Gear Problems: Gear Load

Figure 1 - Typical FFT Showing Gear Load Problems

Gear Load - Often affects GMF and harmonics more than the running speed sidebands which are low amplitude and relatively few. Increases and decreases in GMF and harmonics alone (without significant change in sidebands) does not necessarily indicate a problem. Even if the load itself is fairly constant, the gear that is carrying the load is constantly changing so this amplitude can change from data collection to data collection without any deterioration of the gear condition whatsoever. A change in the load itself can also occur and have an even more dramatic impact on the spectrum amplitudes without reflecting any problem.

Gear Load Symptoms: Higher amplitudes at 1, 2 and/or 3x GMF. Recommended Actions: None unless there is an increase in sideband activity or the appearance of possible gear resonant frequencies.