Gears Flashcards
What are the two types of gear drives?
- open gear drives
- enclosed gear drives
Gear trains that are exposed to the outside environment are called:
open gear drives
What is usually used to lubricate open drive systems?
very thick oil or grease
Which system has more excessive gear wear: an open drive system or an enclosed drive system?
open drive
*particulate matter causing additional wear
Gear drives contained within a gearbox with a lubrication supply are _____________.
enclosed
What are gear sets?
matched pairs of gears manufactured and intended to mate with each other
What 2 types of gears are usually manufactured as gear sets?
- hypoid
- bevel
What can happen if a gear from a gear set is matched with a gear that wasn’t their mate?
failure can result
What is a gear train?
when two or more gears mesh and work together as a unit
When two gears having different numbers of teeth mesh together, the gear with the fewer teeth is called the ___________ gear.
pinion
True or false:
The pinion gear is rarely the drive gear.
false;
it is generally the drive gear
In bevel and hypoid gear sets, the smaller gear is called the 1.____________ gear and the larger gear is called the 2.____________ gear.
- pinion
- crown
The crown gear is also called the:
ring gear
What is the input gear on a gear train called?
drive or driver gear (power in)
What is the output gear on a gear train called?
driven gear (power out)
What is a direct drive gearbox system?
where the input speed = output speed
*transfer power, no increase or decrease of speed
A gear train with a slower output speed is called a:
speed reducer
A gear train with a faster output speed is called a:
speed increaser
What happens to the output torque when a speed reduction occurs in a speed reducer?
the toque increases due to the mechanical advantage
speed ↓ = torque ↑
What effects the amount of mechanical advantage that’s seen in a speed reducer?
the input to output ratio
- the larger the ratio (greater the speed reduction), the greater the mechanical advantage
What is an overhung gear?
A gear with support only on one side
What 2 kinds of gears are overhung loads common on?
- Bevel
- Hypoid
General practice is to keep overhung gears very close to the bearing. Why is this?
For support, as they tend to have more shaft deflection
What is a straddle mount gear?
A gear mounted between two bearings