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Air suspension device: description, principle of operation and diagram

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Air suspension device: description, principle of operation and diagram
Air suspension device: description, principle of operation and diagram

There are many systems and mechanisms in the design of a car. One of these is the chassis. It can be dependent and independent, on longitudinal and transverse levers, with springs or springs. In today's article, we will talk about the air suspension device, its principle of operation and other features.


It is one of the varieties of car chassis.

air suspension device features

Its main task, like any other suspension, is to dampen vibrations that occur when driving on rough roads. But unlike the spring and spring, such a chassis can adjust the clearance through the use of air springs.

Device, design

This system consists of several main elements:

  • Pneumatic reservoir.
  • Control unit.
  • Sensor groups.
  • Airways.
  • Elastic bellows.
  • Compressor.

A receiver is an element inwhich is pumped air from the compressor. Usually has a volume of 5-7 liters. On command from the control unit, air is supplied from the receiver to the air springs.

air suspension device

The latter are an actuator that is involved in maintaining and setting the ground clearance. The compressor is one of the main elements in the air suspension system. Its purpose is to supply compressed air to the receiver.

Depending on the type of construction, air bags can be individual or combined with a shock absorber strut. In the latter case, in addition to a dense casing and cuffs, there is a damping rod with a piston.

The movement of air through the system is impossible without air lines. They are also equipped with solenoid valves. The number of them determines the type of system, but more on that later.

Additionally, the system can be equipped with sensors that will control:

  • The angle of the body relative to the road.
  • Vehicle speed.
  • And more.

So, we have considered the air suspension device. We will describe its operation principle below.

How it works

The algorithm of this system is very simple. It is based on regulating the amount of air in the pillows. After receiving signals from the sensors, the information is processed in the electronic unit. Next, the block sends a command to the actuators. These are solenoid valves that are installed at the outlet of the receiver. At the command of the unit, they open, and pressurized air enters the pillows.

what is air suspension

Next, the valve closes, and the volume of oxygen in the receiver is compensated by the compressor. If you need to reduce the clearance, the unit gives a command to bleed the air. The corresponding valve opens. However, the air does not go back to the receiver (since this requires a very large resistance), but to the street. A new portion of oxygen enters the system again thanks to the compressor. This air suspension principle is cyclical and repeats many times.

Also note that the system can automatically adjust the pressure. In this case, the driver needs to press the "Auto" button of the control unit. You can change the setting manually at any time. To do this, there are up and down buttons that allow you to reduce or increase the height of the car's clearance.

On what cars is it installed?

Basically, such a system is mounted on trucks. These are truck tractors, trailers and other heavy equipment. This is necessary in order to ensure the optimal position of the body when approaching the ramp. Cars with such a suspension are more vibration-resistant, which means that the cargo will not break during transportation. Plus, when loading, the car does not sag, as it happened earlier with springs. At any time, the driver can correct the position of one and the second axle.

But air suspension is also found on cars. Its manufacturer offers as an option. Typically, such a suspension is found on premium cars Mercedes, Lexus, Rolls-Royce and others. Installation outside the factory is also possible.So, BPAN lovers install air suspension on VAZs. The landing of the car becomes very low. In this case, the clearance value can be returned to the factory at any time. In addition, such a suspension is an essential attribute of "stens" cars.

air suspension working principle

It is not only a beautiful sight, but also a must. Indeed, due to the negative camber, it is very difficult to ensure a normal suspension travel in motion. Thanks to the air tanks, it is possible to adjust the position of the wheels to the arches as needed.


Considering the air suspension device, it is worth noting that it is classified according to a different number of circuits. So, there are:

  • Single-loop.
  • Double-circuit.
  • Four-loop systems.
air suspension for vaz

Features of each of them will be considered further.


This type of air suspension device is distinguished by its simplicity. So, the system is installed on only one axis. The pillows on the left and right wheels are inflated evenly and simultaneously. It is usually installed on a car where a leaf spring suspension was previously used. These are pickups, small and medium-duty trucks. Recently, very often single-circuit systems have been mounted on GAZelles and GAZons of the Next series. They are the cheapest of all. The installation price is about 20-40 thousand rubles, taking into account the cost of all components.

The system can be receiver and receiverless. Which one has suchair suspension working principle? In the first case, oxygen is supplied by a compressor to the "receiver", where it is contained under pressure up to 10-15 bar. At the command of the driver, at a certain moment the air is directed to the pillows. On a tankless system, this process takes much longer, since the compressor needs time to inflate both cylinders.

Double circuit

This is the most popular option. It can be installed on both or on one axle. The system combines two circuits with air lines and valves. The receiver and compressor are shared here. So, one circuit is responsible for adjusting the front axle, and the second - the rear. If the system is installed on one axle, the left and right air bellows are configured separately. It is installed on both trucks and cars. Its cost is about 20-30 percent higher than a single-circuit one. Control over the current pressure is ensured thanks to pressure gauges, which are displayed in the cabin during installation.


What is a four-circuit air suspension? This is the most expensive type of undercarriage.

air suspension device

Features of this type of air suspension device is that the driver can adjust the clearance of each wheel separately. All of them are connected to different circuits, which are equipped with their own valves and are independent of each other. The system must be connected to the receiver.

Main benefits

Considering the air suspension device, we note the advantages of this system as a whole:

  • Possibility to adjust clearance. Basicparameter, because of which motorists choose this suspension.
  • Independence from the overall vehicle load. The machine does not sag on the pillows, even if there is a large load "on board".
  • Great ride. Unlike springs with shock absorbers, the cylinders fully absorb all the shocks that occur when driving on rough roads.
  • Ease of control. The driver can adjust the desired clearance directly from the passenger compartment, thanks to the control panel. On trucks, it has a coiled cord to allow the driver to control the raising and lowering of the axle on the street. This is especially important when hitching a semi-trailer.
  • Unpretentious maintenance. There are no complex parts in the system that need to be periodically lubricated, replaced or adjusted.

The air suspension arrangement is such that the system can fully adapt to road conditions and vehicle axle loads.


The main disadvantage is maintainability. If the cylinder began to "poison", it must only be replaced. In the case of a suspension strut, the repair cost can be quite substantial. Also, the system is very afraid of frost. Since the cylinders are made of rubber, they begin to "tan".

How to extend the service life?

No matter how many circuits an air suspension has, the principle of operation is the same. Also the cylinders remain the same. As we said earlier, they can poison the air. This is due to their pollution.

air suspension device working principle

Over time on theirdirt and reagents enter the walls, which begin to work as an abrasive. To prevent this, periodically wash the cylinders in the maximum raised state under a powerful jet of water. Additionally, treat the walls with silicone spray. This is the only way to ensure long-term and reliable operation of the cylinders.

So, we found out what air suspension is and what features it has.

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