Absorbing apparatus: purpose and types

Everyone is familiar with the concept of depreciation - it can be found absolutely in all spheres of life, in particular in machine building. Amortization is a process that allows you to absorb, extinguish some of the impact exerted by one body or force on another body. This principle is used everywhere: from mitigating the impact of traffic on the car to the accounting for the wear and tear of equipment in the enterprise.

However, in this article, it is not specifically about depreciation, but about a thing like an absorbing apparatus. If most people have heard about shock absorbers, then similar devices for many can be a novelty. The matter is that the absorbing apparatus is a narrowly specialized device, which is most often used in trains. In this sphere, this mechanism is very important, it is installed in all cars, but it can differ in the types of absorption. This is exactly what will be discussed in the article. What are the types of apparatuses and for what purposes can they be used in various cases?

What it is?

First of all, it is necessary to understand what an absorbing apparatus is and what it serves. So, this device is designed to extinguish or absorb (so it is called) part of the kinetic energy of impact, thereby reducing the impact of various forces, including stretching and compressing, on the frame of the car where it is installed. How does the absorbing apparatus work? Inside the device there is resistance, which ensures the conversion of kinetic force to other types of forces that do not harm the car. Therefore, the presence of such a device in the car is not a matter of choice, but an obligatory condition, otherwise the acting forces can lead to serious damage to the composition, which will lead to unfortunate consequences. As for the types of absorbing apparatus, there are quite a lot of them, but not all of them are widely distributed. In this article, the main types and their effects will be described in detail, as well as less popular types of apparatus.

Rejection of springs

Now such devices as, for example, absorbing apparatus RT-120 are widespread, however it does not use springs, as it was at the very beginning. The device has the following specifications:

• Machine type: friction.
• Maximum stroke: 120 millimeters.
• Maximum energy intensity: 90 kJ.
• Service life (before repair): 16 years.
• Total service life: 32 years.

Initially, such devices were extremely springy, but over time they were replaced by useful and convenient, as well as much more functional and efficient devices. There were several problems, and the first one was too much spring recoil. That is, they absorbed kinetic energy well, but at the same time gave it almost the same amount that neutralized their usefulness. Secondly, in order for them to function competently in wagons, it was necessary to form products quite large, it can be said cumbersome, so they were refused. Low energy intensity was the decisive factor, because other devices could be made no less effective than spring ones, but much more compact. It is for this reason that currently devices such as the RT-120 absorber are used in cars, and spring models are used exclusively in buffer devices.

Spring-friction devices

However, the fact that spring machines have not caught on practically in any area does not mean that such mechanisms have ceased to be used in this field. Simply, they were not very effective, therefore, spring-friction devices were created, which transfer the main action to frictional motions, while the springs have only an additional function, that is, they are solely responsible for potential, and not kinetic energy. We will analyze how this works. For example, the absorbing apparatus of the APE takes on the kinetic energy, which is produced by the collision of two cars. To begin with, you should indicate the technical characteristics of this device:

• Weight: not more than 165 kilograms.
• Structural stroke of the apparatus: 90 millimeters.
• Power consumption is nominal: 110 KJ.
• Energy intensity is maximum: 130 KJ.
• Initial tightening force: 230 kN.
• Closing force static: 1600 kN.
• Total service life: 32 years.
• Service life before repair: 16 years.

After the impact on the output there is not the energy of recoil of the springs, but the kinetic force of friction (that is, frictions) and the potential energy of deformation of the springs. This result proved to be more than satisfactory for the depreciation of wagons, and therefore such devices have become widespread.

Now everywhere you can meet the absorbing device 73ZW and other similar models. The technical characteristics of the device are as follows:

• Weight of the device: 214 kg.
• Structural stroke of the apparatus: 90 mm.
• Limit of operating temperatures: from + 50 ° С to -60 ° С.
• Dimensions: length - 625 mm, width - 318 mm, height - 230 mm.
• Initial tightening force: 200 kN.
• Force of closing the device: 1600 kN.

Advantages of spring-friction devices

Spring-friction devices have been installed on cars for a very long time and use them to this day. Other types of apparatus exist, but this species is one of the most common. This happens for a number of reasons. First, it's simplicity. Secondly, the installation of absorbing apparatus of this type is quite simple and convenient process. Their dimensions are much smaller than those of spring devices, so absorbing cargo wagons are easy to install and do not cause difficulties in further maintenance. In addition, of course, it is necessary to note the variability and the elementary design of these devices.

Hydraulic devices

The classes of absorbing devices are very diverse, and among them one can distinguish another very popular species. Hydraulic devices in the mode of operation are significantly different from the spring-friction ones, since they take as a basis the liquid, which ensures maximum cushioning. The device has throttling holes calibrated accordingly. The strokes serve to allow a cushioning fluid to flow through them. These holes connect two cavities, which, depending on the load, are filled through these through-passes. As a result, a uniform elastic resistance is created, which effectively works even with fairly powerful impacts.

Initially there was one small problem, which was that the liquid could not return quickly to its original position, so that such a device led to missed shots, that is, to those moments when the liquid from one cavity could not flow into another to soften the car's shaking . That is why over time, to ensure the maximum elastic resistance in the hydraulic apparatus began to use an inert gas. The repair of absorbing apparatus of this type is a little more complicated and expensive, but their use is an efficient and convenient process. The device is considered faulty if a fluid leak, a change in stroke or significant wear is detected.

How is the depreciation in hydraulic vehicles?

If we consider the hydraulic absorber apparatus of the car, then here it is worth more detailing the principle of operation of this device. How can water soften the blow? The answer to this question is given by physics, because the density and viscosity of water ensures the extinction and absorption of the kinetic energy of the impact, which is lost during the passage through the liquid, at the moment of its overcoming and ejection into the adjacent cavity through special holes. Thus, the absorbing apparatus of the coupler, wagon and any other element can be hydraulic, because it is also not too complicated. The use of inert gas in this case is not mandatory. But thanks to this substance the resistance of the liquid increases several times, and also its return to the initial state is accelerated for taking on the next blow.

Power consumption of the apparatus

If the absorbing apparatus is considered, one of its most important parameters is the energy intensity, and it is to it that you should pay attention first. This parameter represents the amount of kinetic energy that the device is able to absorb before it is completely compressed by its cushioning elements, that is, until the moment when the device can no longer absorb the impact. Accordingly, the more this indicator, the better. Springs have an extremely low energy intensity, which is why they are not used on large wagons, where the impact force very quickly compresses the spring, which absorbs too little energy. It is also worth noting that the devices are designed in such a way that the kinetic energy is not completely absorbed - there must be the right amount of energy that can return the device to its initial position. That is why hydraulic equipment uses inert gas, because it requires not so much kinetic energy to return the liquid to its original position.

Other types of apparatus

The types of absorbing apparatus described above are not the only ones - there are many more, but, as was said at the beginning of the article, only the most popular ones will be described here. So, it's worth noting the elastomeric absorbing apparatus, which also has a high popularity in various areas, including when installed in wagons. This type almost exactly copies the described hydraulic devices, but the main difference is that instead of the usual water that is throttled through the calibrated holes, these devices use a special elastomeric liquid with a much higher viscosity, which increases its energy content, but at the same time makes it more difficult Maintenance, and also increases the cost. Also friction devices, which are considered devices from elastic elements, can not be ignored. In them, the absorption of kinetic energy is realized due to deformation of the elements due to their friction. With a similar type, you are already superficially acquainted when you read about such devices as spring-friction devices.

Combined devices

Separately it is worth talking about combined devices, one example of which is almost the most common type - spring-friction. Simply put, the combined devices are those that combine different types of depreciation. In this case, they are spring and friction types. The combinations can be diverse. As mentioned in the article, the combination of the action of springs and friction elements has yielded more than a positive result. It is this combined type of apparatus for today is the most famous. In this field of activity, not all types of combination of two types of absorbing apparatus are allowed. The simplest example is the combination of elastomeric and hydraulic devices, since they are designed in a similar way and differ basically only in the liquid that is used in their maintenance.

Choice of apparatus

Which device should I choose to achieve my goal? First of all attention is drawn to the main parameter of the absorbing apparatus - their energy intensity. It makes no sense to install a high-energy device on wagons or other objects with low kinetic force of impact, since there will be high costs without increasing the productivity. Also, in no case should it be possible to install low-energy devices on objects that are subject to severe impacts, since the energy of the apparatus will simply not be enough to absorb the required amount of energy, and the impacts will be much stronger than is permissible in accordance with established norms.

Of course, there are other parameters to pay attention to, for example, stability, that is, the number of successfully amortized hits relative to their total quantity, or the amount of irreversibly outgoing energy that is completely absorbed by the absorbing device and is not used subsequently to return it to the original position. These parameters are considered individually for each project, agreed before choosing a specific type of absorbing device, in accordance with all established norms and requirements.