The evolution of the car is developing in two main directions. Improving economic and operational characteristics and increasing driver and passenger comfort. Udachnoe constructive solution satisfies both criteria. For example, torsion bar suspension. It was tested on Volkswagen car Beetle in the distant 30s of the last century. The system has successfully taken root in the automotive industry and has survived to this day.
What is a torsion bar?
Directly translated from French, the word “torsion” means twisting. It is this effect, or rather the ability of a metal part with special elastic properties to return to its original position, that was the reason for its use in the designs of many machines. The part is a steel segment of a round or profile shape. Sometimes a set of individual plates with specific characteristics is used. The types, operating principles and characteristics of the mechanism will be discussed below.
Principle of operation
Before the advent of independent suspension designs, the torsion bar was the most effective way ensuring elastic contact of the wheel with the road surface. However, designers do not stop improving this mechanism to this day. Therefore, you can meet him at very prestigious and expensive models. The reason for such longevity was the operating principle:
- Changing the position of the wheel activates a mechanism, part of which is the torsion bar. Under the influence of force, it twists.
- The tension is maintained during the action of the force lifting or lowering the wheel.
- The load is softened and transferred to the power part of the body, protecting it from harsh impacts.
- When the external force stops, unwinding to its original position, the torsion bar returns the wheel to its basic state.
In fact, the function of a spring is performed, but the qualitative difference is significant.
The dynamics of elasticity increase are higher and more comparable to a spring, in which shorter lamellas are sequentially activated. But the torsion bar is simpler and more reliable. Significantly more compact and efficient.
Torsion bar suspension device
The unique spring properties of a special grade had to be used in a real product. Absolutely all torsion bar suspensions operate according to a single algorithm. And here practical implementation they can be structurally different without violating the circuit diagram:
- One end is rigidly fixed to the body. Cars with torsion bar suspension are designed taking into account the powerful impact at the mounting point. The power frame is designed for these loads.
- The torsion bar is movable at both ends. This is ensured by bearings and spline connections, which compensate for geometric changes during operation.
- Being the most important part of the car's design, the torsion bar suspension device provides the necessary qualities for contact with the coating. Vertical mechanism freewheel wheels thus acquires optimal values.
Design solutions for individual suspension elements can differ significantly from each other in different models. The initial task was shock mitigation, tested by wheels, on the body. It is customary to divide the designs of torsion bar suspensions relative to the movement of the vehicle into two types:
- Longitudinal. The torsion bar is located parallel to the movement of the car. Most often used for front wheels.
- Transverse. The size is limited by the width of the car. More complex design and more often used in rear suspension together with other elements of stabilization and wheel control.
Whatever the design of the torsion bar suspension, it successfully copes with the assigned tasks:
- Ensures smooth running.
- When turning, it optimizes the position of the wheels and, through rigid attachment to the body, stabilizes the roll;
- Effectively dampens body vibrations when driving over uneven surfaces:
- Eliminates wheel vibration when quickly changing their position.
Modern car brands are equipped with a new generation of torsion bar suspensions, automatic devices, where the electronics sets the required elasticity of the beam by changing its base position.
Advantages and disadvantages
The experience of using torsion bars has exceeded 80 years, but manufacturers are in no hurry to abandon its use. The reasons are the following:
- Compactness. Small dimensions allow you to increase the size of other functional elements of the car, for example, the trunk.
- Possibility of adjusting the suspension. In many ways performance characteristics depend on the length, which allows you to include the necessary qualities when designing a machine.
- Inexpensive maintenance and repairs. During production, this factor also makes the car cheaper than competitors with other types of suspensions.
- Light weight. It has a beneficial effect on the service life of the machine and its efficiency during use.
- Ease of production of parts and their installation.
The advantages are obvious, but it is not always possible to achieve the tasks set for the designers solely using a torsion bar suspension. Market requirements are extremely strict. The buyer demands new quality, which is difficult to achieve with a torsion bar. So, what, first of all, hinders the use of such suspensions:
- Shaking. It is especially noticeable in the back seat. A rigid connection to the body transmits vibrations, and even torsion bar suspensions with perfect design cannot cope with them. More technologically advanced and efficient mechanisms work better, but their cost is significantly higher.
- Noise. The reason for this also lies in the inability to effectively isolate the body from vibrations due to the rigid connection. Sound insulation systems are not able to completely eliminate this drawback.
- The torsion bar cannot withstand extreme loads. Prefabricated structure, where welding is used to fix individual parts. It does not provide the strength necessary in some cases, although modern designs installed on both SUVs and freight transport, but they are complex and expensive.
- Repair. Torsion bars can burst like springs. If in simple designs replacing a part will not place an unbearable burden on the owner, then in some modern cars The suspension is not cheap, and with the high price of spare parts, you can add up considerable labor costs.
Many buyers do not think about its design features when purchasing a car. But this must be done for the reason that subsequently it will have to be maintained and repaired.
A car with torsion bar suspension will in most cases cost less, and its maintenance will also be more economical.
Torsion bar suspension repair
Typically torsion bar suspension unpretentious in operation. Caring for it is not difficult and mainly consists of visual inspection. However, when extraneous sounds or unusual response to exercise, you should immediately contact a specialist. The most common causes of failure:
- Bearing failure. Only experienced car owners can fix it on their own, and only if there is the necessary tool. The needle bearings used are very fragile. Manufacturers recommend doing planned replacements approximately every 60,000 km.
- The suspension produces excessive vibration. Most often this occurs due to weakening threaded connections. You can fix the problem yourself using the appropriate key.
- Problems with torsion bar suspensions latest generation. Fine-tuning and complexity of the mechanism leave no chance to repair the device yourself. You will have to contact a specialized workshop. It costs a lot in most cases.
The final choice of the car and its configuration naturally remains with the buyer, but the information above will certainly answer many questions regarding the chassis of the car and help you navigate correctly when choosing a car.
When planning to buy a car, you should find out the pros and cons of torsion bar suspension in order to decide whether to choose a car with this type, or turn your attention to more traditional equipment. The installation of a torsion beam is especially popular among the French - almost all Renault models, Peugeot and Citroen are equipped with it.
Often this mechanism is even called a French beam, although it is based on an idea first embodied in a machine Volkswagen Beetle(and this happened in the 30s of the last century), and the part was improved by the Czech Ledvinka and the German Ferdinand Porsche. The main part of the suspension is the torsion bar. It is an elastic metal segment designed to work in torsion.
Most often, a torsion bar is a round rod part with spline connections at the end, but it can be made from a beam or a collection of special plates. On one side, the mechanism is attached to the body or car frame, and on the other - to the lever. In motion, the torsion bar twists, which firmly connects the wheels to the body. The torsion beam can be oriented along the axis of the car (this option is used in heavy trucks), or it can be transverse - this is exactly what is mounted on passenger cars, and mainly rear-wheel drive ones.
The pros and cons of a torsion bar suspension are determined precisely by the peculiarities of its structure. Let's take a closer look at the advantages and disadvantages of this mechanical design, which has already become quite familiar and is used in many cars.
What are our advantages?
The main benefit is the compactness of this type of assembly. Due to the small size, it becomes possible to build quite large trunk and provide enough space to accommodate rear passengers- that is, space is added. A very valuable quality is also the dependence of suspension stiffness on the size of the torsion bar: the longer it is, . In addition, adjusting the hardness/softness is very simple and can be done even on your own at home, so to speak.
There is even the possibility of some adjustment of the ground clearance. Redistributing the dynamic load from the road across the entire frame of the car increases its stability and makes the car more tractable to drive and operate. In maintenance and repair, a torsion bar suspension (in most cases) is simpler and cheaper than a spring one. Its total weight is again significantly less than that of a traditional one, which has a good effect on driving efficiency and the service life of the entire vehicle (a resource is added). In the opinion of the manufacturer, the advantage of a torsion bar suspension is that it is not too expensive to manufacture and is practically easy to install.
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What went wrong?
However, no device, as a rule, can be perfect and ideal. Even the most successful engineering ideas have some unpleasant sides. Experts found the following, not entirely pleasant, disadvantages in the torsion bar suspension:
- The most basic and noted negative is the shaking in the back seat. Additional vibrations are applied to the body, which are felt very well by all rear passengers;
- High-quality sound insulation cannot be achieved even with additional measures - all for the same reason that people behind are not very comfortable;
- You will have to drive more carefully and carefully: the presence of welds and, accordingly, the presence of tension in them limit the maximum permissible load for suspension;
- Torsion bars have a tendency to burst just as well as springs. But they still cost much more significantly;
- The low cost of repairs and maintenance can also be quite relative. It already depends on design features each model. If for repair work it will be necessary to dismantle the entire beam when replacing the torsion bar (and sufficient quantity models are designed in this way), then you will be charged quite a significant bill for services. If you have the opportunity to get to the part being replaced without global dismantling, then yes, the price will be lower than for similar work with a spring suspension.
A torsion beam is a type of suspension in which a torsion bar plays the role of an elastic element. A torsion bar is a metal elastic element that works to twist. This element, as a rule, consists of a set of rods, plates or beams of a certain section. The torsion bar is attached at one end to the guide element -, and at the other - to the frame or body of the car. Thanks to the torsion bar, an elastic connection is achieved between the body and the wheel. Torsion bars are used in various types pendants: on trailing arm x, double wishbone suspension and so on. A similar principle has found application in the design of a torsion beam (suspension with interconnected levers of the right and left wheels). Due to the strong connection between the wheels greatest distribution design found in the rear suspension front wheel drive cars. Today we can safely say that the suspension rear wheels based on a torsion beam - the most common design.
A torsion beam is a hollow steel part of complex configuration, rigid in bending, but flexible in torsion. This allows the wheels to move up and down independently of each other. A torsion beam is usually attached to the body. The rigidity of the beam itself in the transverse direction should ensure a constant distance between the wheels. Additional elastic elements in torsion beam suspensions are most often springs.
History of the creation and development of torsion bar design
The prototype of the current beam is a torsion bar - a device that was first used in the 30s of the twentieth century. Later, the torsion bar suspension was improved by the Czech professor Ledvinka and the German inventor Ferdinand Porsche, who first adapted it for mass production.
Quite widely used in small cars Torsion bars were received in the 50-60s of the last century. The reason for the interest in the device is the relative ease of manufacture and compactness of these elements. Longitudinal swing arms were attached to the ends of the torsion bar, which were connected to swivel fist using ball joints or a pivot assembly.
On the Zaporozhets car, two torsion bars with a square cross-section were used as the front suspension, which were enclosed in steel pipes located one above the other; trailing arms of the suspension were attached to the ends of the pipes. The author of this design was still the same.
The design and principle of operation of a torsion beam
The guiding device of the torsion beam suspension is two trailing arms, which are rigidly connected to each other by a beam. On one side, the trailing arms are attached to the wheel hubs, and on the other, to the body. The torsion beam has a U-shaped cross-section, due to which it has low torsional rigidity and high bending rigidity. This property allows the wheels to move up and down independently of each other.
On modern cars, the torsion beam can be located transversely or longitudinally. The transverse arrangement is used on passenger cars mobile phones And the longitudinal layout is characteristic mainly of large and heavy trucks. In both versions, the torsion bar suspension provides optimal damping values for the wheels and body, ensures a smooth ride and regulates roll when turning.
On some vehicles, torsion bar suspension can be used together. Depending on condition road surface and the speed of movement, this electric motor tightens the beams to obtain the necessary rigidity.
Pros and cons of torsion beam
The main advantages of torsion bar suspensions in general are the compactness of the width of the car and ease of height adjustment ground clearance, low overall weight and, of course, durability. Torsion bar suspensions are very easy to install maintenance and operation. Such pendants are much easier to adjust than spring ones. From the manufacturers' point of view: the torsion beam is cheap to manufacture and easy to install on the car on assembly lines.
One of the most significant disadvantages: additional vibrations transmitted from the wheels to the body, contributing to low passenger comfort rear seats. And as a result, which negatively affects long-distance travel.
Operational issues
If the torsion bar suspension on a car is loose, you can adjust its position using a simple wrench. To do this, you need to get under the car and tighten the loose bolts. The main thing is not to overdo it, because overtightened bolts will cause excessive roughness when the car is moving.
Greetings, my dear car enthusiasts! In this article we have to find out: what a torsion bar suspension is, the operating principle of this design and its features.
If you dig deeper into history, you will find that torsion bar suspension was successfully used in the early, middle and late twentieth centuries, and is also often found today.
Having undergone a lot of modernizations and improvements during its existence, it has become a classic, and you can see it not only on passenger cars, but even as a tank suspension.
In fact, the design of a torsion bar suspension can be different, which we will talk about later. But be that as it may, the key element of the system is the so-called torsion bar (elastic element), hence the name.
What is this? Essentially, it is a metal rod that can have either a round or square cross-section.
The main property of a torsion bar is its high torsional elasticity, that is If you take such a rod by its two ends and twist it in opposite directions, it will naturally spring back and try to return to its original state. This property is the basis for the operation of torsion bar suspensions..
Without problems from the 20th to the 21st century
A little history. As we said at the beginning of the article, this type of pendants did not appear yesterday. More precisely, in the 30s of the twentieth century, and the first car with a similar design was the legendary Volkswagen Beetle. Udachnoe engineering solution Ferdinand Porsche noticed and adopted it in those same years.
Then, During World War II, torsion bars turned out to be indispensable in armored vehicles, and such a suspension was used in both Soviet and German cars.
IN post-war years similar systems have become a real hit - they were and remain in service with almost everyone major automakers in the world.
It's time to talk about execution options. Torsion bar suspension the operating principle of which is based on twisting, can be found in the following designs:
- on double wishbones;
- on trailing arms;
- with associated trailing arms or the so-called torsion beam.
The first two types belong to independent suspensions. In the case of wishbones, the torsion bars are installed parallel to the body.
This positioning allows you to adjust the softness of the system over a wide range - the longer the rod, the softer the stroke. It is attached with one side to the top or lower arm, and the second to the car frame.
This design is used, as a rule, on the front axle of SUVs and crossovers. For example, on a Mercedes M-Class 163 series.
In a suspension with trailing arms, the torsion bars are located transversely to the body and are also attached to the arms at one end. It is worth noting that this option is common for rear axle various small cars.
Torsion bar suspension the operating principle of which, as we know, is based on twisting, refers to the so-called semi-independent suspensions. The wheels on the axle have a rigid connection with each other, but at the same time they have the ability to move up and down separately.
The system is based on a torsion beam that connects the trailing arms of each wheel (there are two such arms in total). You can meet her at passenger cars on the rear axle.
Two sides of the torsion bar coin
Like any other, torsion bar suspension has its pros and cons. TO positive aspects systems clearly attribute its simplicity, low weight and compactness, and the small number of parts leads to reliability and ease of maintenance.
But there is also flaws. For example, worse car handling compared to cars with multi-link designs, difficulties in producing reliable elastic elements, and increased wear needle bearings, which are installed at the junction of the trailing arms and the torsion beam.
I hope, friends, that this material, torsion bar suspension, operating principle, was useful to you. I advise you to read more articles about the suspension - and the car
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See you in the future!
The torsion bar is the main element of the suspension. This is a cylindrical metal rod. Its main feature is high performance by elasticity. For its production, only strong steel is used, otherwise it will not spring back when twisted. In this case, the source material necessarily goes through a special heat treatment.
Large twist angles and high torsional stresses are easily tolerated without permanent deformation mechanical type. The cross-section of torsion bars can be round or square. In addition, they may have metal springs inside.
The operating principle of a torsion bar suspension is as follows: a torsion bar is attached to the car frame at one end. The other end is connected to the wheel hub through a special lever. A spring reaction appears when the wheel moves in a vertical plane, then the torsion bar twists. Thanks to this, the mobile chassis The car and the body form a strong, reliable connection. Hydraulic shock absorbers and coil springs make this part even more reliable. Until recently, many cars used just such a suspension system.
- Double wishbone.
The torsion bar is located parallel to the body. Thanks to which wide range You can adjust the length of this part. One of the ends of the suspension is attached to the frame of the car, and the other is attached to the wishbone. In SUV designs, such parts are often the front suspension. - On trailing arms.
The torsion bar is located in the transverse area of the body. This system mainly serves as a rear suspension. - Linked type trailing arms.
Two trailing arms become guide elements. The beam ensures their reliable connection. In cars with front-wheel drive, this is how the rear suspension is created.
Such structures are often necessary to level an automatic car. And using a motor that tightens the beams to increase rigidity.
Advantages of torsion bar suspension
- When a roll occurs, the car gains better handling.
- Easy adjustment, long service intervals
- High maintainability, reliability
- Now you can easily set the desired value for ground clearance. And there is no need to change any major parts in the design
- Weight always remains low
- Maintenance and installation are as simple as possible
- Compared to the spring system, this one has much more compact dimensions. Takes up less free space.
Tightening the mounting bolts is the main type of maintenance required by torsion bar suspensions. A simple wrench will suffice to solve this problem. But you shouldn’t tighten everything too much, otherwise the stiffness indicators will increase.
Disadvantages of torsion bars
- Oversteer. Almost all cars that have this suspension are prone to this. The driver must be especially careful when turning, because at this moment vehicle It might just turn in the other direction. On ZAZ cars at low speeds, this problem becomes especially noticeable.
- Processing and production technology of torsion bars – quite complex processes on their own. But otherwise, manufacturers cannot provide the required level of material elasticity and high strength. It cannot be done without special procedures to harden the surface, otherwise the metal will not be resistant to cracks appearing on the surface. Plastic deposits are also used. But even this does not stop those who use torsion bars to provide a higher level of comfort while moving in a wide variety of terrain.
- There are needle bearings where the arms are attached to the ends of the torsion beam. This system has a somewhat limited mileage resource. Through cracks in gaskets and seals, dirt, water and dust enter the bearings, which is why the bearings themselves fail faster. At the same time, driving intensity and style do not play a special role in this. Much more important is the impact of aggressive environments plus the aging of the rubber material.
But thanks high level modern service, the problem can be easily solved by changing only the bearings or seals. Sometimes repairs are needed, replacing the torsion beam, but this is only in the worst case scenario.
Features of the torsion system
Using torsion bars, it is quite difficult to obtain an independent suspension system that would fully provide required level comfort. Partly, it is for this reason that the parts are not yet widely used. But, if the torsion bar structure is still present, the system becomes quite free. Rotating shock-absorbing arms at the end of the beam will achieve better results.
Thanks to this solution, the user can get a smoother ride while driving and independence of the wheels. This suspension will be a particularly effective solution for big cars, where she will constantly experience quite serious loads.
Torsion bars, from the history of their development
The Volkswagen Beetle is the first car to use parts with similar functions and main purposes. It appeared back in the 20th century, in the 30s. The first modernization of the torsion bar was carried out by the Czech scientist Ledvinka. In the same 30s, torsion bars were installed on Tatra cars. By the end of the decade, the system was used everywhere and on vehicles produced by Ferdinand Porsche and his company.
The low weight of the suspension at that time became the main advantage for the Austrian engineer. It was especially in demand on cars for sports competitions and the army. For SUVs, such a detail was also not superfluous. This advantage of torsion bars remains relevant in modern world. Torsion bars with double levers were also the invention of Ferdinand Porsche. Cross rods were placed in the steel pipes of these structures. It was this part that was the so-called torsion beam.
The dependence of suspension stiffness on the length of the torsion beam is a design advantage that was used by Andre Lefebvre, an engineer from France. He then created Citroen car T.A. The suspension became softer the longer the torsion bar was. The load that appears on the road surface is distributed over the entire frame. This is achieved thanks to long shaft, located along the longitudinal axis of the entire machine.
Torsion bars were also actively used in automobile and armored vehicles, especially in wartime. And then they became more widespread, having passed the test of time. In Europe and America, this system was used by almost all car manufacturers. Quite quickly the detail gained recognition even in the Soviet Union. If the torsion bar suspension is a little loose, there is nothing to worry about. It is enough to use a regular wrench to adjust the position. It is much more difficult to work with spring structures, but here everything is simple and clear.
