Automatic transmission with variator (CVT)
A continuously variable transmission (CVT) is a type of automatic transmission that uses a belt or chain system to transfer power from the engine to the wheels, providing smooth, continuously variable gear changes.
Design and principle of operation:
* CVT: The main element of a CVT is the variator, which consists of two cone-shaped pulleys connected by a belt or chain.
*Belt or Chain: The belt or chain transfers power from the engine to the pulleys.
*Hydraulic system: Oil pressure from the torque converter or transmission controls the position of the pulleys, changing their diameter.
Working principle:
1. When the gear is engaged, the torque converter or high-pressure pump supplies oil to the variator hydraulic cylinder.
2. The hydraulic cylinder moves one of the pulleys, changing its diameter.
3. A change in the diameter of a pulley causes a change in the diameter of another pulley, since the belt or chain is under constant tension.
4. Thus, the gear ratio between the engine and the wheels changes, which ensures smooth acceleration and deceleration without noticeable gear changes.
CVT types:
* V-belt: Uses a V-belt and cone-shaped pulleys.
* Toroidal: Uses toroidal pulleys and chain.
* Push Belts: Use special reinforced belts that are pushed through cone-shaped pulleys.
Advantages of CVT:
* Smooth and continuously variable gear shifting
* Optimal power transmission at any engine speed
* Fuel savings by keeping the engine in the optimal speed range
* Compact size and weight
Disadvantages of CVT:
*Limited torque transfer
*Higher production and maintenance costs than traditional automatic transmissions
*May be less responsive than manual shift transmissions