adminTORQUE CONVERTERS
The torque converter is a type of fluid coupling that is used to connect and disconnect the engine from the transmission in an automatic transmission vehicle. It takes the place of a mechanical clutch and within certain operating speed ranges multiples the input providing the equivalent of a reduction gear.
The torque converter is mounted on the input side of the transmission gear train and connected to a drive plate. The drive plate is used to connect the converter to the crankshaft flywheel flange of the engine. The ring gear which the starter motor engages to turn the engine is attached to the drive plate.
The role of the torque converter is as follows; it multiplies torque generated by the engine. It serves as an automatic clutch which transmits engine torque to the transmission. It absorbs torsional vibration of the engine and drive train. It smooths out engine rotation. It drives the oil pump of the hydraulic control system.
The torque converter is filled with automatic transmission fluid and transmits the engine torque to the transmission. The torque converter can either multiply the torque generated by the engine or function as a fluid coupling.
A typical torque converter consists of the following components; impeller, turbine, stator and fluid chamber.
The impeller is the component that is connected to the engines crankshaft and provides the input power to the torque converter.
The turbine is the component that is connected to the transmissions input shaft and receives the output power from the torque converter.
The stator is the component that is located between the impeller and the turbine and helps to improve the efficiency of the torque converter.
The fluid chamber is the chamber that contains the fluid that transfers power between the impeller and the turbine.
The advantages of torque converters are as follows; torque converters provide a smooth transfer of power between the engine and the transmission. Torque converters allow the engine to continue running while the transmission is shifting gears, hence improving efficiency and flexibility. Torque converters can handle high torque inputs from the engine, which makes them suitable for use in high performance vehicles. Torque converters require relatively low maintenance compared to other types of fluid coupling.
The disadvantages of the torque converters are as follows; torque converters can be inefficient, especially at low speeds which can lead to a decrease in fuel efficiency. Torque converters can generate a significant amount of heat especially during high performance driving, which can drastically reduce the lifespan of the converter. Torque converters are very expensive, complex, difficult to repair and expensive to maintain.
Torque converters find widespread use in a variety of applications including; automatic transmission, continuously variable transmission (CVTs), hybrid vehicles and for industrial applications such as pumps, generators, conveyor belts etc.
The future of torque converters is predicated on the trends and the developments in the following; electric torque converters, dual-clutch torque converter, wet clutch torque converter, advanced materials such as carbon fibers and advanced ceramics will improve efficiency and lifespan of torque converters.
SOURCES:
- Torque converters: design, selection and application by Bernd Bertsch and Harald Naunheimer.
- Torque converter handbook by John Miller.
- Automotive torque converter system by Richard D. Shultz.
- Torque converter service manual by Robert W.Foster and Chilton.
- Automotive torque converter technology by James D. Halderman.
- Torque converter systems : design, anmalysis and simulation by J.R Wagner.
