P.A.R.I.S.: Pendulum acyclism reducer integrated system 2000-05-0320
Evolution of automotive diesel engines has led to the production
of smaller and smaller engines with increasingly higher torque. The
reduction in external dimensions means smaller flywheels, and the
increase of torque rates, higher cyclic irregularities that
today''s flywheels even with dual mass techniques are no
longer able to cope with.
Because of this, "damper" type absorber devices which
control torque vibrations due to cyclic irregularities are no
longer efficient to decrease rotating vibrations to an acceptable
The best solution to cope with these problems is a tuned
rotating pendulum: P.A.R.I.S. (Pendulum Acyclism Reducer Integrated
System). This vibration absorber system can be easily integrated
into a standard engine flywheel.
P.A.R.I.S. systems show a very high efficiency level. Normally,
in order to decrease the 2nd harmonic level (mainly responsible for
cyclic irregularities in 4 strokes 4 cylinders engines) to 60%, a
standard flywheel would have to have around 15 times its actual
The mean torque level is not affected by P.A.R.I.S., only the
instantaneous torque in counterbalanced by the pendulum.
In addition, the P.A.R.I.S. system device has the great
advantage of being independent of engine speed. It is efficacious
throughout the whole range of speed, as compared to damper
vibration absorbers, which are tuned for a specific frequency.
On the other hand, P.A.R.I.S. is not adapted for the whole
harmonic range generated by the engine, but only for those
harmonics it has been tuned for.
Another positive aspect of this solution is that it is a full
mechanical system, needing no electronic controls, which consumes
hardly any energy and these due only to small friction losses.
Application examples targeted by this patented system are:
torque regulation, due to reduction of cyclic irregularities in
order to achieve smaller vibration levels, idle speed decrease for
consumption and pollutant reductions, in camshaft applications -
increase of the maximum rotating speed.
Fabrice Vidal, Daniel Drecq, Guy Louradour