Gears

Question 1

The direction of rotation of an internal gear is opposite to that of the input rotation of the pinion

Answer 1

False

Internal gears rotate in the same direction as their meshing pinion

Question 2

Module (m) is a fundamental parameter used to define the size of a gear

Answer 2

True

Module (m) is explicitly described as a fundamental parameter to specify tooth size.

Question 3

A pair of helical gears is classified as a type of gear used for power transmission between two intersecting shafts

Answer 3

False

Gears between parallel shafts include spur and helical gears. Gears between intersecting shafts are typically bevel gears.

Question 4

A planetary gear train requires two inputs of rotation to produce a definitive output of rotation

Answer 4

False

Question 5

Scuffing is a form of surface damage due to cyclic bending stresses in operation

Answer 5

False

Scuffing is described as adhesive wear. Pitting is caused by cyclic contact stress, and Bending fatigue is caused by cyclic bending stress.

Question 6

AGMA gear allowable bending and contact stresses are dependent upon the chosen material, heat treatment, and working conditions

Answer 6

True

The allowable stresses are modified values that depend on factors like material properties (affected by heat treatment), life factors (related to working cycles), temperature factor, and reliability factor (related to working conditions).

Question 7

In a simple gear train, each shaft carries only one gear

Answer 7

True

A simple train is defined as a gear train where each shaft carries only one gear.

Question 8

The Working depth (hk) of a gear is the sum of Addendum (a) and Dedendum (b)

Answer 8

False

The Working depth is defined as hk = a + b - c (Addendum + Dedendum - Clearance)

Question 9

Contact stress in gears is calculated based on Hertzian contact theory

Answer 9

True

The basic equation for gear contact stress is stated as being based on Hertzian contact theory.

Question 10

Transmitted load in a pair of spur gears is equivalent to the radial component of the force exerted between the teeth

Answer 10

False

Transmitted load (Wt) is the force responsible for torque transmission and is directed along the line of action.

Question 11

In gear design analysis using AGMA standards, iteration is generally not necessary if the correct material is chosen initially

Answer 11

False

The general procedure for gear design analysis explicitly states that iterations of design and analysis are necessary to reach a satisfactory or optimum design.