Gearing princibles

Question 1

what are the key areas of the gear tooth

Answer 1

Face - flank - heel - toe - centerline - pitch line

Question 2

once a gear tooth has been divided lengthwise, what is the name of the upper half of the tooth

Answer 2

face

Question 3

once a gear tooth has been divided lengthwise, what is the name of the lower half of the tooth

Answer 3

flank

Question 4

when a gear tooth has a larger end and a smaller end what is the smaller end of the tooth called

Answer 4

toe

Question 5

when a gear tooth has a larger end and a smaller end what is the larger end of the tooth called

Answer 5

heel

Question 6

why is the root fillet of a gear tooth rounded slightly

Answer 6

to give the tooth strength and reduce the chances of cracking in this area

Question 7

when the engine is driving a tractor the driving force acting on the gears in mesh is happening on what side of the gear tooth

Answer 7

drive side of the gear tooth

Question 8

when the throttle has been let off and a tractor is coasting down a highway . with the loaded vehicle pushing the powertrain what side of the gear teeth are being used

Answer 8

the coast side

Question 9

what are the three dimensions when looking at a pitch circle of a gear

Answer 9

. root diameter = shortest measurement
. outside diameter = greatest measurement
. pitch diameter = starts at the line that divides face and flank

Question 10

in order to determine circular gear pitch what must first be established

Answer 10

pitch circle

Question 11

why is it important to have the pitch circles of gears in mesh intersect

Answer 11

this relationship provides great gear strength, maximum force can then be delivered through the gears

Question 12

wat is the purpose of having clearance between the root and tip of gear teeth in mesh

Answer 12

helps maintain a lubrication film between the teeth as they mesh together

Question 13

what is the purpose of gear backlash

Answer 13

to allow for tooth expansion and lubrication

Question 14

what is the purpose of having timed gear sets

Answer 14

this ensures that they always operate in a specific relationship with one another

Question 15

what will proper timing of gears promote

Answer 15

long service life because they will develop distinctive wear patterns during operation

Question 16

non - hunting gear sets

Answer 16

will have to be timed - will have a whole ratio 3:1 - 2:1 ect

Question 17

partial - nonhunting gear sets

Answer 17

will have to be timed - will have a ratio without a run on number 4.50:1 - 3.75:1 ect

Question 18

hunting gear sets

Answer 18

will not have to be timed . number of teeth will divide unequally into the crown gear 3.89: 1 - 2.333333:1 ect

Question 19

direct drive

Answer 19

when two gear of identical size are in mesh with each other will have a one to one ratio 1:1

Question 20

how is a gear ratio calculated

Answer 20

number of driven teeth over number of drive teeth

Question 21

how is a reduction created in a gear set

Answer 21

small gear driving a big gear

Question 22

how would a overdrive be created in a gear set

Answer 22

large gear driving a big gear

Question 23

how can you change rotation of gears on mesh

Answer 23

by adding an idler gear

Question 24

what is the most basic type of gears

Answer 24

straight spur cut gears

Question 25

do straight cut spur gears require thrust washers

Answer 25

no because no end thrust is created

Question 26

what is an advantage of internal gear design

Answer 26

very strong and they can handle high loads

Question 27

what is an advantage of helical cut gears

Answer 27

provides great strength and less noise in operation

Question 28

because of the design of helical cut gears what do they need to have

Answer 28

thrust washers because axial thrust is created when they are in mesh

Question 29

what is a herringbone type of gear

Answer 29

a double helical cut gear . used for heavy torque loads

Question 30

what type of gear set can be used to change rotary motion into linear motion

Answer 30

rack and pinion

Question 31

in order to gain strength in design of angle cut gear sets what type of gear was developed

Answer 31

spiral cut gears . allows the contact to be more extensive and noise to be reduced

Question 32

when would a hypoid gear configuration be used

Answer 32

where high torque loads are expected

Question 33

when would a amboid gear configuration be used

Answer 33

when the vehicle is operating off road and this will allow for a higher drive line position

Question 34

what is the difference between hypoid and amboid gear sets

Answer 34

. Hypoid gear sets are positioned so the centerline of the pinion shaft is below the centerline of the crown gear
. Amboid gear sets are positioned so the centerline of the pinon shaft is above the centerline of the crown gear

Question 35

what are the components of a simple planetary

Answer 35

sun gear - pinion gears ( planets ) and internal gear

Question 36

how is direct drive achieved in a planetary

Answer 36

any two members held

Question 37

how is reverse achieved in a planetary

Answer 37

carrier held or planets

Question 38

how is reduction achieved in a planetary

Answer 38

carrier driven

Question 39

how is overdrive achieved in a planetary

Answer 39

carrier drive

Question 40

how is neutral achieved in a planetary

Answer 40

no members held