Gear – Mesh Frequencies
In addition to their fundamental rotational frequencies meshing gears produce a vibration which is the product of the number of teeth and their rotatational frequency and is an indication of machine health. For example a 61 tooth gear rotating at 1705.5 rpm meshes with a 17 tooth gear. The 17 tooth gear will rotate at (61/17)*1705.5 = 6120.09 rpm. The dominant frequencies will be 28.4 Hz and 102.0 Hz for the fundamental rotational frequencies and a gear-mesh of 1734.0 Hz.