Many car enthusiasts are wondering if there is a possibility of gearboxThe lack of classical steps is often confused with the complete absence of transmission as such. At first glance, modern technologies allow you to create machines where the switching of speeds occurs imperceptibly or is not at all in the usual sense. However, the physics of the torque transfer process from the engine to the wheels dictates its own rigid conditions, which cannot be ignored.
If you consider combustion-engineIt is not capable of producing sufficient thrust at low revs to start from a standstill and develop high speed at the same time without changing the gear ratio. That's why. transmission remains a critically important node connecting the power unit and the chassis. Attempts to remove this element lead to either the inoperability of the design, or the need to use fundamentally different types of engines, such as electric motors.
In this article, we will discuss in detail why. gearbox In the classical sense, it is a technical oxymoron for the internal combustion engine, and what alternative solutions are offered by engineers. You will learn about the nuances of work variator, features electric And the reasons why even the most advanced systems require a mechanism to reconcile rotational speeds.
Why an internal combustion engine needs a transmission
The main problem of any combustion engine (ICE) is a narrow range of effective revs. A gasoline or diesel engine is able to produce maximum power only in a certain range of rotational frequency of the crankshaft, usually from 3000 to 6000 rpm. At idle turns, the thrust is catastrophically not enough to move the multi-ton mass of the car from the spot, and at high speeds without a gear shift, the speed of rotation of the wheels would be prohibitive.
That's where it comes in. gearbox (CAT) which acts as a mediator. It allows you to change the gear ratio, providing a balance between the speed of rotation of the wheels and torque. Without this mechanism motor-car I just couldn’t get off the ground or accelerate above the speed of a pedestrian, as the engine would just stall or go into a cutoff.
There is a misconception that if you make the engine very powerful, the box will not be needed. It's not. Even the most powerful. V8 or V12 requires the harmonization of characteristics. Attempt to create gearbox With the ICE will cause the car to either twitch at start or not be able to leave the garage. Engineers have been looking for centuries for ways to simplify this node, but it has not yet been completely eliminated in the combustion engine.
Moreover, the presence of the gearbox allows you to use the engine in an economical mode when driving on the highway, reducing fuel consumption. If the wheels were rigidly connected to the engine, then at a speed of 100 km / h the engine would roar like on a race track, consuming a huge amount of fuel and quickly wearing out. Therefore transmission This is not a whim, but a technical necessity.
Variator and Automatic: When Switching Is Not Feeling
Often drivers, changing from mechanics to modern machines, say that they go by car without gear. That feeling creates this. CVT or hydrotransformer automatic with a large number of stages. In the case of variatorThere are no fixed transmissions characteristic of classical transmissions. Instead of gears, two sliding cones and a belt (or chain) are used here, smoothly changing their diameter.
This design allows for engine work in constant optimal mode while the car accelerates. For the driver, this looks like the absence of switching: the engine speed freezes at one mark, and the speed increases. This creates the illusion that gearbox It does exist. However, technically, the variator is also a box, just stepless.
Modern. robotic boxes Two clutch (DSG, PDK) switch so fast (in milliseconds) that no power flow break is felt. It also misleads inexperienced drivers. But inside these complex units are the same gears and shafts that require maintenance and oil replacement.
⚠️ Attention: Despite the smoothness of the CVT, it is extremely sensitive to overheating and sharp starts. Do not attempt to use CVT tow heavy loads or drift otherwise variator-belt It can break, which will lead to expensive repairs.
It is important to understand the difference between the lack of a sense of switching and the lack of a mechanism. Transmission The variator has a function, and it performs the same function as in mechanics, but it does it continuously. Engineers have achieved this through sophisticated electronics and hydraulics that control cones. Therefore, to call such a car a car without a gearbox is technically incorrect, although subjectively the difference can be imperceptible.
When buying a car with a CVT, be sure to check the history of oil change. Unlike mechanics, where oil is rarely changed, in CVT it is necessary to do it every 40-60 thousand km to avoid bullies on cones.
Electric cars: the only real alternative
The only time the phrase "gearboxThey have a right to exist, they are electric cars. Electric motor It has a unique characteristic: it gives the maximum torque from the first revolutions (actually from 0 rpm). This allows him to confidently start from the spot without having to lower the gear, as does the ICE.
Most modern electric cars, such as Tesla Model 3 or Nissan LeafThey are equipped with a single-stage gearbox. In fact, it is a simple pair of gears that simply transfers rotation to the wheels, slightly reducing the engine speed and increasing traction. There are no complex multi-stage boxes, clutches or hydraulic transformers. In that sense, transmission It's simplified to a minimum.
However, even in electric vehicles, transmission cannot be completely excluded. The electric motor can rotate at a tremendous speed (up to 20,000 rpm and above), while the wheels should not rotate faster than 2000-3000 rpm even at high speed. Therefore gearbox (Downshifting) is mandatory. Without it, the wheels would spin too fast for safe driving, or the motor would not be able to give the desired traction.
Some manufacturers, for example Porsche In the Taycan model, a two-stage box is installed on the rear axle. The first gear is needed for a sharp start, and the second - for movement on the track and achieve maximum speed. This proves that even electricity sometimes needs more than one gear for maximum efficiency.
| Type of power unit | Need for CPT | Number of gears (typical) | Features of work |
|---|---|---|---|
| Gasoline engine | Critically necessary | 5-10 (SLR/ALMA) | We need range for start and speed. |
| Diesel engine | Critically necessary | 6-9 (SLR/ALMA) | High moment but narrow range |
| Electric motor | No need (except for the gearbox) | 1 (rarely 2) | Maximum torque from 0 revolutions |
| Gas turbine | Needed (often electrical) | Depends on the scheme. | It works in a narrow range of speeds. |
Electric cars are the only cars where a complex multi-speed gearbox is replaced by a simple single-speed gearbox, but no car can completely do without torque transmission.
Hybrid systems and their design
Hybrid cars combine in themselves ICE and electric motorThis creates interesting engineering solutions. In popular systems such as Toyota Hybrid Synergy DriveThe planetary mechanism (e-CVT) is used to distribute power flows. There are no classic gears switched by the driver, but the most complex system of interaction between motors and generators performs the function of a box.
In the case of hybrids, such as BMW i3 REx or Nissan e-POWERThe internal combustion engine is not connected to the wheels mechanically. It only works as a generator, charging the battery. Turning wheels is exceptional. electric motors. In this configuration, the engine really works without a gearbox, but the car itself (its running gear) is still driven through the gearbox of the electric motor.
This creates a situation where technically motor-car It has an engine, but it runs like an electric vehicle. However, to call such a car completely devoid of transmission is impossible. The electric part requires its own gearbox, and in parallel hybrids (where the engine can spin the wheels directly on the track), the gearbox is still present, often built into the body of the electric motor.
The complexity of maintenance of such systems is higher than that of conventional cars. Planetary transmissions Electric motors require specific knowledge for repair. It is a mistake to think that a hybrid is just a “machine without a gearbox” that is easier to fix. By contrast, the diagnosis of a hybrid transmission requires expensive equipment.
Myths about non-transmission cars
There are many myths on the internet that exist. gearbox, which supposedly work on compressed air, steam or gravity. None of these projects went beyond the lab prototypes or the fantasies of solo inventors. The physical laws are the same for everyone: to convert energy into motion, you need a transmission mechanism.
One of the popular myths is associated with “air-powered cars”. Even if you imagine an engine running on compressed air, it will need a mechanism for starting and accelerating, that is, an analogue of the engine. transmission. Without changing the gear ratio, such an engine will either stall under load or will work idle.
Another myth is that modern 10-speed machines are marketing, and there are no transmissions. It's not. Engineering physics requires many steps to keep ICE in a narrow corridor of maximum efficiency (CEP). The more gears, the smoother and more economical the engine.
Why can’t ICEs work as electric motors?
The internal combustion engine cannot develop power at low revs due to the features of combustion of the fuel-air mixture and the inertia of the piston group. The electric motor is devoid of these limitations, as a rotating magnetic field creates an instantaneous force.
It is also believed that if you remove the box, the car will become faster. In practice, this will lead to the fact that she simply does not go. Torque. The wheels should be sufficient to overcome the force of inertia. Without reduction (reducing the speed of rotation and increasing the torque), the wheel will not turn. Therefore, the search for a “machine without a gearbox” for the ICE is a dead end.
What happens if you try to remove the CP from the ICE
Let’s imagine a hypothetical situation: we take the usual petrol-engine And we connect it to the wheels directly, without a transmission. When starting the engine, the car twitches and stalls, since the rest resistance will be too large for low revs. If you spin the engine to working turns on weight and try to connect with the wheels, the car will either rip the wheels into a slip, or the engine will instantly stall under load.
Even if you use a very powerful motor, without changing the gear ratio, it will be impossible to climb the slide. Plunge Wheels won't be enough. The machine will only be able to move on a perfectly flat surface at a certain speed, but any ascent or headwind will stop it. This makes the operation of such a vehicle impossible in real conditions.
In addition, without the ability to separate the engine and wheels (the function of the clutch or hydraulic transformer), it will be impossible to stop the car at traffic lights without turning off the engine. Transmission provides not only a change in speed, but also the possibility of idling the engine when the car is stopped.
☑️ Signs of transmission problems
⚠️ Note: Experiments to modify the transmission to "simplify" the engine may collapse or cause fire. Staff gearbox It is designed for a specific torque, and its removal will upset the balance of the entire system.
The Future of Transmissions: Evolution or Disappearance?
With development electric The role of the classic multi-stage transmission is really declining. The world of electric rovers is dominated by single-stage gearboxes. However, for ICEs, which are expected to remain with us for a long time (especially in hybrids and special equipment), difficult problems are expected to arise. P.C. They'll only improve.
Engineers are working on creating a new type of continuously variable transmissions that will be more efficient than variators and more reliable than automatic machines. Perhaps in the future we will see. motor-carThe switching will occur so smoothly that the concept of “transfer” will disappear from the everyday life of drivers, remaining only in the textbooks of mechanics.
However, for the moment gearbox - it is either an electric car (with a reservation on the gearbox), or an inoperable design with an internal combustion engine. The transmission remains one of the key components that determine the dynamics, efficiency and reliability of the machine. And while humanity uses the ICE, the transmission will be its faithful companion.
To prolong the life of any transmission (ACP, manual transmission, CVT) always start driving only after a complete stop and heating of the oil in the transmission in winter (1-2 minutes of engine operation).
Can the car move without a transmission?
car ICE will not be able to move without a gearbox, as the engine does not develop enough torque at low revs. The electric car can start without a multi-stage gearbox, but it needs at least a single-stage gearbox to coordinate the speed of rotation of the motor and wheels.
Why don’t electric cars have a classic transmission?
Electric motors have a wide shelf of torque and can work effectively in a huge range of revolutions (from 0 to 20 000 rpm). This allows for one transmission, while ICE It is effective only in a narrow window (3000-5000 rpm).
What happens if the car with automatic transmission runs out of oil?
If automatic-box The oil will run out, the hydraulic transformer will stop transmitting torque, and the machine will stand up. Long movement without oil will lead to instant destruction of frictions and metal parts, after which the gearbox will have to be changed completely.
Are there any cars with two transmissions?
Yes, there are complex SUVs with demultiplifiers (downshift) and the main gearbox. Some racing or experimental models may also use circuits with two independent transmissions on different axles, but this is rare.