Torque Converter - Hitachi ZW180 Technical Manual

COMPONENT OPERATION / Drive Unit

TORQUE CONVERTER

The torque converter consists of the converter wheel
assembly, pump drive device, turbine shaft, and others.
In the converter wheel assembly, impeller wheel (7)
and turbine wheel (3) are mutually opposed with stator
wheel (4) installed between them and they are all
contained in the case filled with oil.
Engine rotation is transmitted from the engine flywheel
to the transmission through input plate (2), cover wheel
(1), impeller wheel (7), turbine wheel (3) and turbine
shaft (11).
Hydraulic oil for the torque converter supplied from the
transmission control valve enters the converter wheel
through the oil passage of the stator support.
When impeller wheel (7) is rotated by the engine
rotation, oil flows along the blade of impeller wheel (7)
toward the periphery, and flows into turbine (3). This oil
flow collides with the blade of turbine wheel (3).
Therefore, turbine wheel (3) and turbine shaft (11)
rotate. The output torque of turbine shaft (11) is
generated by the reaction force caused by the oil flow
direction change due to the blade of turbine wheel (3).
Stator wheel (4) always rectifies the oil flow from
turbine wheel (3) in the determined direction, and flows
oil into impeller wheel (7) in order to increase torque.
T3-9-2