The dual mass flywheel is an important component in the engine of a car. It is a rotating mechanical apparatus which works with the clutch to disconnect the engine from the wheels, which enables the driver to change gear. The flywheel works with the clutch to actively engage and disengage the power transmission system from the drive shaft. The dual mass flywheel works with the clutch by helping to adjust the friction between the spinning engine and stationary wheels, enabling the driver to change gear with ease and to stop the car smoothly without damaging the engine. The design of the dual mass flywheel enables it to significantly reduce the vibration and noise produced by the engine, creating a much smoother drive. It works to lessen the torsional oscillation of the entire drive train, significantly reducing the harshness, noise and vibration of the engine.
The dual mass flywheel is normally made of steel or, more commonly in modern vehicles, carbon fibre and it spins on bearings which are either of the traditional type or magnetic bearings. It is fixed to both the crankshaft and the clutch, attaching directly to the clutch plate. The other side of the clutch is mounted to the manual transmission, which allows the crucial process of disengaging it to change gear. The dual mass flywheel is basically two flywheels. The inner part joins directly to the engine and the outer part joins to the inner by means of a sprung connection. The benefit of having these two separate parts is that the outer part is able to move separately to the inner part, due to the sprung connection between the two. This means that when a power surge/pulse is produced by the pistons, the inner part of the dual mass flywheel takes this force directly, allowing the outer part to further dampen the vibrations.
Modern, high powered engines produce a high level of torque. Essentially the dual mass flywheel functions primarily as a weight, which works to smooth and dampen the force and vibration produced by the pistons in the engine, creating a more refined driving experience. It works by managing the torsional vibration in the crankshaft, and the drive train as a whole, by levelling the pulses of energy produced by the pistons. It regulates the high torque generated by the rotating engine by sending the energy through a spring system which dampens and cushions the drive to the transmission which serves to reduce the noise and vibration experienced by the people travelling in the car. As well as acting as a weight, the dual mass flywheel has a gear around the length of its circumference which operates the starter motor and functions as a mount for the clutch which provides a variable connection to the transmission. The dual mass flywheel helps to cushion gear changes and makes this process smoother for the driver and it counteracts the rocking of the engine on its mounts, produced by the rotation of the crankshaft, reducing wear on other parts of the transmission. The dual mass flywheel is able to store rotational energy received by torque from the firing of the pistons, and later apply this energy to the crankshaft to compensate for when a piston is not firing but instead compressing the air and fuel mix ready for the next firing.
If you hear a grinding or rattling noise when you start the engine of your car, or are having difficulties engaging the clutch, it could be an issue with the dual mass flywheel and should be looked in to as soon as possible. A faulty dual mass flywheel, if left unaddressed, will inevitably lead to a damaged clutch. The common rule of thumb is to change the dual mass flywheel at the same time that you change the clutch. Both parts need to be in good working order and excellent condition to be able to function correctly. The dual mass flywheel is subjected to great levels of friction and does suffer naturally from wear and tear. Replacing this part with the dual mass flywheel will ensure you get a product that is perfectly compatible with the make and model of your vehicle.