Energy and mechanisms Flashcards
What are the types of motion
Linear - motion goes in a straight line in one direction
Reciprocating - motion moving backwards and forwards
Rotating - motion moving in a circle
Oscillating - motion swinging backwards and forwards
What do levers do
Change the amount of effort or force needed to move a load
What is the first order lever
Load - fulcrum - effort
E.g. scissors and see saw
What is the second order lever
Fulcrum - load - effort
E.g. wheelbarrow
What is the third order lever
Fulcrum - effort - load
E.g. lifting a dumbbell
What do mechanical devices do
Transfer motion or force between mechanisms or to convert between different types of motions
What do linkages do
Transfer motion between two positions. However they can also act as levers
What do cams do and what are the different shapes of them
Convert rotary motion to reciprocating motion
Eccentric circles, pear shaped and snail shaped
E.g. the needle in a sewing machine
What do gears do
Change the speed or force of the motion they transfer
What are the types of gears and what do they do
Spur - transfer rotary motion, e.g. gear boxes
Bevel - change rotary motion through 90°, e.g. hand drills
Worm and worm wheel - change rotary motion through 90°
Rack and pinion - change rotary motion into linear motion, e.g. to move the base on a pillar drill up or down
What do pulleys do
Transfers rotary motion
Change the speed or force of the motion they transfer
