this:
Speed (rpm) load (N) time (%)
1600 3000 90%
1200 3000 2%
900 3000 2%
600 3000 2%
300 3000 2%
50 3000 2%
You can use this data and feed it to a bearing life calculation program. At least one bearing manufacturer has it on the internet.
Hope this helps.
Alex
As such I believe there is nothing like equivalent hours. For frequent shutdown/startup general recommendation from bearing manufacturers is the use of AW or EP additives. Use anti-wear for lightly loaded bearings, and EP for medium and heavily loaded bearings.
You could try to model the startup/shutdown conditions by using average speed/load and time during the startup/operation/shutdown conditions. For example:
If the bearing is running at 1500 rpm you could do something like this:
Speed (rpm) load (N) time (%)
1600 3000 90%
1200 3000 2%
900 3000 2%
600 3000 2%
300 3000 2%
50 3000 2%
You can use this data and feed it to a bearing life calculation program. At least one bearing manufacturer has it on the internet.
Hope this helps.
Alex
