Types of Mechanical Looseness:

  • Rotating looseness - caused by excessive clearance between rotating and stationary elements of the machine (Bearing Wear).
  • Non-rotating looseness - looseness between two normally stationary parts, such as a foot and a foundation, or a bearing housing and a machine.
  • Structural looseness (Weakness)- occurs where there is weakness in the base plate, foundation, or feet, and the machine rocks from side to side.

Rotating Looseness

Diagnosis: 1X Harmonics / 0.5X Harmonics in Severe Cases.

Phase Measurement is not useful tool.

Time Waveform is very useful tool.

Example of Spectrum & Time Waveform
Example of Spectrum & Time Waveform

Structural Looseness

Diagnosis: 1X Strong in Horizontal direction.

1X Horizontal >> 1X Vertical

Phase Measurement is a useful tool.