Figure 7-13. - Simple reduction-direct drive.

direction (fig. 7-14 ).In both cases, the output member is turning in the opposite direction of the input member.

Coupling (Torque Converter Operation)

The automatic transmission is coupled to the engine through a torque converter.

The torque converter is used with the automatic transmission because it does not have to be manually disengaged by the operator each time the vehicle is stopped. The cushioning effect of the fluid coupling within the torque converter allows for shifting without interruption of engine torque application. The torque converter serves two primary functions. First, it acts as a fluid coupling to connect engine power smoothly through oil to the transmission gear train. Second, it multiplies the torque from the engine when additional performance is desired.

Figure 7-14. - Reverse drive.