Mechanical components and devices Flashcards
Rotational Speed =
Rotational Speed = number of revs/time
Linear Speed =
Linear Speed = distance/time
What is a mechanism?
They can increase force and reduce distance
OR
increase distance and reduce force
think of moments in physics
Examples of mechanisms are …..
levers linkages pulleys cams gears rack and pinion
Describe a lever
Levers have: a fulcrum (pivot) a input force (the effort) an output force (the load) They rely are the principle of moments
What is rotational motion?
Movement in a circle
What is linear motion?
Movement in a straight line
What is reciprocating motion?
Movement back and forth in a straight line
What is oscillating motion?
Constant movement from side to side along a curved path
What are the different types of Linkage?
- Pulleys (Linear to Linear in opposite directions)
- Gear systems (Rotary into Rotary)
- Rack and pinion (Rotary into Linear)
- cams (Rotary to Reciprocating)
- bell crank (transfers motion round a corner)
- peg and slot (rotary to oscillating)
- crank and slider (rotary to reciprocating)
What is the mechanical advantage equation?
- MA=Load/Effort
Why do we use levers?
- To gain mechanical advantage
- This makes lifting something easier
What is the moments equation?
F1 D1 = F2 D2
What is a class 1 lever?
- A seesaw
What is a class 2 lever?
- A wheelbarrow
What is a class 3 lever?
- Tweezers
What is the principle of a mechanical device?
- To transform input motion and force into desired output motion and force
What are the 4 types of motion?
linear motion - in a straight line m/s
rotary motion - in a circle revs/sec
reciprocating motion - in oscillations per second eg piston in a car engine
oscillating motion - in oscillations per second eg pendulum
What is a linkage?
component which directs forces and movement to where they are needed
