Our paper mill utilizes Rotojet pitot pumps to provide high pressure shower water for our paper machines. These pumps, operated at speeds between 3400-3800 rpm, are belt driven. We have encountered premature bearing failures specifically at the cylindrical roller bearing on the drive end of the pump. The bearing setup includes one cylindrical bearing and one deep groove ball bearing at the drive end, along with one deep groove ball bearing at the rotor end. If anyone has faced similar issues, we would appreciate any suggestions on improving the reliability of our units.
What are the common causes of bearing failure? Could corrosion or water ingress be contributing factors?
In Heinz Bloch's failure analysis book or the TapRoot system, you may discover valuable pump troubleshooting guides integrated into their Root Cause Failure Analysis (RCFA) process. This resource could be extremely useful for addressing issues related to bearings and pumps.
David, as previously mentioned, it would be beneficial to have information on the failure mode. If you are using a roller type bearing, make sure it is rated for the specific lubrication requirements, such as oil, needed to operate at this speed. This will help prevent any potential issues or breakdowns.
It seems like we have a similar setup, David. I have a 375, 525, 1000, and 175 belt-driven RotoJet pump, each operating at approximately 40 Hz. Bearing failures are rare, usually it's a seal or broken line. We use Mobil white PM grease and grease them monthly. Additionally, I have a smaller TrimJet pump that uses oil. - Mike
Thank you to everyone for your responses. The most common issue experienced is a broken cage in the cylindrical roller bearing located at the drive end. Meanwhile, the deep groove ball bearing remains responsible for carrying the radial load. These bearings are lubricated with grease according to the manufacturer's guidelines. This specific pump design incorporates a rotating casing and pitot tube setup to achieve a pump discharge pressure of around 600 psi. Are there any other users out there utilizing this particular pump design?
In my experience, premature bearing failures can be caused by a variety of factors including incorrect installation, unideal operating conditions, or using unsuitable lubricants. You might want to examine if the bearings are aligned properly during installation. Misalignment can lead to excessive loads, resulting in premature failure. Also, consider checking the type of lubricant being used and confirm if it's appropriate for your operating conditions. Sometimes, the issue could be as simple as the pumps being over or under-lubricated. Finally, ensure that the operating conditions - like temperature and vibration levels - fall within the prescribed range. These are just some starting points, hope this helps!
In my experience, premature bearing failure could be due to a number of factors, such as incorrect bearing selection, improper installation, or lack of lubrication. Given your setup, I would first check to ensure that the bearings are appropriate for the load and speed at which your pumps operate. Next, consider if the bearings were installed properly with the right tools and aren't subjected to any excess forces during installation. Lastly, regularly monitor the lubrication to make sure the bearings are sufficiently lubricated and that the lubricant hasn't degraded over time. You may also want to look into periodic vibration analysis; it can detect changes in vibration signatures, which can signal potential problems before catastrophic failure. Good luck!
Interesting problem you've got there. Based on my experience, premature bearing failure could be due to a few different factors like improper installation, lubrication issues, or misalignment of the shaft. It might be worth exploring if these could be contributing to your problem. Specifically, I'd check if the lubricant being used is suitable for the operation conditions or if there's a contamination issue. Misalignment could also present a problem especially given the high operating rpm. Lastly, consider checking the belt tension, as it could cause additional load on the bearings if it's too high.
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Answer: The paper mill utilizes Rotojet pitot pumps for this purpose.
Answer: The pumps are operated at speeds between 3400-3800 rpm.
Answer: The cylindrical roller bearing on the drive end of the pump has experienced premature failures.
Answer: The bearing setup includes one cylindrical bearing and one deep groove ball bearing at the drive end, along with one deep groove ball bearing at the rotor end.
Answer: The discussion thread seeks suggestions from anyone who has faced similar issues on how to improve the reliability of the units.
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