 Hello everyone, this is Shila Ratna Bansode from Walshan Institute of Technology, Solapur. As a part of machine drawing curriculum, we are going to see the topic free hand sketch and in that we will be dealing with bearings. Learning outcomes, at the end of this session or at the end of this video, students will be able to draw different types of bearings. They will also understand the construction and specific applications of various bearings. Now, moving further, introduction to bearings. In different applications, we use shafts to transfer power from one element or machine elements to another or from prime ore to the machine element. Now, this distance between the two, either the prime ore and the application might be more and the length of shaft goes on increasing. In such case, to support the shaft, we require bearings. When the length of shaft increases, to have an intermediate supports, we go for bearings. Berings not only supports the shaft, but they also provide stability and free and smooth rotation of the shaft. They do not hinder the process of rotation, the process of power transmission for the shaft. So, bearings are very much important as where you have rotational elements like shafts. Berings also absorbs or balance the loads that are acting on the shaft. Now, the load on the shaft might act because of its self-weight, the more the length, the weight of the shaft goes on increasing or because of certain imbalance in the prime ore or the application, there might be certain unavoidable forces. To some extent, the balancing of these forces or sustaining of these forces is also done by bearings. During rotation, there are certain forces developed either axial or radial forces. These forces are also balanced with the help of bearings. No doubt, for different balancing of different loads, we go for different bearings. Then, bearings are classified as sliding contact bearing and rolling contact bearings. Let us see one example from each. Introduction to sliding contact bearing. Here, the shaft has a sliding contact with the bearing. The relation between the bearing and the shaft is in the form of sliding. Here, the friction is quite high as sliding comes into picture. Hence, as friction is high, more lubrication is required and depending upon the direction of load, it is classified as journal bearing and thrust bearings. So, sliding contact bearing prefer high lubrication as high friction is involved. Then, journal bearings. Here, the load on the bearing is perpendicular to the shaft. As you can see in the image, this is the shaft and this is the sectional lines are shown in the bearing. So, the load is acting in perpendicular direction. This arrow indicates the load that is acting in perpendicular direction perpendicular to shaft axis. This is the shaft axis and this is the load that is being acting. Now, here the word journal comes into picture because journal is the part of the shaft that is in contact with the bearing. So, this part, this dotted part, this total part is called as journal. Now, in journal bearing, we have types like solid journal bearing, boost journal bearing and pedestal journal bearing or plumber block. Let us see each solid journal bearing. It is the simple and most common in journal bearings. Most simple form of journal bearing is solid journal bearing. It is made up of cast irons and the cylinder block with rectangular hose. We have a cylinder block with a rectangular hose here. This is the diagram of a solid journal bearing. Here, there is no provision for adjustment in case of wear. As you can see, this is a single entity being found with the help of casting. If there is certain misalignment in the rotation of the shaft, there is no provision for alignment or provision to adjustment. As you can see on screen, as there is no provision for adjustment, once there is wear and tear of the bearing, you need to discard it and you have to apply the new bearing into the applications. Hence, these kind of bearings are used where you have very low load on the bearing or the load on the bearing is quite small. Then, you can see on screen, this is the front view and this is the top view of the bearing. Here, you can see a hole for lubrication. This is the hole for clamping and in this hole, your shaft fits. This is a single unit, no provision for adjustment, hence called as solid. Then, we have boost bearing. It consists of two parts. It consists of two parts, as you can see on screen. One is the body part and the other is bush part. Now, here, body is made up of cast iron as we have seen it in solid journal bearing also. And, bush are made up of small materials like brass, bronze or gun metals. And, the bush is press fitted and can be easily renewed. Here, you can see this unit, this outer unit is a single form and here in this, the bush are inserted by press fit. So, if there is certain misalignment and due to over a period of use of time, the bushes might get wear. Instead of replacing the bearing as a whole unit, you can just replace the inserts. This insert that are called as bushes and the bearing can be back to application by just merely replacing these kind of bushes. This construction is similar to solid bush, but this bush is solid journal bearing, but addition of this bush makes this merely easy for replacement and adjustment of misalignment. Here also, you have a hole for lubrication as you can see on screen. These are the holes for clamping on certain base and through this your shaft moves. Then, we have pedestal bearing. When you have very long shafts and require intermediate supports, we go for pedestal bearing or plumber block. It consists of a pedestal that is a base called as pedestal. A cap and a bush splitted into two halves. This base is called as pedestal. These are the bushes and this is the cap. This is the cap. Here, the split parts facilitate easy assembly and periodical replacement. As you can see, this comes into two parts. This is the upper part and this is the lower part. So, because of these two separate parts, the replacement and maintenance is quite easy as compared to solid journal bearing and the bush type of bearing. So, here instead of replacing the whole bearing as a unit, you can replace these bushes easily and you can separate these two parts. So, during replacement also, the process is quite easy. Then, the axial motion of the bush is prevented by flanges and rotary motion is prevented by a snug. Now, as bush is inserted into this, the rotary motion is prohibited with the help of these flanges and rotational here a snug is used. A lock kind of feature or an insertion kind of feature that bearing has and gets fitted into the hole on the body. So, rotation and movement is fixed with the help of these flanges and with the help of these snugs. Here, a hole for lubrication is also provided. These two parts are joined with the help of nut and bolt arrangement. We will see an orthographic view of the same. See, this is the first part, this is the top most part and this is the bottom most part. Body cap and this is the bush bearings or bushes. Nut and bolt arrangement is provided to connect the two parts. Here again, we have an adjustment for hole to clamp. Then, moving on to thrust bearing. Thrust bearings are used to support shaft subjected to axial loads and in that, we have footstep bearing. It is used to support vertical shaft under axial load. Shaft is terminated in the bearing. You have to insert the shaft in this way. The shaft end fits into this bearing. Then, bush fitted in the body takes care of the radial load on the shaft and rotation of the bush is prevented by a snug. Here, you can see a snug is provided here so that rotation and flanges are provided so that movement of the bushes is prohibited. So, this is journal bearing where the shaft is inserted from the top, footstep bearing. Here, you can see the front view and top view of the same. These are the references. Thank you.