303C: Powershift & Automatic Transmission Mech/Elec. Components

Question 1

What is gear ratio?

Answer 1

Refers to the number of revolutions the input gear makes to complete one revolution of the output gear.

Ratio = Driven/Drive

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Question 2

What is the formula for gear ratio?

Answer 2

Gear Ratio = Driven/Drive

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Question 3

How is 1st speed reduction acheived in a planetary gear set?

Answer 3

Input: Sun
Output: Carrier
Reactionary: Internal

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Question 4

How is 2nd speed reduction acheived in a planetary gear set?

Answer 4

Input: Internal
Output: Carrier
Reactionary: Sun

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Question 5

How is 1st speed overdrive acheived in a planetary gear set?

Answer 5

Input: Carrier
Output: Internal
Reactionary: Sun

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Question 6

How is 2nd speed overdrive achieved in a planetary gear set?

Answer 6

Input: Carrier
Output: Internal
Reactionary: Sun

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Question 7

In a planetary gear set if the carrier is held, you will always get what condition?

Answer 7

Reverse

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Question 8

How is 1st speed reverse achevied in a planetary gear set?

Answer 8

Input: Sun
Output: Internal
Reactionary: Carrier

A reduction

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Question 9

How is 2nd speed reverse achieved in a planetary gear set?

Answer 9

Input: Internal
Output: Sun
Reactionary: Carrier

An Overdrive

Question 10

What are three methodes of acheving neutral in a planetary gear set?

Answer 10

1) No held member
2) No input
3) Sun and internal gear driven in opposite directions at the same tooth speed

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Question 11

How is direct drive acheived in a planetary gear set?

Answer 11

• Locking two members together
• Driving two members at the same speed

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Question 12

What are the two basic design types of powershift and automatic transmissions?

Answer 12

• Planetary
• Countershaft

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Question 13

A dump truck is an example of a machine used in a cycling type application. (T/F)

Answer 13

False
Would use an automatic transmission for its hauling aplication.

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Question 14

A scraper is typically used in a hauling application. (T/F)

Answer 14

True

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Question 15

What are the two type of clutch discs used in transmission clutch assemblies?

Answer 15

Clutch discs - Friction material
Clutch plates - Reaction surface for disks

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Question 16

What is the purpose of the grooves on the face of clutch disc’s friction material?

Answer 16

Lands
- Carry oil to lube the discs when disengaged
- Allow oil to be squeezed out when clutch is applied

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Question 17

How are the transmission clutch packs applied?

Answer 17

Hydraulically actuated
Spring released

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Question 18

Reverse gear in a countershaft transmission is possible through two main components:

Answer 18

• Idler gear on countershaft
• Reverse clutch activation

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Question 19

Gear selection in a countershaft transmission is engaged by:

Answer 19

Drilled oil passages that hydraulically apply clutch discs

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Question 20

Many heavy equipment transmissions provide a place to couple auxiliary components such as hydraulic pumps. This drive is known as:

Answer 20

Power takeoff

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Question 21

What is a major advantage of using powershift or automatic transmissions rather than a manual transmission?

Answer 21

Power flow is not interrupted when shifts are made

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Question 22

A powershift differs from an automatic transmission in that shifts are made solely at the discretion of the operator. (T/F)

Answer 22

True

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Question 23

The planetary gear set component that meshes with the sun and internal gear is called the planet carrier. (T/F)

Answer 23

False
The planet pinions mesh with the sun and internal gear.

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Question 24

With a gear ratio of 0.33:1, how many times must the input gear rotate for the output gear to complete one revolution?

Answer 24

Input must be rotated 0.33 revolutions to produce one output revolution

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Question 25

Which component is being held reactionary when a planetary gear set is producing its deepest speed reduction?

Answer 25

Internal gear

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Question 26

Which component of a single planetary gear set is the input member when the output member is in overdrive?

Answer 26

Carrier

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Question 27

Countershaft type powershift and automatic transmissions transmit power by locking spur gears to a countershaft using a hydraulically applied clutch. (T/F)

Answer 27

True

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Question 28

Why are countshaft transmissions not as compact as planetery type units?

Answer 28

Thrust loads are not balanced which requires larger shafts and bearings

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Question 29

How are powershift transmissions different than an automatic transmission?

Answer 29

Powershift: Speed changes done soley at the discretion of the operator

Automatic: Speed changes done independent of any action from the operator

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Question 30

What type of transmissions are most often used in cycling applications?

Answer 30

Powershift

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Question 31

What type of transmissions are most often used in hauling applicaitons?

Answer 31

Automatic

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Question 32

When a clockwise rotating external gear is meshed with an internal gear, what direction does the internal gear rotate?

Answer 32

Clockwise

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Question 33

What has the greater reduction: 1st speed reduction or 2nd speed reduction

Answer 33

1st speed reduction

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Question 34

What has the greater overdrive: 1st speed overdrive or 2nd speed overdrive

Answer 34

2nd speed overdrive

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Question 35

How many planetaries are used in differential steering on a CAT dozer?

Answer 35

Three
- Steer
- Drive
- Equalizing

https://www.scribd.com/document/576627656/Cat-Dozer-Differential-Steering