The steel pushing
Rubber V Belt
continuously variable transmission (CVT) is now commercially available
in the automobiles of a number of manufacturers but to date it has not
led to a significant reduction in fuel consumption. To develop its full
potential it is necessary to have a good mathematical model of the
system. A number of models have been described in recent years but all
make use of a Coulomb friction model for the shear connection between
the belt and the pulleys. This paper proposes a friction model based on
elastohydrodynamic theory. It is shown that there is good agreement
between measured and calculated slip values for the transmission which
justifies use of the model.
All power transmission belts are either friction drive or positive
drive. Friction drive belts rely on the friction between the belt and
pulley to transmit power. They require tension to maintain the right
amount of friction. Flat belts are the purest form of friction drive
while V-belts have a friction multiplying effect because of wedging
action on the pulley.
Positive drive or synchronous
Automotive V Belts
rely on the engagement of teeth on the belt with grooves on the pulley.
There is no slip with this belt except for ratcheting or tooth jumping.