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Content:
- What is a transmission?
- Mechanical gearboxes
- Automatic gearboxes
- Continuously Variable Transmissions (CVT)
- Transmissions with double clutch
- Sequential gearboxes
- Robotic transmissions (Semi-automatic)
The word "transmission" or "gear box" is one of those terms that many people are familiar with, but most people don't know the differences between the many types of transmissions in use today. In any vehicle with an internal combustion engine, the transmission is one of the most important components. This article explains some of the most popular automotive transmissions today and how they work.
What is a transmission?
Transmissionis a device whose purpose is to change the speed of rotation of the engine according to the amount of power required. Gearboxes ensure the correct transmission of power from the engine.
Try to imagine the movement without it. The drive wheels would rotate the same number of times with each revolution of the crankshaft. Such a car would be unsteerable because the drive wheels would always be turning; stopping the car would mean turning off the engine, and starting it would mean the car would suddenly pull away as soon as you turned the key. Its performance would be low, and fuel consumption - high.
The presence of a gearbox guarantees, that your car's engine rpm is used in the best way, its performance improves and you can put it in neutral gear. Neutral transmission uses a clutch mechanism that separates the rotation of the engine from the rotation of the drive wheels. The transmission is simply an indispensable part of any vehicle with a diesel engine.
Many types of transmissions have been developed and implemented by automotive engineers throughout history. We can divide them into two large groups:automatic and mechanical transmissions. Especially in the last few decades, automatic transmissions have developed much more than manual transmissions. We will tell you the main points that you need to know about car transmissions and help distinguish between their types.
1. Mechanical gearboxes
A manual transmission has been used since the beginning of the automobile era. Correct operation involves depressing the clutch pedal, disconnecting the transmission from the engine, manually selecting the desired gear, and depressing the clutch pedal.Operating a manual gearbox requires certain skillsand coordination of the left foot (clutch), right foot (accelerator), and right hand (gear lever). This is often difficult to learn because shifting gears requires coordinated movements to drive the car smoothly.
The advantages of a mechanical gearboxthere is a physical unity with the car, a strong involvement of the driver and a sense of control. For this reason, enthusiast cars and some sports cars are still often equipped with manual transmissions. Some motorists still find manual transmissions the best option, even though they have less power and slower shift times. But as automatic transmission technology improves, manual transmissions will become increasingly rare.
2. Automatic gearboxes
Most modern cars have automatic transmissions that have been around since the 1940s.The principle of operation of an automatic transmissionas simple as possible. The driver puts the car in position "D" (for movement). The gearbox automatically switches gears. Driving a car with an automatic transmission is much easier, because there is no clutch pedal - brake and accelerator.
An automatic transmission, especially a modern one with complex electronics, is a much more complex device than a manual transmission. A classic automatic transmission has a torque converter that replaces the clutch mechanism of a mechanical transmission, smoothly shifting gears without any driver intervention. A more relaxed driving experience, efficiency and practicality - advantages of automatic transmissions.
Initially, automatic transmissions had 2 or 3 speeds. Modern automatic transmissions have8 or even 10 speeds. The more gears a transmission has, the better it can use the engine's power to achieve high efficiency and performance. Modern advancements have improved shift times in automatic transmissions, making them much faster than manual transmissions ever could be. This is one of the reasons why automatic transmissions dominate the automotive industry today and are indispensable for some types of vehicles, such as SUVs or supercars. Many modern automatic transmissions also have "manual mode" or a function that allows the driver to control the transmission by selecting the desired gear.
3. Stepless gearboxes (Variators or CVTs)
A CVT is an automatic transmission because it does not have a clutch pedal and the driver does not need to shift gears.There are several types of CVTs, but the most common is the pulley type (variator), which uses a V-belt or chain to connect two cones, one driven by the engine and the other connected to the drive wheels. As the pulleys move toward and away from each other, the CVT creates a different gear ratio, resulting in a different amount of rotation of the drive wheels. For this reason, CVTs are often referred to as "continuously variable" transmissions. They do not have a predetermined set of gears. Instead, they contain a continuous set of gear ratios that are used throughout the rev range.
Advantages of variatorsthere is optimal use of power and torque of the engine (because the gear ratio is always in the right ratio), compact dimensions and less weight. However, the CVT transmission is less and less used in passenger cars because it is not designed for heavy use and towing, and is not ideal for highway driving. In scooters, some cheap cars and the Toyota Prius, a variator is common.
4. Transmissions with double clutch
DCT or Dual Clutch Transmission- one of the most interesting automatic transmissions found in modern cars. This design has become popular in sports cars and high-performance vehicles due to its compact size and lightning-fast shifting. A DCT is an automatic transmission, but it has two clutches, one for odd shifts and one for even shifts.Unlike a conventional automatic transmission, the DCT does not have a torque converter. It can switch gears almost instantly, as the system can quickly use one or another clutch package associated with 1-3-5 or 2-4-6 speeds.
Volkswagen has successfully implemented DCT inGolf MK4 R32in 2003, after which it was used on many other cars. The DCT is lighter than an automatic transmission, so it is easier to install on front-wheel drive models with transverse engines. It is also a favorite among sports car fans, as it has proven its durability in high-performance modes and unrivaled speed of shifting gears. Paddles behind the steering wheel can be found in most cars equipped with a DCT transmission.
5. Sequential gearbox
Sequential mechanical gearboxrarely used in passenger cars, but is the best choice for racers. Precisely designed to provide the feeling of control and control of a manual transmission with automatic speed and precision. It is designed for the extreme demands of the race track. A sequential manual transmission has a clutch. However, the clutch is used only for starting and selecting the first gear. After that, the driver uses the shifter or paddle shifters to shift gears. By not having to use the clutch every time, the driver can focus on driving the car while quickly changing gears.
Due to the high cost, this type of transmission is not used in consumer cars, despite its advantages. Also, there are no gear skips or kick-down functions. A sequential manual transmission can only shift up or down, rather than skip two or three gears like a conventional automatic transmission.
6. Robotic transmissions (Semi-automatic)
Over the years, many companies have experimented with hybridizing manual and automatic transmissions to create a semi-automatic transmission.The main ideawas to combine the reliability, efficiency and control of a manual transmission with the convenience of an automatic. So far, the success of semi-automatic transmissions has been mixed, and they have not found widespread use in consumer cars.
Semi-automaticcan use the clutch to start the car, but the rest of the switches are made automatically. The driver does not need to do anything. Another option is a clutchless design (such as a Porsche Sportmatic) that starts like any automatic and then shifts like a manual transmission. The semi-automatic has proven to be problematic, lacking the performance and responsiveness of an automatic or manual transmission, although the basic concept is sound.
Nowcar manufacturers are actively developing automatic transmissions and trying to implement them in the nexttype of car engines-electric. As for cars with internal combustion engines (for which automatic gearboxes were built), most likely, car manufacturers will not introduce anything fundamentally new, because the election standards will come into force very soonEuro-7, which do not provide for the installation of "clean" engines in the car. Therefore, many auto experts conclude that cars with Euro 7 standards will be the last cars with internal combustion engines that allow you to get a true drive from shifting gears and direct interaction in driving the car.
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