Decoupled Pulley Innovation

Decoupled pulley with mechanical overrunning clutch eliminates annoying vibrations and makes automatic start-stop systems more comfortable. 

Fuel-saving start-stop systems are currently the best way of quickly and sustainably reducing carbon dioxide emissions. As the vehicle comes to a standstill, the engine is stopped and is then started again as it moves on. However, this eco-friendly technology causes annoying noises and vibrations which can irritate the passenger of a vehicle over the course of time, especially when stop-and-go traffic is the rule rather than the exception in urban driving. The vibration technology expert has the solution on offer: the decoupled pulley with mechanical overrunning clutch.

This innovation, which is installed between crankshaft and belt drive, consists of a soft elastomer spring to decouple annoying crankshaft vibrations at low engine speeds and a mechanical overrunning clutch to eliminate the severe vibrations which arise as the engine is restarted and the vehicle moves on.


The product combines the outstanding insulation properties of a standard decoupled pulley in stationary operation with a mechanical overrunning clutch function during engine start. This system extends the durability of all belt drive components and ensures silent, vibration-free operation when the engine is started again by the fuel-saving start-stop system.

This TrelleborgVibracoustic system breaks new ground in the field of vibration engineering solutions for energy-saving drivetrains. The benefits of the system merge harmoniously with automakers' lightweight design requirements.


TrelleborgVibracoustic produces a number of different NVH solutions for the crankshaft/belt pulley interface. Development expenses and therefore the cost for our customer can be significantly reduced by combining system simulation and component expertise at an early stage in the process. 

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