Detachable connections: photo, drawing, examples, installation. Types of detachable and permanent connections

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

In mechanical engineering and instrumentation, not only the parts that are used in production, but also their connections play a very important role. It would seem that everything should be extremely simple, but in fact, if you delve into this topic, you will find that there are a huge number of different compounds, each of which has its own advantages and disadvantages.

This article will describe detachable connections - you will learn about exactly what they are, where they are used. They will also be compared with permanent connections.

At the moment, you can hardly imagine what all this means in general, so you should not immediately plunge into not the most simple nuances. Before considering detachable connections in detail, you should understand what they are in general, that is, understand the basic classification of these parts in production.

Classification of compounds

If you take everythingtypes of connections, they are divided into two main groups:

• fixed;
• movable.

It is easy to understand that if the connection belongs to the first group, it means that two parts are fastened with its help so that they are static in relation to each other and do not move. They can move as a whole in the mechanism, but they are “tightly fastened” to each other.

As for the second group, here we are talking about such a mount that allows two parts to move relative to each other during the operation of the mechanism, while remaining connected to each other.

Mobile connections are already divided into detachable and non-detachable. The first subgroup describes those that can be opened at any time in any way, while the second group includes those that can only be destroyed - with the use of force, but without the possibility of restoring the connection. Most often, such connections function until they wear out, after which they are simply replaced.

But it's time to get back to the first big group - fixed connections. There are also two subgroups here - detachable and one-piece connections. In principle, it makes no sense to repeat their description, since it remains the same as in the case of mobile connections.

Now that you've seen the basic classification, it's time to focus on the main topic of the article. Detachable connections will be described in as much detail as possible, indicating all the main types that can be found in production.

Threadedconnection

Types of detachable connections are numerous, but among them the most famous for everyone, most likely, will be threaded. Even if you don't work in manufacturing, you've definitely ever used a bolt or screw to attach a chair leg or something.

This type of connection is characterized by the presence of a thread, which provides fasteners, and, if necessary, the parts can be disconnected - that is why this type belongs to detachable. The threaded group can be divided into 2 subgroups, which are slightly different from each other:

1. One type of such a connection may involve the use of two parts, each of which has a corresponding thread, due to which the bonding occurs. However, this option is not always used.
2. In everyday life, you most likely came across exactly the second option, when two parts are fastened together by means of an additional threaded element, such as a bolt, screw or stud.

This type has a lot of advantages - it is considered reliable, it is used everywhere, it is universal, parts are interchangeable in it, and it is also high-tech.

But, of course, there are also disadvantages - for example, such a connection can unwind under certain conditions, so it must be constantly monitored. Also, fastener holes cause a concentration of stress in one area, which can lead to overload. And, of course, such a connection is notprovides tightness. All this would be bad if this type was the only one, but, fortunately, there are other types of detachable connections, which will be discussed now.

Pin connection

What other detachable connections are there? Photos in thematic books and magazines always show mainly the threaded version, since it is the most massive and widespread. But there is another no less popular - pin. It differs from the previous one in that it has no thread.

A pin is a piece that fits tightly into a hole that goes through both pieces that you need to fasten. As a result, they stay in one place and are securely attached to each other. If you find it difficult to imagine the described option in mechanical engineering, then you can imagine something more mundane - for example, a visit to the dentist. There are also special pins that are inserted into the gum, and then a filling or crown is made on them. As you can see, examples of detachable connections can be found in absolutely all areas of life.

Keyway

This is the first connection type in the list that is movable. Most often it is used to transmit rotational motion. How exactly does it function? Installation of detachable connections of this type is quite simple - there is a shaft for transmitting rotation, in which there is a groove where a key can be inserted. On the hub to which the shaft is attached, there is a groove into which the key enters,which ensures the transfer of rotation.

Everything is extremely simple and effective - in fact, you can hardly imagine a connection that is easier to assemble and dismantle. And even more pluses in the piggy bank of the dowel are added by the low cost. But at the same time, it is not difficult to guess that the grooves with keys weaken the overall strength of the entire structure, and also generate excessive stress concentration.

But in general, this compound is also extremely common, and you will find it in many mechanisms. So if you are asked about which connections are detachable, then you can safely name those that you have already learned about from this article - they are the most popular. But do not think that the enumeration ends here - ahead of you are still a wide variety of types of connections that are used everywhere in production and even in everyday life.

Spline connection

A spline connection is also called a gear connection, since the contact and fastening of parts in it is carried out due to the teeth located along the length of the shaft, while in the part encircling it there are grooves for all these teeth. The main advantage of this type is its great strength, however, special attention should be paid to the fact that with such a connection, the shaft remains able to move along the entire length of the encircling part if necessary. In many ways, this is the difference between detachable and one-piece connections. The drawing of such fasteners is always quite simple, so everyone can easily figure it out.

Onlysuch fastening is rarely found in everyday life, most often it is observed in mechanical engineering and other types of production. The spline connection has a broad classification, which includes division into groups:

• in the shape of the teeth;
• according to what load is transmitted through them to the encircling part;
• on centering mating parts;
• on mobility, etc.

As you can see, this is one of the clearest examples of the fact that some types of detachable connections can belong to two large groups at once, that is, both movable and fixed.

Bayonet connection

You have already learned that a detachable connection is one that allows you to detach the parts that are fastened together if necessary. The bayonet connection is also detachable and can be seen quite often.

It looks unusual - one part has some kind of protrusion, and the other has a special groove into which the protrusion does not just go in, it is attached by pressing and turning, which makes the connection much more durable. The areas of application of mounts are very diverse - from mechanical engineering and electronics, to kitchen appliances and cameras. So there's a pretty high chance you've come across this fastener option before.

Terminal connections

Detachable connections also include terminal connections - they serve to connect the shaft to the hub, but in this caseprocess in a rather unusual way. The fact is that the hub has one or two cuts into which a bolt or other fastener is inserted. When it is fixed, the hub is pulled together, tightly pressing against the shaft inside it. This is a fairly simple compound that is used quite often and in many areas of activity.

It is especially worth highlighting the fact that in most cases, these connections used to fasten the shaft and hub - such as keyed or splined - allow you to fasten parts exclusively coaxially. However, the terminal type allows you to connect them at various angles, as well as mount on any part of the shaft. A drawing of a detachable connection of this type necessarily includes the designations of all these important points.

Cone connection

This type of connection also uses contraction as the main fastening force, like the previous one. However, this time a slightly different approach is used. Its principle of operation is difficult to explain in words, since the hub in this case is a relatively complex mechanism with several built-in elements that, when the key is turned in the holes made specifically for this purpose in the hub, narrow the main hole into which the shaft is inserted.

If this explanation does not seem clear to you, then it would be easiest to imagine an old drill with interchangeable drills - it is precisely such a conical mount that is used there. You insert a special key, spread the fasteners apart, insert the desired drill and fix itby turning the key again. However, such a connection is used not only in drills, but also in many mechanisms in production.

Profile connection

Well, the last popular detachable connection is profile. It differs from all the previous ones in that it has neither keys, nor teeth, nor threads, nor any other fasteners. The fact is that the parts in this case are fastened by combining them with each other so that as a result they form a common inextricable surface. Simply put, they are attached so that they fit snugly together, while forming a strong connection.

Its main advantage is its incredible simplicity and the complete absence of any third-party elements that cause excessive stress concentration in other types of fasteners. But this type of connection also has its drawbacks, such as high contact stress or large spread of force.

Earlier we said that this article will describe the types of detachable and one-piece connections. And although the first ones were mentioned as the main topic of the material, we should still consider the main, most popular, one-piece fasteners.

Permanent connections

Connections that cannot be disconnected with or without the use of tools are few and far between. First of all, it is worth noting the welded joint, which is used almost everywhere in production. Everyone can imagine the welding process, for which a special device is used, which strongly heats up the metal of both parts inattachment point. Then, as it cools, this metal mixes, forming a weld that can no longer be separated just like that - only by destruction.

Another type that functions quite similarly to the first is soldering. To create a solder joint, you also need a special device - a soldering iron. It feeds a special material to the attachment point, and this material has a lower melting point, due to which the parts remain intact, but they are connected to each other due to this material. This method is used when parts cannot be deformed, changed, that is, welding is not suitable for them.

If we are not talking about working with metal, then a glued joint is often used - this type is known to absolutely all people, since you most likely used glue at least once in your life to connect two parts to obtain a single immovable whole. Exactly the same thing happens in production, only on a much larger scale.

Well, one more permanent connection worth mentioning is fastening with rivets. This type is used quite rarely and was popular earlier. Its essence lies in the fact that fastening materials prepared in advance, which are called rivets, are also inserted into the holes prepared in the details. Then the riveting process takes place - the rivets are processed in such a way that they firmly connect the parts to each other, and it was no longer possible to separate them. However, you can imagine how costly and time-consuming such a process was. That's whynow riveting is used extremely rarely, and rivets in modern times can be seen much more often as decorative ornaments on shoes, clothes, and so on.

That's all the main types of industrial connections - both detachable and one-piece. Of course, there are many more of them - especially if we talk about obsolete types that are practically not used now. There are also those fasteners that are not very common, are used in a specific area and are not particularly popular to be mentioned separately. But we can safely say that even this number of connections is enough to be able to choose exactly the one that would be most suitable for a particular task and give maximum strength and ideal fulfillment of all requirements.