1 / 22

Vibration Analysis & Balancing

Vibration Analysis & Balancing. What is Vibration Analysis. The study of Collected data taken with the analyzer, of a machine while it is running. Data is collected at each location or point in the horizontal, vertical and the axial plans.

gareth-cummings
Download Presentation

Vibration Analysis & Balancing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Vibration Analysis & Balancing

  2. What is Vibration Analysis • The study of Collected data taken with the analyzer, of a machine while it is running. • Data is collected at each location or point in the horizontal, vertical and the axial plans. • Numerous bearing, motor and condition fault frequencies are checked and compared.

  3. Vibration Analysis • What is vibration? • Forces that vary in amplitude or direction over time cause repetitive motions called vibration • When is vibration bad? • All rotating machinery generates some vibration • Only vibration that exceeds certain amplitude levels is bad.

  4. Vibration Terminology • Amplitude • The measure of energy or movement in a vibrating object • Three common ways of expressing: • Displacement in mils peak to peak • Velocity in inches/second peak • Acceleration in g’s rms

  5. Vibration Terminology • Frequency • The number of times that a vibrating object repeats its motion per unit of time • The rotational frequency is often called 1X • Other frequencies are often identified as multiples of 1X, such as 2X, 3X, 4X, etc.

  6. Vibration Measurement • We analyze vibration profiles from, motors, fans and pumps, chillers, bearings and overall machine health. • Were looking for bearing condition, mechanical looseness, motor electrical problems, resonance issues

  7. Overall vs. Running speed-1X • Overall amplitude is a measure of the vibration energy over a wide frequency range • 1 times amplitude usually refers to the vibration at operating/running speed • Overall amplitude includes the effects of all sources—even those external to the fan

  8. Vibration Terminology Vibration Spectrum: (a display of frequency vs. amplitude)

  9. PROFILE PLOT (More Than One Equipment) FAN MOTOR POINTS 24-Sep-10 4XTS 09:48:08 To 01-Oct-10 13:15:31 3xTS Full Scale 280. % 2xTS of Fault 1xTS M M M M M M M M M M M F M M M M M F M M M M M F M M M M M M M M M M M M M M M M M M M M 1 1 1 2 2 N 1 1 1 2 2 N 1 1 1 2 2 N 1 1 1 2 2 1 1 1 2 2 1 1 1 2 2 1 1 2 1 1 2 1 1 1 2 2 H H V A H V H V A H V V H V A H V V H V A H V V H V A H V H V A H V H V A H V H A H H A EQUIPMENT H H I I I I I A A A A A A B B B B B B C C C C C C D D D D D E E E E E F F F F F G G G H AREA A A A A A A A A A A A A A A A A A A A A A A A B B B B B B B B B B B B B B B B B B B B B Profile Plot

  10. Dynamic Unbalance • Dynamic (couple) unbalance requires correction in two or more planes • Heavy spot will not “bottom out” when rotor is placed in bearings

  11. Achieving Lower Vibration Levels • Involves better precision of many components • Better balance of all rotatingcomponents • Fan wheel (balance with fan shaft) • Sheaves • Couplings • Motors • Straighter shafts with precision diameter tolerance and roundness • Less hop and wobble in fan wheel • Better fits in attached components

  12. Achieving Lower Vibration Levels • Involves better precision of many components (continued) • Reduced internal clearance in bearings • Bearing mounting surfaces machined flat • Premium quality v-belt drives • Precision alignment of v-belt drives or couplings • Precise tensioning of belts

  13. Achieving Lower Vibration Levels • Involves other special design considerations • Heavier and more rigid components: Use Class III instead of Class II • Aluminum fan wheel (reduced rotor weight) • Use inertia base for flexibly mounted fan • Select lower speed fans if possible • Avoid operation at any critical resonance speeds- vibration can increase up to 10X amplitude

  14. Balance • Balancing • The process of adding or removing weight on a rotor in order to move the center of gravity towards the axis of rotation • The purpose of balancing is to reduce the unbalance forces that damage machines, there surroundings and reduce noise transmitted to tenants

  15. Balance Tolerances • Defines the maximum amount of residual unbalance remaining after balancing • Originally defined in international standard ISO 1940/1 • Many new standards exist today. • We use the manufactures specifications along with years of experience to achieve best balance possible

  16. Balance and Vibration tolerances • Proper balance • Provides for long life, • Higher efficiency and • Reliable operation without excessive cost

  17. Static Unbalance • Static unbalance can be corrected by adding a single weight • Heavy spot will “bottom out” when the rotor is placed in bearings

  18. Dynamic Unbalance • Dynamic (couple) unbalance requires correction in two or more planes • Heavy spot will not “bottom out” when rotor is placed in bearings

  19. 503 657-4467 END

More Related