Car suspension. The device of the dependent suspension of the car, its types, differences and maintenance On which cars is the independent suspension

In an independent suspension, the wheels of one axle do not have a rigid connection, and the movement of one of them either does not affect the second in any way, or has only a small effect on it. At the same time, the setting parameters, such as track, wheel camber, and in some types the wheelbase, change during compression and rebound of the suspension, sometimes within very significant limits.

With oscillating axle shafts

Oscillating axle suspension has one hinge on each of them. This ensures their independent suspension, but during operation of this type of suspension, both the track and the camber of the wheels change over a wide range, which makes such a suspension kinematically imperfect. Due to its simplicity and low cost, such a suspension was at one time widely used as the driving rear axle on rear-wheel drive vehicles. However, with the growth of speeds and requirements for controllability, they began to abandon it everywhere, as a rule, in favor of a more complex, but also more perfect suspension on longitudinal or oblique levers. For example, ZAZ-965 had swinging axle shafts in the rear suspension, but its successor, ZAZ-966, already received oblique levers and axle shafts with two hinges on each. The rear suspension of the second generation of the American Chevrolet Corvair has undergone exactly the same transformation.

On the front axle, such a suspension was used very rarely, and almost exclusively on low-speed, light rear-engined vehicles (for example, the Hillman Imp). There were also improved versions of such a suspension. For example, some Mercedes-Benz models from the 1960s used a rear axle with a single pivot in the middle, the halves of which worked like swinging axle shafts. This version of the suspension is distinguished by a smaller change in its settings during operation. An additional pneumatic elastic element was installed between the halves of the bridge, which made it possible to adjust the height of the car body above the road.

Some vehicles, such as Ford pickups in the mid-1960s, used non-drive axles with oscillating axle shafts, the attachment points of which were located close to the wheels on the opposite side. At the same time, the half-axles turned out to be very long, almost in the entire track of the car, and the change in track and camber was not so noticeable.

On trailing arms

In this suspension, each of the wheels of one axle is attached to a trailing arm, which is movably attached to the frame or body. This type of independent suspension is simple but imperfect. When such a suspension works, the wheelbase of the car changes within a fairly wide range, although the track remains constant. When turning, the wheels tilt in it together with the body significantly more than in other suspension designs. The longitudinal levers perceive forces acting in all directions, which means they are subjected to high torsional and bending loads, which requires their great rigidity and, accordingly, weighting.

In addition, it is characterized by a very low, in the area of ​​the roadbed, the location of the center of the roll, which is a disadvantage for the rear suspension. In addition to simplicity, the advantage of such a suspension is that the floor can be made completely flat between the levers, increasing the volume available for the passenger compartment or trunk. This is especially felt when used as elastic elements of torsion bars, due to which the suspension on trailing arms with transverse torsion bar shafts was at one time widely used on French cars.

At one time (mainly 1970s-1980s) such a suspension with traditional spring or (Citroën, Austin) hydropneumatic elastic elements was widely used on the rear axle of front-wheel drive vehicles. However, later in this role it was supplanted by the semi-independent suspension with tied levers developed by Audi, a more compact and technologically advanced MacPherson type (in English-speaking countries such a suspension on the rear axle is called Chapman) or (already in the late 1980s ... 1990 -ies) the most kinematically perfect on double wishbones

As a front suspension, such a suspension was occasionally used on structures developed before the 1950s, and later, due to its imperfections, almost exclusively on cheap low-speed cars (for example, the Citroen 2CV). In addition, trailing arm suspension is very widely used on light trailers.

On oblique levers

This is essentially a kind of trailing arm suspension, created in an effort to get rid of its inherent flaws. It is almost always used on the rear drive axle. In it, the swing axes of the levers are located at a certain angle. Thanks to this, the change in the wheelbase is minimized compared to the suspension on the trailing arms, and the effect of body roll on the wheel inclination is also reduced (but a change in track appears).

There are two types of such a suspension

In the first one, one hinge is used on each semi-axle, as in a suspension with swinging semi-axles (sometimes it is considered a type of the latter), while the swing axis of the lever must pass through the center of the semi-axle hinges (located in the area of ​​their attachment to the differential), that is, it is located under an angle of 45 degrees to the transverse axis of the vehicle. This makes the suspension cheaper, but when it works, the camber and toe-in of the wheels change greatly, when cornering, the outer wheel "breaks" under the body, and the roll center turns out to be very high (the same disadvantages are characteristic of the suspension on swinging axle shafts). This option was used almost exclusively on cheap, light and low-speed, usually rear-engined cars (ZAZ-965, Fiat 133, and so on).

In the second version (it is he who is shown in the illustration), each axle shaft has two hinges - internal and external, while the swing axis of the lever does not pass through the internal hinge, and its angle with the transverse axis of the car is not 45, but 10-25 degrees, which more advantageous in terms of suspension kinematics. This reduces wheel track and camber changes to acceptable levels.

The second option in the 1970s ... 1980s was very widely used on rear-wheel drive cars, as a rule, directly replacing the dependent suspension with a continuous axle used on previous generations. You can name such models as "Zaporozhets" ZAZ-966 and −968, BMW 3… 7 series, some models of Mercedes-Benz, Ford Granada, Ford Sierra, Ford Scorpio, Opel Senator, Porsche 911 and so on. Both traditional coil springs and torsion shafts, sometimes pneumatic cylinders were used as elastic elements. Subsequently, with the improvement of car suspensions and increased requirements for stability and controllability, it was supplanted either by the cheaper and more compact MacPherson (Chapman) suspension, or by the more advanced double wishbone suspension, and is rarely used today.

On front-wheel drive cars, such a suspension was rarely used, since for them its kinematic advantages are of little importance (in them, the role of the rear suspension is generally much less than that of rear-wheel drive vehicles). Examples include, for example, Trabant, in which an elastic element in the suspension on oblique arms was a transverse spring fixed in its center on the body, the ends of which were attached to the ends of the A-shaped oblique arms.

On the longitudinal and transverse levers

This is a difficult and very rare type of suspension.

In fact, it was a version of the MacPherson strut, but to unload the wing mudguard, the springs were not positioned vertically, but horizontally longitudinally, and rested with the rear end against the partition between engine compartment and interior (bulkhead). To transfer the force from the shock absorber to the springs, it was necessary to introduce an additional trailing arm swinging in a vertical plane from each side, the front end of which is hinged at the top of the rack, the rear end is also hinged on the bulkhead, and in its middle part there was a stop for the front end of the spring. Due to its comparative complexity, such a suspension has lost the main advantages of the MacPherson strut - compactness, technological simplicity, a small number of joints and low cost, while retaining all its kinematic disadvantages.

Such a suspension was used by the English "Rovers" 2200 TS and 3500 V8, as well as the German Glas 700, S1004 and S1204. Similar additional trailing arms were present in the front suspension of the first Mercedes S-class, but the springs were located traditionally — in a vertical position between the body and the lower wishbones, and the small trailing arms themselves served only to improve kinematics.

Double trailing arms

This suspension has two trailing arms on each side. As a rule, such a suspension was used on the front axle of relatively low-speed rear-engined cars; typical examples of its use are the Volkswagen Beetle and the first generations of the Volkswagen Transporter, early models of Porsche sports cars, as well as the S3D and Zaporozhets motorized carriages.

All of them had essentially a common design (the so-called "Porsche system", in honor of the inventor) - transverse torsion shafts located one above the other were used as elastic elements, connecting a pair of levers, and the torsion bars were enclosed in the pipes that formed the cross member of the suspension (in the later models "Zaporozhets" in addition to torsion bars as additional elastic elements were also used cylindrical coil springs located around the shock absorbers).

The main advantage of such a suspension is its great compactness in the longitudinal and vertical directions. In addition, the suspension cross member is located far in front of the front wheel axle, which makes it possible to strongly move the interior forward, placing the driver's and front passenger's legs between the front wheel arches, which made it possible to significantly reduce the length of the rear-engined car. At the same time, however, the trunk located in front turned out to be very modest in volume, precisely because of the suspension cross member extended far forward.

From the point of view of kinematics, this suspension is imperfect: although smaller compared to single trailing arms, there are still significant changes in the wheelbase during rebound and compression strokes, and there is also a strong change in wheel camber during body roll. To this it should be added that the levers in it must perceive large bending and torsional loads from both vertical and lateral forces, which makes them quite massive.

Double wishbone

In this suspension, on each side of the car, there are two wishbones, the inner ends of which are movably fixed to the body, cross member or frame, and the outer ends are connected to the rack carrying the wheel — usually swivel in the front suspension and non-swivel in the rear. Typically, the upper arms are shorter than the lower ones, which provides a kinematically advantageous camber change towards a larger negative camber during the compression stroke of the suspension. The levers can be either parallel to each other or be relative to each other at a certain angle in the longitudinal and transverse planes. Finally, one or both of the levers can be replaced with a transverse spring (see below for this type of suspension).

The fundamental advantage of such a suspension is the ability for the designer, by choosing a certain geometry of the levers, to rigidly set all the main settings of the suspension - the change in camber and track during compression and rebound strokes, the height of the longitudinal and transverse roll centers, and so on. In addition, such a suspension is often completely mounted on a cross member attached to the body or frame, and thus is a separate unit that can be completely removed from the vehicle for repair or replacement.
From the point of view of kinematics and controllability, double wishbones are considered the most advanced type of guide vane, which leads to a very widespread use of such a suspension in sports and racing cars. In particular, all modern Formula 1 race cars have just such a suspension, both front and rear. Most sports cars and executive sedans these days also use this type of suspension on both axles.

If the wishbone suspension is used to cushion swivel wheels, the design must be such that they rotate through the required angles. To do this, either the stand connecting the levers itself is rotated, using special ball joints with two degrees of freedom to connect it to the levers (they are often called "ball bearings", but in fact, the support of them is only the lower hinge, on which the stand really rests) , or the stand is non-swivel and swings on conventional cylindrical hinges with one degree of freedom (for example, threaded bushings), and the rotation of the wheels is ensured by a vertical pivot rod rotating in bearings, which plays the role of a real axis of rotation of the wheels.

Even if pivots are structurally absent in the suspension, and the strut is rotatable on ball joints, they still often talk about the pivot (“virtually”) as the axis of rotation of the wheels, as well as about the angles of its inclination - longitudinal (“caster”) and transverse. Currently, pivots are used as a rule in the suspensions of trucks, buses, heavy pickups and SUVs, and in suspensions passenger cars When it is necessary to ensure that the wheels turn, racks with ball joints are used, since they do not require frequent lubrication.

The intensive development of the automotive industry has led to the creation of new types of engines, chassis, modernization of safety systems, etc. In this article, we'll talk about an independent car suspension. It has a number of features, advantages and disadvantages. It is this type of body suspension that we will now consider.

Suspension on trailing and oblique levers

It should be noted right away that there are many types of pendants. They were all designed to improve technical characteristics car and improve ride comfort. Some types are better suited for off-road driving, while others are great for city driving. First of all, let's talk about the independent suspension on the trailing arms. This design was popular in the 70s and 80s in French cars, and later found application in motor scooters. Torsion bars or springs are used as an elastic element. The wheel is connected to the trailing arm, and the latter is connected to the car body (movable). The advantages of such a system are the simplicity and low cost of maintenance, and the disadvantages are the roll and change in the wheelbase while the car is moving.

With regard to the oblique links, the key difference from the above-described design is that the swinging axis of the trailing link is at an angle. This approach minimized wheelbase change and roll. But the handling was still far from ideal, since the camber angles change when driving over irregularities. Often this arrangement was used on the rear independent suspension of cars.

Oscillating axle shafts

Another popular type of independent suspension. The device is quite simple. There are two axle shafts with hinges at the inner ends that connect to the differential. Accordingly, the outer end of the axle shaft is rigidly attached to the wheel hub. All the same springs or springs are used as elastic elements. One of the main advantages of this design is that the wheel remains perpendicular to the axle at all times, even when hitting obstacles. Actually, in this type of suspension, trailing arms are also used, which reduce vibrations from the roadway.

As for the shortcomings, they are there. When driving over rough terrain in wide values, not only the camber changes, but also the track width. This significantly reduces vehicle handling. This disadvantage is most noticeable at a speed of 60 km / h and above. As for the strengths, it is the simplicity of the design and the relatively cheap maintenance.

Trailing and wishbone suspension

One of the most expensive types, which is extremely rare due to the complexity of the design. In fact, the suspension is of the MacPherson style with some minor differences. The designers decided to remove the load from the mudguard and therefore placed the spring a little further than the shock absorber. One end of it rests against the engine compartment, and the other against the passenger compartment. To transfer force from the shock absorber to the spring, the designers added a swinging arm. He could move in a vertical longitudinal plane. In the center, the lever was connected to a spring, one end of it was attached to the shock absorber, and the other to the partition.

Actually, almost all joints are articulated, and this is a significant drawback, since MacPherson was famous for their small number. Actually, such a front independent suspension is found on Rover cars. It has no particular advantages, therefore it is not popular, and it is difficult and expensive to maintain it.

Double wishbone

This type of suspension is quite common. It has the following construction. The transversely located levers are attached to the body on one side, usually movably, and on the other side to the shock absorber strut. In the rear suspension, the strut is not swivel with a ball joint and with one degree of freedom. For the front suspension - a swivel strut and two degrees of freedom. In this design, various elastic elements are used: coil springs, springs, torsion bars or hydropneumatic cylinders.

Often, the design provides for the attachment of the lever to the cross member. The latter with the body is fixed rigidly, that is, motionless. This implementation allows the entire front suspension to be removed from the vehicle. From a kinematic point of view, the suspension is free from disadvantages and is preferred for installation in racing cars. But maintenance is expensive due to the large number of ball joints and the laboriousness of the work.

Classic multi-link

Structurally, the most complex type of suspension. It is similar in principle to a double wishbone suspension. Most often it is placed in the back on a class "D" or "C" car. In such a suspension, each lever determines the behavior of the wheel. It is due to this design that it is possible to achieve maximum controllability and the effect of "steering" the rear axle. The latter advantage allows not only to better enter corners, but also to somewhat reduce the turning radius.

From an operational point of view, there are no drawbacks. All the disadvantages are that not one independent suspension arm is used here, but much more. Each of them is equipped with a pair of silent blocks and ball bearings. Therefore, the service costs a lot of money.

Rear independent suspension for VAZ

The classic torsion bar suspension mounted on the rear axle is considered semi-dependent. The design has both advantages and disadvantages. To improve handling, car owners often install an independent suspension. It's not hard to guess that all the alterations are done on front-wheel drive vehicles.

The suspension itself is sold assembled. According to the manufacturer, it does not require any modifications and is assembled as a unit without making any changes to the vehicle design. But in practice, this is not entirely true. The muffler barrel interferes, so it's worth buying a shorter version. It was not done without the completion of the mountings. Some need to be finalized with a file, while others should be placed in the right places for this. But most importantly, this design significantly increases the car's handling, although the rear axle drift will become sharper and less predictable.

When choosing a car, it is advisable to pay attention to the type of its suspension. Independent is an excellent choice for city driving, and dependent is indispensable for traveling over bumps and trips to the country. The advantage of the latter is that the ground clearance remains unchanged. This is true for off-road and completely meaningless for asphalt. Many modern SUVs have a leaf spring, while the front is usually a multi-link.

Let's sum up

You should never forget about the maintenance of the car's chassis, and the suspension in particular. After all, even a multi-link with "killed" silent blocks and ball bearings will not give a feeling of safety and comfort. In addition, driving such a vehicle is life-threatening. Therefore, timely maintenance is required. Currently, the most preferred type of suspension can be considered a multi-link. But its maintenance is quite expensive, although much depends on the operating conditions and the quality of spare parts. The dependent suspension is suitable for trucks and SUVs, where cross-country ability is important, maintainability in field conditions and reliability, not comfort.

The car suspension is a set of elements that provide an elastic connection between the body (frame) and the wheels (axles) of the car. Mainly, the suspension is designed to reduce the intensity of vibration and dynamic loads (shocks, shocks) acting on a person, the transported cargo or structural elements of the vehicle when driving on an uneven road. At the same time, it must ensure constant contact of the wheel with the road surface and effectively transmit the driving force and braking force without deviating the wheels from the corresponding position. Correct suspension function makes driving comfortable and safe. Despite the apparent simplicity, the suspension is one of the most important systems of a modern car and has undergone significant changes and improvements over the history of its existence.

History of appearance

Attempts to make movement vehicle softer and more comfortable were undertaken even in carriages. Initially, the axles of the wheels were rigidly attached to the body, and every unevenness in the road was transmitted to the passengers sitting inside. Only soft seat cushions could improve the level of comfort.

Dependent suspension with transverse leaf springs

The first way to create an elastic "layer" between the wheels and the carriage body was the use of elliptical springs. Later, this solution was borrowed for the car. However, the spring had already become semi-elliptical and could be installed transversely. A car with such a suspension handled poorly even at low speeds. Therefore, soon the springs began to be installed longitudinally on each wheel.

The development of the automotive industry has led to the evolution of the suspension. Currently, there are dozens of their varieties.

The main functions and characteristics of the car suspension

Each suspension has its own characteristics and working qualities that directly affect the handling, comfort and safety of passengers. However, any suspension, regardless of its type, must perform the following functions:

1. Absorbing shocks and shocks from the road to reduce stress on the body and increase driving comfort.
2. Vehicle stabilization while driving by ensuring constant contact of the tire of the wheel with road surface and limiting excessive body roll.
3. Preservation of the specified travel geometry and position of the wheels to maintain precise steering while driving and braking.

Rigid Suspension Drift Car

The vehicle's rigid suspension is suitable for dynamic driving, which requires an instant and precise response to the driver's actions. It provides a small ground clearance, maximum stability, resistance to roll and body swing. Mainly applied on sports cars.

Luxury car with energy-intensive suspension

Most passenger cars use a soft suspension. It smoothes out irregularities as much as possible, but makes the car a little rolly and worse controllable. If an adjustable stiffness is required, a helical suspension is mounted on the vehicle. It is a shock absorber rack with variable spring tension.

Long-stroke suspension SUV

Suspension travel - the distance from the uppermost position of the wheel when compressed to the lowest when hanging the wheels. Suspension travel largely determines the off-road capabilities of the vehicle. The larger its value, the larger the obstacle can be overcome without hitting the limiter or without sagging the driving wheels.

Suspension device

Any car suspension consists of the following basic elements:

1. Elastic device- perceives loads from unevenness of the road surface. Types: springs, springs, pneumatic elements, etc.
2. Damping device- dampens body vibrations when driving through bumps. Types: all types.
3. Guiding device—provides a predetermined movement of the wheel relative to the body. Views: levers, transverse and jet rods, springs. Pull-rod and push-rod sport suspensions use rockers to change the direction of action on the damping element.
4. Stabilizer lateral stability - reduces lateral body roll.
5. Rubber-metal hinges- provide an elastic connection of the suspension elements to the body. Partially absorb, cushion shocks and vibrations. Types: silent blocks and bushings.
6. Suspension travel stops- limit the travel of the suspension in extreme positions.

Suspension classification

Basically, suspensions are divided into two large types: and independent. This classification is determined by the kinematic diagram of the suspension guide.

Dependent suspension

The wheels are rigidly connected by means of a beam or continuous bridge. The vertical position of a pair of wheels relative to the common axis does not change, the front wheels are swivel. The rear suspension device is similar. There is a spring, spring or pneumatic. In the case of installing springs or pneumatic bellows, it is necessary to use special rods to fix the bridges from moving.

Differences between dependent and independent suspension

• simple and reliable in operation;
• high carrying capacity.

• poor handling;
• poor stability at high speeds;
• less comfort.

Independent suspension

The wheels can change their vertical position relative to each other, while remaining in the same plane.

• good handling;
• good vehicle stability;
• great comfort.

• more expensive and complex construction;
• less reliability during operation.

Semi-independent suspension

Semi-independent suspension or torsion beam Is an intermediate solution between dependent and independent suspension. The wheels are still connected, but there is a possibility of their slight movement relative to each other. This property is provided due to the elastic properties of the U-shaped beam connecting the wheels. This suspension is mainly used as the rear suspension for budget cars.

Types of independent suspensions

McPherson

- the most common front axle suspension modern cars... The lower arm is connected to the hub by means of a ball joint. Depending on its configuration, longitudinal jet thrust can be used. An amortization strut with a spring is attached to the hub unit, its upper support is fixed to the body.

The transverse link, fixed to the body and connecting both arms, is a stabilizer that counteracts the roll of the car. The lower ball joint and shock absorber cup bearing allow for wheel rotation.

The rear suspension parts are made according to the same principle, the only difference is that there is no possibility of turning the wheels. The lower arm is replaced by longitudinal and transverse rods that fix the hub.

• simplicity of design;
• compactness;
• reliability;
• inexpensive to manufacture and repair.

• average handling.

Double wishbone front suspension

More efficient and sophisticated design. The upper attachment point for the hub is the second wishbone. A spring or can be used as an elastic element. The rear suspension has a similar structure. This suspension arrangement provides better vehicle handling.

Air suspension

Air suspension

The role of springs in this suspension is performed by compressed air bellows. With there is the possibility of adjusting the height of the body. It also improves ride quality. Used on luxury cars.

Hydraulic suspension

Adjusting the height and rigidity of the Lexus hydraulic suspension

The shock absorbers are connected to a single closed circuit with hydraulic fluid. makes it possible to adjust the rigidity and ride height. If the vehicle has control electronics and functions, it automatically adjusts to the road and driving conditions.

Sports independent suspension

Helical suspension (coilovers)

Helical suspension, or coilovers - shock absorbers with the ability to adjust the stiffness directly on the car. Thanks to the threaded connection of the lower spring stop, its height, as well as the amount of ground clearance, can be adjusted.

Suspension type push-rod and pull-rod

These devices were designed for open-wheel racing cars. It is based on a double wishbone scheme. The main feature is that the damping elements are located inside the body. The design of these types of suspension is very similar, the only difference is in the location of the load-bearing elements.

The difference between push-rod and pull-rod sports suspensions

Sports suspension push-rod: load-bearing element - pusher, works in compression.

There are two options for cushioning the car body - dependent and independent suspension. In modern passenger cars as a rule, an independent suspension is used. This implies that the wheels on one axle do not have a rigid connection with each other, and a change in position relative to the car body of one has no or almost no effect on the position of the other. In this case, the angles of camber and toe-in of the wheels can vary within fairly significant limits.

Oscillating axle suspension

This is one of the simplest and cheapest suspension types. Its main element is the axle shafts, which have hinges at the inner ends, through which they are connected to the differential. The outer ends are rigidly connected to the hub. Springs or leaf springs act as elastic elements. The design feature is that when hitting any obstacle, the position of the wheel relative to the axle shaft remains invariably perpendicular.

Additionally, the design may include longitudinal or transverse levers designed to damp the reaction forces of the road. Such a device had the rear suspension of many rear-wheel drive cars produced in the middle of the last century. In the USSR, the suspension of the ZAZ-965 car can be cited as an example.

The disadvantage of such an independent suspension is its kinematic imperfection. This means that when driving on uneven roads, camber and track width change over a wide range, which negatively affects handling. This becomes especially noticeable at speeds over 60 km / h. Among the advantages are a simple device, cheap maintenance and repair.

Trailing arm suspension

There are two types of trailing arm independent suspension. In the first, springs are used as elastic elements, and in the second, torsion bars. The wheels of the car are attached to trailing arms, which in turn are movably articulated with the frame or body. Such a suspension found its application in many French front-wheel drive cars produced in the 70-80s, as well as in motor scooters and motorcycles.


Among the advantages of this design, you can also name a simple device, cheap manufacturing, maintenance and repair, as well as the ability to make the floor of the car completely flat. It has much more disadvantages: while driving, the wheelbase changes within significant limits, and the car rolls heavily in corners, which means that the handling is far from ideal.

Slant-arm suspension

The device of such a suspension is in many ways similar to the previous one, the only difference is that the swinging axes of the levers are located at an oblique angle. Thanks to this, the change in the wheelbase of the car is minimized, and body rolls have almost no effect on the angle of inclination of the wheels of the car, however, on irregularities, the track width changes, and the toe and camber angles change, which means that controllability deteriorates. Coiled springs, torsion bars or pneumatic springs were used in the role of elastic elements. This version of independent suspension was more often used for the rear axle of cars, the only exception was the Czech Trabant, the front suspension of which was made according to this scheme.


There are two types of oblique arm suspensions:

1. single-hinged;
2. double-hinged.

In the first case, the axle shaft has one hinge, and the swing axis of the lever passes through the hinge and is located at an angle of 45 degrees to the longitudinal axis of the machine. This design is cheaper, but also not kinematically perfect, therefore it was used only on light and slow cars (ZAZ-965, Fiat-133).

In the second case, the axle shafts have two hinges, external and internal, and the swinging axis of the lever itself does not pass through the internal hinge. It is located at an angle of 10-25 degrees to the longitudinal axis of the car, this is preferable for the suspension kinematics, since the deviations of the track, wheelbase and camber values ​​remain within the normal range. The rear suspension of ZAZ-968, Ford Sierra, Opel Senator and many others had such a device.

Trailing and wishbone suspension

A very complex, and therefore rare design. It can be considered a kind of MacPherson suspension, but in order to relieve the mudguard of the wing, the springs were placed horizontally along the car. The rear end of the spring rests against the partition between the engine compartment and the passenger compartment. In order to transfer the force from the shock absorber to the spring, it was necessary to introduce an additional lever swinging in a vertical longitudinal plane along each side. One end of the lever is pivotally connected to the top of the shock absorber, and the other is also pivotally connected to the partition. In the middle, the lever has a spring stop.


The front suspension of some Rover models is made according to this scheme. It has no particular advantages over McPherson, and retained all the kinematic drawbacks, but lost its main advantages, such as compactness, technological simplicity, and a small number of articulated joints.

Double trailing arm suspension

Its second name is "Porsche system", after the name of the inventor. In such a suspension, there are two trailing arms on each side of the car, and torsion shafts located one above the other play the role of elastic elements. Such a device had a front suspension of cars, the engine of which is located at the back (models of early sports cars Porsche, Volkswagen Beetle and Volkswagen Transporter of the first generation).


The independent trailing arm suspension is compact, in addition, it allows the interior to be moved forward, and the legs of the front passenger and the driver are placed between the wheel arches, which means that the length of the car is reduced. Of the minuses, we can note changes in the wheelbase when hitting obstacles and a change in camber when the body rolls. Also, due to the fact that the levers are subjected to constant strong forces of bending and torsion, they have to be strengthened, increasing the size and weight.

Double wishbone suspension

The device of this type of independent suspension is as follows: on both sides of the car, two levers are located transversely, which on one side are movably connected to the body, cross member or frame, and on the other - to the shock absorber strut. If it is a front suspension, then the strut is swivel, with ball joints having two degrees of freedom, if the rear one, then the strut is non-swiveling, with cylindrical joints having one degree of freedom.

Various elastic elements are used:

• coil springs;
• torsion bars;
• springs;
• hydropneumatic elements;
• pneumatic cylinders.

On many vehicles, the suspension elements are attached to a cross member that is rigidly connected to the body. This means that you can remove the entire structure as a whole, as a separate unit, and carry out repairs in more convenient conditions. In addition, the manufacturer has the opportunity to choose the most optimal way of placing the levers, thereby rigidly setting the required parameters. This ensures good handling. For this reason, double wishbone suspension is used in racing cars. From a kinematic point of view, this suspension has no disadvantages.

Multi-link suspension

The most complex device has a multi-link suspension. It is similar in structure to the double wishbone suspension and is used mainly on the rear axle of class D and higher cars, although it is sometimes found on class C cars. Each of the levers is responsible for a certain parameter of the wheel's behavior on the road.


The multi-link suspension gives the car the best handling. Thanks to it, you can achieve the effect of steering the rear wheels, which allows you to reduce the turning radius of the car, and better allows you to keep the trajectory in turns.

The multi-link suspension also has disadvantages, however, they are not of an operational nature - the cost of the structure is high, the complexity of design and repair.

MacPherson type suspension

The front suspension of most modern cars of class A - C is made according to the "MacPherson" type. The main structural elements are shock absorbers and a coil spring in the role of an elastic element. In more detail, the MacPherson suspension device, its advantages and disadvantages are discussed in a separate article.

Instead of an afterword

In modern automotive industry, dependent and independent suspension is used. It should not be assumed that one of them is better than the other, since their purpose and scope are different. Under a solid axle, the ground clearance always remains unchanged, and this is a valuable quality for a car that drives mainly off-road. That is why SUVs use a spring or leaf spring rear suspension with a continuous axle. Independent car suspension cannot provide this, and real ground clearance may be less than stated, but its element is asphalt roads, on which it undoubtedly wins over the bridge in handling and comfort.

By the way, since the suspension is independent, the displacement of one wheel does not depend on the other. This is more common in theory. In practice, fully independent suspensions are rare.

Almost always, the suspension design includes such a detail as an anti-roll bar. Thanks to it, the vertical displacements of one wheel are transmitted to the other through the elastic torsion bar. Such a "violation of independence" is necessary to improve the car's handling, or rather, to reduce roll in corners. The solution is not the most elegant, it also has a number of disadvantages, but at the same time it is inexpensive, because active suspensions are orders of magnitude more expensive. And so a fairly simple detail does not allow the car to overwhelm in a turn.

Of course, the handling can be adjusted without this part, and even the ride will improve. There are many examples of this: here Renault Logan, for example, after the first restyling, he lost the front stabilizer, and the classic Zhiguli never had it in the rear suspension. But most modern cars have it in both the front and rear suspensions.

Not uncommon and "active" stabilizers, which are able to change the angular stiffness of the torsion bar or even turn off altogether. These are, for example, or on Nissan SUVs. This allows you to reduce the negative factors from the use of the stabilizer.

In the photo: Nissan Patrol "2014 – present.

It turns out that the suspensions of the vast majority of cars are not completely independent, the movement of one wheel still causes movement of the other. Even to a lesser extent than in the presence of a connection in the form of a common rigid axle, as in a dependent suspension, when the movement of one wheel is always uniquely associated with the movement of the second.

With continuous axles, by the way, an anti-roll bar is also used: cars with any suspensions have rolls.

Semi-dependent: Rare and Most Common

If a stabilizer is still needed, maybe it can be made part of the supporting structure of the suspension? Probably, this is exactly what the engineers reasoned when they came up with the MacPherson strut front suspension for. Do not be surprised, but her MacPherson is semi-dependent, because instead of the front lower arm the suspension uses a powerful anti-roll bar. Both wheels are connected by a single elastic part, which is part of the supporting structure. The eighties were generous with interesting technical solutions, so I would not be surprised if a similar scheme was used on any other machines, because the stabilizer torsion bar is very convenient to use as a lever. In terms of kinematics, the Audi suspension can be considered completely independent for one significant "but": the vertical movement of one of the wheels necessarily causes the movement of the second wheel by a significant amount associated with a sufficiently high torsion bar stiffness.

A very common semi-independent suspension with a twisted beam - also the fruit of the efforts of the engineers of the Volkswagen concern. After all, it appeared on the VW Golf in 1974. The genius of the idea was that here the guide device of both rear wheels was a single piece that was attached to the body at only two points. And the elastokinematics of movement of each of the wheels was almost similar to the kinematics of the suspension on the trailing arms. The H-beam is attached to the body at two extreme points, and the wheel hubs are located at the lower ends of the letter. The most important part of the structure is the cross member, which connects the structure together and provides the necessary rigidity. If the beam is placed close to the attachment points to the body (when the beam turns into the letter P), then the suspension is kinematic diagram will be completely similar to the design on the trailing arms, and if moved closer to the wheel attachment points, it will be more like dependent suspensions. The central part of the beam in this design necessarily has pliability and can bend, providing the wheels with the possibility of independent movement. Such a suspension can be classified as dependent only constructively: the wheels are connected by a single part of the supporting structure. But in operation, such a suspension is nevertheless similar to independent ones.

In the photo: Volkswagen Golf "1974–83

The design is so convenient for the mass automotive industry that it is used for, and sometimes is used in combination with the driving rear axle. For example, there is a twisted H-beam at the back, even on all-wheel drive variants.

The secret to this success is simple. Firstly, the design is extremely reliable: powerful side levers are connected by a powerful torsion bar, and it is attached to the body with large and durable silent blocks. These parts last a long time and are hard to break. And such a design is inexpensive both in manufacture and in operation.

The kinematics of the wheel movement is initially successful and can vary widely by changing the rigidity of the mountings, the rigidity of the torsion bar, side levers and their relative position. In addition, the suspension is very compact, it allows the shock absorbers to be spread as wide as possible, which ensures excellent working conditions. The springs and shock absorbers can be positioned very low and tightly, which increases the interior volume of the rear of the machine. Of all the types of independent suspensions for non-driving wheels, only multi-link designs based on double wishbones or MacPherson struts have the best kinematics, but they are much more expensive.

This scheme also has disadvantages. The elastokinematics of the H-beam is such that the angular stiffness of the beam is always related to the lateral compliance of the suspension and the load. As a result, the beam is always excessively stiff for its role as an anti-roll bar. The unsprung masses of this type of suspension are also quite high, and an attempt to reduce the mass of the beam by reducing the length of the trailing arms leads to a deterioration in the kinematics of its operation and an increase in the rigidity of the connection. And it is structurally difficult to untie the stiffness of the rubber-metal elements in the longitudinal and transverse directions, they will always be connected, because these are only two silent blocks working in torsion and rupture.

The complication of the design by the introduction of jet thrust, for example, in the form of a Watt mechanism, is not a new move. Relatively recently, it was used in mass production at Opel astra J / Chevrolet Cruze, and athletes in the preparation of H-beam cars often used additional reaction arms to improve handling and kinematic control.

Watt's mechanism

They try to set the supporting elements of the beam at an angle to the rolling plane of the beam: in this way, the transmission of vibrations to the body is reduced while the flexibility of the blocks in the transverse direction is reduced and the kinematics are improved. Additional tweaks in the form of moving the spring support pads to the external brackets allow you to provide the required angle of rotation of the wheels under load. But in any case, this type of suspension remains structurally simple and cheap. And that is why it is used so massively.

And in practice, how is it?

Comparing different cars with different types of rear suspension does not make it possible to choose an unambiguous leader. Of course, a multi-link suspension is easier to endow with both good handling and a high ride quality combined with a high load capacity. But here's the trouble: even comparing cars of the same class, it is impossible to draw a conclusion about what kind of suspension is used only on the basis of their driving characteristics. A real gift for those who like to find out what is better and what is worse are cars on the MQB platform: in many of them, depending on the motor, both a beam and a multi-link structure can be used in the rear suspension.