A Look Into Different Types Of Vehicle Transmissions

Transmissions, as the name suggests, are a primary mechanical device that is used universally to transmit power from a power source to a non-powered terminal. In automobiles, transmissions are the primary mode of transmitting power to the wheels from the engine. The first automobile in the world patented by Karl Benz did not have any transmission but courtesy of two gentlemen, Louis-Rene Panhard, and Emile Levassor, manual transmissions came into existence.

While manual transmissions are the oldest type of automobile transmissions, it was followed by automatics which was invented by Alfred Horner Munro. A transmission unit channels power from the engine in a graded way by utilizing gear ratios to deliver a specific amount of power at a specific gear number. In this article, we’ll take a look at the different types of automobile transmissions.

6. Manual Transmission

The most simple and previously widely-used type of transmission in automobiles is a manual transmission. Even at present, semi-trailers and budget cars do get manual transmission as a cost-effective way. In a manual transmission, the driver is required to change the gears manually with the help of a gear shifter lever. While the engine is spinning at a constant speed even at idle, there is a flywheel attached to the crankshaft of the motor and the clutch is placed between the transmission’s input shaft and the flywheel.

The clutch is responsible for engaging or disengaging the transmission from the motor when required. When the clutch pedal is pressed, it disengages the clutch from the motor so that the gears can be changed. Letting go of the clutch pedal engages the clutch and motive power is transmitted to the wheels. This type of transmission is the toughest to drive and takes quite some time to learn as well.

5. Automated Manual Transmission

This type of transmission is quite similar to the manual ones but it offers the ease of shifting gears by eliminating the use of a manually operated clutch. The clutch is internally placed and the gears are changed with the help of multiple sensors and actuating motors. The transmission control module and the engine control unit get pre-programmed gear shift patterns along with predetermined engine RPMs at which the gear shifts need to happen.

As such, it gives automakers the opportunity to optimize both the ECU and the TCM for optimal fuel efficiency and performance. Examples of some cars with AMT units are the Proton Savvy, the 2003 Maserati Quattroporte V, and the 2005 Aston Martin Vantage.

4. Intelligent Manual Transmission

Intelligent manual transmissions are the latest innovative tech from Hyundai and are implemented in a few of its vehicles. This unit is primarily a manual gearbox but the clutch pedal has been eliminated. However, this transmission still needs the driver to select the gears manually.

The gear lever is connected to a series of sensors that predicts instantly if the driver is intending to shift to a higher or a lower gear or to neutral. As such, the system engages and disengages the clutch to smoothly change gears.

3. Automatic Transmission

The other major type of transmission in automobiles is an automatic transmission. Invented back in 1921, automatic transmissions have seen an ever-increasing application in cars and were primarily found in expensive vehicles earlier. However, due to their ease of usage and modernization, automatics have found their way into affordable vehicles as well. It might sound comical but, the three primary components of an automatic transmission are the ring gear, planet gears, and their carriers, and the sun gear.

This planetary gear system is responsible for selecting the best gear ratios or gear numbers according to the engine speed and the throttle input. One spectacular feature of the ATs is overdrive gears where the transmission spins at a higher speed than the engine to allow for a relaxed engine speed with a higher velocity of the vehicle to save fuel on the freeways.

2. Continuously Variable Transmission

CVT or continuously variable transmissions are the third-most-popular type of transmission and are essentially a much simpler version of an automatic transmission. In this transmission, there are fewer moving parts and doesn’t have any fixed gear ratios either. Instead, the transmission works with the ability to produce infinite gear ratios with the help of two pulleys and a rubber or steel belt. The rubber or steel belt is called the V belt and among the two pulleys, one is called a drive pulley and the other is a driven pulley. The drive pulley is connected to the crankshaft of the engine for motive power while the driven pulley is connected to the former with the V belt.

Both the pulleys have variable diameter cones with an angle of 20 degrees in front of them and the belt rides on them. The variable grooves increase or decrease in diameter to keep the tension of the belt tight always. As such, when accelerating, the higher engine speed results in an increased diameter of the driving pulley and a smaller diameter of the driven pulley creating a lower gear ratio while cruising, the driven pulley has a higher diameter and the driving pulley has just the opposite. Some vehicles with CVTs include the Chrysler Pacifica Hybrid, the Honda Accord Hybrid, and the Nissan Altima.

1. Dual-clutch Transmission

Another popular type of automatic transmission is the dual-clutch transmission that finds application in sports cars and supercars. As the name suggests, this transmission gets two clutch sets one for handling odd and another for handling even number of gear ratios. Inside the transmission box, there are two transmission shafts that transfer the power from the engine to the transmission unit. One shaft is hollow and placed on the outside, allowing the other shaft to be placed on the inside.

The outer shaft is responsible for handling the even gears such as the 2nd and 4th while the inner shaft handles the 1st, 3rd, and 5th gears. The primary advantage of this transmission is blisteringly quick gear changes with little to no power loss while shifting. Some cars with DCT are the Nissan GT-R, the Audi R8, and the Porsche 911.

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