Transmission

What is a transmission

The transmission is a device that is connected to the back of the engine. It transmits mechanical power from the engine to the drive wheels. The transmission is used to reduce the revolutions of the crankshaft down to a reasonable value by using interlocking gears to reduce the number of revolutions. By doing so, it makes more effective usage of the engine's torque and helps to keep the engine operating at an appropriate speed. 

Common types of Transmission  

• Manual transmission

• Automatic transmission

• CVT (Continuous variable transmission) 

• Semi automatic transmission

• TipTronic gearbox

• DSG (Direct shift gearbox)       

Manual transmission

Most manual transmissions feature a movable gear selector and clutch. The driver of the vehicle has to manually select and engage the gear ratios. The clutch is a coupling device that is used to separate the engine and transmission. Without it, the engine would stop, causing the vehicle to stop. The clutch allows the engine to continue working when you are waiting at the traffic light. Changing gear without a clutch would be difficult with the crank spinning continuously while the engine is running.

Automatic transmission

                                                                                                                                                                         

An automatic (also called automatic gearbox, or auto transmission) is one type of motor vehicle transmission that can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually. Most automatic transmissions have a defined set of gear ranges, often with a parking pawl feature that locks the output shaft of the transmission.

Similar but larger devices are also used for heavy-duty commercial and industrial vehicle and equipment.Some machines with limited speed ranges or fixed engine speeds, such as some forklifts and lawn mowers, only use a torque converter to provide a variable gearing of the engine to the wheels.

CVT  (Continuously Variable Transmission)

So, you looked at the picture provided and mistook it for the conventional automatic transmission. That had to happen as there is not much of difference between the two. So firstly, let me tell you what is the main difference between a CVT and conventional automatic transmission? The conventional automatic transmission has fixed ratios while the CVT doesn’t. The drive in the CVT goes through two variators and a V shaped steel belt. And the ratios are electronically held according to the throttle position and load on the engine.

Usually in the normal gearbox or any other automatic gear box whenever the car accelerates, it makes noise accordingly. But a CVT equipped car will not make a sudden change in the noise because the CVT holds the engine at the best possible rate for acceleration. But generally CVT’s are not advised for high speed as it will deter its fuel efficiency. Reason being they consume the hydraulic power. Also, the amount of torque is limited. Actually this all is because of the fact that everything is totally dependent on the amount of friction between belt and variators. But on the positive side, CVT’s makes less noise. They are much more compact than the conventional automatic gearshift, hence they take less space. It also improves the ride quality.

Semi automatic transmission

A semi-automatic transmission (also known as automated transmission, self-changing transmission, clutchless manual transmission, automated manual transmission, flappy-paddle gearbox, or paddle-shift gearbox) is an automobile transmission that does not change gears automatically, but rather facilitates manual gear changes by dispensing with the need to press a clutch pedal at the same time as changing gears. It uses electronic sensors, pneumatics, processors and actuators to execute gear shifts on the command of the driver or by a computer. This removes the need for a clutch pedal which the driver otherwise needs to depress before making a gear change, since the clutch itself is actuated by electronic equipment which can synchronise the timing and torque required to make quick, smooth gear shifts. The system was designed by automobile manufacturers to provide a better driving experience through lightning fast overtaking maneuvers on highways.

Tiptronic

These are one of the most underdog types of transmissions. Why so? Because, these types of transmissions are amongst the costliest transmissions and hence, rare because of the same reason (cost).  Usually, in order to change the gear, what does a driver do? First he gets hold of the clutch and then pulls the gear shift to the next level, right? But when we talk about the Tiptronic gear shift, one doesn’t have to do all that. The clutch in the car fitted with a Tiptronic gear shift is automatic. So, one has to only use throttle in order to increase the speed. But what the driver has to do actually? All a driver has to do in order to change the gear in such type of transmission is push the gear selector forward for up-shift and downward for downshift. Now the advantage of a Tiptronic gear shift over the other automatic gear shifts is that, it tends to give more power in the hands of the driver. This more power is a result of the result of more control. Just imagine, ended are those fuzzy days when you had to struggle with the transmission option available in your normal car as now the Tiptronic gear shift is here. Now lets come back to reality and face the heat that this type of transmissions are way above costlier than the any other automatic transmission (at least the cars with Tiptronic gear shifts are). If you really want to know how this gear shift looks like then I’m afraid you have to be satisfied with the picture illustration we have provided until and unless your dad is a millionaire. Anyways, this type of gear shift could be found inside Volvo S80. To add to the “aww”, this gear shift also has a feature wherein, just by shifting maps in the control unit, the gear shift will automatically shift according to the style of driving.

DSG (Direct shift gearbox) 

A direct-shift gearbox (German: Direkt-Schalt-Getriebe), commonly abbreviated to DSG, is an electronically controlled dual-clutch multiple-shaft manual gearbox, in a transaxle design – without a conventional clutch pedal, and with full automatic, or semi-manual control. The first actual dual-clutch transmissions derived from Porsche in-house development for 962 racing cars in the 1980s.

In simple terms, a DSG is two separate manual gearboxes (and clutches), contained within one housing, and working as one unit. It was designed by BorgWarner,  and was initially licensed to the Volkswagen Group, with support by IAV GmbH. By using two independent clutches, a DSG can achieve faster shift times, and eliminates the torque converter of a conventional epicyclic automatic transmission.