1.5 Flashcards
what are the 4 different types of motion
linear,ocillating,rotary and reciprocating
what is linear motion
only moves in a straight line ( one direction)
what is rotary motion
Moves around in a circular motion
what is reciprocating motion
linear motion backwards and forwards in a straight in a straight line
what is ocillating motion
Movement backwards and forwards in a circular arc
what is meant by the term effort
how much force is put in to move the object
what is meant by the term load
the object being moved
what is meant by the term fulcrum
the pivot point
what is a first order lever
the fulcrum is between the effort and the load
what is a second order lever
the load and effort on the same side as the fulcrum
what is a thrid order lever
the load and effort on the same side as the fulcrum but are spread apart
what do linkages do
transfer force and change the direction of motion
what happens in a bell crank linkage
the direction of motion is turned through 90 degrees
when is a push pull linkage (parallel motion linkage) used
when the direction of motion and magnitude of the forces are the same but are used when the force cannot be transfered directly in a straightline
what are the 3 parts of a rotary system cam mechanism
cam slide and follower
describe how a cam mechanism works
when the cam rotates, the follower moves up and down in a reciprocating motion. The pattern the follower moves up and down in is governed by the shape of the cam. It can do 3 things: go up and down or stay still
what a grear train transmitt
rotary motion and torque
how do you work out velocity ratio
number of teeth on the driven gear/number of teeth on the driver gear
what is friction
the resistance of motion when object rubs againts another
what is the co-efficient of friction
the amount of frcition an object has
what type of mechsnism can turn rotary motion into linear or vice versa
rack and pinion mechanism or crank and slider mechanism
what turns rotary to rotary motion
but what does this achieve
chain and sprocket mechanism
increases torque
what does a pulley system do
but what does this achieve
transfers rotary motion to rotary motion
changes the speed of rotation
