Torque Converter: Description and Operation

Construction
The torque converter is composed of the pump impeller which is rotated by the engine, the turbine runner and lock-up clutch which are fixed to the transmission input shaft, and the stator which is attached to the stator shaft via the one-way clutch. The torque converter is filled with ATF.

Operation




The pump impeller is rotated by the engine, which causes a flow in the ATF inside the torque converter.

The flow of ATF caused by the pump impeller strikes the turbine runner, providing a force to rotate the turbine runner, and transmits torque to the input shaft.

The flow of ATF which has hit the turbine runner rebounds and tries to flow in the direction opposite to the direction of rotation of the pump impeller, but the stator returns the flow to the original direction of rotation. So the ATF becomes a force which supports the pump impeller and increases torque.

NOTE: Although the stator is immobilized by the one-way clutch, should the one-way clutch become defective the stator will be rotated by the flow of ATF, the flow of ATF will not be reversed, torque will not be increased and the problem of inadequate acceleration will occur.




The lock-up clutch is pushed against the front cover by fluid pressure so that the engine revolutions are directly transmitted to the input shaft without the medium of the ATF.