CVT or continuously variable transmission is a system with a “stepless” gear ratio effect. CVT is a “stepless” system. It maintains optimum engine rpm according to the speed of the vehicle, which leads to an increased fuel economy of vehicles. This contrasts with other transmissions that offer a restricted or fixed number of staged gear ratios. The CVT transmission adaptability can let the engine operate at constant RPM as the vehicle drives at different speeds. The smooth acceleration of the CVT is also distinctive. The algorithm determines the best transmission gear ratio by understanding the driving trends and then predicting the optimal engine rpm. Therefore, the brains of the powertrain continuously adjust rpm with the driver’s intents. This ensures a pleasant and intuitive driving experience as well as low fuel consumption. The first mass-production car to use a CVT was the 1958 DAF 600 from the Netherlands. Its Variomatic version has been used in several vehicles built by DAF and Volvo, up until the 1980s.
How does the CVT transmission work?
You must understand how a manual and a traditional automatic transmission works to understand a CVT. A manual has a specified number of gears, which are predefined and selected by the driver. An automatic system likewise has a predefined number of gears, but it uses a hydraulic system that responds to the pressure produced to decide the gear ratios required without the driver’s input. A CVT is also like an automatic transmission, because the driver doesn’t have any input, but the similitude ends there. There are no traditional fixed gear ratios for a CVT. It got two pullies instead. One pulley is connected to the flywheel, the other to the wheels. The pulleys are linked by a flexible steel strip. Depending on how much power the vehicle requires, the diameter of the rotating pullies changes. One pulley becomes smaller, while the other pulley gets bigger. Since either the slide or the strap is not fixed, unlike the automatic one which contains a defined number of gears, they can supply infinite gearing possibilities. Not all CVTs are the same though. The popular kind, however, is the Toroidal CVT, which uses rotational discs with power rollers to obtain the same result as pulleys. The CVT hydrostatic controls the fluid flow with pumps, which subsequently generates a rotary motion.
Advantages and disadvantages of the CVT transmission
A CVT’s capacity to adjust its gear ratio continually is one of its biggest advantages. That means that regardless of how fast the car wants to move, the engine is always at its efficiency range. As a consequence, CVTs frequently offer higher fuel economy, especially in the city. Digital trends argue that most automobiles that are fitted with CVTs give a more smooth and automated ride than a similar car fitted with a torque converter-based transmission. When the automobile requires extra power, there is no abrupt downshift and there is no feeling of gear hunting as you sometimes experience in a regular automatic. While the lack of ups and downs is seen as an advantage of the CVT, some drivers miss out on the feeling that the car travels through the shifts. If you like more sporting driving, the lack of fixed gear ratios makes driving less attractive. The loud droning sound that takes place during acceleration is another issue which drivers tend to raise about the CVT. This occurs because the CVT compels the engine to constantly operate at high speeds. The reason behind this is that this is because the noise perception differs from the mechanical or step-automatic transmission, with no proportionate speed gains. Compared to a conventional automatic transmission, CVTs may be costly to maintain or replace. Owners often encounter several problems such as overheating, slippage, and unexpected acceleration loss. Shuddering is also a frequent issue.
The old stigma attached to the automatic transmissions of not being fuel-efficient is slowly fading away and customers are more accepting of them now. The CVT transmission has played an important part in this change. Right from a humble Honda Active to a Toyota Corolla, this technology has been adapted very rapidly in recent years. With a slight sacrifice in the fuel economy, the gains are so much and the driver feels way relaxed with a CVT transmission. CVT is also used mainly in electric hybrid cars, so one can say that CVT transmissions are here to stay in the future.