Mark,

The torque converter used over the last 50 yrs or so is a type of fluid coupling. The main difference is that a fluid coupling does not multiply the torque like a torque converter. The TC consists of 3 main components aside from the outer shell. These parts are..Impeller, stator, and turbine.
As the engine rotates, it is obviously spinning fluid around inside the TC. The 3 parts of the converter all have fins used to direct the flow of fluid through the TC. Fluid first hits the impeller which is driven directly by the engine. This fluid is directed through the stator which redirects the fluid into the turbine fins thus turning the internal parts of the transmission creating movement. The turbine is similar to the impeller except that it is not connected to the engine but the input shaft of the transmission. Now, the stator has fins which direct the fluid from the impeller fins to the turbine fins. The angle of the turbine, stator, and impeller fins determine the relative stall speed of the TC. Is that enough or have I only created more questions? :)

Buddrow