As part of a seismic analysis for a 1000 horsepower vertical 14 pole induction pump motor the reed frequency was calculated using a finite element analysis (FEA) program. This paper will discuss the FEA modeling for the seismic analysis and natural frequency determination. The calculations were done for the
motor only on a rigid support. After the motor completed the standard factory tests, an impact test was conducted in the rigid mount condition to determine the structural natural frequencies. The tested values will be compared to the calculated values from the FEA model. This paper will also discuss the subsequent motor/pump system resonance problems that surfaced after the motor/pump was installed on site. This paper will highlight the importance of the system integrators design of the motor support structure to avoid structural resonance problems such as in this case.

Every day we are used to facing the same problems on the pumps. Sometimes one glance at the vibration spectrum is enough to identify the problem and issue recommendations for its elimination. But sometimes the diagnostician is given the opportunity to work hard. In this article, we will consider a practical case of vibration diagnostics of vertical pumps, conduct a whole study and identify an incomprehensible spectral component.

I want to devote this article to the practical application of modal analysis. I have never dealt with modal analysis, there were no devices with corresponding functions, and now they are not and are not expected. Very expensive. But this is not a reason to despair and put an end to such an interesting method. The solution to the problem is 3D modeling and calculation of vibration modes. How I came to this, how to do it and what I got in the end - read on.

This article discusses another defect in the design / installation of the fan, which led to increased vibration. We determine the cause and find a solution to the problem.

The fight against vibration of fans is a special niche in the practice of vibration diagnostics. In many enterprises, fans turn a blind eye - they say cheap, low-liability, etc. But in my opinion, fans are the main source of experience for a beginner vibration diagnostics / vibration adjuster. Fans, as a rule, are mounted / operated in violation of the requirements, have low rigidity, and accordingly a huge mass of defects is manifested on them. In this article, we consider the effect of improper installation on the vibration of the unit, we localize the defect and eliminate it.

In this article I want to talk about the difficulties encountered during vibration adjustment, the interweaving of many different defects at the rotational speed, the search for solutions to the problem, and the possibilities of the vibration adjustment specialist are not unlimited. A story without a happy ending, as always from our own real practice.