How to use the variator: device, principle of operation, operating tips

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

There are many types of transmissions in the automotive world. The vast majority are, of course, mechanics and automatic transmission. But in third place was the variator. This box can be found on both European and Japanese cars. Often, the Chinese also put the variator on their SUVs. What is this box? How to use the variator? Consider in our today's article.

Characteristic

So, the variator is a continuously variable transmission of a car. Its main feature is the absence of specific steps - the gear ratio changes gradually, as the car picks up speed. This feature allows you to eliminate shocks and jerks when switching, which are possible when driving on mechanics, and also provides high acceleration dynamics. After all, when you press the gas, the car keeps constantly stable speed, at which peak torque is reached.

Butdue to power limitations, these boxes are installed mainly on cars and only on some crossovers (often these are representatives of Chinese brands). As for types, there can be two variators in total:

• Toroid.
• V-belt.

Device

Generally speaking, the design of this checkpoint includes:

• CVT transmission.
• A mechanism used to disconnect the gearbox from the engine and transmit torque.
• Control system.
• Mechanism for reversing.

To transfer torque from the engine to the gearbox, the assembly can use:

• Automatic centrifugal clutch.
• Solenoid with electronic control.
• Torque converter.
• Multi-disc wet clutch.

Now the most popular torque converter. It smoothly transmits torque, which is positively displayed on the resource of the box.

The design of the variator includes one or two belt drives. They are two pulleys that are interconnected by a V-belt. Conical discs are formed that can move and move apart. This changes the diameter of the pulley. To bring the cones together, spring force or hydraulic pressure is used. The disks themselves have a certain angle of inclination (usually 20 degrees). This contributes to the least resistance when the belt moves along the pulley.

Note that the belt material may bedifferent. Rubber was used on the first models. Due to its high flexibility and elasticity, it did not have a large resource. Therefore, most CVTs come with a metal belt. It consists of ten steel strips. And the torque is transmitted due to the forces of friction between the pulley and the side surface of the belt.

How the device works

The action algorithm is to change the pulley diameter depending on the load and engine operating mode. So, the diameter changes by means of a special drive (most often hydraulic). At the start, the drive pulley has a small diameter, and the driven pulley is enlarged as much as possible. As the speed increases, the dimensions of the elements change. So, the leader increases in diameter, and the follower - vice versa. When the machine slows down, the pulley sizes change back.

How to use the CVT correctly? Basics

First of all, you need to understand that a car with a CVT does not have a clutch pedal. Drivers who transfer to such cars from mechanics have a habit of using the left pedal. Using the variator, it is enough to work only with the right foot. The left always rests with the driver. This seemingly insignificant nuance needs to be remembered. As for the operating modes, everything here is similar to an automatic box:

• R. This is a parking lot. It is used in situations where the car arrives at a long-term parking lot. In this case, it activates a special blocking element that prevents the car from moving further.
• D - drive. This is a mode in which the machine moves forward as usual, withsequential shifting.
• N - neutral. It is used in cases where the machine is standing for a long time on an inclined surface. To do this, turn on the handbrake and move the lever to the appropriate position. In this case, we get rid of the need to constantly keep the brake pedal depressed. The mode is relevant when the stop time is more than half a minute.
• R - reverse gear.

Additional modes

It is worth saying that many CVTs have several more modes of operation. Among them it is worth noting:

• L. In this case, the engine runs at high speed with maximum braking effect. This mode is relevant for long descents in the mountains and when towing.
• S. This is the sport mode. In this case, the full potential of the engine is used. As a rule, the car accelerates 0.3-0.5 seconds earlier to a hundred. The mode is suitable for those who want to get a sharp start from a traffic light.
• E. Economy mode. The machine will use the minimum speed. At the same time, the acceleration dynamics worsens, but the consumption also drops. Typically, this mode is used with a calm, measured driving style.

How to start?

We continue to study the question "how to use the CVT". On Toyota and other foreign-made cars, the scheme for using the variator is the same. Therefore, this instruction can be applied to any brand. So, we get into the car and put the key in the ignition. Checking if the car is worth"parking" (mode P). If the lever is in the "neutral" position, the engine should be started after setting the car to the handbrake.

After that, you need to press the brake with your right foot. Without releasing your foot from the pedal, we move the key in the lock to the “start” position. We are waiting for the engine to start (usually no more than two seconds). Next, we translate the gearbox lever into the "drive" mode. Do not release your foot from the brake pedal. After the "drive" mode is turned on, you can start moving. We transfer the right foot from the brake pedal to the accelerator. Here's how to use the CVT on Qashqai and other cars. Do not forget about the handbrake (if it is on, remove it). The car will make further shifts on its own.

CVT neutral

Is it possible to reset the lever to the neutral position on this box? Here everything is similar to the machine. There are cases when this can be done, and there are cases when it is unacceptable. So, it is strictly forbidden to use the neutral mode, trying to move "coasting". When you try to turn on the “drive” again at speed, a significant blow to the clutch occurs, and the box is subjected to stress. Therefore, you should only shift into neutral when the car is in a traffic jam and the idle time is more than 30 seconds.

Warming up

Many questions arise about how to properly use the CVT on a Nissan in winter. It is worth saying here that this gearbox also has oil that acts as a working fluid. However, if it contains about ten liters in the machine, then there are only seven in the variator. That is, you need to warm up the box, but it takes less time. So, how to use the variator in winter? Warming up can be carried out both in park mode and in neutral. These modes are practically the same, except that "parking" blocks the wheels. Therefore, we simply start the car and wait five minutes until the internal combustion engine and gearbox warm up. It is worth saying that the lower the temperature, the more time should be devoted to warming up (and vice versa).

If snow/ice

How to use the variator on this type of coverage? Here you need to know that when the wheels slip on a slippery surface, it is possible to engage them with a harder surface. So, the driver mechanically presses on the gas when the car "grabbed" and was about to go through the snow. But then asph alt comes across on the way, and the wheels meet it at a high speed. The result is a significant impact on the clutch. Hydraulic clutch wears out. For a couple of such tricks, it can completely wear out. The same goes for riding with chains. Do not sharply press on the gas when the car is about to move. All this is significantly displayed on the clutch of the box, especially if it is bracelet chains. Therefore, on a slippery road, we move as smoothly and accurately as possible, even if the car has already started to drive after it has stalled. And of course, you need to monitor the temperature of the oil in the box. The box will definitely not withstand long slips.

About sudden loads

Many have heard that sudden loads on the box led to its early failure. It's reallytruth. Due to their design, these transmissions are not able to "digest" a large torque. However, how can this be prevented? How to use the variator? Everything is simple. It is necessary to abandon frequent aggressive driving and warm up the box in the winter. We also note that on many boxes the electronics are able to signal overheating. So, if the oil temperature is above normal, the corresponding lamp on the instrument panel will light up. And on some cars, the electronics will not let you budge at all until the box cools down.

CVT and off-road

This is also worth talking about separately. Many are wondering how to use the CVT on the Mitsubishi Outlander and other SUVs. The variator is not intended for operation on a primer or off-road. Just a few slips are enough to overheat the transmission. Therefore, if you often drive in such areas, it is better to choose a car with mechanics. But how to use the CVT on the Outlander in such a situation?

If the car has landed on its "belly", do not make desperate attempts to move it. Otherwise, overheating of the gearbox will be ensured. Only evacuation is relevant. Also, do not often switch from R to "drive" mode, trying to rock the car. Because of this, the spline connections of the box wear out significantly.

Towing

Considering the question of how to use the CVT, it must be said that this box is also afraid of towing. So, a car with a CVT cannot be transported in tow.- only a tow truck. As in the previous case, splined connections are severely broken here.

Trailers

How to use the CVT on the Nissan X-Trail if it is equipped with a towbar and you need to transport cargo on a trailer? In this case, it is worth adhering to the rule that the weight of the trailer with the load should not exceed one ton. And as for cars, they should be abandoned (meaning in tow).

Maintenance

You also need to know the nuances of maintenance, and not just how to use the CVT. On Mitsubishi, as on other machines with this gearbox, regular oil changes should be made. The regulation is 60 thousand kilometers. It is important to know that the oil must meet all tolerances and specifications. It is recommended to use only original products. The fact is that the variator is more demanding on the quality and properties of the oil than the automatic and mechanics. Therefore, only liquid from a trusted manufacturer is poured here. As for the repair, with any signs of slipping or other incorrect operation of the gearbox, you need to go for detailed diagnostics to the service station. The device of the variator is quite complicated, so the repair of the box should only be carried out by professionals.

Also note that even with regular maintenance, the resource of such a transmission does not exceed 200 thousand kilometers. This must be taken into account when purchasing a used car.

Causes and signs of breakdown

Let's consider the most common ones:

• Inability to include anyor transmission. This indicates a failure of the gearbox selector. There may also be problems with electrical wiring (oxidation of contacts, connectors, or mechanical damage to wires).
• Shocks when switching from "neutral" to "drive". There is a faulty pressure solenoid valve here. Also, kicks occur due to a faulty control unit.
• Loss of acceleration dynamics. The car cannot move when pressing the accelerator. In this situation, there may be problems with the torque converter, the control unit, or with the forward clutch.

Conclusion

So, we found out how the CVT is arranged and works, as well as how to use the CVT. In order not to "sentence" this box ahead of time, you need to avoid increased loads and service it in time. This is the only way to save the resource of this complex automatic transmission.