Analysis Pdf — Practical Case Studies On Vibration
Practical Case Studies On Vibration Analysis
Case Study 4 — Resonance induced by structural looseness
The axial vibration was negligible (low 1x), but the phase difference across the coupling was 178°. The shaft was bent by 0.002 inches TIR (Total Indicator Reading) near the inboard bearing.
The Outcome:
Early detection allowed for a planned replacement during a scheduled outage, preventing an unplanned shutdown of the high-speed paper machine. 2. Case Study: Standby Fan Motor "False Brinelling" Practical Case Studies On Vibration Analysis Pdf
- Unbalance: Phase difference is typically stable (horizontal vs. vertical ~90° apart on overhung rotors).
- Bent Shaft: Phase difference between axial transducers at the bearing housing is 180° out of phase across the coupling.
The Intervention:
Engineers used a "tuning plate" between the motor base and discharge head to shift the structural natural frequency . Practical Case Studies On Vibration Analysis Case Study
Introduction
- Machine metadata: Speed, bearing model, load.
- Spectrum plots: Before and after repair.
- Time waveform: To confirm non-synchronous impacts.
- Phase data: For misalignment/looseness verification.