1. Ensure the smooth start of the car

The car is in a static state before starting. If the engine and gearbox are rigidly connected, once the gear is put into gear, the car will suddenly rush forward due to sudden power connection, which will not only cause damage to the parts of the vehicle, but also the driving force is not enough to overcome the huge inertia caused by the front impact of the car, so that the engine speed drops sharply and stalls.

2. Easy to shift gears

In order to adapt to the changing driving conditions, different transmission gears are often used in driving process. If there is no clutch to separate the engine from the gearbox temporarily, the transmission gears meshed in the gearbox will be difficult to separate because the load is not removed and the pressure between the meshing tooth surfaces is very large.

3. Prevent overload of drive system

When the vehicle is in emergency braking, the wheels suddenly decelerate sharply, but the transmission system connected with the engine still keeps the original speed due to the rotating inertia, which often produces the moment of inertia far greater than the engine torque in the transmission system, which makes the parts of the transmission system easy to be damaged.

Because the clutch transmits torque by friction force, when the load in the transmission system exceeds the torque that can be transmitted by friction force, the driving and driven parts of the clutch will automatically slip, thus preventing the transmission system from overload.

4. Reduce torsional impact

The working principle of automobile engine determines the instability of its output torque. On the other hand, when the engine is driven by the gas, it will explode in the opposite direction.