GEAR DRIVES

Question 1

T or F: There is no limit to how many gears can be used in a gear set except space considerations

Answer 1

True

Question 2

Metallic gear materials include _____, ______, ______, and ______

Answer 2

Steel, iron, brass, and aluminum

Question 3

Non-metallic gear materials include ______, _______, _______, ________, and ________

Answer 3

Plastics, resins, impregnated fibers, ceramics, and wood

Question 4

______ is simply the distance from a point on one tooth to a corresponding point on the next tooth, measured along the pitch circle

Answer 4

Circular Pitch

Question 5

_____ diameter gears are frequently made to circular pitch

Answer 5

Large

Question 6

The ________ specifies the number of teeth in 3.1416 inches along the pitch circle of a gear. It’s system is the most widely used for all common-size gears

Answer 6

Diametral Pitch

Question 8

The ________ is measured across the pitch circle and is the point in which both gears transfer power

Answer 8

Pitch Diameter

Question 9

_______ is the play between the teeth that prevents binding

Answer 9

Backlash

Question 10

Backlash is necessary because binding of mating gears can result in ________, _____, _______, ______, and _______

Answer 10

Heat generation, noise, abnormal wear, overload, and failure of the drive

Question 11

_______ is the comparison between the pitch diameter of the drive gear versus the pitch diameter of the driven gear

Answer 11

Gear Ratio

Question 12

Gear ratio can be calculated with the following formula:

Answer 12

Ratio= D/d

D= Diameter of the larger gear
D= Diameter of the smaller gear

Question 13

Gear speed is calculated by:

Answer 13

S1/S2 = P2/P1

Question 14

When all modern gear teeth (except worm gears) are similar in shape, this is called _____

Answer 14

Involute tooth form

Question 15

_______ gears are the first gears to be developed

Answer 15

Spur

Question 16

What gear is this:
-Tooth design provides for very few teeth to be in mesh at any one time
-low to medium speed
-noisy
-generally, used in low power applications
-smaller in size

Answer 16

Spur gears

Question 17

____ gears are a variation of the spur gear

Answer 17

helical

Question 19

In a helical gear, the teeth are positioned at an _____. The angle is from ___ to ___ degrees

Answer 19

angle (helix angle); 7 to 23

Question 20

Helical gears come in hands. ____

Answer 20

left hand mates with a right hand (except in crossed axis design)