Overview

• PdM was called on site to investigate the misalignment of the pump.
• Cross phase analysis was conducted along the base of the machine’s platform.
  • 180 degree phase difference was found, causing a momentary misalignment between the sheaves.
• The primary source of vibration on the structure and the machine were at 2X pump speed, seen both in our vibration readings and during the motion amplification study.
• The video below illustrates the high 2X vibration on the pump’s platform, causing momentary misalignment.

Further Analysis

• 1X vibration was also apparent on the pump platform, seen by the rocking motion.
• The lack of structural support is the cause of this vibration however, not as damaging as the 2X vibration and not the cause of momentary misalignment,
  • This vibration will, however, fatigue the structure if not resolved.
    • As the structure fatigues, the vibration will continue to rise at 1X and 2X pump speed.
• The following video shows the rocking motion at 1X pump speed.

Recommendations

• Conclusion: Lack of structural stiffness was causing the equipment to move out of phase. This is causing momentary misalignment, and creating destructive vibration on machine components (bearings, belts, shafts, etc.).
  • Secondary concern is a structural fatigue.
• Angled bracing should be added to each post, where bracing is currently missing.
  • 45 degree bracing on both sides perpendicular to the belt.
    • Similar to the current bracing parallel to the belts.
• Follow up readings should be taken once bracing is added to confirm vibration issue has been reduced.