The main types of suspensions. The main types of passenger car suspensions. Suspension purpose and general structure

What is the most important part of a car? We are sure that most motorists will agree in disputes: someone will argue that this is an engine, since it sets in motion and is essentially the basis of the car, while others will talk about the body, since without a "box" on which everything is attached far from you will leave. However, few remember the functional significance of the suspension, which is essentially the "foundation" on which it will be built. future car... It is the types of car suspensions that determine the dimensions and functional features car body, and also allows you to install a specific engine that will function harmoniously. Car suspension is such an important and complex element that it requires a separate detailed analysis, the most important points of which you can read below.

Purpose of car suspension

Car suspension Is a set of devices working closely with each other, the main functional feature of which is to provide an elastic connection, sprung with an unsprung mass. In addition, the suspension relieves the load on the sprung mass by evenly distributing dynamics throughout the structure. Among the most basic components in the suspension of a modern car are:

• elastic element- Provides a smoother ride, as it reduces the impact of vertical dynamics on the mass;
• damping element- vibrations obtained in the course of loads, converts into thermal energy, thereby normalizing the driving dynamics (in another way called "");
• guiding element- carries out processing of lateral and longitudinal kinetics on the moving wheels of the car.

Regardless of the type of suspension and the structural differences of the vehicle, the general purpose of the suspension is to dampen incoming vibration and noise, as well as to smooth out vibrations that occur when driving on uneven surfaces. Depending on the functional features of the car (for a small Smart model, and an all-wheel drive SUV, they differ significantly, you see), the type and design of the car's suspension will differ.

Vehicle suspension device

Regardless of the type of suspension, any of them includes a set of the most basic parts and components, without which it is impossible to imagine a workable device. The main group includes the following types:

• elastic buffer- serve as analyzers that process irregularities and transmit the information received to the car body. Such elements include elastic elements such as springs, springs and torsion bars, which smooth out the resulting vibrations;
• distributing elements- are attached to the suspension and at the same time to the body, which allows maximum power transfer. They are presented in the form of levers of different types: transverse rods, double ones, etc .;
• shock absorber- actively uses the method of hydraulic resistance, this device allows you to resist the elements of elasticity. The most common shock absorbers are of three types: one-tube, two-tube and combined. In addition, the classification of the device is divided into oil, gas-oil and pneumatic type of action;
• barbell- provides stabilization of lateral stability. It is part of a complex complex of supports and linkages attached to the body, and distributes the load when performing maneuvers such as turns;
• fasteners- is presented most often in the form of bolted connections and bushings. The most common fasteners are ball joints as well.

Types and types of car suspensions

The history of the first types of suspensions used on cars goes back to the beginning of the 20th century, when the first structures had only a connecting function and transferred all the kinetics to the body. However, after numerous experiments were carried out and various developments were implemented, which improved the design itself and increased the potential for future use. Several representatives of different types and even segments of suspensions have reached our days, each of which is worthy of a separate article for consideration.

McPherson Suspension

This type of car suspension is the development of the famous designer E. McPherson, which was first used more than 50 years ago. By design, the suspension is divided into one arm, anti-roll bar and swinging plug. This type is far from perfect, but with all this it is very affordable and popular with many manufacturers.

Two-link suspension

The guide block in this type of suspension is represented by two link devices. It can be of diagonal, transverse and longitudinal rolling type.

Multi-link suspension

In contrast to the previous type, this development has a more advanced design, and therefore a number of significant advantages that provide a smoother and smoother ride, as well as improved maneuverability of the machine. Increasingly, this type of suspension can be found on medium and expensive premium cars.

Torsion bar suspension

Car suspension similar in design, with previous copies. However, this type of suspension uses torsion bar parts instead of standard lever springs. With a simple design, such a solution increases the efficiency of use, and the suspension components themselves are easy to maintain and can be customized to your liking.

Suspension type "De Dion"

Invented by the French engineer A. De Dion, this suspension helps to reduce the load on the rear axle of the car. A distinctive feature of such a suspension is the attachment of the main gear housing not to the axle beam, but to the very part of the body. A similar solution can be found on all-wheel drive SUVs. Use on passenger cars can cause problems in the form of "sinking" during braking and acceleration.

Rear dependent suspension

Everyone is familiar with the type of suspension for passenger cars, which the inventors in the USSR loved to use and integrate. The type of fastening of the beam for this type of suspension is carried out using springs and trailing arms. However, with good handling and stability while driving, the significant weight of the rear beam brings inconvenience to motorists in the form of overloading the crankcase and gearbox.

Semi-independent rear suspension

Unlike the dependent type of suspension discussed earlier, a cross member is used here, which is connected by two trailing arms.

Oscillating axle suspension

As the name implies, in this type of suspension, the basis of the device is the axle shafts. Hinges are applied to one of the ends, and the axles themselves are articulated with the tires. When the wheel moves, the latter will always be at an angle of 90 ° to the axle shaft.

Trailing arm suspension

It is divided into two more subcategories: torsion and spring, in which, depending on the name, the elastic elements are springs or torsion bars. Among the main differences is the location of the wheel in close proximity to the car body. This car suspension is used on small runabouts, trailers, etc.

With longitudinal and transverse levers

As the name suggests, the main structural unit here is the trailing arm, which relieves the supporting forces on the body. By itself, this type is too heavy, which makes it an extremely unpopular model on the market. But with wishbones, things are a little better: this type is more flexible when adjusting, and the use of support arms reduces the load on the suspension mount.

Suspension type with slanting arms

This type of car suspension is very similar in design to the trailing arms, with the difference that the swinging axes of the arms are located at an acute angle. These types are installed on the rear axle most often. German manufacturers... In comparison with the longitudinal type, the roll when turning in the oblique type is comparatively less.

With double trailing and transverse levers

Unlike designs with one lever, this one has two such devices for each axis. They are placed, depending on the type, in a transverse or longitudinal manner, but when connecting such levers, both springs and torsion bars, which we have encountered before, and springs are used. Such designs are compact in themselves, but unbalanced when driving on poor surfaces.

Hydropneumatic and air suspension

A similar car suspension uses pneumatic or hydropneumatic devices (elastic parts). By themselves, they are not the final option, but only offer modern solutions to increase ride comfort. Both options are sophisticated and provide owners with a smooth ride, high handling, and advanced vibration damping. Such suspensions can be combined with both a MacPherson-type suspension and a multi-link car suspension.

Electromagnetic suspension

It is a complex structure based on an electromagnetic drive. This technology fulfills two functional features at once: a shock absorber and an elastic element. The "orchestra" is led by a microcontroller with a sensor. The device is extremely safe, and the switching mechanism is carried out using electromagnets. Naturally, this type of suspension is not on a par with analogues due to its high manufacturability and cost.

Adaptive suspension (semi-active suspension)

By adjusting to the road surface and driving behavior, the system determines the degree of damping and adjusts to a specific operating mode. Tuning is done using electromagnets, or a fluid on a rheological basis (much less often).

Suspensions for pickups, trucks and SUVs

When creating cargo strands, automobile inventors and engineers, as a rule, used options with the placement of axles on longitudinal or transverse springs. Over time, even now, some manufacturers have not changed this setting much, although one cannot say that there has been no progress either. Already, you can find models that use a hydraulic suspension. An unconditional distinctive feature of almost all truck suspensions is the use of simple structures in the form of a standard bridge, which is attached to the body with a bracket and connected by springs.

But for SUVs and pickups, this design is a little more complicated and may differ even on the example of one model (in the back there is one type, for example, dependent, and in front there is an independent one). This adaptability is due to the increased need for such vehicles to overcome difficult terrain. As a rule, the basis for such vehicles is with a spring type of suspension, although some design suspensions on a spring basis.

The suspension of a truck looks like a very complex mechanism, but its design is much simpler than some types of cars.

Car suspension service

To the question "how often do you need to crawl under the car and service the suspension?" no one can give an exact answer. It all depends on the level and quality of vehicle operation. With the proper driving character and careful attitude to the car, there is no special need for this. However, as often happens, in the process of driving on our road, for an hour or so, a characteristic sound will appear, or the presence of "subsidence" of the car in one direction. In this case, it is necessary to apply for the services of a professional workshop as early as possible, or to make sure for yourself whether there is a problem or not.

However, be careful when replacing equipment and parts in the suspension structure. At first glance, it may seem that repair and replacement is nothing complicated. Nevertheless, not every motorist can qualitatively and successfully replace a part, in a sometimes heavy mechanism. A common problem such "unfortunate replacements" are the presence of "swaying", roll when cornering to one side, the appearance of impaired vehicle handling.

Let's go straight to the topic without hesitation. . Moreover, the topics are quite interesting, although this is the second in a row about cars. I'm afraid the female part of readers and pedestrians do not quite like this, but this is how it happened Listening to the topic from :

“How does car suspension work? Suspension types? What determines the rigidity of the machine? What is "hard, soft, elastic ..." suspension "

We tell ... about some options (and oh, how many of them actually turn out to be!)

The suspension provides an elastic connection of the body or frame of the car to the axles or directly to the wheels, softening shocks and shocks that occur when the wheels hit the bumps in the road. In this article, we will try to consider the most popular types of car suspensions.

1. Independent suspension on two wishbones.

Two forked levers, usually triangular in shape, guide the rolling of the wheel. The rolling axis of the levers is parallel to the longitudinal axis of the vehicle. Over time, double wishbone independent suspension has become standard equipment in cars. At one time, she proved the following indisputable advantages:

Light unsprung weight

Little space requirement

Possibility of adjusting the car's handling

Available combination with front-wheel drive

The main 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 suspension settings - changing the 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 optimal and perfect type, 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.

Advantages: one of the most optimal suspension schemes and that says it all.

Disadvantages: layout restrictions associated with the length of the wishbones (the suspension itself "eats away" a fairly large space in the engine or luggage compartment).

2. Independent slanting arm suspension.

The pivot axle is located diagonally to the longitudinal axis of the vehicle and tilted slightly towards the middle of the vehicle. This type of suspension cannot be fitted to front-wheel drive vehicles, although it has proven effective in rear-wheel drive small and medium-sized vehicles.

TO the fastening of wheels on trailing or oblique levers is practically not used in modern cars but the presence of this type of suspension, for example, in the classic Porsche 911, is definitely a topic for discussion.

Advantages:

Disadvantages:

3. Oscillating axle independent suspension.

The independent swing-axle suspension is based on Rumpler's patent from 1903, which was used by Daimler-Benz until the seventies of the 20th century. The left axle tube is rigidly connected to the final drive housing, and the right tube has a spring connection.

4. Independent trailing arm suspension.

The independent trailing arm suspension was patented by Porsche. TO Trailing-arm or slant-arm mounting is practically not used in modern cars, but the presence of this type of suspension, for example, in the classic Porsche 911, is definitely a topic for discussion. In contrast to other solutions, the advantage of this type of suspension was that this type of axle was connected to a transverse torsion spring bar, which created more space. The problem, however, was that there were reactions of strong lateral vibrations of the car, which could lead to loss of control, which, for example, "became famous" of the "Citroen" model "2 CV".

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 oblique levers allow you to partially get rid of the main disadvantages of the suspension on the trailing arms, but when the effect of body roll on the inclination of the wheels decreases, a change in track appears, which also affects handling and stability.

Advantages: simplicity, low cost, relative compactness.

Disadvantages: outdated design, extremely far from perfect.

5. Independent suspension with wishbone and spring strut (McPherson).

The so-called "McPherson suspension" was patented in 1945. It was a further development of the double wishbone suspension, in which the upper control arm was replaced by a vertical guide. The McPherson struts are designed for use with both front and rear axles. In this case, the wheel hub is connected to the telescopic tube. The entire rack is connected to the front (steerable) wheels by means of hinges.

MacPherson first used the 1948 Ford Vedet model produced by the French subsidiary on a production car. It was later used on the Ford Zephyr and the Ford Consul, which also claim to be the first high-volume vehicles with such a suspension, as the Vedette plant in Poissy initially had great difficulty getting the new model up and running.

Much similar suspension was developed earlier, right up to the very beginning of the XX century, in particular, a very similar type was developed by the engineer of the firm "Fiat" Guido Fornaca in the mid-twenties - it is believed that MacPherson partially took advantage of his developments.

The immediate ancestor of this type of suspension is a type of front suspension with two wishbones of unequal length, in which the spring in a single block with a shock absorber was moved into the space above the upper arm. This made the suspension more compact, and allowed a semi-axle with a hinge to pass between the levers on a front-wheel drive car.

Replacing the upper arm with a ball joint and a shock absorber and spring block located above it with a shock absorber strut with a swivel joint attached to the wing mudguard, MacPherson received a compact, structurally simple and cheap suspension named after him, which was soon used on many Ford models European market.

In the original version of such a suspension, the ball joint was located on the continuation of the axis of the shock absorber, so the axis of the shock absorber was also the axis of rotation of the wheel. Later, for example on the Audi 80 and Volkswagen passat of the first generations, the ball joint began to be displaced outward to the wheel, which made it possible to obtain smaller, and even negative values ​​of the run-in shoulder.

This suspension received mass distribution only in the seventies, when technological problems were finally solved, in particular, the mass production of shock absorber struts with the required resource. Due to its manufacturability and low cost, this type of suspension subsequently quickly found very widespread use in the automotive industry, despite a number of disadvantages.

In the eighties, there was a tendency towards the widespread use of the MacPherson strut, including on large and relatively expensive cars... However, subsequently, the need for a further increase in technical and consumer qualities led to a return on many relatively expensive cars to a double wishbone suspension, which is more expensive to manufacture, but has better kinematic parameters and increases driving comfort.

Chapman rear suspension - MacPherson strut option for rear axle.

McPherson designed his suspension to be installed on all wheels of the car, both front and rear - in particular, this is how it was used in the Chevrolet Cadet project. However, on the first production models, the suspension of his development was used only in front, and the rear, for reasons of simplification and reduction in cost, remained traditional, dependent with a rigid drive axle on longitudinal springs.

Only in 1957, Lotus engineer Colin Chapman used a similar suspension for the rear wheels of the Lotus Elite model, so it is commonly called "Chapman's suspension" in English-speaking countries. But, for example, in Germany such a difference is not made, and the combination "MacPherson strut rear suspension" is considered quite acceptable.

The most significant advantages of the system are its compactness and low unsprung weight. Suspension "McPherson" has become widespread due to its low cost, ease of manufacture, compactness, as well as the possibility of further refinement.

6. Independent suspension with two transverse springs.

In 1963, General Motors developed the Corvette with an exceptional suspension solution - an independent suspension with two transverse springs. In the past, coil springs were preferred over springs. Later, in 1985, the first editions of the Corvette were again equipped with a suspension with transverse springs made of plastic. However, in general, these designs were not successful.

7. Independent candle suspension.

This type of suspension was installed on early Madeleys, for example, on the Lancia Lambda (1928). In this type of suspension, the wheel, together with the steering knuckle, moves along a vertical guide mounted inside the wheel casing. A helical spring is installed inside or outside this guide. This design, however, does not provide the wheel alignment required for optimal road contact and handling.

WITH The most common type of independent suspension in a passenger car today. It is characterized by simplicity, low cost, compactness and relatively good kinematics.

This is a suspension on a rail and a single wishbone, sometimes with an additional trailing link. The main idea in the design of this suspension scheme was by no means handling and comfort, but compactness and simplicity. With fairly average indicators, multiplied by the need to seriously strengthen the place of attachment of the rack to the body and a rather serious problem of road noise transmitted to the body (and a whole bunch of shortcomings), the suspension turned out to be so technologically advanced and so liked the linkers that it is still used almost everywhere ... In fact, only this suspension allows designers to position the power unit transversely. MacPherson strut suspension can be used for both front and rear wheels. However, in English-speaking countries, a similar rear-wheel suspension is commonly referred to as "Chapman's suspension". Also, this suspension is sometimes called the term "candle suspension" or "swinging candle". Today, there is a tendency to move from the classic MacPherson strut to the scheme with an additional upper wishbone (a kind of hybrid of MacPherson strut and wishbone suspension is obtained), which allows, while maintaining a relative compactness, to significantly improve handling performance.

Advantages: simplicity, low cost, small unsprung masses, a successful scheme for various layout solutions in small spaces.

Disadvantages: noise, low reliability, low roll compensation ("peck" when braking and "squat" when accelerating).

8. Dependent suspension.

The dependent suspension is mainly used for the rear axle. It is used as a front suspension on jeeps. This type of suspension was the main one until about the thirties of the 20th century. They also included coil springs. The problems associated with this type of suspension relate to the large mass of unsprung parts, especially for the axles of the drive wheels, as well as the inability to provide optimal wheel alignment angles.

WITH The oldest type of suspension. Its history dates back to carts and carts. Its main principle is that the wheels of one axle are interconnected by a rigid beam, most often called a "bridge".

In most cases, if you do not touch upon exotic schemes, the bridge can be fixed both on springs (reliable, but not comfortable, rather mediocre handling), and on springs and guide levers (only slightly less reliable, but comfort and controllability becomes much more) ... It is used where something really strong is required. After all, nothing has been invented yet stronger than a steel pipe, in which, for example, drive axle shafts are hidden. In modern passenger cars, it practically does not occur, although there are exceptions. Ford Mustang, for example. It is used more often in SUVs and pickups (Jeep Wrangler, Land rover Defender, Mercedes Benz g-class, Ford Ranger, Mazda BT-50 and so on), but the tendency towards a general transition to independent schemes is visible to the naked eye - controllability and speed are now in demand more than the "armor-piercing" of the structure.

Advantages: reliability, reliability, reliability and again reliability, simplicity of design, constant track and ground clearance(off-road this is a plus, not a minus, as for some reason many believe), large moves that allow you to overcome serious obstacles.

Disadvantages: When working out irregularities and in turns, the wheels always move together (they are rigidly connected), which, together with high unsprung masses (a heavy axle is an axiom), does not have the best effect on the stability of movement and controllability.

On a transverse spring

This very simple and cheap type of suspension was widely used in the first decades of the development of the car, but as speeds increased, it almost completely fell out of use.
The suspension consisted of a continuous beam of the bridge (leading or not leading) and a semi-elliptical transverse spring located above it. In the suspension of the drive axle, it became necessary to place its massive gearbox, so the transverse spring had the shape of a capital letter "L". To reduce spring compliance, longitudinal jet thrust was used.
This type of suspension is best known for for Ford cars T and Ford A / GAZ-A. This type of suspension was used on Ford vehicles up to and including the 1948 model. GAZ engineers abandoned it already on the GAZ-M-1 model, created on the basis of the Ford B, but with a completely redesigned suspension on longitudinal springs. The rejection of this type of suspension on a transverse spring in this case was due to the greatest extent to the fact that, according to the operating experience of the GAZ-A, it had insufficient survivability on domestic roads.

On longitudinal springs

This is the most ancient version of the suspension. In it, the bridge beam is suspended on two longitudinally oriented springs. The bridge can be either leading or non-leading, and is located both above the spring (usually on cars) and under it (trucks, buses, SUVs). As a rule, the axle is fastened to the spring using metal clamps approximately in the middle of it (but usually with a slight forward displacement).

The spring in its classic form is a package of elastic metal sheets, connected with clamps. The sheet on which the spring attachment ears are located is called the root - as a rule, it is made the thickest.
In recent decades, there has been a transition to small or even single-sheet springs, sometimes non-metallic composite materials (carbon fiber reinforced plastics and so on) are used for them.

With guide levers

There are a variety of schemes of such suspensions with different number and arrangement of levers. The five-link dependent suspension with Panhard rod shown in the figure is often used. Its advantage is that the levers rigidly and predictably set the drive axle movement in all directions - vertical, longitudinal and lateral.

More primitive options have less leverage. If there are only two levers, during the operation of the suspension they tilt, which requires either their own pliability (for example, on some Fiats of the early sixties and English sports cars, the levers are in spring rear suspension made elastic, plate, in fact - similar to quarter-elliptical springs), or a special articulated connection of the levers with the beam, or the flexibility of the beam itself to torsion (the so-called torsion bar suspension with coupled levers, still widespread on front wheel drive vehicles
As elastic elements, both coil springs and, for example, air bellows can be used. (especially on trucks and buses, as well as - flowriders)... In the latter case, a rigid setting of the movement of the suspension guide vane in all directions is required, since the air bellows are not able to perceive even small lateral and longitudinal loads.

9. De-Dion type dependent suspension.

Firm "De Dion-Bouton" in 1896 developed a rear axle design, which made it possible to separate the differential housing and the axle. In the suspension of the "De Dion-Bouton" design, the torque was perceived by the bottom of the car body, and the drive wheels were attached to the rigid axle. With this design, the mass of non-shock-absorbing parts was significantly reduced. This type of suspension was widely used by Alfa Romeo. It goes without saying that such a suspension can only work on the rear drive axle.

Suspension "De Dion" in a schematic image: blue - continuous suspension beam, yellow - final drive with differential, red - axle shafts, green - hinges on them, orange - frame or body.

Suspension "De Dion" can be described as an intermediate type between dependent and independent suspensions. This type of suspension can be used only on drive axles, more precisely, only the drive axle can have the "De Dion" type of suspension, since it was developed as an alternative to the continuous drive axle and implies the presence of driving wheels on the axle.
In the "De Dion" suspension, the wheels are connected by a relatively light, one way or another sprung continuous beam, and the final drive gearbox is fixedly attached to the frame or body and transmits rotation to the wheels through axle shafts with two hinges on each.
This allows unsprung masses to be kept to a minimum (even when compared to many independent suspensions). Sometimes, to improve this effect, even the brakes are transferred to the differential, leaving only the wheel hubs and the wheels themselves unsprung.
During the operation of such a suspension, the length of the axle shafts changes, which forces them to be performed with hinges of equal angular velocities movable in the longitudinal direction (as on front-wheel drive cars). In the English Rover 3500, conventional universal joints were used, and to compensate, the suspension beam had to be made with a unique sliding joint design, which allowed it to increase or decrease its width by several centimeters when the suspension was compressed and rebounded.
"De Dion" is a technically very perfect type of suspension, and in terms of kinematic parameters it surpasses even many types of independent ones, yielding to the best ones only on uneven roads, and then in some indicators. At the same time, its cost is quite high (higher than that of many types of independent suspension), therefore it is used relatively rarely, usually on sports cars... For example, many Alfa Romeo models had such a suspension. A recent car with such a suspension is Smart.

10. Dependent suspension with drawbar.

This suspension can be considered as semi-independent. In its current form, it was developed in the seventies for compact cars. This type The axle was first serially installed on the Audi 50. Today, the Lancia Y10 is an example of such a car. The suspension is assembled on a tube bent in front, at both ends of which wheels with bearings are mounted. The forward bend forms the actual drawbar, which is fixed to the body with a rubber-metal bearing. Lateral forces are transmitted by two symmetrical oblique jet rods.

11. Dependent suspension with tied arms.

The linked-arm suspension is an axle that is a semi-independent suspension. The suspension has rigid trailing arms connected to each other by a rigid elastic torsion bar. This design, in principle, forces the levers to oscillate in sync with each other, but by twisting the torsion bar it gives them some degree of independence. This type can be conventionally considered semi-dependent. In this form, the suspension is used on the Volkswagen Golf model. In general, it has many types of design and is very widely used for the rear axle of front-wheel drive vehicles.

12. Torsion bar suspension

Torsion bar suspension- these are metal torsion shafts operating in torsion, one end of which is attached to the chassis, and the other is attached to a special perpendicularly standing lever connected to the axle. The torsion bar suspension is made of heat-treated steel, which allows it to withstand significant torsional loads. The basic principle of the torsion bar suspension is bending.

The torsion beam can be positioned longitudinally and transversely. Longitudinal torsion bar suspension is mainly used on large and heavy trucks... On passenger cars, as a rule, a transverse arrangement of torsion suspensions is used, usually on rear wheel drive... In both cases, the torsion bar suspension ensures a smooth ride, regulates roll when cornering, provides an optimal amount of damping of oscillations of the wheels and body, and reduces oscillations of the steered wheels.

On some vehicles, the torsion bar suspension is used for automatic leveling using a motor that pulls the beams together to provide additional rigidity, depending on the speed and condition of the road surface. The height-adjustable suspension can be used when changing wheels where the vehicle is raised with three wheels and the fourth is raised without a jack.

The main advantages of torsion suspensions are durability, ease of height adjustment and compactness in width. vehicle... It takes up significantly less space than coil springs. The torsion bar suspension is very easy to operate and maintenance... If the torsion bar suspension is loose, you can adjust the positions with a regular wrench. It is enough to climb under the bottom of the car and tighten the necessary bolts. However, the main thing is not to overdo it in order to avoid excessive rigidity of the stroke when driving. Adjusting torsion bar suspensions is much easier than adjusting spring suspensions. Car manufacturers are changing the torsion beam to adjust travel position based on engine weight.

The prototype of the modern torsion bar suspension can be called the device that was used in the Volkswagen Beatle in the 30s of the last century. This device was modernized by the Czechoslovak professor Ledwinka to the design we know today and was installed on the Tatra Mountains in the mid-1930s. And in 1938 Ferdinand Porsche copied the design of Ledwinky's torsion bar suspension and introduced it into the mass production of the KDF-Wagen.

The torsion bar suspension was widely used on military equipment during the Second World War. After the war, automotive torsion bar suspension was used mainly on European cars (including passenger cars) such as Citroen, Renault and Volkswagen. Over time, passenger car manufacturers abandoned the use of torsion suspensions on passenger cars due to the complexity of manufacturing torsion bars. These days, torsion bar suspension is mainly used on trucks and SUVs from manufacturers such as Ford, Dodge, General Motors and Mitsubishi Pajero.

Now for the most common misconceptions.

"The spring sagged and became softer":

No, the spring rate does not change. Only its height changes. The coils get closer to each other and the machine sinks lower.
1. "The springs are straightened, it means they sagged": No, if the springs are straight, this does not mean that they are sagging. For example, on the factory assembly drawing of the UAZ 3160 chassis, the springs are absolutely straight. At Hunter, they have a bend of 8mm, which is barely noticeable to the naked eye, which, of course, is also perceived as "straight springs". In order to determine whether the springs have sagged or not, you can measure some characteristic size. For example, between the bottom surface of the frame above the bridge and the surface of the bridge stocking under the frame. Should be about 140mm. And further. These springs were not conceived by chance as they are straight. When the axle is located under the spring, only in this way can they provide a favorable floatability characteristic: when heeling, do not steer the axle towards oversteer. You can read about understeer in the "Vehicle handling" section. If in some way (adding sheets, forging resors, adding springs, etc.) to achieve that they become curved, then the car will be prone to yaw at high speed and other unpleasant properties.
2. "I will cut off a couple of turns from the spring, it will sag and become softer.": Yes, the spring will indeed become shorter and it is possible that when installed on a car, the car will sag lower than with a full spring. However, in this case, the spring will not become softer but, on the contrary, harder in proportion to the length of the sawn bar.
3. “I will add springs (combined suspension) to the springs, the springs will relax and the suspension will become softer. During normal driving, the springs will not work, only the springs will work, and the springs only at maximum breakdowns " : No, the stiffness in this case will increase and will be equal to the sum of the stiffness of the spring and the spring, which will negatively affect not only the comfort level but also the cross-country ability (about the effect of suspension stiffness on comfort later). In order to achieve a variable suspension characteristic with this method, it is necessary to bend the spring to the free state of the spring and bend through this state (then the spring will change the direction of force and the spring and spring will start to work at the spring). And for example, for a UAZ small leaf spring with a stiffness of 4kg / mm and a sprung mass of 400kg per wheel, this means a suspension lift of more than 10cm !!! Even if this terrible lift is carried out with a spring, then in addition to the loss of stability of the car, the kinematics of the curved spring will make the car completely uncontrollable (see paragraph 2)
4. "And I (for example, in addition to item 4) will reduce the number of sheets in the spring": Reducing the number of sheets in the spring really clearly means a decrease in the stiffness of the spring. However, firstly, this does not necessarily mean a change in its bend in a free state, secondly, it becomes more prone to an S-shaped bend (winding water around the bridge by the action of a reactive moment on the bridge) and thirdly, the spring is designed as a "beam equal resistance bending "(who studied" SoproMat ", he knows what it is). For example, 5-leaf springs from the Volga sedan and more rigid 6-leaf springs from the Volga station wagon have the same root leaf only. It would seem that in production it is cheaper to unify all parts and make only one additional sheet. But this is not possible because if the condition of equal resistance to bending is violated, the load on the spring sheets becomes uneven in length and the sheet quickly fails in a more loaded area. (The service life is shortened). I really do not recommend changing the number of sheets in a package, and even more so collecting springs from sheets from different brands of cars.
5. "I need to increase the rigidity so that the suspension does not break through to the bumpers" or "the SUV must have a rigid suspension." Well, first of all, they are called "chippers" only in the common people. In fact, these are additional elastic elements, i.e. they stand there specifically so that they can be pierced and so that at the end of the compression stroke the stiffness of the suspension increases and the necessary energy consumption is provided with a lower stiffness of the main elastic element (springs / springs). With an increase in the rigidity of the main elastic elements, the permeability also deteriorates. It would seem what is the connection? The traction limit for adhesion that can be developed on a wheel (in addition to the coefficient of friction) depends on the force with which this wheel is pressed against the surface on which it is traveling. If the car is driving on a flat surface, then this pressing force depends only on the mass of the car. However, if the surface is not level, this force begins to depend on the stiffness characteristic of the suspension. For example, imagine 2 cars of equal sprung mass, 400 kg per wheel, but with different stiffness of the suspension springs 4 and 2 kg / mm, respectively, moving on the same uneven surface. Accordingly, when driving through an unevenness with a height of 20 cm, one wheel worked for compression by 10 cm, the other for rebound by the same 10 cm. When the spring with a stiffness of 4kg / mm is expanded by 100mm, the spring force decreased by 4 * 100 = 400kg. And we have only 400kg. This means that there is no traction on this wheel anymore, but if we have an open differential or a limited-friction differential (DOT) on the axle (for example, a helical "Quife"). If the stiffness is 2 kg / mm, then the spring force has decreased only by 2 * 100 = 200 kg, which means that 400-200-200 kg is still pressing and we can provide at least half the thrust on the axle. Moreover, if there is a bunker, and most of them have a blocking coefficient of 3, if there is some kind of traction on one wheel with the worst traction, 3 times more torque is transferred to the second wheel. And an example: The most soft suspension UAZ on small leaf springs (Hunter, Patriot) has a stiffness of 4 kg / mm (both spring and spring), while the old Range Rover has about the same mass as the Patriot, on the front axle 2.3 kg / mm, and on the rear axle 2.7 kg / mm ...
6. "In cars with soft independent suspension, the springs should be softer" : Not necessary at all. For example, in a MacPherson-type suspension, the springs really work directly, but in double wishbone suspensions (front VAZ-classic, Niva, Volga) through ratio equal to the ratio of the distance from the axis of the lever to the spring and from the axis of the lever to the ball joint. With this arrangement, the stiffness of the suspension is not equal to the stiffness of the spring. The spring rate is much higher.
7. "It is better to use stiffer springs so that the car is less rolly and therefore more stable." : Not certainly in that way. Yes, indeed, the greater the vertical stiffness, the greater the angular stiffness (which is responsible for body roll under the action of centrifugal forces in corners). But the transfer of masses due to body roll has a much smaller effect on the stability of the car than, say, the height of the center of gravity, which Jeepers often throw very wastefully to lift the body just in order not to cut the arches. The car must roll, roll is not bad. This is important for driving information. Most cars are designed with a standard roll value of 5 degrees at a peripheral acceleration of 0.4g (depending on the ratio of the turning radius to the speed of movement). Some automakers use a smaller roll angle to create the illusion of stability for the driver.

And what are we all about suspension and suspension, let's remember, The original article is on the site InfoGlaz.rf The link to the article this copy was made from is

Suspension - how much in this sound ... In every sense. What what, but she knows how to sound. Depending on the design, the suspension can be simple, or it can have the most complex design. In the same way, it can be reliable, and vice versa, "pour in" after every thousand kilometers.

During its existence, the car's suspension has gone through a huge evolutionary path... Once the spring system was considered the height of progress, but today the design of modern suspensions can be compared to a work of art - they are so perfect, complex and expensive devices.

Purpose and device of the car suspension

So what is the purpose of a car suspension? She, like her distant predecessors, installed in horse-drawn carriages, is designed to make movement more comfortable and safe. Resilient suspension elements dampen the shock, shock and vibration that accompany any ride on any road.

However, the tasks of the suspension are not limited to comfort alone. Its second function is to assist with maneuvers. The complexity of the suspension design is often due to this very reason: engineers are still trying to add stability, handling, and safety to the car.

And finally, the modern suspension helps a lot to brake by absorbing the momentum of the forward movement. The quality of braking can sometimes determine how the suspension is tuned and how functional it is.

What is included in the suspension device? Simply put, everything between the wheels and the power frame of the vehicle. These are well-known shock absorbers (where can we go without them), springs, levers, rods, stabilizers, ball joints, silent blocks and other elements. They can be conditionally divided into the following categories:

1. All types of springs, springs and torsion bars are elastic suspension elements. Their task is to take over and spring back the shocks from driving over bumps.
2. All types of shock absorbers (conventional oil and gas-oil, pneumatic, magnetic) are damping suspension elements. They must absorb shock and shock, not letting them further onto the car body.
3. Levers, steering knuckles, transverse rods with these are guiding elements. Their task is to form the correct position of the wheel when turning and driving in a straight line. The steering mechanism is sufficient to turn the wheels, but suspension elements are needed to ensure that the wheel is in the correct position during maneuvers.
4. Silent blocks, ball bearings and other small rubber-metal parts are needed not only to fasten all suspension elements together, but also to partially mitigate vibration and shock.
5. The anti-roll bar, as the name implies, is designed to level the body in corners so that the car does not roll over to the side during sharp maneuvers.

How car suspensions work

Whether it is the suspension of a KamAZ, Mercedes or an old Oka, the principle of its operation does not change. And it is unlikely to change in the near future, despite the abundance of new engineering ideas.

The basic principle of operation of any suspension is as follows: the impact energy (this is a wheel that has fallen into holes or hitting a stone) is converted into the energy of movement of individual parts of the suspension. How does it manifest?

1. The wheel hit the stone. It rose above the plane on which it rolled, and with it the levers, the steering knuckle, and the rods changed their position.
2. Further, the shock absorber is included: it is compressed, using for this the kinetic energy of pushing the wheel from the bottom up. At the same time, the spring, which was previously in a relatively calm position, is compressed.
3. Elastic compression of the shock absorber and the spring, movement of the rod, partial absorption of the shock by rubber-metal bushings - all this dampens the shock and prevents it from going further onto the power frame of the machine.
4. And then there should be "recoil", and again the springs play its role. By straightening, the spring returns the shock to its original position - this is the last step that the suspension takes when it encounters difficulties.

Of course, there are alternative types of construction, but if you look, their principle of operation is exactly the same.

Suspension classification

Improving the design of the car suspension, the engineers went all out. Here you have a multi-link, an ordinary dependent beam, and Bose's jumping suspension ... And they all found their fans and haters. The classification of suspensions is already quite complicated, since different design features and solutions.
What, have you seen the bouncing harness yet?

Dependent

Dependent suspension operation

The oldest design to come from the era of horse-drawn carriages. Its main element is a rigid, inseparable axle that connects two wheels, as a result of which they cannot move relative to each other. That is, if one wheel hits a stone, the second will deviate to the side with it. The easiest option for understanding is the wheels in children's cars, this is how they are mounted on one axis.

True, our cars have gone far ahead of toy cars, so the beam (axle) connecting the two wheels is equipped with shock absorbers, springs, and transverse rods. However, of all the varieties, this is the simplest, indestructible and cheapest suspension, in which malfunctions rarely occur.

Independent

Independent suspension operation

The creation of a gloomy German genius. Independent - because each wheel moves independently of the second in a pair. That is, if one wheel hits a stone, it will rise along with the levers and springs on its side, while the second will not react to this and will not change its position. Independent suspension is very comfortable for passengers, but it can have many separate elements, each of which breaks down sooner or later.

Semi-independent

Semi-independent suspension operation

This is a special type of torsion beam suspension. A U-shaped torsion (twisting) beam is installed as a common axle for two wheels. The scheme of its design gives the wheels a small degree of freedom, since the beam installed with a preload "plays" slightly, partially dampening the rolls in turns.

Pneumatic

Air suspension operation

She migrated to cars from heavy vehicles. Instead of metal springs, it uses compressed air cylinders that are inflated to a certain pressure. The pressure in the cylinders can be different, as a result, the characteristics of the suspension also change. They put it on luxury cars as an additional option.

Torsion bar

Torsion bar suspension operation

This type of suspension is rare in passenger cars. More suitable for large vehicles. A characteristic feature of this suspension is the use of longitudinal torsion bars, which work on twisting, trying to align the car when it hits bumps.

Leaf springs

Spring suspension operation

Such a suspension is rarely used in light vehicles, except for some SUVs. But it is very common on trucks and buses. The peculiarity of the suspension is the use of springs as a damper component to absorb shocks.

Hydraulic

Hydraulic car suspension - general view

It features shock absorbers with an additional reservoir of hydraulic fluid. While the rest of the suspension options are just a boring utilitarian element, the hydraulic suspension opens up new perspectives for them. First of all, it is the ability to control the ride height and the stiffness of the suspension reaction. It can also adapt to the driving style and road conditions.

McPherson

MacPherson suspension device

The same independent suspension, extremely successful - with a MacPherson strut (aka MacPherson, aka a swinging candle), thanks to which it was possible to get rid of one of the levers. The MacPherson strut is attached to the wheel hub and car body, so it successfully replaces one of the suspension arms. In most cases, this is how the front suspension is done.

The peculiarity of the rack is not only in the attachment points. It has combined a shock absorber and a spring in one design, which seriously saves space. In addition, many manufacturers produce a rack that consists of a separate shock absorber unit and a “cup” holder, which significantly reduces the cost of maintenance.

Multi-link

Electromagnetic shock absorber operation

The most progressive type of suspension to date. Instead of liquid or air, it uses transducers with powerful magnets. At the command from the control unit, electricity is supplied to the magnets, due to which the electromagnetic shock absorbers change the rigidity, vehicle clearance, and controllability. If you have ever seen cars dancing or jumping, they will definitely have an electromagnetic suspension.

Conclusion

It's just short description main types of passenger car suspensions. If you look more deeply, there are other, rather unusual design solutions. And the conclusions can be made ambiguous, because each automaker brings some of its own "chips" in the suspension design. But consumers are provided with any type of suspension to choose from: soft, sporty, standard and exclusive. And that's great.

Suspension is an important system that makes it possible for the car to move (after all, with its help the wheels are attached to the car), and at the same time ensures the comfort and safety of passengers and cargo. Read about the car suspension device, its main elements and their purpose in this article.

Purpose of car suspension

Suspension is one of the main systems of the car's running gear, it is necessary to connect the body (or frame) of the car to the wheels. The suspension acts as an intermediate link between the car and the road and solves several problems:

Transmission to the frame or body of forces and moments arising from the interaction of the wheels with the road surface;
- Connection of wheels with a body or frame;
- Provides the necessary for the normal movement of the position of the wheels relative to the frame or body and the road;
- Provides acceptable ride smoothness, compensates for uneven road surfaces.

So the suspension of a car is not just a set of components for connecting the wheels and the body or frame, but a complex system that makes it possible to drive the car normally and comfortably.

General vehicle suspension device

Any suspension, regardless of its type and device, has a number of elements that help to solve the problems described above. The main suspension elements are:

Guiding elements;
- Elastic elements;
- Extinguishing devices;
- Wheel supports;
- Anti-roll bars;
- Fastening elements.

It should be noted that not every suspension has separate parts that play the role of one or another element - often one part solves several problems at once. For example, a traditional spring suspension uses a spring as a guiding and elastic element, as well as a damping device. The package of steel spring plates simultaneously ensures the desired position of the wheel, absorbs the forces and moments arising from the movement, and also serves as a shock absorber, smoothing out the unevenness of the road.

Each suspension element needs to be discussed separately.

Guide elements

The main task of the guide elements is to provide the necessary character of wheel movement relative to the frame or body. In addition, the guide elements absorb the forces and moments from the wheel (mainly lateral and longitudinal) and transmit them to the body or frame. As guide elements in suspensions different types levers of one design or another are usually used.

Elastic elements

The main purpose of elastic elements is the transmission of forces and moments directed vertically. That is, the elastic elements perceive and transmit road irregularities to the body or frame. It should be noted that elastic elements do not absorb the perceived loads - on the contrary, they accumulate them and transfer them to the body or frame with some delay. Springs, coil springs, torsion bars, as well as various rubber buffers (which are most often used in conjunction with other types of elastic elements) can act as elastic elements.

Extinguishing devices

The damping device performs an important function - it dampens vibrations of the frame or body caused by the presence of elastic elements. Most often, hydraulic shock absorbers act as damping elements, but pneumatic and hydropneumatic devices are also used in many cars.

In most modern passenger cars, the elastic element and the damping device are combined into a single structure - the so-called strut, which consists of a hydraulic shock absorber and a coil spring.

The road for traffic is rarely ideal. Even on a paved track, there are always cracks, potholes and bumps. Without the damping system, comfortable driving would be impossible, and the car body would not withstand the shock loads transmitted from the wheels for a long time. The car suspension is designed to absorb such a load, and, depending on the purpose and cost, has a different design.

Purpose and device of the car suspension

When the vehicle is moving, all vibrations arising from road irregularities are transmitted to the body. The task of the suspension is to soften or dampen such vibrations. An additional function is to ensure the connection of the body and the wheels, while the wheels have the ability to change their position independently of the body, by adjusting the direction of travel. Together with the wheels, the suspension is an essential part of the chassis of the machine.

The suspension is a technically complex device consisting of the following parts:

1. Elastic elements - metallic and non-metallic parts that take on all the load from movement over irregularities, and, by virtue of their properties, distribute it to the body structure.
2. Damping devices (shock absorbers) - units with a pneumatic, hydraulic or combined structure, leveling body vibrations obtained from elastic parts.
3. Guide parts - various levers connecting the suspension to the body and controlling the displacement of the wheels relative to each other and the body.
4. Anti-roll bars - elastic metal rods connecting the suspension and the body, and eliminating the possible roll of the machine when driving.
5. Wheel bearings - parts of the front axle in the form steering knuckles that receive loads from the wheels and distribute them over the suspension.
6. Means for fastening parts, assemblies and assemblies, the task of which is to connect the suspension and the body to each other. These are rigid bolted joints, ball bearings or hinges, composite silent blocks.

Damping elements

The parts of the suspension that damp vibrations while the vehicle is in motion are called damping elements. These include the following devices:

1. Double-tube shock absorbers, consisting of inner and outer tubes, and performing the function of a reservoir and a piston, which are communicated by holes and multidirectional valves, which, due to the inertia of the working medium, inhibit reciprocating movements and damp vibrations.

Depending on the internal working environment, shock absorbers are divided into:

• Hydraulic;
• Gas-filled;
• Gas-hydraulic.

Elastic elements

The task of these suspension elements is to absorb shocks coming from the wheels of the car to the body, and represent the following parts:

1. Spring. The simplest element found in almost all types of suspension. For work efficiency, it can have a different shape.
2. Spring. The oldest suspension element is a set of steel sheets joined together and damping vibrations due to mutual friction.
3. Pneumatic element. It acts as an alternative to the spring and is a rubber cushion into which air is pumped.
4. Torsion. An elastic compact element in the form of a rod, one end of which is connected to the suspension arm, and the other is clamped by a bracket on the body. When the suspension arm is moved, the rod acts as an elastic element and twists.
5. Stretcher. It is an intermediate part between the body and the suspension elements, forming one assembly unit with them.
6. Anti-roll bar. It is a rod connected through struts or wheel suspension arms to stabilize the movement of the vehicle.

Suspension principle

Car suspension works by converting the force of impact from a wheel hitting an uneven surface into the movement of elastic parts (springs). The severity of such movements is controlled and mitigated by damping devices (shock absorbers). As a result, the force of impacts transmitted to the body is reduced, which ensures a smoother ride.

Suspension stiffness y different cars varies greatly: the stiffer it is, the easier and more predictable the handling, but the ride comfort decreases. Soft creates ease of use, but at the expense of significantly reduced controllability (which is not recommended). For this reason, vehicle manufacturers are always trying to find a compromise between comfort and safety.

Suspension classification

In the modern automotive industry, the following types of suspensions are most often used:

1. MacPherson. Developed in 1960 by an engineer who gave the structure his name. Consists of the following parts:

• Anti-roll bar, or "swinging plug". It is attached to the body with a hinge and tends to swing when the wheel moves vertically.
• Block (spring element and telescopic shock absorber);
• Lever.

The advantage of the suspension is its low price, simplicity and reliability. The disadvantage is a noticeable change in the camber angle on the wheels.

2. Double-link. Consists of two levers of different lengths - upper short and lower long. This scheme is one of the most perfect, since the car on it has excellent lateral stability and low tire wear due to the minimum lateral movement of the wheels.

3. Multi-link. It has a similar structure to the double-arm, but much more perfect and more complex. In it, all hinges, levers and silent blocks are attached to a special subframe. A lot of ball joints and rubberized bushings perfectly dampen shocks when hitting bumps and reduce noise in the cabin. This suspension arrangement provides the best tire grip, ride comfort and handling. Dignity multi-link suspension the following:

• Optimal wheel steering;
• Insulated longitudinal and lateral adjustments;
• Small unsprung masses;
• Wheel independence from each other;
• Excellent 4WD potential.

But the main drawback of the suspension is its high cost, although recently not only executive cars, but also golf-class cars have been equipped with such a unit.

4. Responsive. It carries fundamental differences from other types of mechanisms, being a logical and improved continuation of the hydropneumatic suspension, first implemented by Citroen and Mercedes. Its advantages are as follows:

• Low swing at high speed and minimal body roll;
• Forced damping;
• Automatic adaptation to any road surface;
• Excellent stability when driving straight ahead;
• Adaptation for the driver;
• High degree of security.

Different firms in the manufacture of the unit are developing their own original scheme, but in general, the design consists of the following components:

• Adjustable anti-roll bars;
• Chassis control unit;
• Active shock absorber struts;
• Various sensors (ground clearance, irregularities, etc.).

The main disadvantage of the device is its complexity.

5. Type "De Dion". The invention of the French engineer has the main goal - to unload the rear axle of the vehicle as much as possible by separating the main gear case, while it is attached directly to the body. The torque is transmitted through the axle shafts and CV joints, which allows the suspension to be both dependent and independent. The main design flaws are "squatting" on rear wheels with a sharp start and "pecking" when braking.

6. Back dependent. The device can be observed on the classic VAZ models, where cylindrical helical springs act as elastic elements. The rear axle beam "hangs" on them and is attached to the body by four trailing arms. The lateral jet thrust dampens roll and improves handling. The design does not provide good comfort and a smooth ride due to unsprung masses, and a massive rear axle, but it is relevant when attaching the main gear housing, gearbox and other massive parts to the beam.

7. Semi-independent rear. It is widely used in many four-wheel drive vehicles, and consists of a pair of trailing arms, attached in the center to the cross member. This suspension has the following advantages:

• Compact size and relatively light weight;
• Ease of repair and maintenance;
• A noticeable decrease in unsprung masses;
• The best wheel kinematics.

The main disadvantage of the suspension is the impossibility of installing it on rear-wheel drive cars.

8. Pickups and SUVs. Depending on the purpose and weight of the car, there are three types of suspension:

• Independent front and dependent rear;
• Completely independent;
• Completely addicted.

In most cases, a spring or spring suspension is installed on the rear axle, interacting with rigid one-piece axles. Springs are used in heavy jeeps and pickups due to their ability to withstand an impressive load, unpretentiousness and reliability. Such a suspension is inexpensive in cost, which influenced the equipping of some budget cars with it.

The spring circuit is long-stroke, soft, and not complicated in structure, therefore it is installed more often on light jeeps. Spring and torsion circuits are installed on the front axles.

9. Trucks. The trucks are equipped with dependent suspensions with longitudinal and transverse springs, and hydraulic shock absorbers. This scheme is as simple and cheap to manufacture as possible. But at high speeds, the driver is faced with poor handling, since the springs do not perform well the function of guiding elements.