Inside Allison Transmissions' Torque Converter

The torque converter can either multiply the torque generated by the engine or operate as a fluid coupling disconnecting the engine from the wheels or allow the engine to turn slightly faster. The torque converter is key to the fully automatic and provides many of the benefits such as reducing shock and strain on the entire driveline, including the engine. It is also highly efficient when it is multiplying torque using a component called a stator. For example, modern automatic transmissions have a lock up clutch that provides a direct connection from the engine to the transmission eliminating wasted energy so that fuel economy can be maximized. It is the torque converter that provides many of differentiators that define performance between a fully automatic transmission and an automated manual (AMT) . With an AMT, every time a shift occurs, the clutch separates the engine from the transmission. Therefore, at every shift, there is a loss of power, momentum and speed. With a fully automatic, engine and transmission are always connected leading to more efficient use of engine power, thus providing faster acceleration and improved productivity. It was these attributes that led to fully automatics being the de facto choice in fire (performance and acceleration) and refuse applications (productivity and protecting the driveline during frequent stop/start operation). It is these advantages and others that are driving fully automatic into new applications such as distribution and construction.