Department of Mechanical Engineering UET Lahore KSK

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					 Cams
  and
Followers
Cam and Follower
 •   The cam and follower is a device which can
     convert rotary motion (circular motion) into
     linear motion (movement in a straight line).


                                                    Follower
 Cams




                                                      Cam




Followers
(valves)
 Cam and Follower
                                         follower

• The cam can have
  various shapes.
  These are know as   Cam
  cam profiles.




Pear         Heart          Circular   Drop
         Types of cams

• OD or plate cam
  – Body of cam is usually
   shaped like a disk with the
   cam contour developed         Contour Meteorological


   along its surface
• Drum or cylinder cam
  – Cam track is normally
   machined around the
   circumference of the drum

                                                     Hikari
         Types of cams


• Conjugate cam
  – Multiple cams joined
   together
• Face cam                      Ih Ching

  – Cam track is cut into the
    face of the disk



                                  Hikari
         Types of cams


• Index cam
  – Similar to drum cam
    except that follower
    motion passes in an
    arc over the cam
    itself


                           Commercial
    Cam and Follower
•   The 'bumps' on a cam are called lobes.
                                                          Follower
•   The square cam illustrated has four lobes,
    and lifts the follower four times each
    revolution.




                                                 Square cam




    Examples of other rotary cam profiles.
 Cam and Follower
Examples of a Rotary cams in operation.




                              Cams used in a pump.
Control the movement of
the engine valves.
Cam and Follower
•    The linear cam moves backwards and forwards in a
     reciprocating motion.



                     Cam Follower

                                                        Linear cam

    Distance
    moved by
    the follower
 Cam and Follower
                       • Cams can also be cylindrical in shape
                       • Below a cylindrical cam and roller follower.




                                           Cam rise and Fall
• The cam follower does not have to
move up and down - it can be an                        Max Lift
oscillating lever as shown above.
                                                        Min Lift
     Cam and Follower
                                                Follower

 •   A follower is a component
     which is designed to move
     up and down as it follows    cam
     the edge of the cam.




Knife edge            Flat foot    Off set    Roller
Follower              follower     follower   follower