Multi-plate clutch (rarely used in cars)

Multi-plate clutch (rarely used in cars)
in its construction it is similar to a single-disc clutch. The difference is this, that instead of one clutch disc, there are several of them, located slidably on the splines inside the driving drum, forming one unit with the flywheel.
On the driven drum, mounted on the input shaft, steel discs are also slidably mounted, between the friction plates. The clutch discs may slide in the drive drum (similar to the steel discs in the driven drum), however, they have a rotary motion with it. The pressure plate under the action of the pressure springs presses all the plates against the flywheel, and thus causes the movement from the flywheel to be transferred to the clutch shaft. Applying pressure on the clutch pedal causes the discs to loosen and disengage the clutch.
The condition for a good operation of the described dry couplings is that the friction lining is protected against grease, otherwise, friction between the parts is reduced and the clutch slips. As a rule, wet clutches have multiple discs. The wet clutch discs run continuously in the oil. Wet multi-disc clutches are used in motorcycles, some small passenger cars and some extra heavy duty cars. Their advantage is very smooth engagement of the drive.