Gene Vogel
Pump & Vibration Specialist
Electrical Apparatus Service Association
St. Louis, MO
The paper "Field Service Vibration Analysis" by Gene Vogel, presented at the EASA Convention 2010, provides a comprehensive overview of the fundamentals and practical applications of field service vibration analysis (FSVA). Vogel emphasizes the importance of FSVA for service centers, highlighting its profitability, the establishment of authority in the marketplace, and the strengthening of customer relationships. The paper outlines the scope of FSVA, discussing dynamic balancing, troubleshooting, and predictive maintenance, and presents typical scenarios encountered in the field.
Dynamic balancing is a common FSVA task, particularly for fans, blowers, grinders, choppers, pulleys, and vertical motors. Vogel explains that dynamic balancing involves vector addition and subtraction to eliminate unbalance. He stresses the importance of verifying that the problem is indeed unbalance before adding weights, as other issues like looseness, misalignment, and resonance can complicate the process. The paper outlines five key steps in dynamic balancing: analyzing vibration, verifying amplitude and phase stability, documenting the "as found" condition, observing coast down data, and using proper balancing calculations.
Troubleshooting is another critical aspect of FSVA, as high vibration indicates potential machine faults. Vogel advises technicians to determine the vibration frequency and severity at each bearing, using vibration spectra to compare frequencies from multiple locations. He emphasizes the importance of identifying harmonic families and matching them to known forcing frequencies. Techniques such as high-resolution spectrum analysis, synchronous time averaging, and phase analysis are essential for accurate diagnosis. Vogel also highlights the need to consider resonance and suggests using Bode or Nyquist plots to identify it.
Predictive maintenance is a valuable service that involves periodic vibration testing to monitor machine condition and detect developing problems. Vogel outlines the process, starting with an initial plant survey to gather information for database setup. The database is then used to schedule and collect vibration data, which is analyzed to identify trends and potential faults. Regular adjustments to the database ensure accurate monitoring and reporting. Predictive maintenance helps customers avoid large capital investments in instruments and training while benefiting from early problem detection.
Vogel concludes by emphasizing the importance of FSVA for service centers, noting that it not only addresses vibration-related warranty issues but also strengthens customer relationships. He encourages service centers to offer FSVA as a valuable service, leveraging their expertise to provide solutions and recommendations.
Key Points Covered:
- Importance and benefits of field service vibration analysis (FSVA)
- Dynamic balancing: techniques, common problems, and key steps
- Troubleshooting: determining vibration frequency, using vibration spectra, identifying harmonic families, and considering resonance
- Predictive maintenance: process, database setup, data collection, and analysis
- Strengthening customer relationships through FSVA
Key Takeaways:
- FSVA is profitable and establishes service centers as authorities in the marketplace.
- Dynamic balancing involves verifying unbalance and addressing complicating factors like looseness and misalignment.
- Accurate troubleshooting requires identifying vibration frequencies and matching them to known forcing frequencies.
- Predictive maintenance helps detect developing problems early, avoiding large capital investments for customers.
- Offering FSVA strengthens customer relationships and supports service centers in addressing vibration-related issues.
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