Mechanisms

Question 1

What do mechanical devices do?

Answer 1

They change an input force and movement into a desired output force and movement they can change the magnitude and direction of force

Question 2

What can mechanisms be used for?

Answer 2

To make a force, bigger or smaller

Question 3

What can mechanical devices be used for?

Answer 3

To produce different types of movement

Question 4

What is linear movement?

Answer 4

Movement in a straight line in One Direction

Question 5

What is reciprocating movement?

Answer 5

Movement in a straight line in two directions

Question 6

What is rotary movement?

Answer 6

Rotational movement on or around an axis

Question 7

What is oscillating movement?

Answer 7

The movement back and forth along a curved path

Question 8

Name is six simple mechanisms

Answer 8

Inclined plane
Wedge
Screw
A lever
Wheel and axle.
Pulley

Question 9

What is mechanical advantage?

Answer 9

A measure of the force amplification achieved by using a mechanism

Question 10

What does MA stand for?

Answer 10

Mechanical advantage

Question 11

What does mechanical advantage measure?

Answer 11

The ratio of the input force (effort) to the output force (load)

Question 12

How do you calculate mechanical advantage?

Answer 12

Load divided by effort

Question 13

What are gears? And what are they used for?

Answer 13

They are toothed wheels attached to shafts. They are used to transmit power and rotational motion around mechanical systems.

Question 14

What do gear trains consist of?

Answer 14

Two or more interlocking gears that transmit torque and rotary motion

Question 15

What is torque?

Answer 15

Determine force that causes rotation

Question 16

What do the teeth of the gears do in a gear train?

Answer 16

1. The teeth of the gears interlock

Question 17

What is the output gear in a geartrain called?

Answer 17

The driver gear

Question 18

What is the output gear in the geartrain called?

Answer 18

The driven gear

Question 19

What happens if the driver gear rotates clockwise?

Answer 19

The driven gear rotate anticlockwise

Question 20

How can the direction of rotation of the driven gear be changed?

Answer 20

By adding an idler gear

Question 21

How does the idler gear change the direction of rotation?

Answer 21

It changes the direction of rotation, so that both the driver gear and the driven gear I’m moving in the same direction

Question 22

Why does the size of the idler gear not matter?

Answer 22

It transfers, the movement without altering the speed of the gears

Question 23

How do you make a faster output speed?

Answer 23

The input gear must be larger than the output gear

Question 24

How do you create a slower output speed?

Answer 24

The input gear must be smaller than the output gear

Question 25

How do you calculate. The number of teeth of a small gear in gear ratios?

Answer 25

by dividing the number of teeth on the last year by the number of teeth on the smaller gear

Question 26

How do you calculate the large gear in gear ratios

Answer 26

The last year always equals one

Question 27

What are cam mechanisms used for?

Answer 27

They used to convert rotary motion into reciprocal motion

Question 28

What do you mechanisms consist of?

Answer 28

mechanisms consist of a cam and a follower

Question 29

What is a cam?

Answer 29

Especially shaped piece of material attached to a rotating shaft

Question 30

How does a cam and a follower create a reciprocating motion?

Answer 30

A rod known as a follower rests on the cam and rises and falls as the cam rotates

Question 31

What depends on the shape of the cam

Answer 31

Whether the follower will either rise, fall or dwell ( Remain stationary)

Question 32

Does a cam mechanism often also include

Answer 32

1.A slide to prevent the follower from slipping. 2.A crack (handle) to manually rotate the camshaft. 3. A wheel follower to reduce friction between the cam and the follower

Question 33

List of four common cams

Answer 33

1.eccentric ( Circular) 2.pear-shaped, 3.snail 4.heart-shaped ( Constant velocity)

Question 34

How do eccentric cams work?

Answer 34

The pivot ( Rotating shaft )is positioned off centre, causing the follower to steadily rise and fall

Question 35

How does a snail cam work?

Answer 35

The follower gradually rises, and then suddenly drops. It can only rotate in One Direction.

Question 36

How does a pear-shaped cam work?

Answer 36

The follower dwells for half a turn It then rises as the point approaches for a quarter of a term before falling for the last quarter rotation.

Question 37

How does a heart shaped cam work?

Answer 37

The follower rises, and falls, with no dwell period is said to have constant velocity

Question 38

What is a simple fixed pulley Mechanism made from

Answer 38

It is made up of a rimmed wheel and a cable which sits inside of the rimmed wheel

Question 39

What are the positives of a simple fixed pulley mechanism?

Answer 39

It provides no mechanical advantage, but it can make items easier to lift by changing the direction of force

Question 40

What can reduce the magnitude of force required to lift a load?

Answer 40

Using two or more police together in a block and tackle system

Question 41

Give an example of a block and tackle system

Answer 41

half the required input force to lift the load

Question 42

What happens in a belt and pulley system?

Answer 42

Two or more pulley are connected by about to transfer rotary, motion, and force from the driver pulley to the driven pulley

Question 43

Give an example of when a belt and pulley system is used

Answer 43

They’re used in car engines and washing machines

Question 44

As the belts need to remain taught in a belt and police system, what are they made out of?

Answer 44

They are often made of rubber to reduce the thing

Question 45

What does crossing the belts and a belt and pulley system do?

Answer 45

It changes the direction of the output movement

Question 46

In a belt and pulley system, what happens when the driver pulley is larger than the driven pulley?

Answer 46

The driven pulley will rotate faster, but the torque will be less

Question 47

In a belt and Pulley system, what happens when the driver pulley is smaller than the driven pulley?

Answer 47

The driven Polly will rotate slower, but the torque will be greater

Question 48

How can the velocity ratio between two pulleys be calculated?

Answer 48

Diameter of driven, pulley, divided by diameter of driver pulley

Question 49

What is a lever?

Answer 49

A mechanical device used to transmit and transform the effects of forces

Question 50

What is transmitted through the lever to move the load?

Answer 50

Motion and input force (effort)

Question 51

What are the three parts to a lever?

Answer 51

Effort, fulcrum/pivot,load

Question 52

What is the effort in A lever?

Answer 52

The input force exerted on the lever

Question 53

What is the fulcrum/ pivot in the lever?

Answer 53

The point around which the lever acts

Question 54

What is the load in a lever?

Answer 54

The force of the object that needs to be moved

Question 55

What are the three classes of levers?

Answer 55

First order second order third order

Question 56

How does the first order lever work?

Answer 56

The fulcrum is position between the Loader and the effort.

Question 57

How can the input effort required to lift the load be reduced in a first order lever?

Answer 57

by moving the fulcrum closer to the load.

Question 58

3 examples of a first order lever….

Answer 58

Scissors Seesaw Crowbar

Question 59

How does a second order lever work??

Answer 59

The load is positioned between the fulcrum and the effort

Question 60

How can the input effort required to lift the load be reduced?

Answer 60

By moving the load closer to the Fulcrum

Question 61

3 examples of a second order lever….

Answer 61

Bottle opener Wheelbarrow Nutcracker

Question 62

What Happens in a third order lever?

Answer 62

The effort this position between the Fulcrum and a load

Question 63

What do third order leavers not have compared to 1st and second order leavers

Answer 63

Mechanical advantage as the effort is closer to the fulcrum than the load. As a result, the input effort is greater than the output force.

Question 64

3 examples of a third order lever

Answer 64

Tweezers Human arm Fishing rod

Question 65

Name, the 3 types of linkages

Answer 65

Push and pull linkages Bell crank linkages. Changing magnitude of force

Question 66

What can be joined together to make linkages?

Answer 66

Leavers

Question 67

What do linkages change?

Answer 67

1.And input motion 2.force into an output motion 3.force

Question 68

What dopush/pull linkages make?

Answer 68

Creates an identical parallel motion at the output

Question 69

What kind of a push/pull linkage also be called

Answer 69

A parallel motion

Question 70

What do bell crank linkages do?

Answer 70

Change the direction of motion through 90°

Question 71

What happens in a reverse linkage? ( changing magnitude and force)

Answer 71

The fixed point (pivot)is an equal distance from the input and output leavers so the output force is equal to the input force

Question 72

In a reverse linkage, what must be done to make the output force greater than the input force

Answer 72

You must move the fixed (pivot) point closer to the output