What is a wishbone? Independent car suspension, description and principle of operation. Main suspension elements

When you start looking for information about what a suspension is and what its design is like, you come across abstruse formulations that you can’t always understand the first time. That's why we came up with our own definition of suspension - a set of mechanisms that protect the entire upper part of the car from sudden loads caused by road irregularities, and ensure constant reliable contact of the wheels with the road.

Design

The suspension consists of the following elements:

guide element;
elastic element;
extinguishing device;
wheel support;
transverse stabilizer.

The guide element holds the wheel in a given space, preventing it from dangling to the sides relative to its normal state. These are various levers: double, transverse, longitudinal and the like.

The elastic element is often called a suspension. It dampens all vibrations that occur on the wheels from the road surface and does not allow vibration to spread further throughout the car. They are divided into metallic and non-metallic. The second are all kinds of rubber cushions. And the first ones are springs, springs and torsion bars.

Two types of suspension

The suspension can be dependent or independent:

Dependent suspension is characterized by the fact that the wheels of one axle are completely dependent on each other, that is, they are fastened to each other with a rigid coupling. This all means that this type of suspension can best be seen in dump trucks of older designs on rear axle(it’s clearer there). Two wheels are connected by one axle. When one wheel rises, the other, under the influence of a change in the position of the bridge, also changes its position.
Independent suspension works in a completely different way. Here each wheel is completely responsible only for itself. That is, if it changes its position, then this phenomenon does not affect the other wheels of the suspension. The most obvious example is buggy cars.

Springs in suspension

We will not consider such a design of spring elastic elements, since they are used very rarely today and only on heavy vehicles in rear suspension or railway freight cars. Instead, we will look at spring elements - they can be found on almost any passenger car.

Spring elastic elements are installed in both the front and rear parts of the suspension. They come in two types:

cylindrical;
barrel-shaped.

They differ in that they react differently to different road irregularities. With a cylindrical one everything is clear and simple. Here a rod of constant cross-section is used; the width and pitch of the spring coils are also the same throughout the entire length of the spring. This ensures exactly the same elasticity both at the beginning of compression and at the end.

With barrel springs, things are more complicated: the tension of the spring changes dynamically as it is compressed. This happens because it is made from a bar of variable cross-section. The coils in it also have different pitches and diameters throughout. That is, if at the beginning of compression the spring gives in easily, then at the end it requires more force. This means that they are better able to absorb the energy of impacts from the wheels when overcoming large bumps, while at the same time remaining comfortable for passengers.

Independent suspension type

In this case, each wheel is connected to the rest of the suspension by movable joints and shock absorbers. This means that the load on the suspension is significantly reduced.

There are two types of independent car suspension:

lever;
MacPherson suspension.

A link-type suspension device uses a lever or a system of levers as a guiding device. They come in single and double lever versions. Depending on how exactly the lever is positioned, there are longitudinal, transverse and diagonal lever systems.

MacPherson strut suspension is characterized by the presence of a shock absorber strut. It only comes with a single lever. Its main advantage over wishbone suspension is its small size and the ability to handle road unevenness more smoothly.

In no dependent suspension A rather simple but effective move has been used, which can significantly increase driving comfort on flat surfaces. The springs here are located at an angle to the wheel. Due to this, less forces are applied to the spring during a turn, and accordingly, the machine does not fall to one side when maneuvers are performed.

Also, the front, like the rear type of independent suspension, has two shock absorbers. They are installed at an angle to the vertical axis of the wheels. Shock absorbers are used to further reduce vertical loads and vibrations.

Semi-independent suspension type

The design of a semi-independent suspension is very similar to a dependent one. But, if in the second the springs were installed on the cross member between the wheels, then here the shock absorbers and springs are installed directly at the ends of the cross beam, which now takes on exclusively torsion (twisting) loads. This type is installed exclusively at the rear of front-wheel drive vehicles.

Along with dependent, semi-independent suspension is considered obsolete, which, however, does not prevent car manufacturers from continuing to install it on budget models. It is distinguished by very high reliability and ease of maintenance. To its undoubted advantages we can add low production costs, which is reflected in the price of the machine for the end buyer.

What to choose?

Based on all of the above, we can conclude that independent suspension is the height of dreams. However, it should be borne in mind that independent suspension is a more “road” option. The fact is that it performs better on road surfaces with small differences in the surface. And modern manufacturers are frankly slacking, installing insufficiently strong shock absorbers and springs. This leads to the fact that the ground clearance may well be less than stated. This means that a car with such a suspension will begin to “sink” under less load.

But it’s also impossible to say that dependent suspension is better. Yes, it performs better on bad roads, working out large differences on the road or off-road. Plus, it's stronger.

Semi-independent suspension is a kind of compromise. But it is no longer used much.

Let's sum it up

As a result, we find that it is better to choose an independent rear suspension for a city and road passenger car, while for heavy vehicles and those that have to drive off-road, it is better to choose a dependent rear suspension.

Just as it is impossible to imagine a car without an engine, it is impossible to do this without a suspension - the most important system responsible for the comfort, safety and durability of a car. This element in the design of the car has received great attention from engineers, who are still finding new opportunities to improve it. performance characteristics, making it more and more perfect.

Regardless of the type of suspension, almost all of them contain springs, which play an important role in absorbing shock and vibration when driving on poor-quality road surfaces. Modern spring suspension is divided into two main types - dependent and independent, which have recently been often replaced by their intermediate version - semi-independent spring suspension. Each of them has certain disadvantages, advantages and specific features.

Dependent design

This is the oldest type of vehicle spring suspension, which is a simple rigid connection of a pair of wheels to each other. Currently, the use of this type continues, which is presented on the market in two designs: on longitudinal springs and on guide arms. The spring design is quite simple. The bridge is suspended from the body on special elements - springs, which are elastic steel plates connected to the body with a stepladder.

The lever-based design is designed differently. The main elements here are levers, of which there may be several in a design. They perform functions similar to springs, and most often use four longitudinal and one wishbone. Despite the considerable age of this design, it has a sufficient number positive aspects- strength, simplicity and low cost service. Among the disadvantages of a car with this type of suspension are less stability and more difficult handling.

Interesting! Despite the shortcomings, the dependent suspension is ideal for heavy SUVs operated in extreme conditions. They will be able to continue moving even if that happens. if the rear axle has been damaged, for example, bent.

Independent spring suspension

This is a system in which the wheels do not depend on each other, each moving in its own rhythm, which is influenced by the characteristics of the surface. An independent spring suspension can be created on the basis of straight or trailing arms, one part of which is fixedly fixed to the car body. Straight control arms in independent suspension are always made too massive because they have to carry too much load. In addition, the disadvantage of such a system can be considered low ground clearance.

The trailing arms in the spring independent suspension were mostly used for the rear drive axle. As a difference with the mechanism described above, it is worth noting the presence of a hinge. Such a suspension costs the manufacturer less, but it also has a rather serious drawback - variable wheel alignment, which requires a lot of pain. The use of this type of suspension is effective only on the rear axles of a car - it is not used on the front axles.

Semi-independent suspension

Semi-independent spring suspension occupies an intermediate link between the two systems described above and is the most optimal option for the rear axle of most modern cars equipped with front-wheel drive. Externally, such a system is simple - two trailing arms are securely fixed by a beam located transversely. The entire design is simple and reliable, but can only be used on the rear axle if it is not the drive axle.

When the car is moving, and especially during acceleration/sharp braking, various forces, including twisting, act on the beam of the semi-independent spring suspension. To be able to adjust the rigidity of the beam, an electric motor can be installed on it - in this case, the driver has the opportunity to change the stiffness of the suspension at his own discretion. Such semi-independent suspension designs are successfully installed on many modern cars belonging to a wide variety of classes.

Advantages and disadvantages of semi-independent suspensions

Like any other automotive unit, the design of a semi-independent spring suspension has both its advantages and some disadvantages. Its strengths include the following:

optimal dimensions and low weight, reducing the percentage of unsprung mass;
ease of installation or self-repair;
low cost;
ability to change characteristics;
optimal kinematics of the wheelset.

Among the main disadvantages, which are inevitable in almost any design, is the possibility of use only on the rear axle, which, at the same time, cannot be the drive axle. Such a suspension places strict demands on the underbody of the car, which must have a strictly defined geometry. However, it is the semi-independent spring system that becomes optimal for most cars. Suspension options are described in sufficient detail in the video:

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 will talk about the independent suspension of a car. 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 arms

It is worth immediately noting that there are a large number of types of pendants. All of them were designed to improve technical characteristics car and increase comfort while driving. Some types are better suited for off-road use, while others are great for city driving. First of all, let's talk about independent trailing arm suspension. This design was popular in the 70-80s in French cars, and later found application in 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 simplicity and low cost of maintenance, and the disadvantages are roll and change in wheelbase while the car is moving.

As for the trailing arm, the key difference from the design described above is that the swing axis of the trailing arm is at an angle. This approach allowed us to minimize changes in the wheelbase and roll. But the handling was still far from ideal, since the camber angles of the wheels change when driving over bumps. 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, the inner ends of which have hinges that connect to the differential. Accordingly, the outer end of the axle shaft is rigidly attached to the wheel hub. 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 axis at all times, even when hitting obstacles. Actually, this type of suspension also uses trailing arms, which reduce vibrations from the road surface.

As for the shortcomings, there are some. When driving over rough terrain, not only the camber changes widely, but also the track width. This significantly reduces vehicle controllability. This disadvantage most noticeable at speeds of 60 km/h and above. As for strengths, then this is simplicity of design and relatively cheap maintenance.

Suspension on longitudinal and transverse arms

One of the most expensive types, which is extremely rare due to the complexity of the design. In fact, the suspension is made according to the MacPherson type with minor differences. The designers decided to remove the load from the mudguard and therefore placed the spring slightly further than the shock absorber. One end of it rests on the engine compartment, and the other on the interior. To transfer force from the shock absorber strut to the spring, the designers added a swing arm. It could move in a vertical longitudinal plane. In the center, the lever was connected to the spring, one end of it was attached to the shock absorber, and the other to the partition.

Actually, almost all joints are hinged, and this is a significant drawback, since MacPherson was famous for its small number of them. Actually, this type of front independent suspension is found on Rover cars. It has no special advantages, so it is not popular, and it is difficult and expensive to maintain.

Double wishbone

This type of pendants is found quite often. It has the following design. Transverse arms are attached to the body on one side, usually movably, and on the other side to the shock absorber strut. The rear suspension has a non-rotating strut with a ball joint and one degree of freedom. For the front suspension - a rotating strut and two degrees of freedom. This design uses various elastic elements: coil springs, springs, torsion bars or hydropneumatic cylinders.

Often the design involves attaching the lever to the cross member. The latter with the body is fixed rigidly, that is, motionless. This implementation allows you to completely remove the front suspension of the car. From a kinematic point of view, the suspension has no disadvantages and is preferable for installation on racing cars. But maintenance is expensive due to the large number of ball joints and labor-intensive work.

Classic multi-link

Structurally, the most complex type of suspension. Its principle is similar to that of a double wishbone suspension. Most often it is placed on the rear of class “D” or “C” cars. 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” of the rear axle. The latter advantage allows you not only to take turns better, but also to slightly reduce the turning radius.

From an operational point of view there are no shortcomings. All the disadvantages are that it uses not one independent suspension arm, but much more. Each of them is equipped with a pair of silent blocks and ball joints. Therefore, maintenance costs a lot of money.

Rear independent suspension on a VAZ

The classic torsion bar suspension, installed on the rear axle, is considered semi-independent. The design has both its advantages and disadvantages. To improve handling, car owners often install independent suspension. It’s not difficult to guess that all modifications are carried out on front-wheel drive cars.

The pendant itself is sold assembled. According to the manufacturer, it does not require modifications and is mounted as a unit without making changes to the design of the car. But in practice this is not entirely true. The muffler barrel gets in the way, so it's worth buying a shortened version. There was also some modification to the fastenings. Some need to be finalized with a file, while others need to be placed in the right places. But most importantly, this design significantly increases the car’s handling, although the rear axle will become sharper and less predictable.

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

Let's sum it up

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

One of the factors you should pay attention to when choosing a car is the type of suspension. Smoothness and comfort during movement play an important role. The desire to own a vehicle that can perform equally well on asphalt and when driving off-road arises in every car enthusiast.

Disputes about which suspension has best characteristics endless. There is no clear answer to this question. The formed stereotypes regarding the scope of application of some types look like this: for SUVs - dependent, passenger cars middle class - combined, sports cars - double wishbone. Each system has its own advantages and disadvantages.

What is a pendant?

The suspension is considered to be a part of the car that is part of the chassis, which serves as an intermediate link between its body part and the road surface. The work of the suspension is to ensure that the shock received upon contact with an obstacle is converted into movement of the elastic element. As a result of this movement Impact energy is dampened and ride smoothness increases.

There are a number of basic requirements for suspensions. These include: maintaining the machine in a horizontal position under any influence; the ability to dampen vibrations that occur; the elasticity of all its elements, their strength and durability.

Pendants are classified as follows:

Dependent (can be on transverse and longitudinal springs, with guide arms, with a thrust pipe, De Dion suspension, torsion bar).
Independent (there are suspensions on oblique and double wishbones, with swing axles, with single or double trailing arms, MacPherson struts, with wishbones).
Active, that is, changing rigidity and position at the command of the control device (pneumatic, hydraulic, pneumohydraulic).

Let's consider and compare the two types of suspensions that are most widely used: dependent and independent.

Dependent suspension type

It is simplified two opposite wheels, rigidly connected to each other by one beam. Impact on one wheel leads to a change in the position of the second. Dependent suspension is more designed for use in difficult road conditions.

Dependent suspension: 1) Coil spring 2) Upper trailing arm. 3)Lower trailing arm. 4) Bridge beam. 5) Shock absorber. 6) Wheel hub. 7) Stabilizer lateral stability. 8) Cross arm (Panhard rod)

The pros and cons of any suspension depend on its design, but there are also properties common to all.

The advantages of such a suspension are:

Permanent cleaner, that is ground clearance remains unchanged, which gives it an advantage in off-road driving.
High resistance to damage and strength.
Inexpensive service.
A small number of components and, as a result, reliability.

Negative aspects of dependent suspension:

Less stability and controllability compared to the independent version.
Quite high demands on the road surface when driving at high speed.
Low level of comfort.
Low information content of the steering.

Independent suspension type

In this type of suspension the wheels not related to each other, that is, they act independently. Independent suspension has an advantage when driving along the highway at high speed and is usually installed on passenger cars.

The advantages of independent suspension include:

Small deviations relative to the longitudinal axis.
Good handling.
Good grip on the road surface.
High level of comfort.

The disadvantages of this type of suspension are:

Expensive maintenance and repairs.
Short travel of the suspension arms, which can lead to a decrease in ground clearance.
A large number of parts that make up the suspension and, accordingly, a greater likelihood of damage compared to the dependent one.
Difficulty of carrying out repair work in the field.

What are the similarities and differences between independent and dependent suspensions?

Both of these types of pendants have one purpose in common - make a stay in vehicle more comfortable and safe.

Structurally, independent and dependent suspensions are united by the presence of elastic elements, guide elements and shock absorbers. These functions can be combined in one part, for example a spring.

Due to their different designs, dependent and independent suspensions have a number of differences:

In a dependent wheel, two wheels are rigidly connected and depend on each other. In independent, everyone acts independently; impact on one will not affect the other.
In independent there is less unsprung mass, since there is no bridge, as opposed to dependent.
Independent suspension is sensitive to the installation of wheels of a different size than the required ones, since they are part of the suspension kinematics.
A necessary condition for the effective operation of an independent suspension is that the kinematic center is above the road surface, in other words, at maximum deviations, the suspension must be above the road level.
Independent suspension has a lower risk of tipping over when falling into a hole at high speed, due to the absence of rigid interaction between opposite wheels.

The buyer decides which suspension to choose. You should pay attention not only to the level of comfort, but also to the cost of maintenance and spare parts, reviews on the service life of suspension elements and the reputation of the manufacturer.

1. What is dependent suspension?

To begin with, speaking about types of suspension, it is worth understanding what kind of “dependence” and “independence” we are talking about. And they are talking primarily about the dependence of the wheels of the same axle on each other when going over uneven surfaces. Accordingly, a dependent suspension is a suspension in which the axle rigidly connects two wheels.

2. What are the advantages and disadvantages of dependent suspension?

The design of the dependent suspension directly follows at the same time its main disadvantage and some advantage: the disadvantage is that when one wheel of the axle hits an uneven surface, the other wheel of the axle also tilts, which reduces the comfort of movement and the uniformity of adhesion of the wheels to the surface, and the advantage is that that when driving on a flat road, the wheels, rigidly fixed to the axle, do not change their vertical position when cornering, which ensures uniform and constant grip on the surface.

However, the disadvantages of dependent suspension do not end there. In addition to the dependence of the wheels on each other, the spread of such suspension in modern passenger cars has been reduced to zero due to the large heights, as well as the need to greatly raise the floor of the car to ensure full suspension, especially in the case of a drive axle.

Speaking about dependent suspension, it is worth noting several important facts. Firstly, dependent suspension in modern cars is practically never found on the front axle - there it has been replaced by a more advanced, lighter and more convenient MacPherson arrangement. On the streets you can still see cars with a bridge in front - but these are either old all-wheel drive SUVs with two driving axles, or trucks and buses. Thus, speaking about dependent suspension when choosing modern car, we mean its application on the rear axle.

Secondly, the dependent suspension can be different in design and be present on both the driving and driven rear axles. In the first case, it is a bridge suspended on longitudinal springs or longitudinal guide arms: this arrangement is still found on some modern SUVs and pickup trucks. In the second case, this is a rear beam, which is used on inexpensive front-wheel drive cars. Sometimes in the design of such a beam, torsion bars are used, and we're talking about about the so-called semi-independent beam - but structurally it is still the same dependent suspension with a slightly different operating principle.

3. What is independent suspension?

An independent suspension is a suspension in which the wheels on one axle are not connected to each other, and changing the position of one wheel does not affect the other.

4. What are the advantages and disadvantages of independent suspension?

In contrast to dependent suspension, one of the main advantages of independent suspension is that when one wheel hits an uneven surface, the other does not change its position. This independence of suspension operation different sides axle provides greater comfort and more uniform grip on uneven surfaces. In addition, independent suspension provides lower unsprung masses, and also allows you to work on reducing them by changing the configuration and materials of suspension elements - for example, aluminum levers today are a fairly popular way to reduce unsprung masses. expensive cars. One of the disadvantages is that wheel position parameters such as camber, toe and track width can change during suspension operation.

There are many more design variations of independent suspensions than dependent ones - over the years, designs have been developed on trailing, oblique and transverse levers, multi-link, pneumatic, hydropneumatic and active suspensions, and even variations with magnetorheological shock absorbers filled with a ferromagnetic fluid that changes its properties under the influence of magnetic field. However, the fundamental goals of the development of all these designs remained the same as before: ensuring maximum comfort when moving, stability in the behavior of the car and improving its handling.

5. Which suspension should you choose when buying a car?

When choosing a car, you should take into account potential scenarios for its operation and your own wishes regarding the cost of its maintenance. In general, the simple principle “the more complex, the more expensive” works here.

A dependent suspension is simpler in design and, accordingly, its maintenance will be simpler and cheaper, and it will most likely require repairs later than an independent suspension for cars in the same price category. However, choosing simplicity and reliability, you will have to put up with slightly less comfort and controllability. SUVs are worth mentioning separately: if you choose an all-terrain vehicle, the dependent axle suspension (at least in the rear) is practically the only choice.

The independent suspension has more complex design- this means that, on the one hand, it will provide greater comfort and more reckless handling, but at the same time its resource will most likely be lower, as well. But, in fairness, it is worth noting that repair and maintenance of multi-link suspensions of popular cars is currently not something prohibitively difficult or expensive.

Thus, if you are willing to overpay a little for greater comfort, and the scenario for using the car is mainly urban or on good roads, then independent suspension will be the best choice. If, when choosing a car, you strive for maximum efficiency in repair and maintenance, or the car will be used in harsh conditions, where the suspension life takes priority over comfort and controllability, then you should prefer a simpler dependent suspension.