Two-plate clutch - two friction plates
The two-piece clutch is actually a clutch with two friction plates.
As we all know, the clutch consists of a pressure plate, a friction plate (also called a clutch plate) and a separate bearing. During normal operation, the pressure plate and the engine flywheel clamp the clutch plates, transferring power to the clutch plates and then to the gearbox shaft.
Obviously, the torque that the clutch transmission can transmit is limited by its size, so if you want to break this limit, you need to add a friction plate and add a medium pressure plate between the two friction plates.
Some of the early heavy-duty trucks used this structure, but the two-plate clutch had a relatively poor heat dissipation effect and was prone to incomplete separation. Nowadays, with the upgrading of material technology and the reduction of overload, it is now basically a single-chip clutch.
Dual clutch transmission - two clutches
The dual clutch transmission is a gearbox with two clutches.
Simply put, there is a clutch connected to the odd gears (1, 3, 5, 7, etc.) of the gearbox, and the other gearbox is connected to the even gears (2, 4, 6, etc.). In this way, when you use 3 speeds to accelerate, the gearbox can hang up the 4th gear in advance, and "depress" the 4th gear corresponding clutch. When the shift is required, "depress" the clutch corresponding to the third gear, "release" the clutch corresponding to the fourth gear, and the shift is completed.
The dual-clutch gearbox was used in racing cars early because of its excellent shifting speed. Since the shifting speed is faster, the engine idle time is reduced, so that it has better fuel economy, so it gradually developed into the field of civilian passenger cars.
In recent years, foreign companies including Daimler, Eaton and Volvo have begun to launch their dual clutch products in the commercial vehicle sector.