EDUARDO HERNÁNDEZ ÁLVAREZ TECHNOLOGY

MECHANISMS

DEFINITION

• Devices that transmit and transform force and motion from a driving force (input) to an output.

TRANSMITTING MOTION

• LINEAR– LEVER: is a rigid bar that is supported by a fulcrum.

• CLASS 1

• CLASS 2

• CLASS 3

ELEMENTS (FORCE, FULCRUM AND RESISTANCE)

APPLICATIONS• http://www.youtube.com/watch?v=PW7ztbwJKBk

– PULLEY• FIXED PULLEY: IS A WHEEL THAT HAS A GROOVE

AROUND IT INTO WHICH A ROPE, CHAIN OR BELT FITS.

• MOVABLE PULLEY: IS A SET OF TWO PULLEYS , ONE IS FIXED WHILE THE OTHER CAN MOVE IN A LINEAR DIRECTION.

• COMPOUND PULLEY: IS A SYSTEM OF FIXED AND MOVABLE PULLEYS, OFTEN CALLED A BLOCK AND TACKLE.

APPLICATIONS• http://www.youtube.com/watch?v=9T7tGosXM58&feature=endscreen

• CIRCULAR– FRICTION DRIVES: ARE MADE UP OF TWO

OR MORE WHEELS THAT ARE IN CONTACT. THE FIRST WHEEL IS THE PRIMARY DRIVE WHEEL AND THE SECOND IS THE OUTPUT WHEEL.

– PULLEYS WITH BELTS: CONSIST OF TWO PULLEYS OR WHEELS THAT ARE A CERTAIN DISTANCE APART.

– GEAR MECHANISMS AND COGWHEELS: ARE SETS OF WHEELS THAT HAVE TEETH CALLED COGS.

– WORM GEAR: THIS IS A SCREW THAT MOVES A HELICAL COGWHEEL THAT IS SET PERPENDICULAR TO THE SCREW.

– GEAR MECHANISMS WITH A CHAIN: THESE ARE TWO COGWHEELS WITH PARALLEL AXLES THAT ARE A CERTAIN DISTANCE APART.

– GEAR TRAIN: THIS IS A SYSTEM OF MORE THAN TWO GEARS, CONNECTED TOGETHER AS SHOWN IN THE DIAGRAM.

– PULLEY TRAINS WITH BELTS: THIS IS A SYSTEM OF PULLEYS, OR WHEELS, WITH A BELT FORMED BY MORE THAN TWO WHEELS.

TRANSFORMING MOTION• FROM ROTARY TO LINEAR– RACK AND PINION SYSTEM: THIS

IS A PINION THAT IS A SMALL COGWHEEL, MOUNTED ON A RACK THAT IS A TOOTHED BELT OR BAR.

– NUT AND BOLT SYSTEM: THIS CONSIST OF A BOLT OR THREADED BAR AND A NUT THAT HAS THE SAME INTERIOR DIAMETER AS THE DIAMETER OF THE BOLT.

– WINCH AND CRANK HANDLE: THIS IS A DRUM THAT ROTATES AND A CRANK HANDLE THAT ALLOWS US TO LIFT OBJECTS.

• FROM ROTARY INTO RECIPROCATING MOTION

– CRANK-LINK-SLIDER: THIS IS A COMPOSED OF A CRANK AND A ROD CALLED A CONNECTING ROD OR LINK.

– CRANK SHAFT: THIS IS A SET OF CONNECTING RODS ATTACHED TO A JOINTED AXLE. EACH OF THE JOINTS OF THE AXLE ACTS AS A CRANK.

APPLICATIONS• http://www.youtube.com/watch?v=rG5ipR9S07U• http://www.youtube.com/watch?v=ESRsd1TeOSg&feature=related

– CAM: THIS IS A BASICALLY A ROTATING OBJECT THAT PUSHES A FOLLOWER AS IT MOVES.

– ECCENTRIC CAM: THIS CONSIST OF A WHEEL WITH AN OFF-CENTRE ROTATION AXLE THAT DOESN´T COINCIDE WITH THE CENTRE OF ITS CIRCUMFERENCE.

APPLICATIONS• http://www.youtube.com/watch?v=ONIaIdOV3R8• http://www.youtube.com/watch?v=p1sgaqwDpL4&feature=endscreen

CONTROLLING AND DIRECTING MOTION

• RATCHET: IT ALLOWS ROTATION IN ONE DIRECTION BUT IMPEDES IT IN THE OPPOSITE DIRECTION.

APPLICATIONS• http://www.youtube.com/watch?v=NJ6t42ADGfM&feature=related

• BRAKE: IT ALLOWS TO REDUCE VELOCITY.

– DISC: CONSIST OF PADS AND A DISC ATTACHED TO THE OBJECT THAT WE WANT TO SLOW DOWN.

– BAND: CONSIST OF A METAL BAND THAT PUTS PRESSURE ON A DRUM ATTACHED TO THE AXLE OF THE OBJECT WE WANT TO SLOW DOWN.

– DRUM: INCLUDE ONE OR TWO BRAKE SHOES THAT COME INTO CONTACT WITH THE DRUM.

APPLICATIONS• http://www.youtube.com/watch?v=ol-wDa6kAgQ• http://www.youtube.com/watch?v=g4HqLoDjVRA• http://www.youtube.com/watch?v=B9XYJrTwhcM• http://www.youtube.com/watch?v=yU5CuxR2nDc

STORING ENERGY• SPRING: ARE DEVICES THAT ABSORB ENERGY THAT CAN BE RELEASED LATER,

LITTLE BY LITTLE OR ALL AT ONCE. SPRINGS WORK IN DIFFERENTS WAYS.

– COMPRESSION

– TRACTION

– TORSION

• SHOCK ABSORBER: ARE MADE OF STEEL SPIRAL SPRINGS.

• SUSPENSION SYSTEM: USE VERY FLEXIBLE METAL STRIPS, JOINED AT THE CENTRE.

APPLICATIONS• http://www.youtube.com/watch?v=mdXld_gQo-Y&feature=related• http://www.youtube.com/watch?v=QKlzdBU2u2E&feature=fvsr• http://www.youtube.com/watch?v=y_XAPNePnJY&feature=related

JOINING• CLUTCH: ARE MECHANISM THAT ALLOW AXLES OR SHAFTS TO BE CONNECTED

OR SEPARATED.

– FRICTION

– WITH TEETH

APPLICATIONS• http://www.youtube.com/watch?v=6BaECAbapRg• http://www.youtube.com/watch?v=XunM7yUC06M&feature=related

JOINING– FIXED: ARE USED TO MAKE PERMANENT CONNECTIONS BETWEEN AXLES

AND SHAFTS.

– MOVABLE: ARE USED TO CONNECT SHAFTS THAT CAN MOVE ALONG THE AXLE OR AT AN ANGLE TO EACH OTHER.

APPLICATIONS• http://www.youtube.com/watch?v=f9a83nakHOg• http://www.youtube.com/watch?v=4oUFbv927nU

SUPPORT

• BUSHING: THE AXLE OR THE SHAFT IS INSERTED IN A PLAIN CIRCULAR PIECE THAT IS PLACED INSIDE A HOUSING TO PROVIDE A BEARING SURFACE (AREA OF CONTACT BETWEEN TWO OBJECTS.

• BEARINGS: ARE MADE UP OF TWO CONCENTRIC RINGS WITH BALLS OR ROLLERS BETWEEN THEM.

APPLICATIONS• http://www.youtube.com/watch?v=RihQOUNsN9c

CURIOSITIES• http://www.youtube.com/watch?v=kdomzDVsNCM&feature=related• http://www.youtube.com/watch?v=0gjyVqwrf3E&feature=related• http://www.youtube.com/watch?v=Odr5bcVCMbc&feature=related• http://www.youtube.com/watch?v=pvvxAgn1cx8&feature=related• http://www.youtube.com/watch?v=fgbUV7xv_sk• http://www.youtube.com/watch?v=CIGa52qPVvA&feature=related• http://www.youtube.com/watch?v=YRlK2-JzyiA&feature=iv&annotation_id=anno

tation_538864• http://www.youtube.com/watch?v=dEHiAItVdiw&feature=fvwp• http://www.youtube.com/watch?v=PFKovH8I-9w• http://www.youtube.com/watch?v=mEg6z9391R4&feature=related• http://www.youtube.com/watch?v=kjF00xkmT9g• http://www.youtube.com/watch?v=g5VgReD3ejU&feature=related

THE END