We have a Buffalo Forge motor-belt driven blower (Ty E, Size 6) used to provide ambient air for ventilation. The unit was recently refurbished (new shaft, balanced, aligned, new bearings) and running very smooth.
While taking vibration data (very smooth), I noticed both pillow block bearings very hot to the touch. These are Fafnir RSAO type supporting fan shaft, mounted with offset cam, running at 3550 RPM and, according to the installation notes, not normally needing periodic greasing. Took temp readings and the outside block temperatures were as high as 207 deg F. In comparison, another identical blower's bearings measured almost ambient ~ 93 deg F.
I contacted Fafnir and they stated that this temp would not degrade the bearing but could offer no advice on why it was hot in the first place. Based on this information, we decided to continue operation and monitor the temperatures.
Today, after 1 day of operation, the highest temp dropped from 207 to 179 deg F.
My question is whether other maintenance personnel have seen similar temp swings as this? One concern I still have is that the bearings have been in storage for over 10 years. Discussions with Fafnir tech's indicate that the rust preservative shelf life is typcially 6 years.
Is it possible that some oil/base seperation or lose of preventative is a root cause here? If so, why is temp dropping?
In any case, would appreciate any comments on similar observations and possible explanations. I will continue to monitor the trend of these temps.
Regards
Jim P
While taking vibration data (very smooth), I noticed both pillow block bearings very hot to the touch. These are Fafnir RSAO type supporting fan shaft, mounted with offset cam, running at 3550 RPM and, according to the installation notes, not normally needing periodic greasing. Took temp readings and the outside block temperatures were as high as 207 deg F. In comparison, another identical blower's bearings measured almost ambient ~ 93 deg F.
I contacted Fafnir and they stated that this temp would not degrade the bearing but could offer no advice on why it was hot in the first place. Based on this information, we decided to continue operation and monitor the temperatures.
Today, after 1 day of operation, the highest temp dropped from 207 to 179 deg F.
My question is whether other maintenance personnel have seen similar temp swings as this? One concern I still have is that the bearings have been in storage for over 10 years. Discussions with Fafnir tech's indicate that the rust preservative shelf life is typcially 6 years.
Is it possible that some oil/base seperation or lose of preventative is a root cause here? If so, why is temp dropping?
In any case, would appreciate any comments on similar observations and possible explanations. I will continue to monitor the trend of these temps.
Regards
Jim P
