Vibration Control - Diesel Driven Generator Sets
29 October 2019Diesel Generators are naturally prone to inducing Mechanical Vibrations. These undesirable vibrations are caused by the out of balance forces and gas fluctuations of the engine and vary depending on the number of cylinders, firing order and engine configuration.
Excessive vibration of a Diesel Generator can result in disturbances to adjoining structures and buildings, failure of components such as bearings, and reduced functionality of the Generator, which can ultimately result in breakdown. Vibration Control is therefore an important factor during the design stage and installation stage of the Generating Set.
A typical 4 cylinder engine running at 1500RPM (25Hz) will have its dominant vibration harmonic at 2nd Order Frequency (i.e. 50Hz) - This 2nd Order Harmonic is caused by the difference in inertia forces during the upward and downward stroke, due to the mass of the Pistons.
Spring Mountings
have a comparatively lower level of damping compared to Rubber mounts and generally provide high levels of deflection (typically 25mm, but can be up to 50mm). This high level of deflection results in extremely low natural frequencies, result in high levels of vibration reduction of up to 99%. However the low stiffness of these products can cause issues during Start-Up, Shut Down, Resonance and Mobile applications. Additional snubbers or restraints can be incorporated to control movement which could otherwise harm the spring mountings and any flexible connections