Half-shaft torsional damping
Half-shaft torsional damping
(OP)
Hi,
FWD cars often seem to use a clamp-on or spline-on torsional damper. Some seem to be simple masses, others have an elastomer component too.
Can anyone point me to a calculation of how these dampers work, and what their capabilities are? Google just throws up countless references to parts manuals & 'auto 101' type references.
Thanks, Ian
FWD cars often seem to use a clamp-on or spline-on torsional damper. Some seem to be simple masses, others have an elastomer component too.
Can anyone point me to a calculation of how these dampers work, and what their capabilities are? Google just throws up countless references to parts manuals & 'auto 101' type references.
Thanks, Ian





RE: Half-shaft torsional damping
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Half-shaft torsional damping
I can understand where the damping comes from in the elastomer versions, but not the bolt-on masses.
Maybe they are trying to create two stiffer shafts connecting an inertia?
Regards, Ian
RE: Half-shaft torsional damping
Adding inertia is an inelegant solution, but it is quick, robust and cheap.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Half-shaft torsional damping
The only real torsional dampers I'm aware of were in the late 80's early 90's upper end GM FWD cars had torsional dampers to lessen the clunk in the transmission while shifting into drive from reverse.
RE: Half-shaft torsional damping
Your post is very interesting. I can imagine coupled modes being a problem for auto drivetrain components when it comes to minimizing every potential source of noise or vibration in modern production vehicles. But I also can see how difficult it would be to design an elastomeric mass dampener that is effective at mitigating a low-frequency (and energetic?) bending mode in a driveshaft without creating problems at other operating conditions. The huge combination of gear ratios and engine firing frequencies possible between the engine flywheel and drive wheel would seem to make the design task extremely difficult.
RE: Half-shaft torsional damping
Decouplers are much more useful.
Litens Automotive is the leader, but does not make much readily available for public study. http://www.litens.com/vibprod2.cfm
Cheers,