Module - Gearing Fundamentals

Question 1

Gears are positive power transmission devices that are used where there can be no slippage.

a) True
b) False

Answer 1

TRUE

Question 2

The pinion gear is usually the smallest gear in the set.

a) True
b) False

Answer 2

TRUE

Question 3

Most gears are be made to the standards set by the AGMA.

a) True
b) False

Answer 3

TRUE

Question 4

A drive using helical gears can have the gears set up so they are overhung.

a) True
b) False

Answer 4

TRUE

Question 5

In a compound gear system there can be six gears and four shafts.

a) True
b) False

Answer 5

TRUE

Question 6

The gear set shown in Figure 3 has a left-hand pinion and a right-hand ring gear.

a) True
b) False

Answer 6

FALSE

Question 7

The flank of the gear tooth is located in the addendum.

a) True
b) False

Answer 7

FALSE

Question 8

If the circular pitch is known, it is the best defining description of the gear teeth.

a) True
b) False

Answer 8

FALSE

Question 9

A gear set that has a 20° pressure angle is stronger than a gear set with a 14° pressure angle.

a) True
b) False

Answer 9

TRUE

Question 10

It is best to measure the backlash of a gear set at the pitch circle.

a) True
b) False

Answer 10

TRUE

Question 11

A herringbone gear with a diametral pitch of 20 should have at least 0.005 inch backlash.

a) True
b) False

Answer 11

FALSE

Question 12

A gear with a diametral pitch of 4 has very small teeth.

a) True
b) False

Answer 12

FALSE

Question 13

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

Answer 13

FALSE

Question 14

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

Answer 14

FALSE

Question 15

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

Answer 15

FALSE

Question 16

Spur gears have high axial thrust and require thrust bearings on each side of the gearbox.

a) True
b) False

Answer 16

FALSE

Question 17

Helical gears with parallel shafts must use gears of the opposite hand.

a) True
b) False

Answer 17

TRUE

Question 18

Double helical gears are good for high speeds and heavy loads.

a) True
b) False

Answer 18

TRUE

Question 19

A spur gear set that intersects at 90° must be of the same hand.

a) True
b) False

Answer 19

FALSE

Question 20

Herringbone gears are light duty drivers.

a) True
b) False

Answer 20

FALSE

Question 21

Bevel gears cross over at 90° and can be straight, spiral or Zerol.

a) True
b) False

Answer 21

FALSE

Question 22

Spiral bevel gears look very similar to hypoid gears. a) True

b) False

Answer 22

TRUE

Question 23

Hypoid gears have high sliding action and require an EP additive in the oil.

a) True
b) False

Answer 23

TRUE

Question 24

The heel of a hypoid or spiral bevel gear is near the inner circle.

a) True
b) False

Answer 24

FALSE

Question 25

Worm gears have a lot of sliding action.

a) True
b) False

Answer 25

TRUE

Question 26

Worm gears are less efficient than most other types of gears.

a) True
b) False

Answer 26

TRUE

Question 27

A worm gear that has 10 starts will be considered a self-locking gear set.

a) True
b) False

Answer 27

FALSE

Question 28

A double-throated worm and worm wheel gear set will have maximum gear tooth contact.

a) True
b) False

Answer 28

TRUE

Question 29

Light-duty open gear drives are often made from synthetic materials like nylon or phenolics.

a) True
b) False

Answer 29

TRUE

Question 30

A planetary gear system has a sun, stars and ring gear as part of the whole planetary system.

a) True
b) False

Answer 30

FALSE

Question 31

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

Answer 31

FALSE

Question 32

A planetary gear system can be considered a single reduction unit.

a) True
b) False

Answer 32

FALSE