CLASSIFICATION OF MECHANISMS

A. TRANSMITTING MOTION.

                    - Linear: Lever, Fixed pulley, Movable pulley, Compound pulley.
                    - Rotary: Friction drives, Pulleys with belt, Gear mechanisms, Worm gear, etc.

B. TRANSFORMING MOTION.

                    - Rotary to Linear: Rack and pinion system, Nut and bolt system, Winch and crank handle
                    - Rotary to Reciprocating: Crank-link-slider, Crankshaft, Cam, Eccentric cam

C. CONTROLLING AND REGULATING MOTION.

                   - Disc brakes.
                   - Band brakes.
                   - Drum brakes.

D. STORING ENERGY.

                   - Spring.

E. JOINING ELEMENTS.

                  - Clutch.
                  - Fixed connections.
                  - Movable connections.


EXERCISE : Choose at least three mechanisms and describe them. Include diagrams, pictures, formulas, real applications, etc.You have to do each machine in a single worksheet. 
 It´s not compulsatory. If you do it you can add maximum 0.50 to the final mark of the revision test.

Here you have interesting links to do the work


Mechanisms

Technology student

DEFINITION OF MECHANISM

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.

UNIT 8. MECHANISMS.

VOCABULARY

TRANSLATE INTO SPANISH

Inclined plane

Wheel

Axle

Lever

Pulley

screw

wedge

force

speed

ramp

motion

frictionless

pivoting point

 fulcrum

lever

arm,

moment of force

Examples of levers: wheelbarrow, fishing rod, scissors, hole punch,

broom, pincers, scales, tongs, nutcracker, pliers,

fire extinguisher, handle, paper cutter, tweezers,

crowbar, shovel, can opener, stapler, brake, oar, bottle opener,steering wheel,

windlass, coffee grinder, pepper mill, water tap, crane, flag pole, fixed, movable,

http://www.xtec.cat/monografics/cirel/pla_le/nile/carles_egusquiza/student/student.pdf

REVISION ACTIVITIES

PLASTICS, CERAMICS AND FABRIC MATERIALS.

Exercises:
1,3,5,6,7,8,9,12,13,15,17 and 20

You have to do these exercises if you want to add 0.5 to the  final mark of the revision exam. It´s not compulsatory.

TRABAJO FINAL 3º ESO

PAIR 1,2

Nuclear Energy. - Definition
                        - Fission Vs Fusion
                        - Parts of a Nuclear Power Plant

PAIR 3,4

Solar Energy.    - Definition
                       - Parts of a Solar Panel
                       - How it works?
                       - Picture

PAIR 5,6

Biomass.          - Types of waste.
                       - Process to obtain energy
                       - Picture

PAIR 7,8

Hydroelectric Energy. - Definition
                                - Basic Components
                                - Picture
                                - How it works?

PAIR 9,10

Wind Energy.    - Definition
                       - Parts of a wind turbine
                       - How it works?
                       - Picture

PAIR 11,12    

Mechanisms.    - Classification
                       - Types of levers
                       - Lever`s Law
                       - Picture

PAIR 13,14

Formation Techniques of Plastics. - Extrusion. Picture
                                                  - Vacuum Forming. Picture.
                                                  - Molding. Types. Pictures.

PAIR 15,16

Classification of Plastics.              - Thermoplastics.
                                                 - Thermosetting.
                                                 - Elastomers.
                                                 - Examples. Pictures.

PAIR 17,18

Electricity.                                 - Circuit Symbols.

PAIR 19,20

ITC. - Device´s Definitions.
       - Input Devices.
       - Output Devices.
       - I/O Devices.

PAIR 21,22

OHM´S LAW

100 PROBLEMAS DE LA LEY DE OHM

MEANS OF TRANSPORT

1. COCHE ----------------------------  CAR
2. VEHICULO TODOTERRENO ---  ALL-TERRAIN VEHICLE
3. DESCAPOTABLE  ------------ ---  CONVERTIBLE
4. MONOVOLUMEN ---------------  PEOPLE CARRIER
5. LIMUSINA  ------------                            ---  LIMOUSINE
6. BICICLETA                               ---  BIKE // BICYCLE
7. CARAVANA                             --- CARAVAN
8. AUTOBUS                                 --- BUS
9. AUTOCAR                                --- COACH
10. AUTOBUS DOS PISOS         --- DOUBLE-DECKER BUS
11. CAMION                                --- TRUCK // LORRY
12. CAMION CISTERNA            --- TANKER
13. CAMIONETA                        --- VAN
14. HORMIGONERA                  --- CONCRETE MIXER TRUCK
15. QUITANIEVES                      --- SNOWBLOWER
16. BARREDORA                        --- STREET SWEEPER
17. TREN                                     --- TRAIN
18. TRANVIA                              --- TRAM
19. AVION                                   --- PLANE //AEROPLANE
20. BARCO                                  --- SHIP
21. BARCA                                  --- BOAT
22. AERODESLIZADOR             --- HOVERCRAFT
23. PETROLERO                         --- OIL TANKER
24. YATE                                      --- YACHT
25. LANCHA                               --- RUNABOUT
26. HELICOPTERO                     --- HELICOPTER
27. GLOBO AEROSTATICO     --- BALLOON
28. MOTOCICLETA                   --- MOTORBIKE// MOTORCYCLE
29. SCOOTER                            --- SCOOTER
30. METRO                                 --- UNDERGROUND // SUBWAY // TUBE

PARTS OF A BIKE

PARTS OF A CAR

Aerial (GB)	antena
Antenna (US)	antena
Bodywork	carrocería
Hood (US)	capó
Bonnet (GB)	capó
Trunk (US)	maletero
Boot (GB)	maletero
Brake	freno
Engine	motor
Exhaust pipe	tubo de escape
Gear lever (GB)	palanca de cambios
Gear shift (US)	palanca de cambios
Handbrake	freno de mano
Headlight	faro delantero
Horn	bocina
Rear-view mirror	espejo retrovisor
Seat belt	cinturón de seguridad
Steering wheel	volante
Tire (US)	neumático
Tyre (GB)	neumático
Windscreen (GB)	Parabrisas, luna
Windscreen wiper (GB)	limpiaparabrisas

MECHANISMS

MECHANISMS

1.CLASSIFICATION

-         TRANSMITTING MOTION

    LINEAR

     ROTARY

-         TRANSFORMING MOTION

 ROTARY TO LINEAR

 ROTARY TO RECIPROCATING

2. LINEAR MOTION MECHANISMS

2.1.         LEVERS

A lever is a rigid bar that is supported by a fulcrum

F: Force or Effort

R: Resistance or Load

d: distance from  force to  fulcrum

r: distance from  resistance to fulcrum

Law of the lever  F.d=R.r

Types:       Class 1: hammer, scissors

                 Class 2: wheelbarrow

                 Class 3: pincers

2.2.         FIX PULLEY        F=R

2.3.         MOVABLE PULLEY     F= R/2

2.4.         COMPOUND PULLEY    F=R/2*N

3.ROTARY MOTION MECHANISMS

3.1.FRICTION DRIVES

N1*D1=N2*D2

1  PRIMARY DRIVE WHEEL

2  OUTPUT WHEEL

i= GEAR RATIO   i=D1/D2

D= DIAMETER

N= VELOCITY (RPM) Revolution per minute

3.2.  PULLEYS WITH BELT

N1*D1=N2*D2

3.3.  PULLEYS TRAIN WITH  BELT

N4/N1= D1*D3/D2*D4

N1*D1=N2*D2

      N2=N3

N3*D3=N4*D4

i=D1/D2

i=D3/D4

i_TOTAL= D1*D3/D2*D4

3.4. WORM GEAR (TORNILLO SIN FIN)

4. MECHANISMS THAT TRANSFORM MOTION

4.1.         FROM ROTARY TO LINEAR

A.    RACK AND PINION SYSTEM (PIÑON-CREMALLERA)

L= P*Z*N

L= VELOCITY OF THE RACK (mm/min)

Z= NUMBER OF TEETH

N= NUMBER OF ROTATIONS PER MINUTE

B.     NUT AND BOLT SYSTEM (TORNILLO-TUERCA)

F*2Πr= R*ρ

ρ= thread (paso de rosca)

C.     WINCH AND CRACK HANDLE (MANIVELA-TORNO)

F*l=R*r

r=radius of the winch

l= length of the crack handle