As the car 3 big one of, the action of gear-box is self-evident, its are the acceleration to car, stability, oily bad news expression and comfortable sex have immediate effect, choose a good transmission case to appear then particularly important. It is at present in market of our country car, automatic gear-box has become very popular, current, 3 kinds of more popular gear-box on the world are, AT (planetary gear group is automatic gear-box) , CVT (infinitely variable speeds implement) , DCT (gear-box of double separation and reunion) , so these a few kinds of gear-box, which a bit better? Which ability is suit oneself most, oneself favorite transmission case?
AT hydraulic is automatic gear-box
This kind of gear-box is to look most extensive automatic transmission case is used on preexistence bound, its working principle is to pass hydraulic power and the pattern that planetary gear sets to implement automatic speed change, when throw-over, do not need too much and artificial interpose, need the strength according to driver pedal only, gear-box can change namely archives. This gear-box shift gears it is direct, good to feel quickly, can bear torque is big, ride comfort is good, it is the gear-box that matures quite at present. BMW is this used transmission case for years so.
But AT gear-box must want to be controlled strictly as a result of gear-box bulk, weight, gear-box material demand is very high also, also need to compare complex control logic at the same time, change with hydraulic quadrature implement the lock stops the strict requirement of limits, commercialize at present AT gear-box delivered 10 file, be had achieved bottleneck.
CVT is not had extremely gear-box
Compare at AT gear-box for, because do not have archives the process of switch, accordingly CVT gear-box won't have " frustration sense, all? Archives form through computer simulation. This gear-box basically is in by day department car with, its working principle is to use electronic-controlled hydraulic pressure drive undertakes actively changing with driven cone pulley diameter, change transmission comparing, impaction metal strip uses attrition to deliver torque, meet so very good compliance of the economy that assured a car peace.
But CVT gear-box cannot bear for an instant the output of big torque, in urgent quicken or start the instant, the computer on the car can restrict engine torque output automatically to skid in order to prevent, accordingly, urgent answer quickly general.
Gear-box of DCT double separation and reunion
This can see from the name, its working principle can regard as by two electric machinery, taking two groups of clutch piece, correspondence of a clutch is odd block, even number of correspondence of a clutch is blocked, when shift gears, an archives be in transport condition, another is in ready state, this kind of mechanism is in the car is normal when travel, promoted shift gears rate well, make gear-box can complete switch in 0.2 seconds less than. Be in at present domestic popular " TSI+DSG " be known as gold combination.
But this kind of fast and active shift gears, start what bring namely tremble, clutch piece overheat. Be in that is to say engine high rotate speed when, gear-box has grade switch, of the instant block a change, can bring sharp frustration move.
