Title: Cams,%20Eccentrics,%20and%20Rachets
1Forging new generations of engineers
2CAMS, Eccentrics, and Ratchets
3CAMS ARE MECHANICAL DEVICES THAT CHANGE ROTARY
MOTION TO LINEAR MOTION
LEVER LINEAR MOTION
4CAM Followers and Linkages Transfer the Linear
Motion of the CAM Lobe to the place where it is
used
5CAM Lobe Parts
Toe
Flank
Ramp
Base Circle
Heel
6CAM Lobe Lift
7CAM Displacement Graph
- AS ECCENTRIC CAM ROTATES ONE REVOLUTION OR 360
DEGREES THE MOVEMENT OF THE FOLLOWER IS SHOWN BY
THE LINE ON THE GRAPH. AT 180 DEGREES THE
FOLLOWER IS AT ITS MAXIMUN HEIGHT.
8Basic CAM Shapes
Circle
Heart
Acceleration
Pear
9Flat Plate CAM With Roller Follower
10Groove Box and Grooved Flat Plate Cam
Groove Box CAM
Grooved Flat Plate CAM
11CYNDRICAL CAM and FACE CAM
- Both provide a rocking motion
12Peripheral CAMS
- Peripheral cams are the most widely used form of
an eccentric cam - In the peripheral cam, a follower rides on the
outside edge of the cam - The high spot on the cam is called the lobe
- The low spot is called the dwell
- Cams can also move the follower at different
levels
13Eccentric and Strap
- The eccentric is inside a device called an
eccentric strap - The eccentric is used where heavy loads are
moved - The strap is connected to a link or rod which in
turn is fastened to a pivot on an object which
moves linearly
14Cloverleaf and Swash plate CAM
- Cam Variations
- Cloverleaf
- drives the follower bar in both directions
- Swash plate
- provides rocking motion
15Different Style of a Swash Plate CAM
16Types of CAM Followers
- POINT SLIDING ROLLER ANGLE
17Using CAMS
3 Port pneumatic valve is opened and closed
Rotating CAM Controls the operation of a car
distributor
18Using CAMS In Gas Engines
19 Small Engine CAM
Engine CAMS
20Eccentric CAMS
Concentric Circle
Eccentric Circle
21Fuel Pump Design Using An Eccentric CAM
22Connecting Rods
- Sometimes called coupling rods these are used to
transfer energy from one moving part to another,
without using gears or axles - Used to synchronize the movement of parts, to
convert rotary motion to oscillating movement
23Ratchet Wheel And Pawl
24Types Of Ratchets and Pawls
25Ratchet Wheel and Pawl Used To Arrest Motion
26Fishing Reel Uses a Ratchet Wheel and Pawl
27Hand Crank Winch Using a Ratchet and Pawl
28Come Along Uses A Ratchet Wheel and Pawl
29Answer The Following
- What is a CAM?
- What Does a CAM Do?
- Name 5 Different Types Of CAMs.
- What is a Follower?
- Name 4 Types of Followers.
- What is a Ratchet?
- What is a Pawl?
- What is a Ratchet and Pawl used for?
- What is an Eccentric?