MECHANISMS
mechanisms are devices that transmit and convert forces and motion from a driving force or input element to an output element.
they allow us to carry out certain tasks more easily and more efficiently.
classiffication of mechanisms
controlling and regulating motion
joining elements
transforming motion
storing energy
transmitting motion
rotary
linear
rotary to linear
rotary to reciprocating
levers are rigid bars supported by a fulcrum
the law of the lever= F x d = R x r
class 2 where the resistance is between the fulcrum and the effort applied. The effect of the effort is multiplied
class 3 where the effort applied is between the fulcrum and the resistance. The effect of the effort is reduced
class 1 where the fulcrum is between the effort applied and the resistance. The effect of the effort can be multiplied or reduced
pulleys
movable F = R/2
compound is a system of fixed and moveable, often called block and tackle
fixed F = R
rotary motion mechanisms they transmit motion and effort in a circular way, from the input to the output
pulley systems consist of two pulleys or wheels that are a certain distance apart
gears
friction drives are made up of two or more wheels that are in contact
worm gears
mechanisms that transform motion
from rotary to linear
from rotary into reciprocating
nut and bolt system
rack and pinion system
winch and cranck handle
the ratio between the number of rotations of the pinon and the velocity of the movement of the rack is expressed by this equation: L = P x Z x N
a bolt of threaded bar and a nut that has the same interior diameter as the diameter of the bolt
a winch is balanced when it satisfies this equation: F x d=R x r
cam
eccentric cam
Crankshaf
crank-link-slider
composed of a crank and a rod called a connecting rod or link.
set of connecting rods attached to a jointed axle.
a rotating object that pushes a follower as it moves
a wheel with an off-centre rotation axle that doesnt coincide with the centre of its circumference
other mechanisms