Rush Engineering, Inc.

Structural Testing and Acoustic Noise Analysis

Motor vibration creating excessive noise in pump station.
Vertical Pump Motor Installation

 

 

Motor shell instrumented to measure starting and running transients.
Instrumentation on Motor
 

 

Internal components on motor instrumented for vibration and noise measurements.
Motor Internal Instrumentation

 

 

Components bend due to electromagnetic and mechanical forces of operation.
Motor Internals

 

 

External shell components vibrate like drum surfaces transmitting acoustic noise to surroundings.
Motor Internal Instrumentation

 

 

Starting and rundown transients indicate noise is sensitive to frequency band near 700 Hz.
Speed Spectral Map

 

Acoustic noise transient increases with speed.
Acoustic Noise Transient

 

Vibration acceleration transient increases with speed.
Acceleration Transient

 

Motor side panel radiating high acoustic noise levels.
Motor Panel

 

 

Motor shell drumming loud acoustic noise due to "panel resonance."
Vibration Deflection Shape

 

Acceleration spectrum shows vibration resonance amplification of 683.8 Hz and 720.7 Hz components.
Acceleration Spectrum

 

Acoustic noise spectrum shows highest amplitude at 683.8 Hz and 720.7 Hz components.
Acoustic Spectrum

 

RESULTS:
Motor shell braced to detune panel resonance,
and rotor windings modified to eliminate exciting force.

If it's dynamic, it's a Rush job!

Contact Rush Engineering, Inc.

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