Explore BrainMass
Share

Explore BrainMass

    Shaft misalignment, vibrational analysis type multiple choice

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    1. The rotational speed of a pump shaft is 19.5 Hz. The frequency spectrum of
    accelerometers placed on inboard and outboard bearings in the vertical
    direction generally indicate shaft imbalance at a frequency of
    A. 19.5 Hz. B. 39 Hz. C. 9.75 Hz. D. Always a sub-synchronous value of shaft
    speed.

    2. A ceiling fan has a rotational speed of 600 RPM and has five blades. The
    blade pass frequency at this speed is
    A. 60 Hz. B. 50 Hz. C. 30 Hz. D. 10 Hz.

    3. The oil whirl phenomenon in a sleeve bearing (journal bearing), with a shaft
    frequency of fr , occurs approximately at the following frequency.
    A. 0.45 x fr. B. 1 x fr. C. 2 x fr. D. 2.45 x fr.

    4. Which one of the following is not a condition-based (predictive maintenance)
    technology?
    A. Lubrication oil analysis
    B. Vibration monitoring
    C. Periodic replacement of pump seals
    D. Ultrasonic testing for flaw detection
    E. Thermography for inspecting hot spots on equipment

    5. The coherence function between two detector signals is given by

    A. 1/10. B. ½. C. 0.0 D. infinity.

    © BrainMass Inc. brainmass.com October 10, 2019, 8:30 am ad1c9bdddf
    https://brainmass.com/engineering/aerospace-engineering/shaft-misalignment-vibrational-analysis-type-multiple-choice-629687

    Solution Preview

    Please find attached. Note that as posted you have not supplied all the information provided to answer question 5 without ambiguity. I therefore did a Google search and found the exact same set of questions, however, there were 2 similar format questions pertaining to Q5, one if f goes to large values and one for f going to zero. As you can see I have provided both answers based on either option but you need to use the answer dependent on what you actual question says and the missing part of the information that you can see but I cannot see. Note also that Q1 is not explicit as it just refers to imbalance so I am assuming this is question is referring to an imbalanced shaft due to parallel misalignment

    1. The rotational speed of a pump shaft is 19.5 Hz. The frequency spectrum of
    accelerometers placed on inboard and outboard bearings in the vertical
    direction generally ...

    Solution Summary

    Shaft misalignment, vibrational analysis type multiple choice questions and answers.

    $2.19