a driving force to the driven member.
However, in the torque
converter, the vanes are curved and additional rotatable members
provide the means of increasing torque through the unit.
additional members can reverse the direction of the moving oil before
it reenters the driving member, thus nullifying any negative effect
produced by vane curvature.
Thus, the torque converter not only acts as a fluid coupling, it also
provides a speed-producing, torque-multiplying connection between the
driving and the driven shafts. It actually can take the place of the
conventional transmission because, with the torque converter, there
is no need for gearshifting; the vehicle can be accelerated from a
standing stop to high speed with the torque converter providing, in
Partical Cutaway View of a Torque Converter.
In actual practice, the torque converter is used with a gear system
(including planetary gears) to provide a high range for normal
operation, a low range for steep hills or pulling out of mud,
reverse, and neutral. A parking position is also provided