Mechanical Systems 1 and 2 Flashcards
Name the four types of motion.
Oscillation
Linear
Reciprocation
Rotary
What is the phrase to know what class of lever something is?
1-2-3 = F-L-E
What is a lever?
It helps provide mechanical advantage. It it made up of a bar and a fulcrum (pivot).
What is the equation for Mechanical advantage?
MA = Load/Effort
Written as a ratio or a (multiple) MA
MA = 300N/100N = 3/1
3:1 or 3 MA
What is Equilibrium?
When the load and the effort are equal.
What is a linkage?
They are mechanisms that use rigid parts to:
Change magnitude of force
Change direction of force
Transform it into different motions
What is a reverse motion linkage?
It changes the input motion, to opposite of what it was.
Push = Pull
Linkages uses a fixed central point
What is a parallel motion linkage (Push/Pull linkage)?
It keeps the output motion = input motion
What is the bell crank linkage?
Input direction is converted 90 Degrees
Horizontal motion = Vertical motion
Used in steering/throttle
What is a crank and slider?
It converts rotary motion into reciprocating motion and vice versa.
E.g Car pistons
What is a treadle linkage?
It converts rotary motion into oscillating motion and vice versa.
E.g Wind screen wiper
Name at least two types of linkages.
Treadle
crank and slider
Bell crank
Parallel motion
Reverse motion
What is a rotary system?
They drive machinery and equipment
A cam (rotating axel) change rotary motion into reciprocation motion through a follower (a rod that runs along the cam).
What is an Eccentric cam?
Circular shaped cam
What is a Pear-Shaped cam?
A cam that is shaped like a Pear
What is a snail cam?
A cam that has a drop on it.
What is a heart shaped cam?
A cam that is shaped similarly to a heart.
What is a cam?
A cam is a rotation axel, that allows a follower to run along the surface creating linear motion.
What is a follower?
A follower is a loose fitting rod that runs along the surface of a cam.
What is a flat follower?
A flat follower has a flat bottom.
Creates lots of friction
What is a knife edge follower?
A knife edge follower has a sharp edge.
Creates lot of friction
What is a roller follower?
It has a spherical edge on the bottom.
What is a gear train?
Interconnected cogs
How do you work out the gear ration?
Gear ration = Driven teeth/Drive teeth
GR = 10/20
GR = 1/2 or 0.5
