Cams and Followers – Theory of Machine


Hello students let us start with the new chapter in theory of machines I will write the name of the chapter the name of the chapter is cams and followers now what is cam what is follower I write the definition first so here I have written the definition that cam is the rotating machine element which provides reciprocating or oscillating motion to the follower I can explain it with a diagram now this diagram which I have drawn this member is called as cam and the other member over it it is called as follower so as per the definition cam is a rotating machine element so when the cam is rotating it is provided rotation so when cam is rotating follower is reciprocating or oscillating in this diagram it is reciprocating so it is very much clear that follower is that member which follows the motion of the cam that is as the profile of the cam is there and when it is rotating follower will move up and down that is when the cam rotates follower will move up and down here in this case it is a reciprocating follower which we have here so this mechanism it can be used in many applications like cams and follower the mechanism they are used for operating the valve of IC engine the inlet valve and exhaust valve of IC engine or internal combustion engine is operated with cam and follower mechanism similarly in case of paper cutting machines we have cam and follower mechanism so the applications are huge it is also used in case of lathe machines so cam and follower as we can see it is a very simple mechanism just we need to have a cam which is having some special profile here and then we need to have a follower which is kept in contact with the cam and it will just follow the motion of this cam so this was a brief concept a very small concept regarding the chapter which is cams and followers where I have given you all the description and explanation that what is a cam and a follower next I will write down the classification of different kinds of followers classification of followers the first part is based on surface of contact here we have knife edge follower then we have roller follower then flat faced follower or the last one it is spherical follower here whatever the examples I have given Y all based on surface of contact these are all examples of reciprocating followers so I will say that follower it converts the rotary motion of cam into reciprocating or oscillating motion now let us start with the first kind of follower which is knife-edge follower in case of knife edge follower the point of contact of the follower and cam it is in the shape of a sharp edge so here as we can see the follower is having a sharp edge and hence it is called as knife edge follower again the cam will be rotating and follower will reciprocate so here the point of contact depends the point of contact defines the types of follower here we have knife edge follower because the edge is sharp here so I will write down knife edge has sharp area of contact then the knife-edge follower is the most simplest type of follower so the construction part is very easy so here I will say that it is the simplest follower in construction they it is used only for use only for slow applications that is where the cabmen follower are not moving at very high speeds so it is used only for slow applications means this knife-edge follower is not suitable for precision applications that is where we where the timing is more important it is not used in those cases like to operate the valve of IC engine we cannot use knife edge follower there because the opening and closing of valves is a precision application so there we cannot use knife edge follower knife edge follower since the edge is very sharp here then it can result in wear and tear here we have more wear and tear that is because of friction there is metal to metal contact and because of that either the camp or the follower they may get borne out so this is the disadvantage of knife edge follower it is mostly used in paper cutting machines so here I have given you a brief description of knife-edge follower next we will go on to roller follower I hope you are getting this now in case of roller follower the point of contact between the follower and the roller it is in the form of a line or we can say just a point and then we have a roller follower the construction is at the end as we can see in case of knife edge follower here we were having sharp edge of the follower that is replaced with the help of roller here so because of the roller present here the motion becomes it is more smooth and as we compare it with knife edge here again the cam will be rotating and when the cam rotates follower will reciprocate so here the amount of wearing tear is less so I can say that cam and follower form a higher pair as we have seen in the previous lectures what is the meaning of higher pair that is the kinematic pair in which we are having point or line contact so here as we can see there is we can say point contact between the follower and cam so it is higher pair next we can say that there is less wear and tear between cam and follower then such kind of followers they are used roller followers they are used in precision applications that is where time is considered mostly used for the operation of walls of I say engine and then it operates or it can operate at very high speeds because here we are not having a sharp edge the surface of the roller is smooth so we can get very high speed here only thing is to avoid any action CEL thrust or to avoid any actual movement of the roller here you are having guide ways which prevent the axial motion of the rollers we are having a guide here these are called as guide ways and these guide ways avoid any lateral movement of the follower that is follower can only reciprocate it cannot move in the lateral direction and since it is used in for high speed applications here we need to provide guide ways so this was regarding the roller follower next we have flat-faced follower also called as mushroom follower here I will draw the diagram of a flat face follower in case of flat face follower as we can see the point of contact or the surface in contact with the cam here the follower is flat faced it is having a flat surface we can compare it in case of knife edge follower the point of contact was in the form of a sharp edge in case of roller follower the point of contact was a roller and here the point of contact is a flat face so here the follower it has a flat face and again the rotary motion of the camp is converted into reciprocating motion of the follower these followers they are preferred when they are used when the space is limited next they are used in those applications where we are getting more axial thrust because such kind of followers flat-face follower they are able to resist more side thrust that is the sideways motion of this follower is very less when we compare it with knife edge or roller follower in both my fashion roller followers the sideways movement is more and compared to that the flat facing the bearing area the area which is in contact it is more so here this follower will have less lateral movement so this is the advantage of this flat face follower and such kind of followers can also be used in case of precision applications so this is regarding flat face follower next we have the last kind of follower based on the surface of contact we have spherical followers as it is very much clear in case of spherical follower the surface is curved like we can see that it is just a modification of spherical follower it is a modification of flat face follower that is if we are having a flat face and we are grinding we are making the surface smooth of the flat face follower then it becomes a spherical follower here we have spherical end and when we give rotation to the camp this flower follower will reciprocate so this was regarding the types of follower based on the surface of contact next let me classify the follower based on the motion of the follower so based on motion of follower we have two kinds of follower one as a reciprocating follower and the other one is oscillating follower reciprocating follower is same as the previous examples we have seen of the pole different kinds of followers they were all reciprocating it means here if I can show it with a diagram so here when the cam is rotating follower will reciprocate so such kind of followers they are called as reciprocating follower that is moving up and down this end it can be knife edge it can be roller flat-faced Oh spherical follower but the motion of the follower is reciprocation when the cam rotates follower is moving up and down so that is a reciprocating follower next oscillating follower in case of oscillating follower the follower is attached to one end which is called as fulcrum and now when the cam is rotating where it would be rotating follower will oscillate that is it won’t be completing one complete revolution it will just oscillate so here this is an example of oscillating follower so based on the motion of follower we have two kinds one is a reciprocating that is up-and-down motion of the follower other is the oscillating follower which moves in an angular direction and it does not rotate completely but the cam has to rotate 360 degree that is complete revolution and follower it will just be oscillating that is it would be moving like a pendulum so this is an example based on motion of the follower next based on the axis of follower n cam so here I am giving the third classification based on axis of camel follower here we have two kinds of followers one is called as radial follower and the second one is called as offset follower I’ll draw the diagram for this now if we have the axis of the cam and the axis of the follower passing through the same line that is the axis they are same then it is called as a radial follower for offset follower it is very much clear from the diagram that in case of offset follower the axis of the cam and the axis of the follower they are not passing through the same line it means there is some distance between the two axis and that distance is called as offset so here in case of radial follower the axis was same between cam and follower in case of offset follower the axis is different we have some distance between them so it is called as offset follower so we have classified the follower based on axis of cam and follower now after the classification of followers the other classification of followers is over next we will see the classification of cams here we have the classification of cam it is based on the construction of camp the first one is called as radial cam radial cam is also called as disc cam second one is called as cylindrical cam third one is called as wedge cam so here we have three different types of CAM based on the construction radial that is this camp previously whatever diagrams I have drawn for the camp they were all dis camp next cylindrical cam and which camp I will draw the diagram for each one of them three different diagrams for radial camp it is very much simple previously whatever diagram I have drawn they were all of radial camp this force diagram is of radial camp where we are having the cam profile it is radial in the form of a circumference next cylindrical cam in case of cylindrical cam the profile of the cam is cut inside a cylinder as we can see in this diagram and the follower would be in contact and mostly this is used for transferring motion in horizontal direction here the cam profile s cut inside the cylinder so these are the cam profiles and the follower will move in horizontal direction that is as this cam the cylinder rotates the profile changes and the follower would be moving in horizontal direction so this is a cylindrical cam and the last one is also very much simple now in wedge cam the cam is in the form of a wedge shape that is having an increasing height so this breaks the myth that is we might be assuming that cam is always circular or it is always in the shape of radial so cam cannot be only radial it can be cylindrical like we have seen a profile which is cut inside the cylinder cam can even be in the shape of a wedge like a trapezium shape here and then follower would be again moving up and down that is a reciprocating as the cam in this wedge shape it moves in horizontal direction it would be moving in horizontal direction and the follower would be moving in the vertical direction so here we have seen various kinds of camp based on their construction after this we would be seeing the terminologies visa which are associated with cams and followers

58 thoughts on “Cams and Followers – Theory of Machine

  1. thanq sir ,cam n followers ka itna acha se basic knowledge samjhane ke lye,,I'm a mechanical student so plz make videos on mechanical topics

  2. we want to design a cam to rotate 25 mm shaft at 45 degree , the cam will be driven by rotating motor and follower will give 45 degree motion can you suggest that how to design the cam , we need the same displacement time pls suggest

  3. thanks sir but aap hr subject ki playlist bna shkteh hai jissey subject kai corresponding video search krna easy hon

  4. Thnx for the tutorial
    Ps-7 ads in one video that's distracting i support your channel watching the ad but 7 come on

  5. Our aim to provide reciprocating and oscillating motion to FOLLOWERS by using CAMS…but is it necessary to use CAMS ? Now it's time to avoid CAMS.

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  7. thxx alto sir superb the numberical of belt dirve is hard definetly but you have explained in easy way thxx.

  8. Excellent and extremely well done just repetitive enough to help a person not get lost emits the cams and followers

  9. When we search cam and follower we mean displacement equation and classification based on motion of followers like uniform velocity , shm , this is all theory i can get it from book

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