Gearbox Flashcards
Name 3 transmissions you may encounter in everyday life
Gear, chain, belt
Which type of transmission is commonly used in a bicycle?
Chain transmission
Which type of transmission commonly used in power drills?
Gear transmission
Describe what a gear transmission looks like. Do the same for chain transmission and belt
A bunch of cogs connected together.
A chain wrapped around a cog at one end and a cog at the other.
A rubber belt wrapped around a cog at one end and a cog at the other.
What kind of transmission is used in an engine?
Belt transmission
What are gear teeth?
The things that jut out and connect the gears (like cogs)
Name the 2 types of gear teeth
Straight, involute
What is the term for 2 or more gear wheels in series?
A gear train
What do straight gear teeth look like? What do involute gear teeth look like?
Square/angled.
Rounded.
When gear teeth are diagonal across the gear, what are they called?
Helical gears
Give 3 benefits of helical gears
Transmit greater force
Smaller gear wheels can be used than with spur gears
Less noisy
List 4 types of commonly used gears
Straight cut gear
Bevel gear
Worm gear
Rack gear
Give 1 advantage of using gears
High power density
Give 2 disadvantages of using gears
High production cost, noisiness
What’s another name for belt transmission?
A belt drive
How is gear ratio connected in a belt drive/transmission?
By using pulleys of different sizes
Name the 3 modern belt shapes
V-belt
Poly belt
Toothed belt
Why are belts shapes to slot into their corresponding pulleys?
To increase the friction as much as possible, to reduce chance of slippage
Give 2 advantages of belt transmissions
Relatively quiet, because of flexible belt
No lubrication needed
Give 2 disadvantages of belt transmissions
Prone to slippage, other than toothed belt
Power transfer is limited
In chain transmission, there are 2 things on either end connected by a chain. In belt transmission, there are 2 things on either end connected by a belt. What are the name for the ‘things’ in chain transmission. What about belt transmission?
Sprockets
Pulleys
How do you create a gear ratio?
By using sprockets/pulleys of different sizes
List the 5 parts of a chain
Pin
Outer plate
Inner plate
Roller
Bush
List 2 advantages of chain transmission
Does not slip
Greater forces can be transferred
List 2 disadvantages of chain transmission
Heavier than a belt
More expensive
Where is the gearbox located in rear wheel drive?
Between the clutch and the differential
What are the x and y axes of an engine graph
x = engine speed (rpm x 1000)
y = torque (Nm)
To put car in motion in first gear, is a high or low torque required?
High torque
What do gears in a gearbox do to torque?
Increase it
What’s the name for a reduction ratio in a gearbox?
A low gear
What happens to the rotational speed of the output shaft of the gearbox when second gear is selected in the gearbox?
The rotational speed increases
What is the gear where input and output revs are equal called?
The direct drive
What is/are the gear(s) where the output rotational speed is higher than the input rotational speed called?
The overdrive(s)
In what direction are the engine and gearbox mounted in a rear wheel drive car?
Longitudinally
What are the 2 kinds of reduction ratios that are possible in a gearbox?
Single reduction
Double reduction
When higher gears are selected, what happens to the reduction ratio?
There is less reduction
In direct drive, what is the reduction ratio? What has changed?
1:1
From double reduction to single reduction
What is the spur gear that reverses rotational direction, used for reverse called?
The idler gear
Do fifth and sixth gear have a high or a low ratio?
Low ratio
List 6 of the main components of the gearbox
Input shaft
Output shaft
Secondary shaft
Reverse gear auxilary shaft
Gear stick
Selector mechanism
What’s another name for the gear stick?
The gear lever
What are the 3 ways the gear lever and gear box can be linked
Hydraulic
Rods
Cables
In linking the gear lever and gearbox, how does gear selector linkage work?
The gear lever is linked to the gearbox by a system of rods
When gear selector linkage is used to link the gear lever and gearbox, what is moved to engage a specific gear
A synchroniser sleeve
Name the 3 main components of gear selector linkage
Shafts
Gear-selector forks
Synchroniser sleeve
What does the gear-selector fork fit into?
A recess in the synchroniser sleeve
Are the selector shafts stationary or moveable?
Moveable
How is the selector shaft moved?
Longitudinally