How Torque Converters Work

The torque converter is used to transfer power from the engine to the transmission.

Impeller

The impeller is a centrifugal pump that is attached to the engine. As the engine rotates the fluid is pushed through the impeller transferring mechanical energy from the engine to the fluid, as the fluid exits the impeller it is pushed into the turbine.

Turbine

The turbine receives fluid from the impeller, the turbine absorbs the energy from the fluid as it enters the turbine vanes. The fluid energy is absorbed by the turbine and converted to mechanical energy rotating the turbine. After the energy is absorbed by the turbine; the fluid exits the turbine opposite of engine rotation. The oil exiting the turbine is now directed to the stator section of the converter.

Stator

The stator is located between the impeller and the turbine of the torque converter. The stator creates torque multiplication. Torque multiplication is possible because of the increased fluid speed that exits the turbine. The wasted energy that is not absorbed from the turbine is channeled into the stator. The stator has vanes that redirect the fluid back into engine rotation creating torque multiplication. The stator is also largely responsible for stall speed. Stall speed is the point where the engine will not accelerate any higher RPM with out spinning the wheels.

Lock-Up Clutch

The lock-up clutch is a mechanical clutch that is connected to the input shaft of the transmission. When the torque converter clutch is engaged to the lock-up position the converter clutch is hydraulically pushed into the cover of the converter. This lock-up engagement transfers power through the lock-up clutch lining. At this point all of the engines torque must be transferred through the clutch lining bypassing the fluid coupling portion of the impeller, stator and turbine section of the torque converter