6-42. VIBRATION DAMPER, CRANKCASE FRONT COVER AND CRANKSHAFT PULLEY.
a. Vibration Damper.
The double (rubber) damper shown below is made up of a light damper, a heavy damper, a hub, an inner cone, and
an outer cone. The light and heavy dampers in the assembly are in turn made up of rubber blocks bonded to an inertia
mass in the form of metal ring on one side, and a stamped metal disc on the opposite side.
The two metal parts are, therefore, entirely separated and free to move freely within certain prescribed limits by
virtue of the rubber blocks. The light and heavy dampers are bolted and doweled together and to the driving hub. The
hub in turn is secured in place at the front end of the crankshaft between an inner and outer cone as shown. The two
cones provide an adequate rigid mounting when the crankshaft pulley is drawn up tight against the outer cone by the bolt
in the end of the crankshaft.
Even though these vibration dampers are rigidly constructed, and should give no trouble if given proper care;
nevertheless, since rubber is used in the assembly, certain precautions are necessary. Fuel oil and lubricating oil, as well
as excessive heat, are destructive to rubber. The assembly, therefore, should be protected against these destructive
agents. Furthermore, for the damper to function properly and safeguard the crankshaft, it should be securely fastened to
the shaft by the cones and the crankshaft pulley.