Industrial Maintenance Solutions

Submersible pumps are commonly used in various industries such as construction, mining, wastewater treatment, agriculture, and general manufacturing. Typically, these pumps consist of a vertical electric drive motor that is directly connected to the impeller, and they are designed to operate for long periods with minimal maintenance. BEARING ARRANGEMENT The bottom bearing, also known as the locating bearing, usually consists of a double-row angular contact ball bearing or a pair of angular contact bearings, which are responsible for supporting the axial and radial loads generated by the pumped fluid. Since the bearing is subjected to heavy loads, it is important to select the appropriate bearing to achieve the desired service life. On the other hand, the top free bearing is generally a deep groove ball bearing that takes a light radial load. Typically, C3 clearance is used to compensate for the reduction in clearance caused by the heat generated by the electric motor. CREEP PHENOME...

Assuming proper design, application, and lubrication, rolling element bearings will fail sooner or later due to their natural material fatigue life limit, but all bearings will fail prematurely from abuse or neglect. BY L. (TEX) LEUGNER Troubleshooting of rolling element bearing problems and recognizing their root cause of failure is often difficult, because many failure types look very similar. This is because bearing failures are almost always precipitated by spalling or flaking conditions of the bearing component surfaces. Spalling occurs when a bearing has reached its fatigue life limit, but also when premature failures occur. For this reason, it is important for the troubleshooter to be aware of and able to recognize all the common failures of rolling element bearings. This ability to correctly troubleshoot and recognize the root cause of bearing failures will lead the analyst to the right conclusions. We often hear the comment, even by knowledgeable and well-meaning enginee...

Definition : Ensuring that all maintenance practices for components associated with the bearing are at a level to allow the maximum performance of the bearing . These include installation practices, tools used, skills of millwrights, the accuracy of mating components, alignment, and balancing of the rotating assembly. BY DOUGLAS MARTIN. Let's start with a discussion about the effects of a lack of precision maintenance. There was a case of an oil refinery that was having a recurrent failure of a fan. The mean time between repair (as the vibe crew would pick out a defect) was six months. Looking back, I remember how proud the vibe team was and how an outer ring of a bearing on display, marked in paint pen $10,000 in savings, to demonstrate their successful diagnostics. When attending the installation, the first question the millwright asked was why was the tapered adapter sleeve so loose on the shaft prior to driving the bearing up the sleeve? Indeed, it easily slid onto the sh...

Whether selecting new or maintaining existing process equipment, bearings are a critical component in the equipment’s reliability, efficiency, and life. The majority of rotating process equipment today relies upon either rolling element or fluid film bearings to counteract gravity and developed forces in the equipment and allow for free rotation of the shaft. Selecting the right bearing for the equipment and application is essential to the successful operation of that equipment. A key difference between rolling element and fluid film bearings for personnel concerned about the maintenance of process equipment is the expected life of the bearings. Rolling element bearings typically have a predictable life based on the operating conditions; fluid film bearings, when properly designed and maintained, can operate for decades. Additional comparisons of rolling element and fluid film bearing characteristics, such as lubrication needs and the ability to handle impact loads, are provided in t...

  There are literally dozens of ways bearings can fail. Some of the more common include: • Babbitt fatigue • Babbitt wiping due to rotor to stator contact • Babbitt flow due to high operating temperatures • Foreign particle damage • Varnish build-up • Electrostatic discharge damage (frosting) • Electromagnetic discharge damage (Spark tracks) • Oil “burn” or additive plating due to high temperatures • Loss of bond between babbitt and base metal • Chemical attack • Pivot wear in tilting pad bearings • Unloaded pad flutter • Cavitation damage This is taken from a paper, Babbitted bearing health assessment" by John Whalen of John Crane, Thomas Hess of Rotating Machinery Group, Jim Allen of Nova Chemicals Corporation and Jack Craighton of Schneider Electric. Babbitt fatigue Babbitt fatigue is caused by dynamic loads on the babbitt surface. Typically in bearings of this type, the dynamic loads are caused by vibration and result in peak film pressure fluct...

What is the ISFD Bearings? Integral squeeze film damper  ( ISFD) technology, a Flexure Pivot tilt pad journal bearing, provides precise stiffness and damping to increase the dynamic stability of the rotor/bearing system. Reduce Dynamic Bearing Forces ISFD technology reduces the dynamic load that is transmitted to the bearings, which reduces pedestal vibration and increases bearing life, particularly for rolling element bearings. For fluid film bearings, the technology can mitigate pivot wear and reduce babbitt fatigue. Decrease Unbalance Sensitivity ISFD technology helps reduce the sensitivity to unbalance, protecting impellers and seals from rubbing and increasing maintenance intervals. Versatile Design The ISFD design, manufactured through electrical discharge machining (EDM), can integrate the bearing and damper into one unit for a space-saving solution suitable for new and retrofit installations. ISFD technology can be used with tilt pad, Flexure Pivot tilt pad, fixed profile o...