Dual Mass Flywheel.

["Neil Deshpande" <Ndeshp@xxxxxxxxxxxx>]

Someone asked about a dual-mass flywheel.

A dual mass flywheel divides the mass of the flywheel into two and =
installs dampers between the two masses.  What this does is torsionally =
decouple the driveline from the engine.  The engine is the main exciter of =
the driveline - this is no surprise - and generates torsional vibrations =
of the DRIVELINE.  The first mode - resonant condition - is about 10 Hz, =
the second below 30 Hz and so on usually.  The decouple could lower the =
third to below 30 Hz, which means it would not be excited/resonant most of =
the time, unless you were driving at really low engine RPM or something.

The split flywheel results in a quiet vehicle, but has the following =
disadvantages:
1. A significant cost increase
2. Increased ENGINE torsional vibration due to reduced primary flywheel =
inertia
3. Other natural frequencies may be moved into the operating range of the =
vehicle
4. Damper operation at high RPM may be affected by centrifugal forces on =
the springs

My apologies for the technical content.

Neil Deshpande
1988 325 is
1989 325 iC

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