These two terms, when it comes to transmissions, are often used interchangeably, which is false. Automatic transmission and automated manual transmissions are completely different types of equipment. The most critical difference is the automatic transmission uses a torque convertor rather than a typical two-plate manually activated clutch. Here are some key similarities and differences that any driver should be aware of.
One of the big differences between an automated and automatic transmission is that automatic transmissions use the same set of gears to produce all of the different gear ratios. A planetary gearset makes this function possible.
Rather than a traditional gearshift as in the case of a manual transmission, the ratios in a planetary gear rotate, driven through a set of clutches that make the planetary ratios change.
This then becomes a gear shift, but because the input shaft passes through a hydraulic torque converter, the engine does not have to decelerate during a gear change. The engine turns a turbine inside the torque convertor housing at the front of the transmission. The torque is then transmitted through the planetary gears to the output shaft, which drives the wheels.
The gear ratios are actually determined by the number of teeth on the gears inside the planetary gears, and which of those gears is actually in use. Automatics are also used in heavy trucks, which typically have five to six forward speeds, and one reverse speed.
Automated transmissions are a standard manual gearbox with electrical servos that automatically execute gear changes and manage the clutch. Beyond the electric control and actuation of the gear changes, the manual is not much different from its fully manual siblings.
The manual transmission engages and disengages different sets of gears on two countershafts linked to the output shaft to create various gear ratios.
The gear steps are more or less equally spaced to improve the predictability of a gear change for the driver. Multi speed manuals such as 13 and 18 speed models have a close gear step to permit better matching of engine to road speed. Generally, North American manuals have 8-18 gear ratios, plus a two or three range reverse gear.
If you have any questions regarding both automatic and automated transmissions, and simply just transmissions in general, call Grisham Transmission today. With over several years in the transmission industry, they have the required experience it takes to tackle any transmission or car problem. Contact them today at 615-226-2789.