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(2) Hydraulic torque converter
a) Function of hydraulic torque converter
Its main functions include: achieving automatic shift(wich means to vary speed
without pause), increasing traction force, improving the working performance of
engine, preventing engine from extinguishing, upgrading speed-varying quality and
facilitating gear shift .
b) Structure of hydraulic torque converter
The hydraulic torque converter consists mainly of pump wheel, turbine and guide
wheel. The pump wheel is fixed on input shaft, turbine on output shaft and connected
with the input shaft of gearbox through a spline, playing the role of transferring power
to hydraulic gearbox. The guide wheel is fixed on the shell of torque converter.
c) The working principle of Torque Converter
The pump wheel is rotated by the drive shaft, so that the flow in the pump is
forced out by the centrifugal force along the vanes of pump wheel (at this time
mechanical energy is converted to kinetic energy).
Thereby the fluid flows into the impeller of turbine wheel, transmitting torque to
output shaft. The direction of flow leaving the turbine wheel is changed by the startor
wheel so that the liquid flows into the pump wheel at the best angle. At this time a
reaction torque pushing the startor in generated ,as a result of which the output torque
becomes larger than the input torque by the valve and the dispersion is equal to the
reaction torque.
As the rotational speed of turbine wheel increases, approaching to the input
rotational speed, the change of flow angle reduces, and the output shaft torque also
reduces. And finally the fluid begins to flow contrary to the direction of stator vanes,
as a result of which the reaction torque beings to affect in the reverse direction.
In this case the output shaft torque becomes smaller than the input shaft torque.
So as to prevent this phenomenon, a free wheel(one-way clutch) is provided on the
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