The chassis of a car is a complex of components and mechanisms, the main purpose of which is to move the vehicle while dampening vibrations, shaking and other factors that negatively affect the level of comfort.
Elements of the vehicle's chassis unite the body and wheels of the vehicle, reduce swaying, receive and ensure the transmission of acting forces.
As the car moves, people in the cabin experience various types of vibrations:
The role of “absorbers” of rapid vibrations are seats, rubber mounts (gearbox and engine), as well as other “softening” elements.
The elements of the vehicle's chassis - suspension units, tires and others - protect against the second type of vibrations (slow).
Structurally, the chassis of the machine includes:
Below we will consider each component from the perspective of functions and features in detail.
The type of connection between the wheels and the car body deserves special attention.
People who have ridden a wooden cart at least once in their lives have experienced the “charms” of moving on uneven surfaces.
This is easy to explain, because the wheels of this vehicle sit rigidly on the “base”, and potholes and holes are transmitted to the “passengers”.
On TV you can see a picture where, as the speed increases, the cart literally falls apart.
The reason is precisely the rigidity, due to which the elements of the chassis receive a huge load.
To extend the service life of modern vehicles and increase the level of comfort of “riders,” the body part and wheels of the car do not have a rigid connection.
This is easy to confirm if you lift the vehicle a certain distance from the ground and pull the wheels - they will move freely and sag slightly.
This is due to a special type of fastening using special springs and levers.
The group of mechanisms that provide “flexible” connection refers to the suspension.
Its elements (springs and levers) are made of metal and have a certain level of strength.
But during the manufacture of a car, a certain margin is provided, allowing the wheels to move in relation to the body part in certain planes.
To be more precise, freedom of movement of the body is ensured in relation to the wheels moving on the road surface.
Suspension is an element of the car’s chassis, which can be of two types:
The disadvantage of rigid fastening is obvious. Almost all unevenness of the road surface is transmitted to the car body, and then to the people in the cabin.
Only the tires that take the “blow” act as a savior. With this design, the body swings more strongly and with higher acceleration.
Adding an elastic component (springs or springs) to the design of the chassis allows you to more effectively absorb impacts from uneven road surfaces.
The disadvantage is that the car begins to sway, and the vibrations themselves persist for a long time. As a result, the car is less controllable and movements become dangerous.
A car with this type of suspension will sway in all directions, which increases the risk of a breakdown. It can occur if two components coincide - a shock from the road surface and suspension operation due to prolonged vibration.
Today, the chassis elements are more thought out. The design of the suspension includes not only elastic, but also damping units - shock absorbers.
The task of the latter is to control the operation of the spring and dampen excessive oscillatory movements.
After hitting a bump, the spring is compressed, and during the expansion process, most of the energy is absorbed by the car's shock absorber.
It prevents the spring from stretching beyond its intended length. As a consequence, the oscillatory process is limited - on average, one 0.5 to 1.5 cycles.
There is an opinion that the quality of contact with the road surface depends only on tires, elastic and damping units (shock absorber, springs).
In practice, additional elements of the chassis that interact with each other and the kinematics of the guide devices are no less important.
Thus, to ensure a sufficient level of safety and comfort, the following elements must be located between the body and the covering:
We looked at the main elements of the car's chassis, which are structurally different from each other on different car models, but ultimately serve the main purpose - to ensure comfortable and safe movement of the vehicle.
The chassis is a connecting chain running from the wheels to the body. The chassis of the car absorbs all the unevenness of the road surface. Thanks to this unit, the driver may not even feel collisions or hitting minor bumps. And in order for you to feel only comfort while driving throughout the entire operation of the vehicle, you need to know what the structure of the vehicle’s chassis is and from time to time check the condition of all parts of this unit. In this article I will try to explain in the most accessible way for every driver, regardless of experience, what it is and what elements and components are associated with this part of the car.
There is a very big recommendation for drivers: always listen for knocks, squeaks or malfunctions of the car. This will allow you to contact a service station at the right time and fix the problem that has just appeared. This is especially true for the chassis, since it is the shell that keeps the vehicle moving.
The chassis structure consists of the following elements:
The chassis may also include other, additional elements, but it is these parts that play the main role in creating comfort and ease of control. Each of these elements performs a separate function, but their work is designed to minimize vibration, oscillation, and shaking of the vehicle while driving. This is the chassis diagram.
The frame and body are the backbone of the entire mechanism, since it is to it that the main elements of the vehicle suspension are attached. The frame is a direct element that takes part in the formation of the chassis. As a rule, it is generally accepted that frames do not belong to passenger cars. They are commonly seen on trucks. For passenger cars, it is customary to use the word “body”. And it is to the body that all other parts that relate to such a thing as the chassis of the car are attached. All other elements are connected to the frame.
In order for the body to withstand all the hardships of our roads, some of its elements must be made of durable iron. In other areas, profile sheets can be used as cladding, as they are highly resistant to corrosion.
Suspension and its purpose: it is this element of the chassis system that allows the driver to more smoothly tolerate all the unevenness of the road surface. The suspension is used to soften or dampen vibrations, the appearance of which is provoked by unevenness on the surface of the roadway. This occurs due to the fact that the suspension eliminates rigid adhesion between the wheels and its body, at the expense of other parts. 
Depending on the type or version of suspension installed on your vehicle, these bumps may not be noticeable to the driver. The service life of the suspension is long, but how long the suspension of your car will last depends only on you. In order to extend this period as long as possible, you need to operate the vehicle in accordance with the requirements and from time to time carry out diagnostics not only of the suspension components, but also of all components and parts of the vehicle.
Today it is customary to distinguish between two types of suspension: independent and dependent. Vehicles with dependent suspension have rear wheels connected to each other by a special connecting beam. The suspension of vehicles whose wheels are not connected by a beam is called independent. 
Axles not only connect two wheels, but also perform a supporting function for the vehicle frame. They can be attached to the car, directly to the frame itself (on a truck) or to the body, in the case of a passenger vehicle.
Considering the fact that bridges must support the entire weight of the car, as well as passengers, they are made only from durable iron. In addition, they must be treated so that these parts are resistant to any irritants, especially metal corrosion.
It's no secret that these parts of the car are the first suspension elements that feel the whole situation on the road. It is the wheels that fall into holes and run over hills. Therefore, first of all, they suffer. Depending on how you operate the vehicle, the service life of the wheels and related parts directly depends. The rougher its exploitation, the shorter this period will be. To preserve your suspension, you need to take good care of your vehicle, be sure to undergo timely maintenance and listen to the car’s performance, so that in the future you don’t have to spend money on repairs and such precious time.
The main role in creating a comfortable ride is played by the suspension. This device dampens vibrations arising from uneven surfaces.
The chassis allows the car to move, while creating comfortable conditions for the driver and passengers. Knowledge of the system as a whole, the scheme of its operation and its component elements is not necessary for every driver, but if you know all this, it will help you control the car correctly and cope with any difficulties that arise on the road. The structure of this part is not as complicated as it seems; any specialist at a service station or even a familiar driver can tell you about it, but it is better to refer to the manual for your car to know the details of your particular model. Good luck and take care of your car!
After watching the recording, you will learn how the steering system of a car functions and what elements it consists of.
Car owners often do not carefully select a service center for repairs or routine inspection of the car. But in vain. After all, a master is a kind of doctor for a vehicle. One wrong step or an incorrectly established “diagnosis” - and the car will go into a long “coma”. And this will lead to even greater costs and inconvenience. You should be especially whimsical when repairing a running car. Without this unit, the car would not be able to move, since the power unit, together with the transmission and drive, would not be able to transmit torque.
Still looking for a reliable service station? Then we recommend that you pay attention to the car repair service in Moscow “Autoclinica” - http://www.autoclinica.ru/. Here, first-class craftsmen will take care of your car at the highest level. No overpayments or incorrect “diagnoses”. You will be informed about the details of the problem and suggested a method to solve the problem. All breakdowns are repaired quickly and efficiently.
The chassis is a connecting chain that goes from the wheels to the body itself. This unit of the car takes on all the road bumps along the way. If the chassis is properly adjusted, the driver of the car may not feel any discomfort while driving, even when driving off-road. Therefore, to fully operate the car, you should know the basic characteristics of the unit and at least its basic structure. In this article we will tell you what you should pay special attention to.
The design includes the following elements:
In general, the chassis can be supplemented with other components. But the elements presented above are considered the main ones. They are responsible for comfort and ease of control. Any of these components performs its function, but in tandem they provide:
Every detail must be lined up correctly. This is the only way to achieve ideal results. And repair of the car chassis, as in the link - http://www.autoclinica.ru/page/Remon-hodovoy.html, will occur much less frequently.
This type of design, on the one hand, is considered obsolete, but is still used quite widely. This is especially true for trucks, full-size SUVs, as well as ordinary passenger cars. In car design, dependent suspension has become widespread due to its simplicity and reliability.
This design is divided into 2 types: spring and spring. In the first type, the main element is a spring, which consists of a complex package of sheets of special spring steel. They are slightly bent into an arc. The lugs are attached to the frame of the machine, and the center is connected to the axle. Vehicles use two springs, which are installed closer to the wheels. They have a springy structure and absorb all imperfections in the road surface.
The operation of the spring suspension is based on the use of coil springs. The design is more convenient, as it has significantly reduced dimensions. This includes a system of traction and levers, which, thanks to the hinges, act as a connecting link between the body and the axle of the car.
This type is characterized mainly by the fact that all wheels have a personal fastening and a system for damping various vibrations. In this case, there is no transmission of motion between the four wheels. In fact, independent suspension eliminates the axle.
The most widely used design is the McPherson type. This type of pendant is very simple. The work is based on the fact that the hub is connected to the body using hinges thanks to levers. The types of such levers and location may vary. There are A-shaped structures, single, connected from two parts, lower and upper. The simplest car suspension consists of 1 lower arm.
Based on the type of design, certain types of faults are distinguished. In dependent suspensions, the shock absorber often suffers due to oil leakage or mechanical damage. Rubber elements also wear out and springs or springs are destroyed. With independent suspension, the breakdowns are almost the same. With regular use of vehicles with intense loads, the rate of chassis failure increases. Therefore, find a reliable service station in advance.
Let's immediately deal with the topics without delay . Moreover, the topics are quite interesting, although this is the second one in a row about cars. I’m afraid the female readership and pedestrians don’t quite like this, but that’s how it happened. Let’s listen to the topic from :
“How do car suspensions work? Types of pendants? What determines the ride roughness of a car? What is a “hard, soft, elastic…” suspension?”
We'll tell you... about some options (and oh, how many of them actually turn out to be!)
The suspension provides an elastic connection between the car body or frame and the axles or directly with the wheels, softening the shocks and impacts that occur when the wheels hit uneven roads. In this article we will try to consider the most popular types of car suspensions.
1. Independent suspension on two wishbones.
Two fork arms, usually triangular in shape, direct the rolling of the wheel. The swing axis of the levers is parallel to the longitudinal axis of the vehicle. Over time, double-wishbone independent suspension has become standard equipment on cars. At one time, it proved the following indisputable advantages:
Low unsprung weight
Low space requirement
Possibility of adjusting vehicle handling
Available with front-wheel drive
The main advantage of such a suspension is the ability for the designer, by selecting a certain geometry of the levers, to rigidly set all the main setting parameters of the suspension - changing the wheel 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 represents 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 determines the very wide distribution of such suspension on sports and racing cars. In particular, all modern Formula 1 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.
Flaws: layout restrictions associated with the length of the wishbones (the suspension itself “eats up” quite a large space in the engine or luggage compartments).
2. Independent suspension with oblique wishbones.
The swing axis is located diagonally with respect to the longitudinal axis of the car and is slightly inclined towards the middle of the car. This type of suspension cannot be installed on cars with front-wheel drive, although it has proven its effectiveness on small and medium-class cars with rear-wheel drive.
TO Mounting wheels on trailing or oblique arms 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 reason for discussion.
Advantages:
Flaws:
3. Independent suspension with swing axle.
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 pipe of the axle shaft is rigidly connected to the main gear housing, and the right pipe has a spring connection.
4. Independent suspension with trailing arms.
The independent suspension with trailing arms was patented by Porsche. TO Mounting wheels on trailing or oblique arms 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 reason 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 reactions of strong lateral vibrations of the car occurred, which could lead to loss of controllability, which, for example, is what the Citroen 2 CV model became famous for.
This type of independent suspension is simple but imperfect. When such a suspension operates, the wheelbase of the car changes within fairly large limits, although the track remains constant. When turning, the wheels tilt together with the body significantly more than in other suspension designs. Oblique arms allow you to partially get rid of the main disadvantages of the suspension on trailing arms, but when the influence of body roll on the inclination of the wheels is reduced, a change in the track appears, which also affects handling and stability.
Advantages: simplicity, low cost, relative compactness.
Flaws: outdated design, extremely far from perfect.
5. Independent suspension with wishbone and spring strut (McPherson strut).
The so-called “McPherson suspension” was patented in 1945. It was a further development of the double wishbone type suspension, in which the upper control arm was replaced with a vertical guide. MacPherson spring struts are designed for use with both front and rear axles. In this case, the wheel hub is connected to a telescopic pipe. The entire rack is connected to the front (steered) wheels via hinges.
McPherson first used the 1948 Ford Vedet model, produced by the French branch of the company, on a production car. It was later used on the Ford Zephyr and Ford Consul, which also claim to be the first large-scale cars with such a suspension, since the Vedette plant in Poissy initially had great difficulty mastering the new model.
In many ways, similar suspensions were developed earlier, right up to the very beginning of the 20th century, in particular, a very similar type was developed by Fiat engineer Guido Fornaca in the mid-twenties - it is believed that McPherson partially took advantage of his developments.
The immediate ancestor of this type of suspension is a type of front suspension on two wishbones of unequal length, in which the spring in a single unit with a shock absorber was placed in the space above the upper arm. This made the suspension more compact, and made it possible to pass an axle shaft with a hinge between the arms on a front-wheel drive car.
Replacing the upper arm with a ball joint and a shock absorber and spring unit located above it with a shock absorber strut with a rotary joint mounted on the mudguard of the wing, McPherson 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 extension of the axis of the shock absorber strut, so the axis of the shock absorber strut 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 shifted outward towards the wheel, which made it possible to obtain smaller and even negative values of the running-in arm.
This suspension became widespread only in the seventies, when technological problems were finally solved, in particular, the mass production of shock absorber struts with the necessary service life. Due to its manufacturability and low cost, this type of suspension subsequently quickly found very wide application in the automotive industry, despite a number of shortcomings.
In the eighties, there was a tendency towards the widespread use of MacPherson strut suspension, including on large and relatively expensive cars. However, subsequently, the need for further growth in technical and consumer qualities led to a return on many relatively expensive cars to double wishbone suspension, which is more expensive to manufacture, but has better kinematic parameters and increases driving comfort.
The rear suspension is Chapman type - a variant of the MacPherson strut suspension for the rear axle.
McPherson created his suspension for installation 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 design was used only in the front, and the rear, for reasons of simplicity and cost reduction, 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, which is why in English-speaking countries it is commonly called “Chapman suspension”. But, for example, in Germany such a difference is not made, and the combination “MacPherson rear suspension” is considered quite acceptable.
The most significant advantages of the system are its compactness and low unsprung weight. The MacPherson suspension has become widespread due to its low cost, labor-intensive manufacturing, compactness, and 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 leaf springs. In the past, coil springs were preferred over leaf springs. Later, in 1985, the first production Corvettes were again equipped with a suspension with transverse springs made of plastic. However, in general, these designs were not successful.
7. Independent spark plug suspension.
This type of suspension was installed on early models, 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 housing. A coil 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 passenger car suspension these days. It is characterized by simplicity, low cost, compactness and relatively good kinematics.
This is a suspension on a guide post and one wishbone, sometimes with an additional trailing arm. The main idea when designing this suspension scheme was not controllability and comfort, but compactness and simplicity. With fairly average performance, multiplied by the need to seriously strengthen the place where the strut is attached to the body and the rather serious problem of road noise transmitted to the body (and a whole bunch of other shortcomings), the suspension turned out to be so technologically advanced and was so liked by the assemblers 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 suspension of the rear wheels is usually called “Chapman suspension”. This pendant is also sometimes called the term “candle pendant” or “swinging candle”. Today, there is a tendency to move from the classic MacPherson strut to a design with an additional upper wishbone (the result is a kind of hybrid of MacPherson strut and wishbone suspension), which allows, while maintaining relative compactness, to seriously improve handling characteristics.
Advantages: simplicity, low cost, small unsprung masses, a good design for various layout solutions in small spaces.
Disadvantages: noise, low reliability, low roll compensation (“dive” during braking and “squat” during acceleration).
8. Dependent suspension.
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 springs with 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 basic principle is that the wheels of one axle are connected to each other by a rigid beam, most often called a “bridge”.
In most cases, if you do not touch on exotic schemes, the bridge can be mounted either on springs (reliably, but not comfortable, rather mediocre controllability) or on springs and guide arms (only slightly less reliable, but the comfort and controllability becomes much greater) . Used where something really strong is required. After all, nothing stronger than a steel pipe, in which, for example, drive axle shafts are hidden, has been invented yet. It practically never occurs in modern passenger cars, 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, etc.), but the trend towards a general transition to independent circuits is visible to the naked eye - controllability and speed are now in greater demand than the “armor-piercing” design.
Advantages: reliability, reliability, reliability and once again reliability, simplicity of design, constant track and ground clearance (on off-road this is a plus, not a minus, as for some reason many believe), long travel, allowing you to overcome serious obstacles.
Flaws: When working off uneven surfaces and in turns, the wheels always move together (they are rigidly connected), which, coupled with high unsprung masses (the axle is heavy - this is an axiom), does not have the best effect on driving stability and controllability.
On a transverse spring
This very simple and cheap type of suspension was widely used in the first decades of automobile development, but as speeds increased, it almost completely fell out of use.
The suspension consisted of a continuous axle beam (driving or non-driving) and a semi-elliptical transverse spring located above it. In the suspension of the drive axle there was a need to accommodate its massive gearbox, so the transverse spring had the shape of a capital letter “L”. To reduce spring compliance, longitudinal reaction rods were used.
This type of suspension is best known for the Ford T and Ford A/GAZ-A cars. This type of suspension was used on Ford vehicles up to and including the 1948 model year. GAZ engineers abandoned it already on the GAZ-M-1 model, created on the basis of the Ford B, but which had 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.
This is the most ancient version of the pendant. In it, the bridge beam is suspended on two longitudinally oriented springs. The axle can be either driven or non-driven, and is located both above the spring (usually on cars) and below it (trucks, buses, SUVs). As a rule, the axle is attached to the spring using metal clamps approximately in its middle (but usually with a slight shift forward).
A spring in its classic form is a package of elastic metal sheets connected by clamps. The sheet on which the spring mounting ears are located is called the main sheet - as a rule, it is made the thickest.
In recent decades, there has been a transition to small or even single-leaf springs, sometimes non-metallic composite materials (carbon fiber reinforced plastic, etc.) are used for them.
With guide arms
There are a variety of designs for such suspensions with different numbers and locations 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 movement of the drive axle in all directions - vertical, longitudinal and lateral.
More primitive options have fewer levers. If there are only two levers, when the suspension operates they warp, which requires either their own compliance (for example, on some Fiats of the early sixties and English sports cars, the levers in the spring rear suspension were made elastic, plate-like, essentially similar to quarter-elliptical springs) , either a special articulated connection of the arms with the beam, or the flexibility of the beam itself to torsion (the so-called torsion bar suspension with conjugate arms, still widespread on front-wheel drive cars
Both coiled springs and, for example, air cylinders can be used as elastic elements (especially on trucks and buses, as well as lowriders). In the latter case, a strict command of the movement of the suspension guide vane in all directions is required, since pneumatic cylinders are not able to withstand even small transverse and longitudinal loads.
9. Dependent suspension type "De-Dion".
The De Dion-Bouton company in 1896 developed a rear axle design that made it possible to separate the differential housing and the axle. In the De Dion-Bouton suspension design, the torque was perceived by the bottom of the car body, and the drive wheels were mounted on a rigid axle. With this design, the mass of non-damping parts was significantly reduced. This type of suspension was widely used by Alfa Romeo. It goes without saying that such a suspension can only operate on the rear driven axle.
De Dion suspension in a schematic representation: blue - continuous beam suspension, yellow - main gear with differential, red - axle shafts, green - hinges on them, orange - frame or body.
The De Dion suspension can be described as an intermediate type between dependent and independent suspensions. This type of suspension can only be used 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 a continuous drive axle and implies the presence of drive 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 main gear reducer is fixedly attached to the frame or body and transmits rotation to the wheels through axle shafts with two hinges on each.
This keeps unsprung mass to a minimum (even compared to many types of independent suspension). Sometimes, to improve this effect, even the brake mechanisms are transferred to the differential, leaving only the wheel hubs and the wheels themselves unsprung.
When operating such a suspension, the length of the axle shafts changes, which forces them to be carried out with joints of equal angular velocities movable in the longitudinal direction (as on front-wheel drive cars). The English Rover 3500 used conventional universal joints, 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 released.
“De Dion” is a technically very advanced type of suspension, and in terms of kinematic parameters it surpasses even many types of independent ones, being inferior to the best of them only on rough roads, and then only in certain indicators. At the same time, its cost is quite high (higher than many types of independent suspension), so it is used relatively rarely, usually on sports cars. For example, many Alfa Romeo models had such a suspension. Recent cars with such a suspension can be called 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 of axle was first serially installed on the Audi 50. Today, an example of such a car is the Lancia Y10. The suspension is assembled on a pipe curved in front, at both ends of which wheels with bearings are mounted. The bend protruding forward forms the drawbar itself, secured to the body with a rubber-metal bearing. Lateral forces are transmitted by two symmetrical oblique reaction rods.
11. Dependent suspension with linked arms.
The linked-arm suspension is an axle that is semi-independent. The suspension has rigid trailing arms connected to each other by a rigid elastic torsion bar. This design, in principle, causes the levers to oscillate synchronously with each other, but due to the twisting of the torsion bar, it gives them a certain degree of independence. This type can be conditionally considered semi-dependent. This type of suspension is used on the Volkswagen Golf model. In general, it has quite a lot of design variations and is very widely used for the rear axle of front-wheel drive cars.
12. Torsion bar suspension
Torsion bar suspension- these are metal torsion shafts that work in torsion, one end of which is attached to the chassis, and the other is attached to a special perpendicular 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 operation of a 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. Passenger cars typically use transverse torsion bar suspensions, usually on rear-wheel drive. In both cases, the torsion bar suspension ensures a smooth ride, regulates roll when turning, provides optimal damping of wheel and body vibrations, and reduces vibrations of the steered wheels.
Some vehicles use a torsion bar suspension to automatically level itself using a motor that tightens the beams to provide additional rigidity, depending on speed and road surface conditions. Height-adjustable suspension can be used when changing wheels, when the vehicle is raised using three wheels, and the fourth is lifted without the help of a jack.
The main advantage of torsion bar suspensions is durability, ease of height adjustment and compactness across the width of the vehicle. It takes up significantly less space than spring suspensions. The torsion bar suspension is very easy to operate and maintain. If the torsion bar suspension is loose, you can adjust the position using a regular wrench. All you have to do is crawl under the car and tighten the necessary bolts. However, the main thing is not to overdo it in order to avoid excessive harshness when moving. Adjusting torsion bar suspensions is much easier than adjusting spring suspensions. Car manufacturers vary the torsion beam to adjust the driving position depending on the weight of the engine.
The prototype of a modern torsion bar suspension can be called a device that was used in the Volkswagen “Beatle” in the 30s of the last century. This device was modernized by the Czechoslovakian professor Ledvinka to the design we know today, and installed on Tatra in the mid-30s. And in 1938, Ferdinand Porsche copied the Ledvinka torsion bar suspension design and introduced it into mass production of the KDF-Wagen.
Torsion bar suspension was widely used on military vehicles during World War II. After the war, torsion bar suspension was used mainly on European cars (including cars) such as Citroen, Renault and Volkswagen. Over time, passenger car manufacturers abandoned the use of torsion bar suspensions on passenger cars due to the difficulty of manufacturing torsion bars. These days, torsion bar suspensions are primarily used on trucks and SUVs by manufacturers such as Ford, Dodge, General Motors and Mitsubishi Pajero.
“The spring sank and became softer”:
Without the chassis, the car simply would not be able to move, since the power plant, along with the transmission and drive, would simply have nowhere to transmit torque.
The chassis of the car includes wheels, which perceive this torque, rotate and move the car. However, this is not the main task of the chassis. The car does not move on a perfectly flat surface; there are always bends, protrusions, potholes, holes, etc. on the road.
If the wheels were attached to the car body or frame without suspension - the second component of the chassis, then there would be no need to talk about comfort - almost all irregularities would be immediately transmitted to the body, only slightly lowered by the pneumatic tire of the wheel. So the chassis not only drives the car, but also provides comfort by reducing oscillatory movements from the wheel to the body.
Suspension that reduces oscillatory movements began to be used even before the appearance of the car itself. Some carriages were equipped with elements made of springy sheet steel. These elements consisted of two steel arcs, hingedly connected to each other. The upper arc was attached to the carriage itself, and the lower one to the axle of the wheels. When moving, these springy arches were partially absorbed from the wheel axis. The suspension of the carriage became the prototype of the dependent suspension of the car.
The essence of the suspension itself is the possibility of vertical movement of the wheel relative to the body or frame when driving over uneven surfaces. Thanks to the suspension elements, the impact that the wheel receives from the road surface is not transmitted to the body, but is absorbed. That is, the wheel mount in the car is not rigid relative to the body.
In total, two types of suspension are used on vehicles - dependent and independent. At the moment, this type of suspension, such as dependent, is considered somewhat outdated, but it is still used quite widely on trucks, full-size frame SUVs and ordinary passenger cars. Dependent suspension has received such application in transport due to the simplicity and reliability of the design.
The main element of this pendant is. It consists of a package of spring steel sheets, slightly bent into an arc. Moreover, this package often has a pyramidal shape. The ends of the spring are attached to the car frame, and the axle is attached to its central part. Each car uses two springs, installed closer to the wheels. These springs, thanks to the springy steel, absorb road unevenness, allowing the wheel to move relative to the body.
Rear dependent suspension of a front-wheel drive car
However, this also has a negative quality - the work of the spring is accompanied by inertial oscillatory movements. That is, when the spring perceives unevenness in the road, it receives energy, which leads to its oscillatory movements. And although over time the amplitude of the vibrations will decrease until it fades, they will be transmitted to the frame. The car will sway even on a smooth road after passing a bump.
To significantly reduce the oscillation time of the spring, shock absorbers are included in the suspension design, which absorb oscillatory energy. To put it simply, the shock absorber stops the spring after an unevenness, preventing it from rocking the car.
There is another type of dependent suspension - spring. This suspension uses coil springs instead of springs. They are more convenient to use because they have significantly smaller dimensions.
But there are also some nuances here. If the spring itself acted as a fastening element connecting the frame to the wheel axle, then the spring cannot act in such a capacity. Therefore, the design of the spring suspension includes a system of rods and levers that pivotally connect the body to the axle (beam, bridge).
A spring, like a spring, also receives inertial oscillatory movements as a result of the impact on it, so such a suspension could not do without the use of shock absorbers.
There were other types of dependent suspension, for example, but they were not widely used in vehicles.
The main disadvantage of a dependent suspension is the partial transfer of the movement of one wheel relative to the body to the second. The wheels are fixed to the axle, and it transmits these movements. Therefore, dependent suspension is not very suitable for installation on a steered axle.
But it is still widely used on the rear axle, both driving and driven. On frame SUVs of the latest generations, spring suspension is still found. Spring suspension is often used on passenger front-wheel drive cars. Moreover, the technical characteristics of a car do not always indicate that the rear suspension is dependent; it is often called a spring-loaded beam.
Independent suspension
The second type of suspension is independent, characterized by the fact that each wheel of the axle has its own fastening and vibration damping system, which does not transfer the movement of one wheel to the other. In fact, in an independent suspension there is no wheel axle (beam, bridge) as such.
The most widely used type is the “McPherson” type. The design of such a suspension is quite simple - the wheel hub is hinged to the car body using levers. The types of these levers and their location may vary. There are A-arms, single, double, lower and upper. The simplest independent suspension consists of one lower control arm.
MacPherson strut suspension
Additionally, the hub is attached to the body with a shock absorber strut, which also serves as a steering knuckle. The main elements of this strut are a coil spring and a shock absorber. The strut itself is a housing in which the shock absorber is placed, and a spring is located on top of the strut.
At the top the rack rests against the body. Between them there is a rack cushion, on which it rests. A thrust bearing installed inside allows the rack to rotate around its axis. This makes it possible to turn the wheel.
No matter how well the shock absorber strut works, there is the possibility of transmitting vibrations to the body. This may result in lateral sway of the body. To prevent this from happening, the design includes an anti-roll bar that connects both wheel suspensions. By working in torsion, this stabilizer dampens lateral vibrations.
These are the main elements of an independent suspension. But there are also a large number of auxiliary elements that you cannot do without. Such an element, for example, is the counter cushion. These also include all rubber elements:
All of them are also involved in damping vibrations. Silent blocks, ball joints and bushings are placed wherever the suspension elements are connected - arms with the body and hub, anti-roll bar with hubs and subframe, etc.
Since the suspension, no matter what it is - dependent or independent, moves the wheels relative to the body and dampens all vibrations, it experiences significant loads, leading to failure of one or another element.
In dependent suspension, the most common malfunctions are loss of shock absorber performance due to oil leakage and physical damage. It is also often necessary to change all the rubber elements that are also present in this type of suspension. Over time, the rubber component “aging” occurs - it shrinks and begins to delaminate. It is quite possible that the springs or springs may be destroyed; due to significant loads, they may burst.
In the independent suspension the faults are the same:
Therefore, you need to constantly monitor the suspension, promptly replace consumables, and monitor the condition of shock absorbers, springs and springs.
