How a car clutch works.

However, in the first place, this node is always associated with a car. By the way, the happy owners of cars equipped with both mechanical and, for sure, will be surprised to learn that their car has not one clutch, but several.

But before I start explaining how a car's clutch works, let's define what it is.

What is clutch?

So, the clutch is a useful device located between two moving shafts, one of which is usually driven by a pulley or engine, and the other is geared.

The main task of the clutch is to connect these shafts (so that they rotate at the same speed) or separate them (so that they rotate at different speeds).

Thus, a car needs traction because the wheels move inconstantly, while the motor is always in motion during its operation. Therefore, so that during each stop it was not necessary to turn off the engine, it must be somehow disconnected from the wheels. This is what the clutch does, while at the same time contributing, by smoothly “grinding” the shafts, to a soft connection of the engine, which rotates during operation, with a stationary transmission.

Automobile clutch device.

In order to understand the meaning of the clutch, you need to clearly understand what the friction force is, with the help of which it is determined how hard it is for objects to slide over each other. After all, as everyone probably knows, even on the smoothest surface there are microscopic irregularities, and the larger these irregularities, the more difficult it is for objects to slide against each other. This is the reason for the coefficient of friction, on which the operation of the clutch is based (due to the friction of the pressure plate and the clutch disc, about its replacement). It looks like this.

When the driver presses the clutch pedal, a hydraulic piston or cable pushes the fork, which pushes the release bearing against the diaphragm spring. The petals of this spring bend, and the edge of the spring (outer edge) moves away from the pressure plate, thereby releasing it and, accordingly, interrupting the transmission of torque to the transmission. By the way, the springs located on the clutch disc also have their purpose: they are needed to absorb transmission shocks that can occur in cases of a sharp throw of the clutch.

How does a clutch work?

Types of clutches and how they work.

The following types of clutches can be used in cars:

• dual clutch (usually included with automatic transmission)

These clutches engage and disengage planetary gears in an automatic transmission. Each of the clutches performs its work (action) using hydraulic fluid under pressure. When the pressure drops, the clutch is released by the springs.

• electromagnetic clutch (installed in car air conditioners)

Thanks to this type of clutch, the compressor can be switched off even while the engine is running. And this system works when an electric current passes through the magnetic coil. In cases of interruption of the current supply (turn off the air conditioner), the clutch is disconnected.

• viscous coupling (used in some cars to control special cooling fans powered by a motor)

Its operation occurs depending on the temperature of the special liquid in it. The coupling is mounted in the fan hub and is located on the side of the passing air flow, which moves through the radiator.

The principle of operation of the clutch here is as follows: in cases of increasing temperature in the clutch, the viscosity of the fluid increases, which also leads to an increase in the speed of the fan; and in a cold car, the fluid in the clutch is not heated, therefore, the fan rotates more slowly, which contributes to the speedy heating of the engine to operating temperature.

• viscous differential clutch (its use provides improved traction)