Independent suspension. Cars with independent suspension Independent wishbone suspension

One of the factors to look out for when choosing a car is the type of suspension. Smoothness and comfort during movement play an important role. The desire to have a vehicle that can behave equally well on asphalt and when driving off-road arises in every motorist.

The debate over which suspension has the best performance is endless. There is no single answer to this question. Formed stereotypes regarding the field of application of some types look like this: SUVs - dependent, passenger cars of the middle class - combined, sports cars - double wishbone. Each system has its own advantages and disadvantages.

What is a suspension?

Suspension is the part of the car that is part of the chassis, which serves as an intermediate link between its body part and the roadway. The suspension's job is to convert the shock received on contact with an obstacle into movement of the elastic element. As a result of this movement the impact energy is extinguished and the smoothness of the stroke is increased.

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

Pendants are classified as follows:

1. Dependent (can be on transverse and longitudinal springs, with guide levers, with a thrust tube, De Dion suspension, torsion bar).
2. Independent (distinguish between the suspension on oblique and double transverse levers, with swinging axle shafts, with single or double trailing arms, "MacPherson", with wishbones).
3. Active, that is, changing the stiffness and position at the command of the control device (pneumatic, hydraulic, pneumohydraulic).

Let us consider and compare the two types of suspensions that have found the most widespread use: dependent and independent.

Dependent suspension type

It is simplified as 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. The dependent suspension is primarily 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) Anti-roll bar. 8) Control arm (Panhard rod)

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

The advantages of such a suspension are:

• Constant cleaners, that is, the ground clearance remains unchanged, which gives it an advantage in off-road driving.
• High damage resistance and durability.
• Inexpensive service.
• A small number of component parts and, as a result, reliability.

Negative aspects of dependent suspension:

• Less stability and controllability compared to the independent version.
• Quite high requirements for 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 wheel suspension not related to each other, that is, they act independently. The independent suspension has an advantage when driving on the highway at high speed and is usually installed on passenger cars.

The advantages of independent suspension include:

1. Small deviations about the longitudinal axis.
2. Good handling.
3. Good grip.
4. High level of comfort.

The disadvantages of this type of suspension include:

• Expensive maintenance and repair.
• 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.
• The complexity 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 being in a vehicle more comfortable and safe.

Structurally independent and dependent suspension combines the presence of elastic elements, guide elements and shock absorbers. These functions can be combined in one detail, for example, a spring.

Due to the different design, dependent and independent suspension have a number of differences:

1. In a dependent, two wheels are rigidly connected, dependent on each other. In an independent, everyone acts independently; impact on one will not be reflected on the other.
2. In the independent, there are fewer unsprung masses, since there is no bridge, as opposed to the dependent.
3. Independent suspension is sensitive to out-of-size wheel alignment as they are part of the suspension kinematics.
4. A necessary condition for the effective action of an independent suspension is the location of the kinematic center above the road surface, in other words, at maximum deviations, the suspension should be above the road level.
5. Independent suspension has less risk of overturning when hitting a hole at high speed, due to the lack of rigid interaction of opposite wheels.

In favor of which suspension to make a choice, the buyer decides. 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.

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

Regardless of the type of suspension, almost all springs are present, 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 recently are often replaced by their intermediate version - semi-independent spring suspension. Each of them has certain disadvantages, advantages and specific features.

Dependent construct

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 levers. The sprung structure is quite simple. The bridge is suspended from the body on special elements - springs, which are elastic steel plates, connected to the body by a stepladder.

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

Interesting! Despite its drawbacks, dependent suspension is ideal for heavy SUVs operating in extreme conditions. They will be able to keep moving even if they do. 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 arms in an independent suspension are always made too massive, because they have to take too much stress. In addition, the disadvantage of such a system can be considered a low clearance.

The oblique wishbones in the spring independent suspension were mostly used for the rear drive axle. The difference with the mechanism described above is the presence of a hinge. Such a suspension is cheaper for the manufacturer, but it also has a rather serious drawback - variable wheel alignment, with which you have to suffer a lot. 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

The semi-independent spring suspension is an intermediate link between the two systems described above and is the most optimal option for the rear axle of most modern front-wheel drive vehicles. Outwardly, such a system is simple - two trailing arms are securely fixed by a beam located across. The whole design is simple and reliable, but it can only be used on the rear axle if it is not a leading axle.

When the car is moving, and especially during acceleration / hard braking, various forces act on the beam of the semi-independent spring suspension, including twisting. For the possibility of adjusting the stiffness 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 the most diverse classes.

Advantages and disadvantages of semi-independent suspensions

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

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

Among the main drawbacks that are inevitable in almost any design is the possibility of using only on the rear axle, which, at the same time, cannot be the driving one. Such a suspension imposes stringent requirements on the underbody of a car, which must have a strictly defined geometry. Nevertheless, it is the semi-independent spring system that becomes optimal for most cars. There is enough detail about the suspension options in the video:

Independent suspension - a suspension design in which there is no rigid connection between the right and left wheels of one pair. It is actively used in modern cars, as it provides good handling at high speeds.

Chassis

In the most general classification, car suspension is divided into two types: dependent and independent. The main feature of a dependent suspension is that two wheels, being on the same axle, are rigidly connected to each other. There is no common axle in an independent suspension. As a result, the handling and overall comfort for the driver are significantly higher in vehicles with such a suspension.

Types of independent suspension

Built, as the name implies, on semi-axles equipped with hinges. It was used in combination with springs, but it was not widely used due to imperfections - the wheels get too much degrees of freedom, which does not have the best effect on handling.

Given these features, most often such a suspension was supplied to cars with a rear drive axle. Such a suspension, in particular, was used at the rear in the domestic "Gorbat" Zaporozhets ZAZ-956.

This type of independent suspension is notable for its simplicity, which has provided it with a fairly widespread use. From the name it is clear that the basis of the structure are trailing arms attached to the body, which have the ability to swing up and down. The disadvantage of such a suspension was and remains its relative "dependence", since during rolls the wheel on the opposite side of the body rises too much, partially losing traction. Due to this negative quality, it is found mainly on the rear axle of front-wheel drive vehicles. Suspension of this type in the second half of the twentieth century, equipped with cars Citroen and other "French". A relative advantage of the trailing arms is that they practically do not take up space under the body, allowing you to increase the volume of the trunk.

In the eighties, the trailing arm suspension was gradually replaced by the MacPherson strut and later by the double wishbone suspension.

Pendant "MacPherson"

The most common type of independent suspension. It is often used in the front axle of a car, regardless of whether it is driven or not. MacPherson strut is a type of double wishbone suspension in which the upper wishbone is removed and the shock absorber strut acts as the second support.

The compactness of the McPherson suspension allows the structure to be successfully used on front-wheel drive cars, since it does not interfere with the transverse installation of the engine and gearbox and leaves enough space for the drive drives (CV joints).

This is a modification of the trailing arm suspension, created in an effort to rid the structure of "congenital diseases". Oblique levers are called because they are not installed strictly parallel to the body, but at a certain angle, which prevents the wheels from "moving apart" in the direction perpendicular to the axis of motion. This circumstance made it possible to improve handling in comparison with cars equipped with a suspension on trailing arms. Slanting levers can be seen in early BMWs of the third series, Ford Granada, Sierra and Scorpio, i.e. rear-wheel drive models.

A rather rare type of suspension in our time with two trailing arms on each side. It was used mainly on the front axle of rear-engined vehicles. The most striking example is the Volkswagen Beetle and the first two generations of Transporter minibuses.

The world owes this type of suspension to the notorious Ferdinand Porsche. In Russian automotive history, the most famous example of application is the design of the front axle suspension of the "Humpbacked" Zaporozhets. Motorists with a long experience probably remember the torsion bars enclosed in pipes, which played the role of elastic elements in the ZAZ-956 suspension, its most noticeable detail, but they hardly know that they, together with double trailing arms, form the basis of the "Porsche System"

In this design, on each side of the car, there are two transverse levers, one end movably attached to the body, subframe or frame, and the other, external, on a pillar, to which either a steering knuckle carrying a wheel (front axle) or a hub (rear axle ).

The main advantage of this type of suspension is the ability, even without adjusting screws or other elements, by choosing the length of the levers, to set all the main characteristics (for example, wheel camber parameters). Due to this extremely important factor, in most modern cars, the suspension of both the front and rear axles is based on the principle of two arms.

Active suspension

In principle, this type of suspension can be a variation of any of the above. The essence of the concept, reflected in the name, is the ability to change the position and stiffness of the elastic elements on command from the control unit. It is built on the basis of pneumatic cylinders, hydraulic or pneumohydraulic cylinders. It is rarely found in passenger cars due to the complexity and high cost. A classic example is the ride height control system found in Citroen cars from the DS in the early fifties to the Xantia in the mid nineties.

Pros and cons of independent suspension

Low unsprung weight. The unsprung mass is the weight of all suspension elements (including the weight of the wheel). The less weight, the better the suspension works, the more vibration damping, the longer the "life" of the suspension elements.

More suspension settings.

Better handling and traction at high speeds.

The design is more complicated, more parts and, accordingly, more difficult and more expensive to repair.

In the material, we talked about the existing types of suspensions, and dwelt in detail on the types of dependent suspension. Today we will talk about the types of independent suspension.

So, there are nine types of independent pendants, moreover, two of them have several varieties.

The first type of suspension of this type is with oscillating axle shafts. Already from the name itself it is clear that the main structural elements of such a suspension are the axle shafts. There are hinges at their inner ends, by means of which the axle shafts are attached to the main gear with a differential. The outer ends of the axle shafts are firmly connected to the wheels. Springs or springs serve as elastic elements in such suspensions. The peculiarity of this independent suspension design is that when hitting an obstacle, the wheel always retains its perpendicular position relative to the axle shaft, and the reaction forces of the road are dampened by the axle shafts themselves and their hinges.

In some subspecies of such independent suspension, transverse or trailing arms are used, which act as "absorbers" of road reaction forces. As a rule, the design of such a suspension was used on the rear axle for rear-wheel drive vehicles. Such suspensions were installed on Ford, Mercedes-Benz and Chevrolet cars of the mid-twentieth century. In the USSR, a similar suspension was installed on ZAZ cars. The advantages of a suspension with oscillating axle shafts include simplicity of design, low cost of maintenance and repair. The disadvantages are large fluctuations in track and camber when hitting obstacles. These disadvantages were especially evident when driving at speeds over 60 km / h, which negatively affected the car's handling.

The second type of independent suspension is on trailing arms. This suspension has two subspecies: spring (elastic elements - springs) and torsion (elastic elements - torsion bars). The peculiarity of the suspension design is the arrangement of the wheels on the trailing arms, which are movably attached to the body or frame of the car. This type of suspension was installed on the rear axles of Citroen, Austin cars, scooters and small trailers.

The advantages of this type of suspension are the simplicity of its design, which, in turn (especially in the torsion subspecies), made it possible to make the floor of the car flat, and the low cost of manufacturing, repair and maintenance. It has more disadvantages: significant changes in the parameters of the wheelbase while driving, large rolls in corners (due to the low center of roll).

The third type of independent suspension is with oblique wishbones. By its design, it resembles a trailing arm suspension, with the difference that the swinging axes of the levers are at an oblique angle. It, in turn, is divided into two subspecies: with single-hinged semi-axles with diagonal levers (located at an angle of 45 degrees) and double-hinged semi-shafts with oblique levers (hinges are located at both ends of the semi-shafts). This type of suspension was mainly installed on the rear axle (on cars such as Ford, Mercedes-Benz, Opel, Porsche, Fiat and ZAZ), with a suspension on oblique arms on the front axle, Trabant was manufactured. The advantages of such a suspension, in comparison with a suspension on trailing arms, were the reduction of fluctuations in the parameters of the wheelbase, the roll of the car in a turn. The disadvantages of this type of suspension include a strong change in toe and camber, a high roll center (for a subspecies with single-joint semi-axles).

The fourth type of independent suspension is on trailing and transverse levers. The design of this suspension uses a guide strut, which uses a trailing arm to take over the upper support forces to relieve the mudguard of the fender. This type of suspension is cumbersome, structurally complex, and therefore unpopular. Rover and Glas cars had such a suspension. As such, the advantages of the suspension on the longitudinal and transverse levers are few: this is a large distance in height between the support nodes (reduces the effect of forces on the fastening of the suspension to the body) and the variability of the structural travels of the suspension. The disadvantages include the complexity of the design (a large number of parts - hinges, levers), large dimensions, poor kinematic parameters (a significant change in the camber angle with large suspension strokes).

The fifth type of independent suspension - double trailing arms. The peculiarity of its design is that on each side of the axle there are two longitudinal levers, which are combined by transverse torsion bars that play the role of elastic suspension elements. As a rule, such a suspension was installed on the front axle of rear-engined Volkswagen and Porsche cars of the early to mid-20th century. The advantages of such a suspension are: compactness, the ability to move the front of the car body forward (which had a positive effect on the comfort of the driver and front passenger). Cons: changing the parameters of the wheelbase when hitting obstacles, a large mass of levers (increases the weight of the car).

The sixth type of suspension is double wishbone. It, depending on the elastic elements used, is divided into five subspecies: spring, torsion, spring, hydropneumatic and pneumatic. The commonality of this design for all subspecies lies in the presence of transverse levers, which, with their inner ends, are movably articulated with the body or frame of the machine, and with their inner ends, with swivel (for the front suspension, with ball joints with two degrees of freedom) and non-swivel (for the rear suspension, with cylindrical hinges with one degree of freedom) rack. The upper arm in such a suspension is shorter than the lower one; they can be located both parallel to each other and at a certain angle.

Spring suspension on double wishbones in its design has coil springs, which play the role of an elastic element.

They are located between the wishbones, or above the upper control arm with an emphasis on the mudguard of the wing. Jaguar cars have such a suspension structure.

The double wishbone torsion bar suspension has longitudinal torsion bars attached to the lower wishbones as an elastic element. In this type of suspension, they can be attached both longitudinally and transversely. With such a suspension, cars of the brands Packard, Chrysler, Fiat, Simka and ZIL were produced.

The leaf spring suspension uses springs as an elastic element, which are located transversely to the double wishbones.

Suspensions with one, two, four springs were installed on cars, which were attached at one or two points. Also in the first half of the twentieth century, cars were produced that had four trailing springs (two on each side of the side), located transversely. The sprung suspension structure was used by Tatra, Fiat, Ford, Autobianci, Chevrolet, Lancia, Packard cars.

In the hydropneumatic and pneumatic subspecies of independent suspension on double wishbones, the role of elastic elements is played by pneumatic cylinders or hydropneumatic elements combined into one whole with the power steering system and the hydraulic brake system. Air suspension on double wishbones was used by Mercedes-Benz, Austin, and hydropneumatic suspensions were common in Citroen models.

The advantages of double wishbone independent suspension are structural and functional. The design of such a suspension is unique in that all its elements can be attached to a special cross member, which is rigidly mounted in the body or frame. Thus, during repairs, this suspension can be removed completely as a separate unit for repair or replacement. The functional advantage is that by choosing a specific geometry for the placement of the levers, any desired suspension settings can be rigidly set. This contributes to a high degree of vehicle handling, which is why double wishbone suspensions are often used in sports cars.

The seventh type of independent suspension is “candle”. It became the structural forerunner of the MacPherson suspension. In the design of this type of suspension, a rigid frame is used, on which a steering knuckle is mounted. From above, it is supported by a spring or spring. When hitting an obstacle, the steering knuckle slides up and down the frame to provide cushioning. Today, only sports cars from the Morgan company have this suspension; this type was most widespread at the beginning of the twentieth century. The advantages of this suspension include the simplicity and compactness of the design, low weight, and high reliability. By cons - large longitudinal vibrations.

The eighth type of independent suspension -. In its design, shock-absorbing struts are used, and a coil spring acts as an elastic element.

Installed primarily on the front axle. We will consider in more detail the design, pros and cons of this suspension in a separate material. The MacPherson suspension is installed on most modern passenger cars.

The ninth type of independent (semi-independent) suspension is a torsion-link suspension, which combines in its design two trailing arms and a torsion-bar twisted beam. This type of suspension was used on the rear axle of front wheel drive vehicles. The torsion bar suspension was developed by Audi, on whose models it was installed in the 1970s and 90s.

Today, such a suspension is rarely used on budget models by Chinese companies. The advantages of such a suspension include their durability and reliability, and the relative simplicity of the design. The disadvantages are rigidity, which affects the comfort of passengers in the rear row of the car, a predisposition to roll in a corner (due to the low location of the roll center).

Cars with independent suspension are in deserved demand among Russian buyers - such a chassis design improves handling, information content, and allows better control of the car. Therefore, in this article we will talk about the design features of this type of suspension and tell you what cars are available.

Independent car suspension structure: rear and front

To begin with, let us determine how this type of chassis design differs: when using it, the wheels of one axle are either not connected at all to each other, or are loosely connected, therefore, the movement of one wheel has almost no effect on the other. For front and rear independent suspension, different types of structures are used: in the first case, as a rule, they use the MacPherson scheme, in the second - levers. The optimal solution in the latter case is a multi-link suspension - it is more comfortable than others, and provides excellent handling. The main feature of its design is that each lever is responsible for its own parameter of the wheel's behavior on the road. Thanks to this, the car behaves better: the rear axle "steers" in a corner and increases the stability of the car during active maneuvers. This type of rear independent suspension is mainly found on Class D and higher cars, but some manufacturers also equip more compact C-Class cars with this design.

Advantages

• Controllability
  Independent structures have a positive effect on handling - the stability of the car increases, it reacts weaker to unevenness, which is especially important at high speeds.
• Informativeness
  The driver receives more feedback and can adjust course and speed based on the situation.
• Comfort
  The independent movement of the wheels provides an increased level of comfort for the driver and passengers - vibrations from shocks are damped more efficiently and are not transmitted to other chassis elements.

For the front suspension in almost any car, the MacPherson scheme is used, but with the rear, options are possible. Most of the cars available on the Russian market are equipped with a semi-independent rear suspension. We will tell you about the most popular models.

Cars with semi-independent rear suspension

This chassis design provides decent ride comfort with a fairly simple design, so it is used on most inexpensive cars.

Volkswagen polo

The German sedan is highly praised for its handling. Most of the cars of class B when evaluating this component are compared with it. At the same time, the engineers were able to achieve such results using the usual semi-independent design of the rear of the chassis. However, many buyers complain about slight problems with the smoothness of the ride when driving any significant irregularities. Other pluses of the car include good equipment and practicality. The main disadvantage is the high price tags. The car is driven by 1.6 engines with a capacity of 95 and 110 hp.

Hyundai solaris

The main bestseller of the Russian market also cannot boast of an independent rear suspension (there is a torsion beam at the rear), but at the same time it provides a level of comfort sufficient for moving around the city. However, handling is a source of criticism: the chassis and steering wheel are not tuned well enough. Other disadvantages of Solaris include the relatively high cost of average and maximum configurations and the tightness of the cabin. Engines 1.4 (107 hp) and 1.6 (123 hp) are installed on the car. The latter adds good accelerating dynamics to the Solaris's list of advantages.

Lada Vesta

Vesta is positioned as a Russian competitor to the already mentioned Polo and Solaris. And AvtoVAZ engineers did a lot to make their brainchild in terms of comfort and controllability close to competitors. Experts and buyers note that the Lada is controlled really well - the suspension settings are matched quite well, and the steering effort is quite natural. At the same time, the car also uses a semi-independent structure of the rear part of the chassis. Disadvantages of a car are traditional for the Russian car industry: assembly flaws, quality of interior materials. There is only one engine available - a 1.6-liter unit producing 106 hp.

Auto with independent rear suspension

As we said earlier, this design provides improved comfort and good handling. Therefore, individual representatives of class C are equipped with this particular type of chassis device. However, most of them are not affordable, and cannot be compared with the cars already reviewed.

Ravon Gentra

"Ravon Gentra" is just a full-fledged class C sedan, equipped with an independent rear suspension with a multi-link scheme. It provides good handling and comfort: the driver can control the car on the road with loving quality, while the passengers feel less vibrations. The classic MacPherson pattern is applied at the front. The main advantage of "Gentra" is the combination of an affordable price, a good level of equipment, comfort and controllability. A variety of trim levels and options will help you choose a car that suits your needs. The Ravon has one engine, but it is quite interesting. This is a technologically advanced and reliable engine 1.5 with a capacity of 107 hp, which is combined with a 5-speed manual or a modern 6-speed automatic. The latter is more affordable than similar boxes offered by competitors, so by choosing such a transmission you will get a reliable and comfortable city car. "Gentra" is an affordable and high-quality car with an independent suspension, so it can handle both operation in a city and a trip out of town. Ravon overcomes uneven surfaces with comfort and is stable at high speeds and during active maneuvers.

Conclusion

When choosing a new car, consider its handling and comfort parameters. The independent suspension will provide comfortable travel on Russian roads, and control over the car even in difficult situations. These advantages will make the machine easier and more enjoyable to operate. At the same time, do not forget about other aspects: the cost of the car, the level of equipment, reliability, dynamics and economy. Choose a car that combines all these qualities - to own such a car is much more pleasant than an expensive, but "empty", tough, and demanding vehicle.