Module - Gearing Fundamentals Flashcards
Gears are positive power transmission devices that are used where there can be no slippage.
a) True
b) False
TRUE
The pinion gear is usually the smallest gear in the set.
a) True
b) False
TRUE
Most gears are be made to the standards set by the AGMA.
a) True
b) False
TRUE
A drive using helical gears can have the gears set up so they are overhung.
a) True
b) False
TRUE
In a compound gear system there can be six gears and four shafts.
a) True
b) False
TRUE
The gear set shown in Figure 3 has a left-hand pinion and a right-hand ring gear.
a) True
b) False
FALSE
The flank of the gear tooth is located in the addendum.
a) True
b) False
FALSE
If the circular pitch is known, it is the best defining description of the gear teeth.
a) True
b) False
FALSE
A gear set that has a 20° pressure angle is stronger than a gear set with a 14° pressure angle.
a) True
b) False
TRUE
It is best to measure the backlash of a gear set at the pitch circle.
a) True
b) False
TRUE
A herringbone gear with a diametral pitch of 20 should have at least 0.005 inch backlash.
a) True
b) False
FALSE
A gear with a diametral pitch of 4 has very small teeth.
a) True
b) False
FALSE
A gear train has 15 gears meshing together with the input gear rotation in the clockwise direction (CW). The output gear should turn in the counter-clockwise (CCW) direction.
a) True
b) False
FALSE
If there are several gear reductions in a gearbox, with ratios of 4:1, 5:1 and 2.5:1, the final reduction of the gearbox will be 45:1.
a) True
b) False
FALSE
A gearbox has a 10:1 reduction driven by a 1hp electric motor at 1750 rpm. The output from the gearbox will be 10 hp at a speed of about 175 rpm. a) True
b) False
FALSE
Spur gears have high axial thrust and require thrust bearings on each side of the gearbox.
a) True
b) False
FALSE
Helical gears with parallel shafts must use gears of the opposite hand.
a) True
b) False
TRUE
Double helical gears are good for high speeds and heavy loads.
a) True
b) False
TRUE
A spur gear set that intersects at 90° must be of the same hand.
a) True
b) False
FALSE
Herringbone gears are light duty drivers.
a) True
b) False
FALSE
Bevel gears cross over at 90° and can be straight, spiral or Zerol.
a) True
b) False
FALSE
Spiral bevel gears look very similar to hypoid gears. a) True
b) False
TRUE
Hypoid gears have high sliding action and require an EP additive in the oil.
a) True
b) False
TRUE
The heel of a hypoid or spiral bevel gear is near the inner circle.
a) True
b) False
FALSE
Worm gears have a lot of sliding action.
a) True
b) False
TRUE
Worm gears are less efficient than most other types of gears.
a) True
b) False
TRUE
A worm gear that has 10 starts will be considered a self-locking gear set.
a) True
b) False
FALSE
A double-throated worm and worm wheel gear set will have maximum gear tooth contact.
a) True
b) False
TRUE
Light-duty open gear drives are often made from synthetic materials like nylon or phenolics.
a) True
b) False
TRUE
A planetary gear system has a sun, stars and ring gear as part of the whole planetary system.
a) True
b) False
FALSE
If the input power is on the sun gear and the carrier is locked to the sun, the output will be a forward reduction.
a) True
b) False
FALSE
A planetary gear system can be considered a single reduction unit.
a) True
b) False
FALSE
