Torque Converter: Description and Operation

Torque Converter
The torque converter is a 4 element assembly. The torque converter contains an impeller, a turbine, a reactor and a torque converter clutch (TCC) for increased fuel economy. It couples the engine to the turbine shaft assembly, provides torque multiplication and absorbs engine shock of gear shifting.

Impeller and Cover
The impeller and cover assembly drives the impeller blades and pump assembly. The impeller is primarily responsible for driving the turbine with hydraulic fluid by means of centrifugal force. The cover provides a mating surface for the torque converter clutch piston plate and dampener assembly.

Turbine
The turbine is driven by centrifugal fluid force from the impeller. The turbine transmits input torque to the drive chain and driven sprocket through the turbine shaft.

Reactor
The reactor redirects fluid flow from the turbine back to the impeller so that fluid rotates in the same direction as the impeller. This action also assists in torque multiplication.

Torque Converter Clutch (TCC)
The torque converter clutch (TCC) provides a mechanical link or direct drive between the engine crankshaft and turbine shaft when applied. The application of the TCC is controlled by the powertrain control module (PCM). Under certain conditions, the PCM sends the appropriate signal to the TCC solenoid, which allows fluid pressure within the torque converter to force the TCC piston plate and dampener assembly against the cover creating a mechanical link between the engine and transaxle.

Turbine Shaft





The turbine shaft connects the torque converter stator with the forward/coast/direct clutch cylinder. When applied, the forward/coast/direct clutch cylinder transmits input torque to the reverse/overdrive ring gear assembly, which also acts as the drive sprocket. This allows input torque to be transmitted from the torque converter to the drive chain and driven sprocket.