Gearing Principles

Question 1

Gear teeth may be parallel to one another or they may be tapered, with one large end and one smaller end.
True
False

Answer 1

True

Question 2

The gear pitch line is used to divide the following gear tooth areas:

a. heel and toe
b. drive and coast
c. face and flank
d. fillet and profile

Answer 2

c. face and flank

Question 3

Explain why some angle drive gear sets may need to be timed.

Answer 3

The manufacturer may design the gear set is such a manner that a very distinctive wear pattern will exist between the mating gear teeth during operation. The gears have been lapped in this pattern and need to be timed to continue this specific relationship.

Question 4

If a simple gear set has a gear ratio of 4:1. Explain which member is turning at 4 revolutions.

Answer 4

The driving gear.

Question 5

When installed between a drive and driven gear, an idler gear affects speed and torque changes between the two gears.
True
False

Answer 5

False

Changes direction of rotation.

Question 6

Name and explain, the tooth design used on two types of external gears.

Answer 6

Straight cut spur gear teeth cut inline mounting shaft.

Helical gear teeth cut at an angle to the mounting shaft.

Question 7

What is another name for a double helical gear?

Answer 7

Herringbone gear

Question 8

Identify the three main components of a simple planetary gear set.

Answer 8

Ring gear
Planet pinion gears and planet carrier assembly.
Sun gears.

Question 9

A gear tooth ca be sub divided into four distinctive quadrants. Identify the names of each of those quadrants.

Answer 9

Face
Flank
Heel
Toe

Question 10

When two gears are in mesh, a gap is formed between the tip of one gear tooth and the root in the opposite gear. This gap is called the:
Fillet
Profile
Backlash
Clearance

Answer 10

Clearance

Question 11

Gears may operate together as direct drive assemblies. Identify two other types of gear configurations and explain the type of speed and torque changes that would be expected between the input and output members.

Answer 11

Reduction. Speed reduction, torque increases.

Overdrive. Speed increases, torque reduction.

Question 12

Which of the following gear ratios would be a reduction gear ratio?

0. 10:1
   1: 1
   10: 1
   1: 2

Answer 12

10:1

Question 13

Explain the purpose of an idler gear.

Answer 13

An Idler gear is used to change the direction of rotation of the driven gear to the same direction of rotation as the drive gear. This action could make the selection of reverse gear possible.

Question 14

Identify one common gear set where internal gears may be used.

Answer 14

Planetary gear sets.

Question 15

Straight cut spur gears and helical gears both produce axial thrust loads during operation.
True
False

Answer 15

False

Only helical gears produce thrust loads.