The smooth start of a car depends on the clutch, which is probably known to most drivers. In addition, the clutch also plays a significant role in shifting gears and braking during rapid driving of the car. Automobiles clutch accessories provide the basic conditions for the functioning of the clutch.
During the driving process of a car, different transmission gears are often used to adapt to constantly changing driving conditions. If there is no clutch to temporarily separate the engine from the gearbox, the meshing transmission gears in the gearbox will be difficult to separate due to the high pressure between their meshing tooth surfaces due to the load not being removed. On the other hand, meshing gears may be difficult due to their unequal circumferential speeds. Even if forced into engagement, it will generate significant tooth end impact, which can easily damage the machine components. By using the clutch to temporarily separate the engine and gearbox and then shift gears, the originally engaged pair of gears can be easily separated due to the load being removed, and the pressure between the meshing surfaces is greatly reduced. As the Moment of inertia of the other pair of gears to be meshed is very small after the driving gear is separated from the engine, the circumferential speed of the gears to be meshed can be equal or nearly equal by using appropriate shifting action, so as to avoid or reduce the impact between gears.
When a car undergoes emergency braking, the wheels suddenly slow down sharply, while the transmission system connected to the engine maintains its original speed due to the inertia of rotation. This often generates a moment of inertia in the transmission system that is much greater than the engine torque, making the components of the transmission system vulnerable to damage. Due to the fact that the clutch transmits torque through friction, when the load in the transmission system exceeds the torque that can be transmitted by friction, the main and driven parts of the clutch will automatically slip, thus preventing overload of the transmission system.
From the above two points alone, the wear and tear of automotive clutch accessories is essential, as inertial friction keeps them in a state of motion. This also explains why the clutch sometimes malfunctions continuously.