Each motorist has a complete understanding of the device, as well as the principles of operation of a manual and automatic transmission. Standard mechanics, on average has 5 gears. Automatic transmission, includes seven modes of operation. But not every car owner knows the principle of operation of the variator. The specificity of this device, in a large variety of operating modes. Accordingly, the variator has much more gears. Today we will find out the main features of the device and compare it with analogues.
A variator is a device that changes the moment of rotation of the active and driven disks. This device is a transmitter between the wheels and the engine of the car. CVT, often used on small mopeds, similar tracked vehicles or jet skis. On cars, this device has been used for a long time. At the same time, it has received widespread use relatively recently.
Transmission comparison.
CVT or automatic, a private matter for every motorist. But it is worth noting that each device has a unique number of features. One of the differences in the operation of the devices can be noticed when starting the car. The CVT makes it possible to move off more smoothly than an automatic transmission. When moving from a standstill, an analogue of automatic transmission, it resembles the start of powerful engines. Also, the variator allows you to pick up speed very smoothly. The device works much quieter than the analogue and does not emit extraneous sounds. Everything described refers to the operation of a fully functional device. Of course, if the functionality is broken, the device can make significant noise. With correct operation, the noiselessness of the device can be noted as one of the advantages. If the car is equipped with a variator, the speed increase is fast enough. The device does not waste time switching modes and is rapidly gaining momentum. If the issue is in the set of speed, the variator will be the clear leader.
A car with a CVT suffers from many mistakes of a novice driver. This device will not allow the engine to stall at a traffic light. With a CVT, it is enough just to learn how to drive a car. The device allows you to move smoothly without much effort and special skills. In addition, driving comfort is fully preserved. This type of car has the same number of pedals as an automatic, which completely prevents the possibility of confusing them. Therefore, to learn how to drive, a CVT is a more suitable option.
Not every car enthusiast likes the smooth and constant sound of the engine. Analogue of automatic transmission, completely prevents noise, even with a rapid increase in torque. Not surprisingly, some motorists want to hear a characteristic sound when accelerating. This characteristic, nevertheless, should be attributed to the advantages of the device. When choosing, yet not everyone likes the “smooth” sound of the motor.
The fact is that the device is equipped with electric speed stabilizers. Therefore, the operation of the engine is always under control. The engine does not over-rev and accelerates gradually. This function of the device prevents a set of critical revolutions of the machine engine. CVTs may have a different look and functional part, depending on the manufacturer. There are devices that repeat the change of classical programs. This type, most similar to classical mechanics, but still fully automatic. Also, there are devices more similar to an automatic transmission. Data rapidly gaining momentum when you fully press the gas pedal. This type is suitable for lovers of speed and a quick start.
The question of what is better CVT or automatic, also does not have a clear answer.
Yet, the foregoing shows a significant number of advantages of the first device. Let's highlight the main advantages of the variator over the automatic transmission.
The main advantages of the variator.
- Quick start and short-term torque buildup.
- Economy in use. The variator allows you to save a significant amount of fuel, compared with the box - automatic.
- Prevent overload on the motor. Stabilizers built into the device also evenly distribute the load on the car drive.
- Rare service. The variator functions thanks to electronics, which significantly reduces the frequency of repairs. The operating mode of the device determines a certain stability and prevents possible breakdowns.
- The exhaust of a car equipped with the mechanism in question contains a smaller amount of harmful substances. Despite the complex principle of operation, the device is very environmentally friendly. Compared to mechanics and automatics, exhaust gases become less saturated.
- Quiet work. This device allows you to significantly reduce the noise of the car. In comparison with mechanics and automatic transmission, the car is several times quieter.
Like any device, in addition to the advantages, the variator has a number of characteristic disadvantages. For a reliable choice, a variator or an automatic, it is still worth mentioning the shortcomings in the operation of the variator.
Disadvantages.
- Cars with a high-powerful engine are rarely equipped with this device. To date, nevertheless, worthy representatives with a variator have appeared. The complexity of their device, respectively, affects the price.
- For the correct operation of the device, a special mixture is required. In this case, classic automatic transmission oil will not work. The mixture for the variator is quite whimsical to use and requires constant attention. The liquid is very expensive, but it is not difficult to find it. The composition for the operation of the variator has its own characteristics. Depending on the brand of the manufacturer, it is required to select a specific mixture.
- When the battery charge is low, the device automatically optimizes its operation.
- Expensive service. The variator does not break down so often, but if it does happen, a significant amount of expenses will be required. The device is complex and not every mechanic will take it for restoration. Repair of the variator is difficult for independent execution.
- A car equipped with the device in question is difficult to tow. There are a number of specific rules that do not allow you to tow another car or a heavy trailer.
- Complex chain of operations. For the correct operation of the variator, the good condition of most sensors is required. The device functions thanks to electronics and, accordingly, depends on pressure and speed sensors. If one of the sensors fails, the operation of the variator is disrupted.
The variator is constantly being upgraded and optimized for modern cars. CVTs are becoming more reliable and less whimsical to use. According to most manufacturers, the variator is able to completely replace a manual gearbox and an automated counterpart. Today, the variator is not used very often in the automotive industry. The reason for this is a complex device and expensive maintenance. CVT or automatic is still a popular issue. In most cases, the choice depends on the driving style of a particular motorist. Which of the devices is more reliable, all the same depends on the model and manufacturer of the device.
Knowing the complexity and cost of repairing the variator, it is worth highlighting the basic rules for using the device. These recommendations will significantly reduce the frequency of repairs and maintenance, thereby saving the owner of the car.
Prerequisites for proper operation:
- Warm up the engine before using the vehicle to avoid overloading. This rule is especially true in the cold season. Avoid starting on a "cold" engine.
- Carefully monitor the level and condition of the working mixture. Liquid is an important component in the operation of the device. Change the fluid according to the manufacturer's recommendations.
- Given the specifics of this transmission, avoid a sudden start. This device is not designed for sports cars. Do not use the resources of your machine to the maximum.
- Monitor the health of the sensors and service them in a timely manner. As mentioned, the transmission is completely dependent on the correct operation of the pressure and speed sensors.
- Diagnose the device in a timely manner. If there are signs of a malfunction, you should contact the professionals. Do not repair the device yourself, in order to avoid serious problems.
With proper operation, the life of the transmission is quite long. One of the main criteria is the intended use. Do not overload the transmission to prevent costly repairs.
Right choice.
Automatic transmission is the most common and well-known type of transmission. Like the electronic counterpart, it has its advantages and disadvantages. When choosing, you must be guided by your driving style. Small cars are equipped with an electronic transmission for a measured ride. In pursuit of speed and a sharp start, it is still worth giving preference to a mechanical counterpart. Regardless of the choice, the transmission requires responsible and careful use. Manual, automatic transmission and CVT - it is required to diagnose and service in a timely manner. Subject to all operating requirements, you will significantly increase the life of the device. In order to make the right choice, you need to familiarize yourself in detail with the features of all transmissions. For every driver, there is the most suitable type of gearbox. Depending on the manufacturer's brand and model, each device has a number of features. Consider them when buying a car or changing a transmission. Good luck with your choice!
The good old manual transmission is gradually disappearing from the market. Modern motorists prefer the comfort and some sense of "freedom" behind the wheel, which has become available to everyone with the advent of automatic transmissions. But technological progress tirelessly rushes forward, bringing new automotive units to the market. We are talking about variators - transmission, which was the result of a symbiosis of mechanics and automatic. Many modern car models are equipped with this type of box. Like everything new, CVTs undergo experimental testing in practice, are finalized, updated and improved.
So, until all automakers have endowed their cars with the possibility of unmanned control, drivers are faced with a dilemma: which gearbox to choose. And the more cars are equipped with variators, the more questions arise: what is the principle of operation of the variator based on? Is this box secure? What is the difference between a variator and an automatic if the car also has 2 pedals? Finally, which is better: automatic or CVT? These and some other questions will be answered in this article.
What is the difference between an automatic and a variator?
Buying a car is an act that cannot be called spontaneous. One way or another, motorists prepare in advance for this event, find information about design features, power, operation, “sores”, etc. If you miss this moment, you can quickly become disillusioned with any car. To avoid negative emotions, you need to buy a car that meets your own requirements. For example, it is worthwhile to clearly understand what is the fundamental difference between an automatic transmission and a CVT, since some put an equal sign between these units.
How automatic transmission works
The operation of the “machine” is based on the principle of the interaction of two main components: a torque converter and a gearbox. The torque converter builds up pressure, so the gearshifts are smooth and automatic. In fact, it was this assembly that replaced the mechanical clutch.
The second automatic transmission unit - the gearbox - is responsible for the mechanical part of the transmission, consists of several steps, indicated by pairs of gears that are in constant engagement.
How the variator works
A feature of CVTs is the stepless gear shifting. A pair of conical pulleys is responsible for a continuous set of speeds, one of which is the leading one, the second is the driven one. The pulleys interact with each other through a metal trapezoidal belt or chain.
What happens inside the variator during operation?
Tapered pulleys are not monolithic parts. Each pulley is a series of sliding elements. The lowest gear (initial or first) occurs at the moment when the drive pulley is in the maximum extended state and the chain runs along a small diameter. Accordingly, when the drive pulley is extended to the minimum distance, the chain travel diameter increases to the maximum, which is typical for fifth, sixth and higher gears.
This is the whole essence of the work of the variator: the movement of the pulleys changes the gear ratios, which entails a decrease or increase in the speed of the car.
Automatic transmission VS CVT. Advantages and disadvantages
To put an end to the question “which is better: automatic or CVT?”, It is necessary to evaluate all the advantages and identify all the disadvantages of these types of transmission:
Advantages of automatic transmission
Disadvantages of automatic transmission
- Automatic transmission has a relatively low efficiency due to the design features of the torque converter. As a result, cars with an "automatic" cannot be called economical in terms of fuel consumption.
- Weak acceleration dynamics, "stupidity" and "failures" when accelerating - another significant drawback of the automatic transmission in comparison with the variator.
Advantages of the CVT
Disadvantages of the variator
- CVTs appeared relatively recently and are constantly being improved. Therefore, statistics have not yet been accumulated on them, and therefore, maintenance, and even more so the repair of these boxes, are very costly procedures.
- CVT boxes require regular maintenance using specific oils, which have fundamental differences depending on the manufacturer and design features.
Conclusions. Which is better: automatic or CVT?
Having information about the features and principles of operation of various types of transmission, knowing their advantages and disadvantages, each car owner will find his own answer to the question "which is better: automatic or CVT?".
They overheat at high speed and are not viable outside of smooth asphalt! They fail even under non-critical loads!
Rumors about the dubious reliability of continuously variable transmissions (CVT) appear almost faster than the next new model with a CVT comes out. Moreover, they are born more often around all-wheel drive crossovers, the transmissions of which are the most loaded and often work at the limit of their capabilities - primarily on rough terrain. And these rumors are not unfounded: there are problems! As practice shows, they also happen in less offensive situations - even on urban asphalt.
That is why we brought three all-wheel drive crossovers together in diverse tests - the new Nissan Qashqai with a modernized transmission of the latest generation, the Subaru Forester and the updated Mitsubishi Outlander. And out of standings in our tests participated monoprivodnoy "Toyota-RAV4". Now you can buy one, and it is with a variator.
Talk about continuously variable transmissions overheating at high speeds has been heard by many more than once. The Za Rulem testers know this from their own experience: the overheating of the Outlander transmission in last year's test (ЗР, 2013, No. 7) prompted the idea to start these tests. Moreover, this time we took the updated Outlander, to which the manufacturer returned the variator radiator (at our insistence - see ZR, 2014, No. 8). It is clear that the radiator must provide the optimal temperature regime of the node and protect it from overheating. Did it help?
We checked the cars with a regime close to the limit and more typical for unlimited German autobahns. We have so few people who travel, and there is nowhere to travel like that, but the purity of the experiment is important to us! We drove 250 km along the high-speed ring of the polygon at an average speed of about 170 km/h. If the variators can withstand such a pace, then you can not worry about their health under normal operating conditions.
Winding circle after circle, we closely monitor the behavior of the machines. And ... we do not find anything interesting. Not a single car showed even a hint of transmission overheating - all worked without the slightest complaint. So there is no winner in this test. But more importantly, there are no losers either! So, the variator radiator implanted in the Outlander in these conditions copes with its task brilliantly.
1. You don’t have to worry about the transmission of the Outlander updated this year: it will withstand high speeds.
2. Forester with a 241-horsepower engine, of course, is able to go faster than its rivals, but we did not find any signs of transmission overheating.
3. Qashqai also passed the speed test without any complaints.
4. The front-wheel drive Toyota successfully passed the speed test in the same mode as the all-wheel drive rivals.
This test turned out to be the most difficult for cars. The height of the obstacle is 185 mm (this is not yet the highest curb among those that drivers are ready to storm). Task: climb it with the front and then the rear wheels, placing the car at a right angle to the "sidewalk". Then you need to repeat the exercise, but in reverse. You should, of course, drive in tight, because even the most ardent conquerors of the sidewalks will not dare to jump on such a high curb from acceleration.
Moving forward, "Subaru" overcame the obstacle without tension. And he refused to go back to the curb. Moreover, the electronics, protecting the transmission, simply does not allow the wheels to spin, and the engine forbids gaining momentum. How so? In the city, you can refuse such an assault and turn around one hundred and eighty, but what if such an “ambush” happens off-road? All in reverse - no way?
Mitsubishi did the same. Moreover, he refused to drive into the curb in reverse even after turning on the Lock mode, which rigidly blocks the rear wheel drive clutch.
And then the photographer suddenly asked me to go to the curb again - again in the forward direction. The Outlander confidently jumped over the curb with its front wheels, but refused with its rear wheels, although not a single emergency lamp flashed on the instrument panel. It's just that the engine did not spin up over 1200 rpm, and the wheels stood still. We decided to wait ten minutes. And they guessed it: the car with a cold transmission, like the first time, jumped over the barrier with its rear wheels.
Qashqai turned out to be the most persistent. Moving forward, he easily passed the curb with both front and rear wheels - and just as confidently went back. But, having overcome the obstacle with the rear wheels, Qashqai stood up. Then there was not enough gunpowder: the front wheels do not spin, the engine refuses to gain momentum. Nevertheless, according to the number of exercises performed the first time, Qashqai is the leader in this test. Mitsubishi and Subaru tied for second and third places.
Let the curb and monoprivodnoy "Toyota". Having turned the wheels a little, she refused to overcome it both forward and reverse. It is logical - and for a front-wheel drive car, it is not at all ashamed.
5. "Mitsubishi" without a hitch passed the obstacle forward, but could not overcome it in reverse.
6. Moving forward, Subaru easily took the 185 mm curb, but refused to go back.
7. The winner of the test was Qashqai. He drove into an obstacle even in reverse - however, only with the rear wheels.
8. A front-wheel drive Toyota can't handle those obstacles.
At high speeds, we failed to overheat the variators. Let's try to do this in transitional modes, simulating frequent overtaking?
We make several accelerations in a row in the "pedal to the floor" mode - from 60 to 100 km/h and from 80 to 120 km/h. Not a single car showed signs of dissatisfaction: the acceleration time varies within the margin of error.
We complicate the task. After reaching 100 and 120 km / h - a sharp deceleration to 60 and 80 km / h, respectively. And immediately - a new acceleration, again in the "pedal to the floor" mode. Only after such a mockery did we manage to catch a certain thoughtfulness. After a sharp press on the gas pedal, the engines at first do not gain more than 2500 rpm and hold the car for a few moments. What are these moments? For "Mitsubishi" and "Toyota" - 0.2–0.3 s, in normal operation they are completely invisible. "Nissan" lost to itself 0.8-1.0 s. But the owner is unlikely to feel this “in everyday life”. Moreover, we received this data in an almost racing mode - with sharp acceleration and deceleration.
Nevertheless, according to formal criteria, we give the first place to Subaru, the second to Mitsubishi, and the third to Nissan. And the out-of-class Toyota in this test performed no worse than the second Mitsubishi.
Cars pass through the dry country road calmly. We climbed here mainly in order to test the cars on a steep but dry dirt-sandy slope. Cars did not compete in speed - too different engines. The task of testers is extremely simple: several times to get up and evaluate the behavior of transmissions. On all machines, they used the maximum of their capabilities: in Nissan they chose the Lock mode, in Mitsubishi they pressed the 4WD button, in Subaru - X-Mode.
All four-wheel drive cars drove up the hill confidently, without whims, which means that there are no losers or winners again. We did not find any signs of excessive stress or overheating of the transmissions.
The front-wheel drive Toyota didn’t drive up this hill - there wasn’t enough “hook”: if we put it in more toothy tires, it would overcome the climb, but it still can’t compete with all-wheel drive here.
Probably, ironing the site for hours, you can achieve dissatisfaction with the variators. But to imagine such a need for crossovers in real life is difficult. So, another draw.
1. The Outlander passed the Overtaking test with flying colours.
2. "Subaru" - the winner of the "Overtaking" test: overcame all the tests without the slightest criticism.
3. The biggest delay in the operation of the variator after a series of “racing” accelerations and decelerations is with Nissan, but it turned out to be scanty.
4. The thoughtfulness of the Toyota variator after several mocking accelerations and decelerations is minimal.
5. "Outlander" passed the test "Rise" without remarks.
6. The capabilities of the engine and transmission of the Forester are such that a steep climb can be overcome with little or no acceleration.
7. We did not find any signs of dissatisfaction with the Nissan transmission on a dry country road with steep ascents and descents.
8. Front-wheel drive "Toyota" did not take the rise, but had every right to do so.
SPIN-SPIN
To change the gear ratio in the variator, a multi-link steel belt is used that connects two sliding pulleys with conical surfaces. The belt consists of many plates fastened with steel bands. It contacts the tapered pulleys with the side surfaces of the plates, which have small, barely visible diagonal notches that improve grip. The simultaneous approach and divergence of the cones of the driving and driven pulleys changes the radii along which the belt moves. Accordingly, the gear ratio changes. This happens all the time, depending on the driving conditions. Therefore, the so-called gears of the variator are virtual. The variator includes a mechanism for selecting the direction of movement, two pairs of cones with a steel belt, a gearbox, a final drive with a differential, and control units.
On the Mitsubishi Outlander (the operation of its variator is shown in the diagrams), the most common variator, the Jatko-JF011E, is installed. Torque from the engine is transmitted through a torque converter (similar to those in automatic transmissions) to the direction-selection mechanism, in which there is a planetary gear and two sets of pressure plates - friction clutches. Depending on the direction of movement (forward or backward), the control unit sends a command to compress one of the disk packs. Further, through the belt, the moment is fed to a downshift. From it - to the main pair and to the drive wheels.
In the "neutral" mode - N - both packs of disks of the mechanism for changing the direction of movement are dissolved. The epicycle of the planetary gear rotates freely together with the drive shaft of the variator - no torque is transmitted to the drive pulley.
In parking mode - P - the situation is similar, only the locking mechanism is also activated, the latch of which engages with the ring gear of the driven pulley.
When the selector is moved to position D, one of the disc packs is compressed, connecting the epicycle to the sun gear mounted on the drive pulley, between the cones of which the belt is clamped. Further, the moment is transmitted through the belt to the driven pulley, from it to the reduction gear, the main gear - and to the wheels.
To drive in reverse (R), the front disc pack is unclenched and the rear disc pack is compressed accordingly. The carrier, on the axes of which the satellites, stops. The moment from the drive shaft goes to the epicycle, and from it to the satellite. The sun gear connected to the satellite rotates in the opposite direction due to the stop of the planet carrier. When reversing, the pulley radii remain in their original position. This is monitored by the control unit.
1. This year, the CVT radiator was returned to the updated Outlander. And they did it right!
2. The Forester variator does not have a radiator. However, we failed to overheat the transmission.
3. There is a variator radiator on Qashqai.
4. The CVT radiator on the RAV4 is combined with the cooling system radiator.
The Subaru Forester has a different variator - its own design. The TR580 model is installed on cars with atmospheric engines, and the TR690 model is installed in a pair of turbocharged engines. The fundamental difference from the Jatko variator is a different belt design (produced by the German company Luk). It also transmits the force by the end surfaces, but not by the plates, but by the pins connecting the belt links together.
The moment from the engine is transmitted through a torque converter, a reduction gear (a safety clutch is located in it), a drive pulley, a belt, a driven pulley, a second reduction gear, a mechanism for changing the direction of movement, a driven shaft. The safety clutch between the first reduction gear and the drive pulley is open when the engine is started, while the oil pump is not running. As soon as the pressure rises, the clutch is blocked. This is done to protect the belt from slipping during load surges when starting the engine.
On cars with a start-stop system, when the engine stalls at stops, the input shaft of the variator does not rotate, and therefore its oil pump does not work - the pressure in the system is low. So that at the next start of the engine it is high enough, the variator is equipped with an additional booster electric pump.
The scheme for transmitting torque from the engine is similar to that of Dzhatkovo, but there are some kinematic features. For layout reasons, the reduction gear is divided into two mechanisms - before the chain and after it. The mechanism for changing the direction of movement and switching to "neutral" is located after the pulleys, so they always rotate with the chain when the engine is running. The main gear is a conical hypoid, in a separate crankcase with its own lubrication system.
CVTs for Toyota are manufactured by Aisin. Structurally, they are similar to the Jatko CVTs. The belt also consists of plates connected with steel bands.
Nissans have Jatko CVTs. The new Qashqai received an improved model based on the JF011E. All components have been changed, even the transmission fluid is different. The range of gear ratios has been expanded, a different control algorithm has been applied.
LEGENDS AND FACTS
It was not possible to identify a clear winner in the sum of four tests. It seems that Nissan, which, recall, has the latest version of the variator (this unit will soon be registered on other models of the Japanese brand), scored half a point more than Subaru. But after consulting, we decided to share the first and second places between these cars. After all, the fractions of a second lost by Nissan during intensive accelerations are fully compensated by good results in the Curb test. "Mitsubishi" lagged behind rivals quite a bit. In general, all cars performed very well and helped to dispel some myths about the unviability of CVTs. In normal, everyday use, continuously variable transmissions will not cause trouble. Of course, if you remember simple truths: crossovers, especially with a continuously variable transmission, are not SUVs at all! These are city and highway cars, allowing from time to time to overcome not very difficult obstacles. And it’s even more honest to call a monodrive one a station wagon with increased ground clearance.
Good afternoon, today we will talk about which automotive better gearbox - automatic or CVT, what is reliability And resource nodes, as well as from which main components mechanisms are composed. In addition, we will talk about how benefits And shortcomings possess gearboxes automatic and variator type, which service interval mechanisms to be observed and which transmission parts most exposed wear and tear during operation. In conclusion, let's talk about what kind of automotive Transmission most preferred for urban And countryside conditions, as well as what is the difference between transmissions from each other.
WHAT OIL TO FILL INTO AUTOMATIC TRANSMISSION
AUTOMATIC TRANSMISSION. PRINCIPLE OF OPERATION
Today, based on statistics sales vehicles equipped automatic transmissions, varieties of which are considered classical automata , variators And robots , then gearboxes with action type machine almost in 2 times more often bought than competing mechanisms. Based on the exact numbers of studies buying activity over the past 5 years, then on the market of the countries of the Customs Union ( Russia, Belarus and Kazakhstan) was sold to car buyers with manual transmission - 45 percent , from machine guns - 30 percent , from variators (CVT ) - 15 percent and with robotic transmission - 10 percent . Concerning boxes of robots , then literally in recent years, sales of cars with such a transmission doubled, and such mechanisms can be increasingly found in domestic Lada Vesta , xray , Priora And grant .
AUTOMATIC TRANSMISSION: FEATURES, FAULTS, RESOURCE, PLUSES AND MINUSES
How and when did the first machine appear?
It is believed that the first automatic type gearbox appeared in shipbuilding at the beginning of the 20th century in Germany. Its inventor was a German scientist, Karl Fettinger
, it was he who first proposed the use of hydrodynamic transmission, which made it possible to combine the work engine And transmission, which led to the effective spinning of the propeller of the ship. Thanks to this invention, such a gearbox element as fluid coupling which is currently considered one of the key elements of modern machine gun.
As for cars, the first vehicles that began to be equipped with such transmission were American cars" oldsmobile"and this event happened in 1939
. First gearboxes were called " Hydromatic
"and to this day they design almost didn't change. For reference, we note that any modern machine has in its equipment two key knots
- this reducer
And torque converter
.
Such an element of an automatic transmission as torque converter replaces clutch. The purpose of this node is to gear shift happened in the box without jerks, i.e smoothly. Redcutor
which in turn includes pairs of gears, which are in constant engagement together. Thanks to such dense
" designs, modern machine represents a compact mechanism
, which is equipped with a certain number steps. For reference, we note that until recently, most cars were rear wheel drive and, as a rule, were equipped with everything 2-3 gears
in automatic, which was quite enough for optimal movement. However, at the present stage of the automotive industry, most cars, on the contrary, have front-wheel drive, which contributed increase in speed
, so the quantity gear has become large since 4th
and ending 8 steps
.
Concerning technical component, then machine has been tested over the years and today brought to almost its perfection. Technically - automatic transmission
is enough solid system, which has proven itself mainly with positive side.
How does the machine work?
As we know the movement of any car is based on torque, which is transmitted from the power plant. in the machine, torque transmitted through torque converter, in which no hard grip
and the mechanism operates from pressure transmission fluid. Thus, it turns out that once in the system no hard grip, and therefore break almost here nothing. However, in building machine available shafts from planetary gear And discs from clutches made from become that are in constant motion.
Items such as clutches in their own way functions similar to clutch in manual transmission
. Thanks to them, during compression or expansion, connect the necessary couplings, which at one time or another correspond to certain broadcasts. In addition to the above details, machine includes a special High pressure pump, as well as hydroblock. In fact, the elements in automatic transmission much more and we are only talking about its main components who are directly involved functioning systems.
What parts in the machine are most prone to breakage?
Majority breakdowns in automatic And variator occur due to improper operation And untimely service node. For automatic transmissions the most important thing is observance of the service regulations
. In the event that on machine simply " Score
" And do not change ATF oil after a long run, for example more than 100 thousand kilometers
, this often results in the valve body is clogged, radiator And filters. Ultimately, all this leads to the fact that oil pump stops holding optimal working pressure in the system, which clutches on steel rims start scroll, which leads to slippage or as auto mechanics say, the machine starts " kick
"
or"
skid
". In the very running state
, transmission gears can simply not turn on or twitch while driving. In the end, the result is for everyone machine guns one - they go on emergency mode
.
That's why most specialists strongly recommend before buying a used car in the first place check on the wear automatic and its components. There is even such rule which helps determine the degree of wear. It concerns smell transmission fluid. In case if machine oil smells burning, then this indicates that clutches burnt and are in a strong worn condition. Therefore, if there is foreign smell boxed is better refuse from purchases such a car. Moreover, if, transmission strongly launched, then faults it can contain a large number, ranging from planetary gears and ending friction linings of the torque converter. For reference, we note that each machine has its nuances, that's why breakdowns And degree of wear at the details of one or another transmission models may differ.
What is the resource of the machine?
If the transmission operated And served in accordance with manufacturer's regulations, then resource node can be at least service life vehicle power plant. How recommend mechanics, if you change the transmission fluid every 40-50 thousand kilometers
, then machine able to pass 350-400 thousand kilometers
, and this applies mainly to 4 step models
. For reference, we note that opinion specialists, namely 4-speed gearboxes
considered the most reliable, especially Japanese manufacturers
.
In order to prolong the life of the machine, it is necessary to adhere to certain rules
: Firstly
, change the working fluid no later than 1 time in 60 thousand kilometers
, or even more often reference: there are no maintenance-free machines, do not trust dealers); Secondly
, together with the transmission fluid, you need to change the oil filter; third
, it is advisable to flush the transmission radiator with each oil and filter change; fourthly
, clean the pan and transmission magnets from wear products in the form of metal chips. Thanks to these simple rules, machine resource
can increase average by 10-15 percent
from the values specified by the manufacturer.
Advantages of the machine :
- Simple and understandable control of the vehicle, that is, there is no need to reach for the gearbox selector every time you change gears, since everything happens automatically;
High design reliability with proper maintenance and operation, and much greater than that of the variator;
Maintainability at a high level, as the system has long been studied by most auto mechanics;
Transmission fluid requirements are lower than those of a CVT and are significantly cheaper;
Less electrics in the system on average by 25-30 percent than the variator. Basically everything works on the mechanics;
Longer service intervals than CVT. On average, an oil change in a unit occurs 1 time in 60-80 thousand kilometers.
Disadvantages of the machine
:
- Accelerating dynamics is worse than that of CVT and manual gearboxes;
The lowest efficiency among competing types of transmissions, due to the fact that the machine does not have a rigid engagement with the power plant and the operation process is carried out using a torque converter under the pressure of a technical fluid. By the way, because of this, such a transmission has gears in the system;
The presence of shocks at the time of switching gears, due to the presence of gears;
The volume of transmission fluid required for replacement in the machine can be from 8 to 15 liters, at the variator 5 to 8 liters, and for mechanics, in total 2 to 4 liters oils;
The highest fuel consumption compared to the variator, robot and mechanics. all this is due to the fact that the system has the lowest efficiency.
In this way, automatic transmission
or torque converter
type is enough reliable And verified node time. but positive sides machine block such limitations, how low efficiency
, increased fuel consumption
, weak dynamics
And aftershocks
at the time of the gear change reference: on 6-speed automatics, shocks are almost imperceptible). However, if properly serve
this gearbox and fill only quality liquids
then you don't have to worry about resource node.
CVT TRANSMISSION: FEATURES, FAULTS, RESOURCE, PLUSES AND MINUSES
Official name CVT transmission
- CVT
, which when decrypted means Continuously Variable Transmission
. According to some motorists, variable speed drive
appeared later than other types of transmissions. However, this is fundamentally not true. Since on my own principle of operation of the variator was described back in the 15th century by a famous inventor at that time - Leonardo Da Vinci
. Operating principle variator based on two cones, which are directed in different directions relative to each other, and between them are stretched belt. That's exactly this construction and invented Da Vinci
By the way, such a system was adopted from windmills. But as we understand variable speed drive was not created in the 15th century, as there simply were no opportunities for this.
As such given transmission type gradually began to move from theory into practice only in the middle of the 19th century, when it began to be used on industrial machines. And only in 1957 the Dutch designer Hubert Van Doorn decided to move variator design from machine tools to the automotive industry. Van Doorn is considered the first person on the planet who created continuously variable transmission which he named Variomatic . For reference, we note that this variable speed drive since 1959 began to be installed on small trucks of the company DAF . As a rule, cars were equipped with small volumes power plants: 0.6 - 1.2 liters . Thanks to the high efficiency transmission, system Van Doorna received many positive feedback at that time, automakers adopted stepless variator for their models.
Concerning technical component, then variable speed drive just like machine belongs to one of the varieties automatic transmission. The main thing the difference between a variator and an automatic
- lack of speed or gear. True in some modern variators(example:
CVT X-Tronic
JF015E
from Jatco
) have the so-called virtual transfers so that the driver can switching translation speeds selector boxes in different positions.
Structure variator painfully simple and based on 2 pulleys (leading And slave ), which are located opposite each other and connected belt drive, usually with metal trapezoid belt. Concerning cones such a gearbox, they not whole, as it was originally, but in the form sliding halves. Principle of operation variator based on drive pulley, which is located in extended condition. drive belt in turn, moves along a small diameter, leaning with its faces on pulley surface. For reference, we note that if pulley is in shifted position, then belt will rotate along large diameter, resulting in the maximum possible ratio, which corresponds first gear.
Also note that when sheave shift, then a smooth decrease gear ratio, which provides the so-called gear shift. interesting variator nuance is the fact that gear ratios almost completely correspond to the indicators of the classical machine gun, although again note that steps in the system as such missing. Due to this specific principle of action, variable speed drive in terms of efficiency between the power plant and the wheels, has best efficiency. All this is due to the fact that torque transmission from motor on the transmission and then on wheels,transmitted mechanical efforts, i.e hard way, rather than using pressure technical liquid.
What parts in the variator are most prone to breakage? Unlike machine gun , variable speed drive very picky about exploitation And service. Transmission fluid must be variator is changing every 60 thousand kilometers , or even more often. Otherwise, if do not change according to the oil regulations, very serious Problems with system components. As a rule, with a disregard for variator,first thing valve body is clogged from oil pump, which subsequently can't pump optimal oil pressure in the system. Because of this shafts can't properly pinch And loosen the drive belt, which leads to it slippage. When it starts slip belt, then this leads to its accelerated wear and tear, which may subsequently lead to cliff element. When broken belt, variable speed drive instantly collapses and that's where his life ends, and restoration, as a rule, he is not subject to. In addition, often in variators going on erasing the mirror surface of the shafts, what also affects on the belt resource. Well, we must not forget about a bunch of unreliable electronics, which controlled modern variable speed drive.
What is the resource of the variator?
talking about variator service life must always be remembered timely replacement of the transmission fluid, since this action will directly depend survivability transmission. Often in violation of the car owner variator maintenance schedule, his life may come to an end already on 90-100 thousand kilometers
. However, apart from oils, attention should also be paid drive belt, which usually changes to 130-150 thousand kilometers
. If view drive belt replacement then the case may end it cliff, and this is already replacement Total variator. Auto mechanics say variable speed drive
- this transmission, which will always keep its owner in good shape. Maximum resource contemporary variators averages around 250-280 thousand kilometers
.
Advantages of the variator
:
- Good acceleration dynamics, in comparison with the classic machine;
Reduced fuel consumption, in comparison with a torque converter type automatic ( reference: consumption is less by 9-14 percent);
The absence of gears, therefore, there are no jerks when switching speeds, which gives smoothness and dynamism when moving;
High efficiency, in comparison with the machine, the indicator of the variator is higher by an average of 6-9 percent;
Ease of driving, and less time required to warm up the unit to operating temperature.
Disadvantages of the variator
:
- The mechanism is considered difficult to repair, since not many auto mechanics are well acquainted with the design of some models, therefore, in case of breakdowns or maintenance, you will have to contact official dealers, which will cost a penny to the car owner;
The need for frequent replacement of transmission fluid and a flexible drive belt mechanism, which is not a cheap procedure;
There are a lot of electronics in the system and in case of failure, you will have to contact specialized service stations or dealers, which is again expensive;
Transmission fluid is used only special, with high tolerances, which a priori simply cannot be cheap and you need to change it as often as possible.
Dec, which is better - automatic or CVT?
Based technical features in terms of operating principle, speakers, ride And fuel consumption, then variable speed drive
definitely bettermachine gun
. But as soon as it comes down to it service And repair, then variable speed drive
- it's solid headache for the car owner. Machine considered to be more studied than maintainability, it can faster And cheaper to fix, reestablish, as well as finalize. However, in one, both transmissions similar if the car is bought supported, then diagnostics you need to do both mechanisms.
Video review: "Automatic or CVT - which is better. Reliability, malfunctions, resource, pros and cons"
In conclusion, we note that it does not matter which transmission installed in purchased vehicle, if purchased new at dealer. Often in the process exploitation a new car, with the appearance of certain faults, everything closes warranty manufacturer. However, the opposite is true if the machine bought by hand, that is mileage, for example after warranty period, which is often 100 thousand kilometers. In this case, more preferable looks machine, because it easier And cheaper to fix, in case of occurrence breakdowns. Besides, resource classical machine guns, usually on 25-30 percent more than variators.
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Cars are equipped with a gearbox, which affects the change in speed and direction of movement. Initially, the "mechanics" became widespread, later the version of the car, where there is an automatic transmission, began to gain popularity. In the modern Japanese and American markets, more and more cars are being produced where a CVT is installed, for example, Toyota RAV4, Nissan Teana, Ford Mondeo.
It is necessary to resolve such a question that worries many potential car owners:
- what is better variator or automatic;
- which box has a longer working life;
- what is the difference between a variator and an automatic transmission;
- which type is more reliable?
Distinctive features of the variator and machine
How to distinguish an automatic transmission from a variator:
- driving feature. With a variator, jerks will not be felt when the speeds are switched;
- modern car brands behind have the name of the model itself + the designation of the type of transmission CVT / AT (A);
- there are fewer modes on the selector inside the car if there is a stepless mechanism;
- documents accompanying the machine include information about which box is on the vehicle.
Technical components
What is the difference between a variator and an automatic? The automatic transmission includes a gearbox and a torque converter. The gearbox includes pairs of gears, the torque converter provides clutch. Their interaction guarantees fast switching of speeds.
Automatic transmission in the context
The variator works without switching speeds. It is a type of automatic transmission. It consists of two pulleys (slave and lead), pulled together by a belt. Auto mechanics note: this device is controlled by the selector lever.
Scheme of a variator gearbox
The difference between the variator and the automatic machine lies in the fact that in the first case, the dynamics of the acceleration of the vehicle is faster.
CVT and automatic which is better? In terms of the quality of the oil being poured, cars with an automatic transmission are less demanding when compared. Difference between variator and automatic:
- less fuel is spent (when compared with automatic transmission);
- the CVT does not have jerks when switching speeds (because there are no gears);
- a machine with a continuously variable transmission has a high level of safety when maneuvering on an icy road. Simplified driving is noted. The automatic transmission also has this advantage.
What is more reliable CVT or automatic transmission?
Choosing a CVT or automatic is an individual matter. The main thing in this matter is to take into account all the pros and cons of each device. When choosing a car, many are guided by the service life of these types of transmissions.
Performance drove demand for automatic transmission cars in the early 2000s. The resource of automatic transmissions can exceed 300,000 km, which is almost 2 times more than that of the variator. However, automatic transmission efficiency is lower.
Due to the long working period, many decide to purchase a car where there is an "automatic". Its technical part is recognized as reliable. Professionally executed high pressure pump and hydraulic unit. As a rule, breakdowns occur as a result of untimely maintenance of this system by a motorist, for example, a trip took place for a long time with a clogged filter or valve body. This is the cause of the characteristic twitches between gears.
Both options are difficult to restore in the event of a breakdown. However, in this case, the advantage remains on the side of the automatic transmission. In addition, restoration work at the machine will be cheaper. At 50,000 km, an excellent quality transmission oil needs to be replaced. It should be noted that not every service center undertakes repair and restoration work that is associated with a CVT gearbox. In some cases, auto repair shop workers may offer to replace the box itself. It takes a lot of time to restore technology. With a run of 100,000 km, it may be necessary to install a new belt between the pulleys. This consumable has a considerable cost. In addition, CVTs cannot be overloaded with high power. It is because of this that this option is not found on sports cars. How to determine the visual difference is quite possible. The design of the variators is somewhat different than that of the automatic transmission.
Automatic transmission variator and classic machine provides easy control of the machine. Thanks to independent gear shifting on the automatic transmission, the power unit does not experience overloads. Fans of trips out of town prefer automatic transmission. Those who often operate vehicles around the city choose a CVT gearbox.
Thus, the characteristics of both types of transmissions are well studied by auto experts. The variator differs from the automatic transmission in technical features, the general specifics of work. You can visually find out whether there is a continuously variable transmission or not on a car during a test drive. A car with such a mechanism smoothly accelerates and picks up speed.