Hello everyone, what I want to introduce today is the linear bearing article. The linear bearing is one of the types of bearings. If you don’t know or know about bearings, you can go to the instructions at the bottom of the video. There will be an introduction to bearings. If you have After watching it, you will have a better understanding of the bearing. Today , it is in this way. In fact, there are different types and categories of linear bearings. What type of linear bearings does it belong to? The most important thing is that it does reciprocating linear motion, so the linear bearings used are from Literally, it can be known that it is a linear motion. Today, I will use this kind of action simulation to see what types of linear bearings are there and where are these types of uses and usage? Know what kind of structure and parts a linear bearing is. The main purpose of its parts is to use this part to perform structural reciprocating linear motion , so such bearings are generally cylindrical and there will be two grooves on the outside . The purpose of the groove is that we are going to fix it because there are no screws on both sides of the groove. The part of the groove is to use the C buckle to fix both sides . If you are interested in the C buckle, you can go to the bottom of the video to explain , there will be chapters to go to For learning, let's look at the interior. Generally, linear bearings have steel balls to make the circulation system . This circulation system will be a bit like a ball screw, which is as interesting. There will also be some relevant chapters at the bottom of the video . As long as it is applied to steel balls, such as bearings, lubricating oil needs to be used for lubrication, because let's think about these steel balls when they have been doing non-stop cyclic friction. If there is no lubricating effect, its life will be shorter. If there is increased lubrication Oil and so on, its effect will be better and smoother, and its life will be longer. Basically , the oil seal is to prevent dust from running in, and then it needs to seal the lubricating oil in it. When doing reciprocating linear motion, when doing reciprocating linear motion The whole effect will be better. This part is about the oil seal . The instructions at the bottom of the video also have relevant chapters. You can learn what kind of parts the oil seal is. Here, after knowing the general structure of the linear bearing, we will explain how to use it later .
Find out how the linear bearing is used to use it. Generally, it is matched with the mandrel . You may be curious to say that these circulation systems of the linear bearing do not need grooves on the mandrel to cooperate with its steel balls. In fact, everyone here You can think of a simple thing, as long as the cylinder and round bar are simple, just put the linear bearing directly through the mandrel and directly pass it in . You will find that it is very smooth to enter. The circulation system will work on the outside of the mandrel, so the steel ball and the mandrel will work There is point contact between them, so its friction coefficient is very small. Here you should pay attention that generally when doing this kind of fit, it is a precision fit . Generally, the outer diameter of the mandrel will be ground to make the surface roughness as high as possible. meticulous And the tolerance can't be too different, because it needs to be precisely matched . Here you can check how to mark the tolerance. The details are left for everyone to discuss. Here we mainly talk about its use. After I came in, I found that because its steel balls do not limit it , it is It can be moved arbitrarily, so it can be found that although it is a linear reciprocating motion , it still has a little rotation , like this, so generally when using a linear bearing, if only one set is used as shown on the screen, it is possible to use only one set. In this direction, it needs to be positioned for rotation , so it is generally seen more often, and it may be used less often. Only one set is used . Generally , it will be used like this. There will be at least two linear bearings to make a set of units. Of course, the front and rear ends of the mandrel are used. It needs to be fixed to do reciprocating linear motion , so let's take a look at this place. The most commonly seen linear bearing is used . There will be grooves on both sides. This groove is for us to use C buckles for fixed use. So two The C buckle can be fixed on the side. Generally , there will be a gap here. Sometimes it can be controlled by processing methods. Generally , the gap is often there. Although you control it very small , you will still find it slightly moving when you move. If your structure does not want this gap, you may have to rely on other methods to overcome it. Let’s take a look here . In fact, it is more commonly used. Four groups should be used because if only two groups are used, the strength used here is not supported. So good, so let 's see that if the distance between the two mandrels is larger and the linear bearing is larger, the relative capacity it can carry will be larger, but we should pay attention that the mandrel should also be relatively larger. If it is a small mandrel, then the If the support is very large, the mandrel may be deformed . It needs to be paid attention to here . Let’s take a look at the more commonly seen types . It looks like this on the screen. The distance between the two mandrels is elongated. If you look at the transparency , you will see that in this group of linear reciprocating motions, four linear bearings are used, and then a machining part is used on both sides to process the cylindrical part to make it sink in . Of course, this part will have other screws or some machining, etc. Come and fix the linear bearing, it will rotate a little in it, it has no effect on us, as long as the axial freedom is limited. Generally, when processing here, if it is like the picture, we need to dig a hole here , and also dig a hole here. When processing the hole, you must pay attention to the concentricity of these two. If this concentricity is not done well , you will find that the overall structure is not smooth. So we see that when we use linear bearings and then cooperate with it, these processing concentricities, Parallelism, etc., must be paid special attention , otherwise there will be problems in assembly. Maybe the slide table will not slide, so we will find that when we use linear bearings to use some tolerances or to process and assemble, we must pay great attention, including the fixation of the mandrel The same is true here . Let everyone familiarize yourself with how to use it in general linear bearings . After a while The most important thing to talk about is other types. The next thing to introduce is the grooved linear bearing . Here you may be curious where the groove will be used. Let’s take a look here. In fact, most of them are the same as ordinary linear bearings. The difference is that this groove is actually simple. One point, it also has a cylindrical part, but it may be a two-piece mandrel and a workpiece, or this place is an aluminum extrusion shape. The difference here is that it may be fixed in place. The screw is measured under or on the side . The side is not the same as the general mandrel. Generally, the mandrel is fixed on both sides , so the main ditch here is to flash the fixed structure on this side, so you will find that the difference between the two sides of the general mandrel is that its overall strength It will be better, and it will be less prone to deformation. The main purpose is to make ditching. The same usage here is very similar to what was just introduced. It may be two groups as a unit or four groups as a unit, like this, here Of course, it is necessary to use some structures or machining parts to connect these four together . Because if machining is used, it is generally not possible to do half-hole type . There is no such demonstration here. For this part , it can be overcome in other ways , etc. I will introduce other types later, and I will directly overcome this method. I will give you a detailed explanation when I introduce it later. Let 's understand the purpose of the original grooved linear bearing . It is a similar type of slide rail. Next Introduce the flange type linear bearing. The flange type can be seen from the picture, and there will be an additional disc-like shape . Of course, it is integrally formed here. Here you will see the flange surface. There will be screw holes, which can be locked with screws. It will be more convenient to fix. Generally speaking, this place will be a bit like a lathe, and it will make an escape angle. Sometimes there will be an escape angle in this place . When assembling, we will ensure that this surface is completely fitted, and it will not be vertical due to the processing of small rounded corners . Here you can pay attention to it It is fixed to limit the rotation , and the second is to limit the axial direction with the workpiece or the slide table. Through such transmission , it can become a linear bearing steel ball circulation system , making point contact with the outside of the spindle, and linear reciprocating motion. Directly look at the schematic, like this, just use it. The method is to make a translucent like you explained. You will be more clear. In this way , it needs to be processed. When you see four places, you need to process a cylinder and let it sink in. The difference here is that you need to do more tapping before you can use it. Screw it to lock it . If you don't know about the tapping part or are interested in getting to know it, you can go to the bottom of the video to explain it. You can get to know it there. Let's take a look at how to do it here. It's the same as four groups of two . After the mandrel is widened, the overall slide table will be more stable, so it will be more convenient to fix it, so you do n't have to worry about using the C buckle. There will be a small gap, or you can directly lock it with screws , and then disassembly and assembly will be smoother . Let everyone understand its use here. Next , I will introduce the linear bearing with a seat. The most important thing is The four types are all very similar , so they are put together here to explain. Generally speaking, it is more simple to see if it is connected with a seat, that is, there is one more seat. This seat is generally made of aluminum material , and the linear bearing or the above-mentioned linear bearing is directly placed in the middle. Grooved linear bearing , so this place is generally put in, and the inner C buckle is used to fix both sides of it. Let everyone understand it here . The main difference is that after it becomes a seat, there will be screw holes to fix it from this direction. The usage will be different. Of course, this part will be divided into closed type and grooved type. Grooved type and closed type have an extension , that is, the elongated type. Generally, there are two sets of linear bearings in the elongated type. Look at the usage, first look at the first one. This is a general type of linear bearing with a seat. It is more commonly used in four groups. Like this, there will be a slide table in this place, and the slide table will have screw holes to fix it . You can make it move back and forth in a straight line. This is also one of the very common structures. Here you can watch peripherals or similar machine tools, or 3D printers, etc. It is very common to see this type of pattern and learn straight lines through this method. What occasions will the bearing be used in? The same thing to pay attention to here is that these holes need to be fixed like a mandrel. Relative to these parallelisms, etc. , the roughness of the surface needs to be paid attention to. Think about using this kind of reciprocating linear motion . Be very careful when assembling or processing , because if there is some deviation here , it is not horizontal and may move to one side in a reciprocating linear motion. Will it affect the whole structure ? Here we have to think about it , or the tolerance is not grasped, it is slightly There is some deflection. The two mandrels are not parallel or on the same plane , so that the slide table cannot slide. Grooves generally do not use machined parts, and then plug the grooved linear bearings directly. This kind of connecting seat is directly grooved. Like this, the connecting seat is more convenient , just do screw locking directly. What is introduced here is The extended type is just introduced. The general type will use four. If the extended type is used, it may be enough to use two. Here it depends on you. Whether the support structure is enough to support it will be more convenient here . When it uses this mode , the bottom will be a bit like a slide rail . Of course, it will be compared with the mandrel. Generally , when the two sides of the mandrel are fixed, the strength of this side will be much worse than that of this side. If it is a slide rail type, the fixing hole The position may be the side and the bottom, the whole row is fixed, the whole rigidity will be better, and the support force will be better . Finally , let's summarize the knowledge of linear bearings. When we see that the linear bearings are matched, the first main part is the mandrel , so the mandrel is one of the most important parts, so special attention should be paid when selecting. Of course, this type of mandrel generally has Specifications can be selected. Maybe you don’t have to worry about the surface roughness or how to match the tolerance. Sometimes it is possible to do the processing yourself. Because there may be some customized requirements, you must pay attention to its tolerance . The mandrel is too big or too small. Influence and surface roughness or surface hardness, if the hardness is not enough, there may be scratches on the mandrel after a long use There is no need to worry too much about the connecting seat type. The main sliding table seat needs to be matched with other parts. There may be some screw holes, so a lot of processing is needed to match. Sometimes the connecting seat type is used . It may be used similar to the slide rail type, and the grooved type should be used. The grooved and closed type should be paid attention to. If it is used, it depends on our occasion. If the use environment has a lot of dust or water, it is necessary to pay special attention to it. Be careful of this kind of ditch. The ditch type may cause water or dust to run in, which will cause the steel balls inside to rust or get stuck. Pay special attention. If this is the case, the closed type will be more suitable. Generally , there will be oil seals here for protection. Others like It is connected to the seat. Generally , there will be an oil filling hole , which can be used for oil filling. This will make the whole service life longer . Here, let everyone know and understand. Today 's teaching ends here, and we look forward to the next teaching. Bye~ Bye ~
