The two fans represent a torque converter in its simplest form. A torque converter, however, is filled with transmission fluid. The fan (called an ‘impeller’) that moves the fluid is connected to the engine – that impeller is permanently connected to the inside the shell of the torque converter, which is what you see when you look at an automatic transmission somebody has removed from a vehicle. What you can’t see is the other fan (called a ‘turbine’) that is inside the shell – that fan is connected to a shaft (called the ‘turbine shaft’) that runs through the center of the transmission and as it turns, it applies power to the components in there. When the transmission is in neutral or park and the engine is running, the shaft is free to turn without doing much of anything else.