Vibration control is the dynamic (running) element of the total tension control strategy. It’s the most important part of the picture because ultimately the dynamic tension behaviour of the system will define the pre-set or static tension. High static and dynamic tensions reduce belt life, reduce accessory component bearing life, increase noise, waste fuel and add weight and cost through coping strategies.

Large dynamic belt tensions are usually caused by one or more of the following factors;

Engine Torsional Vibration with sufficient acceleration can cause large speed fluctuations with each cylinder firing pulsation. This results in strong instantaneous torques and consequent belt tension fluctuations. Typical consequences include belt rumbles, vibration and belt slip. Contributing factors include high compression, direct fuel injection, low engine friction, low inertia and dual mass flywheel.

Accessory system response to even moderate input fluctuations can be harsh if a component torsional resonance is excited. Most commonly the alternator rotating mass in combination with the belt as a spring can vibrate independently of the engine input amplitude with same results as if the engine vibration fluctuation were large.

Computer simulations can identify the root cause. Litens provides unique and effective products to eliminate large tension fluctuations, and thus improve noise, vibration, reliability and efficiency.