free ppt download

           Cam and Follower power ponit presentation

In this ppt we include topics are following :-

     1- Cam
     2- Application of cam
     3- Classsification of cam
     4- Types of cam

        a- Wedge cam
        b- Radial or disc cam
        c- Cylindrical cam
        d- Globoidal cam
        e- Spiral cam
        f- Spherical cam

    5- Types of follower

                                Definition of Cam

•A cam is a rotating machine element which gives reciprocating or oscillating motion to another element known as follower.
•The cam and the follower have a line contact and constitute a higher pair.
•Three elements :
–Driver member – CAM
–Driven member – Follower
–Frame – to support the cam and guide the follower

                             Application :
–Internal combustion engine for operating valve
–Shoe making machines
–Sawing machine
–Punch press
–Paper cutting machine
–Fuel pump diesel engine

                            Wedge cam
Wedge has translation movement
• Follower can translate or oscillate
• Spring is used to maintain the contact between cam and follower

                            Classification of Followers
1.According to Shape
2.According to the motion of the follower.
3.According to the path of motion of the follower

                             Terms used in cams

•Base Circle : It is the smallest circle that can be drawn to the cam profile.
•Trace point : It is a reference point on follower and is used to generate the pitch curve.
–In case of knife edge follower knife edge represents the trace point and pitch curve corresponds to the cam profile.
–In a roller follower center of the roller represents the trace point.
•Pressure angle : It is the angle between the direction of the follower motion and a normal to the pitch curve. This angle is very important in designing a cam profile. If the pressure angle is too large, a reciprocating follower will jam in its bearing.
•Pitch point : It is a point on the pitch curve having a maximum pressure angle.
•Pitch circle : It is a circle drawn from the centre of the cam through the pitch point.
•Pitch curve : It is a curve generated by the trace point as the follower moves relative to the cam.
–For knife edge follower pitch curve and cam profile are same.
–For roller follower they are separated by radius of roller.
•Prime circle : It is the smallest circle that can be drawn from the centre of the cam and tangent to the pitch curve.
–For a knife edge and flat faced follower prime circle and base circle are identical.
•For roller follower prime circle is larger than the base cirl by the radius of the roller.
•Lift or stroke : It is the maximum travel of the follower from its lowest position to top most position.


http://www.2shared.com/file/W6ypHuHh/Cam_and_Foolower.html