190303c Flashcards
What is another name for the reactionary member in a planetary?
Held member or being held.
What is the middle gear in a planetary called?
The sun gear.
What is the gear called that is in constant mesh with the sun and the internal gears?
Planetary gears or planet pinons.
Planetary gears are mounted, what is the member called the gears are mounted to?
Planetary carrier.
What are the two names of the outside gear that is a constant mesh with the planetary pinions?
Internal gear or ring gear.
What determines the number of planetary pinons in a gear set?
Depends on the load or torque the gearset is required to transmit. The greater the number of pinons, the greater the torque.
What is gear ratio?
Refers to the number of revolutions the input gear makes to complete one revolution of the output gear.
What is the formula for gear ratio?
Drive
What is an example of a 3 to 1 ratio gear set?
Non hunting reduction gear set.
What is an example of 4.25:1 gearset?
Partial non-hunting reduction gear set.
What is an example of a 4.11111111:1 gearset?
A hunting reduction gear set.
Why are planetary gears used in powershift and automatic transmissions?
These are used as a basic means to modify torque and speed from the engine.
In a planetary gear set how do you get 1st speed reduction?
Input is the sun gear
Output is the carrier
Held is the internal gear
How do you get a 2nd speed(mild) reduction in a planetary gear set?
Input is the internal gear
Output is the carrier
Held(reactionary) sun gear
Explain 1st speed overdrive?
Input is the planet carrier
Output is the internal
Sun gear is held
Explain 2nd speed overdrive?
Input is the carrier
Output is the sun
Internal gear is held reactionary
In a planetary gear set if the carrier is held you will always get what condition?
Reverse
Explain reverse reduction in a planetary?
Carrier is held
Sun is the input
Internal gear is the output
How is reverse overdrive is achieved ?
Carrier is held reactionary
Internal gear is input
Sun gear is output
3 way to get neutral in a planetary?
1) no held member
2) no input(drive)
3) sun and internal gear driven in opposite directions at the same TOOTH SPEED
Direct drive in a planetary
1) locking 2 members together
2) driving 2 members in the same direction at the same rpm
A clutch that holds an internal gear to transmission case is also know as?
Brake
A single planetary gear set must meet what 3 conditions?
1) One member must be drive or input
2) one member must be driven or output
3) one member must be reaction(held)
What are the two basic design types of powershift and automatic transmissions?
Planetary type and countershaft type.
A dump truck is an example of a machine used in a cycling type application. (T/F)
False
A scraper is typically used in a hauling application. (T/F)
True
What are the two type of clutch discs used in transmission clutch assemblies
Clutch discs and clutch plates
What is the purpose of the grooves on the face of the friction material?
Carry oil to lube the discs when the clutch is disengaged and allow the oil to be squeezed out when clutch is applied
How are the transmission clutch packs applied?
Hydraulically Actuated piston assemblies
Reverse gear in a countershaft transmission is possible through two main components
Idler gear on countershaft and reverse clutch activation
Gear selection in a countershaft transmission is engaged by
Drilled oil passages that hydraulically apply clutch discs
Countershaft transmissions are made by combining?
Reversing countershafts with countershafts that provide multiple speed ranges through clutch disc operation
The function of the transmission in a piece of mobile heavy equipment is to modify
the engine power that propels the machine. The transmission allows the operator to
decrease vehicle speed and increase torque under conditions of heavy load. Speed can
be increased and torque decreased when the load is light.
Many heavy equipment transmissions provide a place to couple auxiliary components
such as hydraulic pumps. This drive is known as:
power takeoff.
The major advantage of using powershift or automatic transmissions rather than a
manual transmission is that
is that power flow is not interrupted when shifts are made.
A powershift differs from an automatic transmission in that shifts are made solely at
the discretion of the operator.
a) true
b) false
true
The planetary gear set component that meshes with the sun and internal gear is called the planet carrier.
a) true
b) false
false
The planet pinions do
A gear ratio that is expressed .33:1 means that:
the input must be rotated .33 revolutions to produce one output revolution.
Which component is being held reactionary when a planetary gear set is producing its
deepest speed reduction?
the internal gear
. Which component of a single planetary gear set is the input member when the output
member is in overdrive?
the carrier
Countershaft type powershift and automatic transmissions transmit power by locking
spur gears to a countershaft using a hydraulically applied clutch.
a) true
b) false
true
How are transmission clutch assemblies applied?
A pressurized oil flow from the transmission charging pump.
How are clutch assemblies applied and released
Hydraulically applied
Spring released
What are two friction materials used to make clutch discs
Sintered bronze
Composite materials
Where are clutch plates located
Between every pair of clutch discs
