6.9

Question 1

What is used to change direction of control runs?

Answer 1

Chains

Question 2

What is meant by pitch in relation to chains?

Answer 2

The distant between the centre of chain links

Question 3

What is a bi-planer block?

Answer 3

A mechanical link that turns a chain 90°

Question 4

Why must a chain wheel have more than 12 teeth?

Answer 4

The wear will be too high otherwise

Question 5

What is the minimum amount of teeth on a gear chain?

Answer 5

17

Question 6

Why are chain retainers used?

Answer 6

To prevent the chain jumping from the sprocket

Question 7

Why are couplings used?

Answer 7

To connect two shafts together?

Question 8

What are the different types of couplings?

Answer 8

• solid coupling
• safety coupling
• movable and disconnectable couplings

Question 9

What are the two types of solid couplings?

Answer 9

Disk and sleeve couplings

Question 10

Where are disk couplings used on voyager?

Answer 10

Slat drive shafts

Question 11

When are movable couplings used?

Answer 11

When shafts are not aligned or if position changes during operation

Question 12

When are extension couplings used?

Answer 12

When small longitudinal movement is needed (such heating during operation)

Question 13

What is a drive gear?

Answer 13

A gear that is giving an input/ driving into something

Question 14

What is a driven gear?

Answer 14

When a gear is being driven by something

Question 15

If a drive gear is turning clockwise, what direction is the driven gear turning?

Answer 15

Anti-clockwise

Question 16

How do you gain mechanical advantage when using gears?

Answer 16

By having gears with different amount of teeth

Question 17

How do you reduce the noise of toothed-wheel gears?

Answer 17

Ground tooth flanks and operate in oil

Question 18

When are external spur gears used?

Answer 18

When a change of speed is required and shafts lie parallel to each other

Question 19

When are internal spur gears used?

Answer 19

When a change of speed is required whilst maintains an overall minimum diameter

Question 20

What is the smallest of the pair of spur gears referred as?

Answer 20

The pinion

Question 21

What is the largest of the pair of spur gears referred as?

Answer 21

The spur

Question 22

What is special about the internal spur gear?

Answer 22

Both gears turn the same direction

Question 23

Why do helical gears transmit more power that straight gears?

Answer 23

More teeth in mesh for larger contact area

Question 24

Why is a rack and pinion used?

Answer 24

When you want to transform rotational motion into linear motion

Question 25

How does a worm gear work?

Answer 25

A gear will rotate and turn a spiral shaft to make it spin

Question 26

When are beverages gears used?

Answer 26

When transmitting the drive between shafts which have intersecting axes (two shafts at 90°)

Question 27

What angle should the teeth on a herringbone gear not exceed?

Answer 27

20°

Question 28

When are herringbone gears used?

Answer 28

When transmitting large forces

Question 29

What is meant by gear ratio?

Answer 29

The ration of the rotational speeds of multiple gears

Question 30

What happens if the drive gear is bigger than the driven gear?

Answer 30

The smaller driven gear will rotate quicker

Question 31

What is the formula for gear ratios?

Answer 31

T2/T1 | teeth on gear 2/ teeth on gear 1

Question 32

What is meant by backlash?

Answer 32

The clearance between gear teeth at the point of mesh

Question 33

Why must you have some backlash in gears?

Answer 33

To allow for lubrication and expansion

Question 34

What would happen if the backlash was too high?

Answer 34

The gears would start to wear

Question 35

What is meant by meshing?

Answer 35

The point at which the teeth are engaged with each other and ready to transmit power

Question 36

If you have a larger mesh angle what does this mean to the gear teeth?

Answer 36

They are also larger

Question 37

Why must all the gears in the chain have the same mesh angle?

Answer 37

Because they wont function correctly otherwise

Question 38

What is a idler gear?

Answer 38

The gear in between the drive and driven gears

Question 39

What is a intermediate gear?

Answer 39

It just like an idler gear but it has its own shaft

Question 40

What is a lay-shaft?

Answer 40

A term used to describe a shaft that supports an idler or intermediate gear

Question 41

What is a step-up drive?

Answer 41

When a gear train has a rotational speed output higher than the input

Question 42

What is a step-down drive?

Answer 42

When a gear train has a rotational speed output lower than the input

Question 43

What is a gear train?

Answer 43

A series of gears

Question 44

What is a compound gear?

Answer 44

A gear that has more than on driving face

Question 45

Where is a planetary reduction gear train mostly used?

Answer 45

In a aircraft propeller engine

Question 46

What are toothed wheel gears?

Answer 46

It’s a shaft with multiple gears on to be able t select the gear ratio you desire

Question 47

What are driving-key-type gears?

Answer 47

When a load of gears are set on two shafts that are constantly engaged and a spring loaded key selects the ratio it desires

Question 48

What is a infinitely variable rotational speed?

Answer 48

A machine that allows you to pick any rotational speed you desire within its speed range

Question 49

What are friction gears?

Answer 49

The driving friction wheel is movable so the rotational speed is infinitely variable

Question 50

What is a cone pulley drive?

Answer 50

A device that is infinitely variable by adjusting the pulleys to move the belt resulting in different speed

Question 51

If an aircraft doesn’t have fly-by-wire then what is its primary transmission component?

Answer 51

Cables

Question 52

What forces can cables transmit?

Answer 52

Pulling

Question 53

What forces can push rods transmit?

Answer 53

Push and pull

Question 54

If you adjust a push rod what must you check for?

Answer 54

To see threads in the witness hole