31-07-2013, 03:53 PM
Study of various types of Cams and Followers
various types of Cams.doc (Size: 589 KB / Downloads: 32)
Theory:
A cam may be defined as a rotating machine part designed to impart reciprocating and oscillating motion to another machine part, called a follower.
Cam and follower mechanisms are used in modern machines. Example - for operating the valves in I.C engines, textile machine tools, paper cutting machines, feed mechanisms of automatic lathes, switches etc.
Various types of Cams
Cams are classified on the basis of physical shape:
1. Radial cams, Disc or Plate cams
In the figure shown below, both the cams are plate cams.
In radial cams the working surface is so designed that the follower moves in a plane perpendicular to the axis of cam. The position of the follower is determined by radial distance from the axis of cam.
Follower is held in position with the cam by means of spring force or gravitational force.
2. Cylindrical cams
In these types of cams, follower either reciprocates or oscillates in a plane parallel to the axis of the cam. In this a circumferential contour is cut in the surface of the cylinder which rotates about its own axis as shown in figure. The follower rides in the groove of the cylindrical surface and it reciprocates /oscillates in the plane parallel to the axis of rotation.
3. Wedge and Flat Cams
A wedge cam has a wedge which in general has a translational motion. The follower can either translate or oscillate. A spring is usually used to maintain contact between the cam and follower.