190303C

Question 1

What are the two general categories of powershift and automatic transmission application?

Answer 1

cycling
hauling

Question 2

how do these applications differ from each other?

Answer 2

by the arrangement of speeds and input/output direction that tranny offers

Question 3

what are the two general categories of power shift and auto trannys based on design of internal gearing?

Answer 3

planetary type
countershaft type

Question 4

what is the function of a transmission?

Answer 4

to modify engine power to propel heavy equipment through operating conditions it was designed for

Question 5

what torque/speed relation would you need with heavy loads or a steep grade?

Answer 5

high torque, low speed

Question 6

what torque/speed relation would you need with light loads or even ground?

Answer 6

low torque, higher speed

Question 7

what is another function that transmissions provide?

Answer 7

power can be drawn off to drive components. (PTO)

Question 8

What is the similarity between power shift and automatic transmissions?

Answer 8

they allow speed and direction change with no interruption to power flow from engine

Question 9

How does a power shift tranny differ from an auto?

Answer 9

speed and direction changes are made at the discretion of the operator

Question 10

all auto trannys are power shifts, but not all______ are autos

Answer 10

power shifts

Question 11

how many reverse speeds are there on a power shift tranny?

Answer 11

as many as there are forward speeds

Question 12

how does an auto tranny differ from a power shift?

Answer 12

spend changes are made independent of the operator action

Question 13

how does an auto tranny make shifts?

Answer 13

receives info from ground speed and operator demand for power

Question 14

what application uses power shift trannys?

Answer 14

cycling applications (repeated forward and reverse)

Question 15

what units perform cycling applications?

Answer 15

loaders, dozers

Question 16

what application uses auto trannys?

Answer 16

hauling applications

Question 17

what does an auto tranny allow the operator to do?

Answer 17

focus their attention on maneuvering the machine

Question 18

the gears used in planetary gear sets are in constant mesh, what does this prevent?

Answer 18

grinding and missed shifts when changing gears

Question 19

a smaller, more compact planetary gear set is capable of transmitting the same amount of torque as a larger spur gear set because gear tooth loading is spread among all of the contact points in the gear set
T or F

Answer 19

True

Question 20

why can smaller bearings and thrust washers be used on planetary gear sets?

Answer 20

axial and radial thrust loads are offset in a planetary set

Question 21

planetary gear sets are extremely versatile in that they are capable of providing many _____ of speeds and directions particularly when multiple sets are used

Answer 21

combinations

Question 22

Why are planetary gear sets used in heavy equipment power shift and auto shift trannys?

Answer 22

to modify torque and speed from engine

Question 23

What gear style is usually seen on planetary gears?

Answer 23

straight cut spur or helical

Question 24

what can the planetary carrier metal be made from?

Answer 24

cast iron, aluminum, steel

Question 25

what do planetary gears commonly rotate on to reduce friction between gears and pinion shafts?

Answer 25

needle bearings

Question 26

how is end thrust absorbed between gear ends and carrier?

Answer 26

on brass or steel thrust washers

Question 27

what conditions can a simple planetary gear set create?

Answer 27

1. reduction in fwd ranges 2. reduction in reverse ranges 3. direct drive 4. neutral 5. overdrive in fwd and reverse

Question 28

what does gear ratio refer to?

Answer 28

of revolutions the input (drive) gear makes to complete one revolution of the output (driven) gear.

Question 29

what are planetary pinions only used for?

Answer 29

transfer torque or change direction

Question 30

what is gear reduction?

Answer 30

input speed is higher than output speed

Question 31

what is overdrive?

Answer 31

torque reduced, speed increased

Question 32

what is neutral/freewheeling?

Answer 32

power input but no power output

Question 33

What are two speed reduction conditions?

Answer 33

first speed slow, second speed fast

Question 34

what are two overdrive conditions?

Answer 34

first speed slow, second speed fast

Question 35

what are two reverse speed conditions?

Answer 35

first speed reduction, second speed overdrive

Question 36

When does first speed reduction occur?

Answer 36

when the sun gear drives the carrier. smallest turning biggest. ring held

Question 37

when does second speed reduction occur?

Answer 37

when ring gear drives carrier. medium turning biggest. sun held

Question 38

what is a constant fact in planetary overdrive?

Answer 38

carrier being input member is always an overdrive

Question 39

what is a constant fact in planetary reduction?

Answer 39

carrier being the output member is always a speed reduction

Question 40

when does a first speed overdrive occur?

Answer 40

when carrier drives ring gear. sun held. biggest driving medium. mild

Question 41

when does second speed overdrive occur?

Answer 41

when carrier drives sun. biggest driving smallest. ring gear held

Question 42

what is a constant fact in planetary reverse?

Answer 42

carrier being held is always a reverse condition

Question 43

when does a first speed reverse occur?

Answer 43

sun drives ring gear. small driving medium. carrier held. reduction

Question 44

when does second speed reverse occur?

Answer 44

ring gear drives sun. medium driving smallest. carrier held. overdrive

Question 45

what are 2 ways to achieve neutral from a single planetary set?

Answer 45

1. when there's an input but no held member 2. when there's no input to gear set

Question 46

what are 2 ways to achieve direct drive from a single planetary set?

Answer 46

1. locking 2 members together 2. driving 2 members at the same speed (rpm) in the same direction

Question 47

all clutches are hyd applied, ______________

Answer 47

spring released

Question 48

what do clutches hold together in a planetary tranny? what do brakes hold together in a planetary tranny?

Answer 48

2 components together a component to the housing

Question 49

What is a quick way to remember what clutches/brakes are held for reverse?

Answer 49

first clutch, last brake

Question 50

what is the definition of a differential planetary gear set?

Answer 50

has a simple planetary with three rotating members, for dual input single output

Question 51

What happens to carrier speed when the sun and ring gear are turning the same direction?

Answer 51

carrier speed always in between both speeds.

Question 52

when the sun and the ring gear rotate in same direction, are there more or less teeth?

Answer 52

less teeth per rotation

Question 53

what does a rotating clutch do?

Answer 53

hold 2 components together, rotates with components

Question 54

what does a stationary clutch do?

Answer 54

hold component to tranny housing. "brakes" internal gear

Question 55

the output speed and torque of the differential planetary set with sun and internal gear inputs is determined by?

Answer 55

tooth speed of the sun and ring gear

Question 56

what does tooth speed refer to?

Answer 56

number of teeth passing by a given point in a given period of time. measured in teeth per second.

Question 57

if ring gear is rotated in opposite direction of sun gear, what does the carrier speed do?

Answer 57

decreases

Question 58

if ring gear is rotated at an equal negative tooth count speed to the sun gear, what does the carrier do?

Answer 58

carrier speed goes to 0

Question 59

rotating the ring gear in reverse to the sun at a higher speed causes the carrier to?

Answer 59

start to travel in reverse as well

Question 60

a direct drive within a planetary set exists when?

Answer 60

2 rotational speeds are equal, not tooth speed.

Question 61

if tooth speeds are equal in opposite directions, what is the carrier doing?

Answer 61

carrier is not moving

Question 62

All transmission clutches are _____ released?

Answer 62

spring

Question 63

where do tranny clutches get their oil from?

Answer 63

tranny charging pump

Question 64

what are 2 types of clutch discs used?

Answer 64

clutch discs (friction discs) clutch plates

Question 65

what are clutch discs?

Answer 65

made from sintered bronze or composite, steel discs that have friction material bonded to them.

Question 66

what do the grooves on friction discs serve as a purpose for?

Answer 66

when disc is disengaged, allows oil to lubricate the groove lines when disc engaged, allows oil to escape from grooves

Question 67

what is the purpose of clutch disc teeth?

Answer 67

spline to the compound to be held reactionary

Question 68

what are clutch plates?

Answer 68

located between every pair of clutch discs. provide a reaction surface where the clutch discs can act

Question 69

what are the tangs on the outside of the clutch plates for?

Answer 69

holding a component stationary ( to tranny housing)

Question 70

what are teeth on the outside of the clutch plates for?

Answer 70

spline to a clutch drum to hold 2 components together

Question 71

what is used to apply the clutch?

Answer 71

hyd actuated pistons

Question 72

what type of seal is common on a clutch piston?

Answer 72

lip seal

Question 73

what is the difference between manual and power shift trannys regarding the gears being held?

Answer 73

gears in power shift/auto are held to their countershafts with multiple disc oil applied clutches rather than mechanical clutches

Question 74

do countershaft transmissions use stationary clutches?

Answer 74

no, only rotating

Question 75

what are high-low countershaft units for?

Answer 75

providing various speed ratios, from deep reduction, direct drive, or overdrive.

Question 76

where do the clutch plates and discs spline to in a high-low countershaft unit?

Answer 76

clutch plates spline to the drum clutch discs spline to the hub on the output shaft

Question 77

the planetary gear set component that meshes with the sun and internal gear is called the planet carrier T or F

Answer 77

False it is the pinions not the carrier

Question 78

what condition is it when both internal and sun gear rotating forward at the same tooth speed?

Answer 78

reduction

Question 79

what condition is it when internal gear rotates forward and sun gear rotates in reverse at same tooth speed as internal?

Answer 79

neutral

Question 80

wha condition is it when internal gear is rotating in reverse at a much higher tooth speed than the sun gear is rotation forward?

Answer 80

reverse

Question 81

what condition is it when the internal gear and sun gear are rotating forward at equal rpm?

Answer 81

direct drive