The continuously variable transmission of an automobile refers to an automobile equipped with a continuously variable transmission. Continuously variable transmission is different from automatic transmission. Continuously variable transmission is a kind of automatic gearbox, also called CVT gearbox.
Second, the characteristics and principle of automobile continuously variable transmission
Continuously variable transmission. There is no gear transmission structure of the traditional gearbox, but two transmission wheels with variable diameters with a transmission belt in the middle. The basic principle is that the two ends of the transmission belt are wound on a conical pulley, and the outer diameter of the pulley changes steplessly according to the oil pressure. When starting, the diameter of the driving pulley becomes the maximum diameter, while the diameter of the driven pulley becomes the minimum, achieving a higher transmission ratio. With the increase of vehicle speed and the change of various sensor signals, the computer control system determines the control oil pressure of two pulleys, and finally changes the continuous change of pulley diameter, thus realizing stepless speed change in the whole speed change process.
And a transmission belt between the conical pulley and the conical pulley. In the past, due to the material, the tension and torque were limited, so it could only be used in motorcycle-type small-displacement vehicles. In recent years, with the continuous improvement of material technology and processing technology, rigid transmission belts and tapered pulleys made of special materials have been produced. The requirements of high power and torque for automobiles are fully realized.
The biggest feature of CVT is the stepless control of output speed ratio, which achieves the feeling of running water during driving, so there is no feeling of shifting gears. Passengers can't feel the shift impact, and the power connection is coherent. In this way, CVT increases the comfort when driving, and the acceleration will be faster than automatic transmission.
Compared with ordinary automatic gearbox, stepless speed change is smoother, without impact, and fuel consumption is lower than ordinary automatic gearbox. The disadvantage is that the maintenance cost is high and the service life is shorter than that of ordinary automatic gearbox.