To understand how the clutch of a car works, first of all, let’s look at the clutch anatomy.
The clutch of a car consists of the following elements:
- clutch cover, drive (pressure) disk;
- a thin driven disk with friction pads and a torsional vibration damper;
- pressure mechanism – pressure (drive) disk, circumferentially located cylindrical springs or one central diaphragm spring;
- the clutch engagement mechanism — pulling fingers, deactivation levers (four or three), the clutch engagement with a thrust ball bearing (graphite bearing);
- Clutch release drive – traction and leverage systems, switch forks (hydraulic clutch release drive);
- Clutch release amplifier – pneumatic or pneumatic-hydraulic (for trucks).
Car clutch anatomy:
a – single-disk; b – two-disk; 1 – engine crankshaft; 2 – flywheel; 3 – a driven disk with friction pads; 4 – pressure plate; 5 – clutch housing; 6 – clutch cover; 7 – a pulling finger; 8 – support of the pulling lever; 9 – pull lever, 10 – clutch; 11 – the drive shaft of the gearbox; 12 – pedal; 13 – thrust; 14 – shutdown plug; 15 – a tightening spring; 16 – pressure spring; 77 – a directing finger; 18 – roller bearing; 19 – squeezing spring of the intermediate disk; 20 – an adjusting bolt of an intermediate disk; 21 – pressure drive disk; 22 – rear driven disk; 23 – an intermediate leading disk; 24 – front driven disk.
According to the number of driven disks, friction clutches are divided into single and double disk. Double disc clutches are installed on trucks to transmit large torque.
How the clutch works when the clutch is on
When the vehicle’s clutch is engaged, the torque is transmitted from the crankshaft to the flywheel, then to the clutch cover and through the leaf springs to the drive (push) disk. On the light car there are square windows in the clutch cover, which includes the tides of the clutch release levers. On trucks, grooves are made on the flywheel, which include the tides on the drive disks. Thanks to the friction forces, the torque is transmitted from the flywheel and the driving pressure disk to the driven disk sandwiched between them, the hub of which has a spline connection with the drive shaft of the gearbox.
How the clutch works when the clutch is off
To deactivate the vehicle’s clutch, depress the pedal, which, through a system of rods and levers, transfers force to the fork, clutch, levers and fingers retract the drive pressure plate. In this case, the springs are compressed and release the driven disk, on both sides of which gaps are formed. In the double-disc clutch, to ensure the necessary gaps between the master and driven disks in the off state, there are squeezing springs and an adjusting bolt of the intermediate disk. When the pedal is smoothly released, the pressure springs return all the details of the shutdown mechanism to its original position, the driven disk is pressed against the master (pressure) disk and the flywheel.