Engineering Mechanics
Statics: things are not moving
Dynamics: things are moving
Basic Machines
Basic Machines
Basic Machines
Mechanical Advantage
Mechanical Advantage = 3
Mechanical Advantage = 4
Mechanical Advantage = 12
½ inch
6 inches
Mechanical Advantage = ½
Mechanical Advantage = 4
Mechanical Advantage = 2
Mechanical Advantage …
MA = 1
MA = 2
Mechanical Advantage = 3
FE = 33 1/3 N
30 cm
Mechanical Advantage = 4
Gears and Belts
Circular Motion to Circular Motion
GR
1
=
32
8
x
30
10
=
960
80
=
12
1
MINUTE HAND (12 revolutions) to HOUR HAND (1 revolution)
SECOND HAND (60 revolutions) to MINUTE HAND (1 revolution)
Cam Shapes
Cam Dwell
Cam Follower and Spring
Circular Motion to Linear Motion
Cam Follower and Slot/Groove
Linear Motion to Linear Motion
output
Circular Motion to Linear Motion …
https://www.youtube.com/watch?v=UuTNtg7-Bwg
https://www.youtube.com/watch?v=vwxxKMe8Wdg
Linear Motion to Circular Motion …
https://www.youtube.com/watch?v=sqL2LfmT66Y
Circular Motion translated to Linear Motion
Output: Linear Motion
Linear Motion
turn buckle
target
To control the target, adjustments are made to the:
1. Stroke (range) … cam follower
2. Timing … cam
CAM
3. Position … turnbuckle
cam
90o
270o
Input: Clockwise Circular Motion
Fixed Pivot Point
cam follower
0o
180o