 Hello friends, myself, assembly assistant professor from Walsh and the Institute of Technology at Solaapur Mechanical Department. Today I am going to explain the general introductions of the power transmission system. For this, the learning outcome of this topic is at the end of this session, the student will able to describe the construction and working of the power transmission system like belts, ropes, chains, gears, so these are the different type of what you call power transmission systems are there. So, these are the contents power transmission systems that is belt and ropes the first one, second one is a chains one, third one is a gear one. In the first one, when you have to select the any type of power transmission system, we have to know what are the different media you can use it. For that you can three type of varieties are to be there regularly used that is a belts and ropes then chains are there, gears are there in the gears different type of gears and gear trains are to be used here. The first of all the belts and ropes are there, the motion is transmitted between the input shaft and output shaft the driver and the follower that is due to the friction between the belt and the pulley surfaces. The pulleys are to be mounted on the driver and the driven or follower shafts are there and the frictional resistance between these pulleys and the belts the reason of for the power transmission systems basically there are two type the belts are there flat belt v belt and sometimes circular type that is core type belts are to be used for the power transmission. So, these are the some diagrams I am showing here it is a flat belt type, it is a belt and this section one that is a pulley one, it is a v belt type when you to go for the v belt type the angle this angle is to be minimum or sorry maximum 30 degrees to be there and it is a rope type that is a circular just I am explaining once now you go for a next one chains. So, when you to go for a belt drive belt drive is not a positive drive because there is a slippage to be there and the creep is to be there. So, chain drive is a positive drive chain is to be used for the transmission larger center distance between the two shafts that is the distance between the input shafts and the output shaft is a more one you can use the chain and positive power transmission system is to be there and these are made of some linkages are there metal linkages to be there heavier metal linkages to be there with respect to the belt one when you to go for the belt material belt is a leather is there cotton is there metal threads are there plastic threads are there and when the friction between the belt and the pulley is to be motion is to be transmitted heat is to be produced and when the heat is to be produced elongation is to be there expansion is to be there of that belt of that belt material and due to which the length of the belt is slightly increased when the length of the belt is slightly increases slippages are to be there. So, that is not happened in the chain drive because in the chain drive instead of chain some linkages of the metals are to be used for that the main only importance for the chain linkages to be there regular lubrication is to be required that is lubrication is at the required time to time and these are the some diagrams I am showing the block chains inverted tooth chain roller chains are there these lower bushings and these are distance between the pin and is called as a pitch. So, these are the just a simple example is a bicycle chain that is a simple example of the chain. So, friends when you know the type of the belt, belt material belt drive you know the chain chain drive then you have to think that which is the most favorable one regarding the power transfer system think over that we get pause for some seconds we think over that and give me answers yes. So, when you to compare the belt drive and the chain drive chain is a positive transmission system is to be there with respect to the belt because in the belt due to the friction heat is produced and due to that heat elongation is there due to the elongation length of the belt is increased and due to which slippages is to be there, but that is not happening in the chain pause the video question is why chains are to be used think over that the answer for this one is chain drives are used to transmit a power from one end to another end. Now, the third type you have to go for the gears. So, gear is 100 percent most power transmission is to be there and in this gear the power transmission is because of the outer surface teeths are there and these teeths are come in contact with each other driver and the follower and they are in a tapered intersection because slightly come in contact and then initially two teeths come in contact with the 20 percent then you are then increasing gradually 40 percent then 60 percent then 80 percent because all of a sudden load is not transmitted in the gear. So, that's why when you have to go for some simple example for the scooter when you have to engage that scooter where to start the scooter and it is to be moved on you have to go for the first gear then go for a second gear then go for the third gear and due to that rotational the what you call rotational mechanical energy to increase. If you go for a directly transmit first gear to the fourth gear you get a jerk because the teeths are not matched with each other. So, that's why the motion is transmitted in the gear that is due to slightly come in come in contact then gradually goes on increasing and the motion is to be transmitted. So, gear is also a positive drive chain also is a positive drive when you have to compare the belt ropes chains and gears gear is a 100 percent motion transmit system is to be there and these are the some different type of the gears are there spur gears helical gears these are double helical gears are there bevel gears are there and in the gear the spur gear the teeths are a parallel to the shaft these call as the simple gear is to be there sometimes the outermost teeths are not parallel here it is a parallel here in this case in the it call as the helical gear they are making helix angle it is a double helical angles are to be there here in the spur gear helical gear double helical gear the driver shaft and the driven shafts the driver shaft and the driven shafts they are on the same plane that is horizontal to the horizontal and roti to the roti here horizontal to horizontal roti to roti but sometimes you have to required the motion from horizontal to the vertical one or vertical to the horizontal one at that we go for a bevel gears. Here the motion is rotary to the rotary but the input shaft horizontal and output shaft is a vertical one. This is another type and the another type is to be there. Sometimes you have to required rotary motion to the reciprocating motion is to be there. So at that go for racket and pinion arrangements are to be there. So these are the different type of the gears are there. In the gears also there are gear trains are there simple gear train and the compound gear train. In the simple gear train only one gear is attached on each shaft that is driver shafts and the followed shafts and only one motion is to be transmitted. When I go for a compound gear drive here more than one motion you get it from a single input shafts means what? In the single input shafts only one gear is attached but in the output shaft driver shafts more than one gears are attached. So more than one motion you have to get it. That is a under type of gear drive that is a compound gear drive okay. Now you think that when you to compare the chain drive chain motion transmission is there and gear motion transmission is there which is more positive transmission think over that. Yes comparing to the chain drive gear drive is a more positive transmission systems are to be there. Here with the belt drive two types are there open belt drive and the cross belt drive. In the open belt drive motion is transmitted from rotary to the rotary on the same motion but in the cross belt drive motion is transmitted from rotary to the clockwise to the anticlockwise directions. So both are moving in a different directions. In the chain drive comparing with a belt drive positive transmission is to be there. When you to go for a belt drive there are no slipages are there due to the slipages power is get wasted. Gears gear is a hundred percent motion transmission is to be there but the initial cost is to be more and here the gear drives are there and the outermost motion is transmitted due to the teeth and teeth are in tapered conditions. So these are the different type of the power transfer systems are to be there. So for these references I am going for this ignore YouTube link is to be there. Thank you.