HET 4 GEARING

Question 1

What are components of a gear tooth?

Answer 1

Face, Flank, Heel and Toe

Question 2

Is the concave side or the convex side the drive side?

Answer 2

Convex side is a drive side

Question 3

The larger end of a gear is the?

a) heel
b) toe
c) face
d) flank

Answer 3

Heel

Question 4

What is special about the root fillet area?

Answer 4

Its rounded, to give strength

Question 5

When the is off the throttle and is in a coasting moment, what happens to the drive and driven side of a gear?

Answer 5

The opposite side becomes the driven, concave is drive and convex is driven

Question 6

What three circles are measurable in on a gear?

Answer 6

Root
Pitch
Outside

Question 7

What needs to be found before the circular gear pitch can be determined?

Answer 7

Pitch circle

Question 8

If the gears in mesh have the same circular gear tooth pitch, what does it achieve?

Answer 8

Greatest strength

Question 9

The clearance between the root and tooth tip of two gears is there for what reason?

Answer 9

To provide a space for lubrication

Question 10

Why are gears not installed in tight contact?

Answer 10

No room for expansion during operation

Question 11

What tool is used to measure backlash?

Answer 11

Dial indicator

Question 12

When gears have run together for a long time what can happen?

Answer 12

change in tooth profile/shape, gears have worn into eachother

Question 13

What types of timing are possible with gears?

Answer 13

Hunting, Non-Hunting and Partial Non-Hunting

Question 14

Why are timing marks important in a non-hunting gear set?

Answer 14

The timing marks must line up - proper timing - longer service life

Question 15

What type of timing design would a gear set be if the ratio is 5:1?

Answer 15

Non-hunting

Question 16

What type of timing design would a gear set be if the ratio is 8.5:1?

Answer 16

Partial non-hunting

Question 17

What type of timing design would a gear set be if the ratio is 3.89:1?

Answer 17

Hunting

Question 18

Describe hunting gear sets?

Answer 18

No specific wear pattern is created, every tooth in one gear will touch every tooth in the other gear, no timing

Question 19

If a few teeth on one gear constantly mesh with only a few teeth on another gear, the gears are timed or not?

Answer 19

Timed - non or partial non hunting

Question 20

Which type of gear timing has the most distinctive wear pattern?

Answer 20

Non-hunting

Question 21

When two external gears are in mesh what is produced?

Answer 21

A reverse

Question 22

What is the speed difference between input and output gears when they are identical size?

Answer 22

No speed differences

Question 23

Why is path-of-power important to understand when looking at gears?

Answer 23

Helps determine gear ratios, troubleshoot faults

Question 24

Gear rations are written in relation to drive and driven gears, in a 1:2 ration which is driven and which is drive?

Answer 24

1 is drive and 2 is driven

Question 25

To find the gear ration what is divided or multiplied?

Answer 25

Driven is divided by drive Driven over Drive Driven (24) ÷ Drive (12)

Question 26

If a gear starts to show blue colouring what could be the problem?

Answer 26

No backlash - No lube - Heat

Question 27

Crankshaft and Camshaft timing is considered which design? a) hunting b) non-hunting c) partial non-hunting

Answer 27

Non-Hunting, specific timing

Question 28

If a drive gear rotates twice and the driven gear rotates once, what type of drive is it?

Answer 28

Reduction

Question 29

What does an idler do between to external gears?

Answer 29

Changes output gear direction of rotation

Question 30

True or False | Idlers are used to change speed and torque?

Answer 30

False - only direction of rotation

Question 31

Are gear ratios added together or multiplied?

Answer 31

The gear ratios are multiplied against eachother

Question 32

Without an idler what three conditions can two gears run in?

Answer 32

Direct drive, Reduction and Overdrive

Question 33

Is it more likely for the pinion gear to be the drive member or the crown gear?

Answer 33

Pinion gear is usually the drive gear

Question 34

What are three types of external gears?

Answer 34

Spur/straight cut, helical cut, double helical cut

Question 35

True or False | Internal gears mesh with other internal gears?

Answer 35

False

Question 36

What thrust loads are produced by single helical gears?

Answer 36

Axial thrust

Question 37

Why are double helical gears great?

Answer 37

No/little axial thrust

Question 38

What is a negative feature of a herringbone gear?

Answer 38

Cost to manufacture

Question 39

What is commonly the drive (input) in a simple planetary?

Answer 39

Sun

Question 40

Tapered roller bearings can handle what types of thrust loads?

Answer 40

Axial and radial thrust loads

Question 41

What are the four basic components of a simple planetary?

Answer 41

Sun, Planets, Carrier and Ring Gear

Question 42

Direct drive can result if two components are held, what other way can direct drive be created?

Answer 42

two components being driven at same RPM

Question 43

Hypoid gears have the pinion above or below the center line of the crown gear?

Answer 43

Below the center line

Question 44

In what set up are pinion gears above the center line of the crown gear?

Answer 44

Amboi gears

Question 45

In a basic spiral bevel gear set where is the pinion gear in relation to the crown gear center line?

Answer 45

Centered with the center line

Question 46

Rack and pinion gears do what with rotary motion?

Answer 46

Rotary motion is turned into linear motion

Question 47

What situations are worm gears good for?

Answer 47

High Torque loads

Question 48

Is it common to see worm and worm wheel gear sets on a high speed on-highway trucks?

Answer 48

No | unless it has a winch!

Question 49

What is the purpose of an amboid gear set up?

Answer 49

Driveline is higher - off road

Question 50

Does a hypoid gear set up have more or less tooth contact during meshing, when compared to a pinion that is centered on the crown gear?

Answer 50

More tooth contact

Question 51

True or False | Hypoid angle gears are used in LOW torque situations?

Answer 51

False, High torque loads

Question 52

Angle gears can have a maximum angle of?

Answer 52

90°

Question 53

A reactionary member can also be referred to as a?

Answer 53

Held member

Question 54

To have a planetary operate, what conditions must the components be in?

Answer 54

one member is a DRIVE one member is DRIVEN one member is HELD

Question 55

If none of the members of a planetary are held what condition is created?

Answer 55

Neutral

Question 56

Why is extreme pressure lubricant used in hypoid gear sets?

Answer 56

Sliding contact and pressure between gear teeth during meshing process is very high

Question 57

Do hypoid gear sets have the same load handing abilities as an amboid gear set?

Answer 57

Yes

Question 58

When the carrier is held what is created?

Answer 58

a reverse