Cam and followers

1. CAM and FOLLOWERS

2. What is Cam and Follower?
• A cam is a mechanical member used to impart
desired motion to a follower by direct contact.
• The cam may be rotating or reciprocating
whereas the follower may be rotating,
reciprocating or oscillating.
• Complicated output motions which are otherwise
difficult to achieve can easily be produced with
the help of cams.
• Cams are widely used in automatic machines,
internal combustion engines, machine tools,
printing control mechanisms, and so on.

3. CAD Model:

4. CAD Model:

5. Governing Principle:
• In a cam and follower system, the cam is a
mechanical element often in the form of a flat
piece of metal tooled into an oblong shape
that rotates or slides. The follower travels
along the surface of the cam, tracking the
shape by its edge and translating that shape
into a movement pattern. The cam follower
operates on a very simple principle and can be
applied to a wide number of tasks, because
although it is basic, it is also highly versatile.

6. Displacement Diagram:

7. Displacement Diagram
• a displacement diagram is merely a plot of
two different displacements(distances). These
two displacements are:
1. the distance travelled up or down by the
follower
2. the angular displacement (distance) of the
cam

8. Types Of Cams And Followers:
Different types on the basis of cams and
followers used:
CAMS:
• Plate cam
• Cylindrical cam
• Face cam
• End cam

9. Types Of Cams And Followers:
FOLLOWERS:
• Knife edge follower
• Roller follower
• Flat face follower

10. Application of Cam And Follower:
The function of Cam and follower Systems in
Engines:
The use of cam and follower systems
are vital in engines, where they are used to
open and close the inlet valve and the exhaust
valve to the cylinder head. The cam and
follower system is a plate cam and flat
follower system, and of course the function of
the system is to open and close the valves at
the correct time during the four stroke cycle of
the engine.

11. Camshaft of an Engine:

12. Camshaft of an Engine incorporating a Rocker Arm
The diagram shown below is another typical cam and follower system that could be used
in an engine. This system incorporates a rocker arm (shown in blue in the image). In this
case the motion the cam imparts on the follower is translated to the valve through a push
rod amd the rocker arm.

13. Animation of a Pump Working
Another common use of a Cam and Follower system is within a pump, such as an oil
pump. In such pumps the cam and follower system is used to suck oil in through one
non-return valve and push it out through on other non-return valve. The suck action is
achieved by the system because the follower is cylindrically shaped and moves within a
tight fitting cylinder so oil is sucked in and pushed out as the follower moves up and
down.

14. Relationship with Course:
• Cam and follower mechanism is a basic
mechanism for operating various machines.
• Cam and follower converts circular motion to
reciprocating motion as is our design
requirement.
• Cam and follower mechanism gives us motion
when it is required.It acts as an on off switch
mechanism for motion.

15. Alternating Modules:
Following mechanisms can be used in place of cam
and follower:
GEARS :
Gears also Transmits power with velocity
variations as desired.
PULLEYS AND BELTS
They are also used for power
transmission and also provide velocity variations.
But we use cam and follower because it is simple
in construction and working and also relatively
cheaper than gears and pulleys.

16. Flaws And Losses:
Frictional losses:
Contact between cam and
follower can produce friction between them.
This friction can cause wearing of surfaces.
• In case of Flat face follower, contact area is
more so more friction is produced.
• In case of Knife edge follower, contact area is
less but due to sharp edge of the
follower,wearing of the cam surface is more.

17. Motion Analysis And Recommendations:
Cam can be shaped so as to give different types
of motion to the follower. These different types
of motions can be used accordingly for different
scenarios.
• Linear motion

18. Motion Analysis And Recommendations:
• Simple Harmonic Motion:

19. Motion Analysis And Recommendations:
Cycloid Motion:

20. Final year project streams:
We can work on several final year projects
related to cam and follower mechanism such
as:
• Internal Combustion Engine
• Steam Engines