Transmissions Flashcards
What are the 6 gear types
Spur, miter, herringbone, helical, bevel, hypoid
What is backlash
It is the amount of play between gear mesh
What is pre load
It is the force between objects not caused by external load
What is rolling drag
It is the amount of force/ torque when the object is moving
What is end play
The amount of axial play in an object
How to find a gear ratio
It is driven % driver :1
How to find speed in a gear ratio
Input speed divided by gear ratio
What does an idler do
It changes direction not gear ratio
What does mfwd stand for
Mechanical front wheel drive
What does cv stand for
Constant velocity
What is the purpose of phasing a driveshaft
To reduce whip
What is an epicyclic gear set
A planetary gear-set which consists of sun planetary gears, a planetary carrier and a ring gear
What is a annulus gear
It is a ring gear
What happens if you lock 2 epicyclic gear set components together
It creates direct drive
Why would you preload a bearing
It allows for thermal expansion and stops excessive side to side movement
What is a sliding mesh gearbox
All gears are straight cut
What is a constant mesh gearbox
It is a gearbox where all gears are splined but not until a synchro is moved do they engage
What are the 4 tasks of a synchroniser
Prevent early engagement
Synchronise speed
Mesh gear
Lock into gear
How to work out a compound gear ratio
Driven over driver x driven over driver : 1
To calculate overall gear ratio you can times all ratios to get the answer
What does a brake do in a gearbox
It stops a component from moving
What does a clutch do within a gearbox
It grabs onto the component and spins with it
To achieve reverse what must be held on a planetary set
The planetary carrier must be held
How can backlash be tested
With a dti
What are the 4 parts of a torque converter
Impeller
Stator
Turbine
Lock clutch
What does preload allow
To rotate without excessive thrust
What is the purpose of an interlock mechanism on a transmission
To lock the gear into place once it has selected it
What is the purpose of a differential
To allow wheels to carry at different speeds round corner
Fully floating hubs are viable to what stress
Torsional stress
Electronic gearbox will often include ?
Switches and solenoids
What is a positive drive system
A fixed system that can’t slip eg a gear or chain
What are the 3 shafts in a transmission
Input , lay and output
What is the optimal place for gear mesh
In the middle of the tooth
How to work out torque
It is ratio x torque input
What is cone point
How far a pinion sticks out of a housing can be adjusted with shims and a dti
What is a dampening clutch plate
One which springs on the face to reduce shock
What is a cvt
Constantly variable transmission
What are the 2 types of flywheel
Duel mass has a torsion dampener in it
And solid mass
Torque converter and a fluid flywheel are both what ?
A fluid coupling
What are the parts of a torque converter
Stator , impeller, turbine and locking clutch
How does a torque converter work
The flywheel is attached the the outer casing which is the impeller.
This drives the fluid causing the turbine to drive
The stator recycles the vortex flow and pushes it back into the impeller to stop starvation
What are the 3 phases of drive
Stall
Acceleration
And coupling
What is a non positive drive
Something which can slip such as a belt
How do you lock a gear in place
Using a ball and spring detent
What gear set is a diff
A hypoid gear set transfers power 90 degree
How do you stop whip in a driveshaft
Align the yokes so they are in the same direction which balances the shaft
Customer has exited a muddy field and it is now hard to steer vehicle what could this mean
This diff lock is still on
What component of a torque converter is fitted with a lock clutch
Stator
What is the purpose of clutch free play
To allow the clutch to disengage and engage properly
What is a gear type with angled cuts
Helical
What component drives the input shaft
The clutch drives the input shaft
What are the 2 types of manual gearbox
Sliding mesh and constant mesh
What is a normal tractor axel semi floating or fully floating
Semi due it having 2 bearings for support
What does a reactionary refer to in a planitary gear set
Anything which is held
How to achieve overdrive in a planetary gear set
Make the planetary carrier the input
What is a femar valve
Is it to assist in modulation a solenoid which can operate multiple things at once
What is electro hydraulic modulation
Is it valve operated/ electrical, to achieve metered fluid output
What does an air pump do in a gearbox
It pressurises the gearbox and prevents overheating
What does an anti cavitation valve do
It provides a back stop for the oil to ensure no cavitation occurs in the clutch packs
What does an overspeed relief valve do
It helps to reduce unwanted clutch activation, by keeping oil pressure equal
What does a modulator valve do
It fills slightly with pressure and once it has arrived through back pressure it allows full oil flow to come through this allows a smoother engagement
