Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
1. False: True or false. A herringbone gear with a diametral pitch of 20 should have
at least 0.005 inch backlash.
2. 1. Open gear drive
2. Enclosed gear drives: What are the two types of gear drives?
3. Gears that are exposed to the outside environment: What is an open gear
drive?
4. Thick oil or grease: What is typically used to lubricate an open gear drive?
5. Gears contained in a gearbox with a lubrication supply: What are enclosed
gear drives?
6. oil, grease: Enclosed gear drives can be lubricated with or
.
7. Matched pairs of gears manufactured together and intended to mate with
each other: What are gear sets?
8. made in sets: Hypoid and bevel gears are usually .
9. When two or more gears mesh or work together as a unit.: What is a gear
train?
10. The gear with fewer teeth between two gears that have different numbers
of teeth mesh: What is a pinion?
11. drive: The pinion is generally the gear.
12. The larger circular gear of a bevel and hypoid gear set with the teeth
pointing upwards around the ring when the gear lays flat.: What is a crown gear
(ring gear)?
13. The input gear of the gear train causing the mating gear to turn.: What is
the power in drive gear?
14. The output gear of the gear train that the the drive gear forces to turn: What
is the power out driven gear?
15. When the input speed of the gearbox is the same as the output speed: What
is direct drive?
16. A gear train with a slower output speed than the input speed: What is a
speed reducer?
17. A gear train wiht a faster output speed than the input speed: What is a speed
increaser?
18. the ratio of the force produced by a machine to the force applied to it, used
in assessing the performance of a machine: What is mechanical advantage?
19. Using a speed reducer increases torque: How is mechanical advantage in-
creased in a gear train?
20. mechanical advantage: The larger the driven gear is compared to the drive
gear, the greater the .
, Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
21. A gear with a support bearing on one side only: What is a overhung gear
(overhung load)?
22. A gear mounted between two bearings: What is a straddle mounted gear?
23. Gears with teeth on the inside diameter: What are internal gears?
24. A gear train with 3 or more shafts and 4 or more gears: What is a compound
gear train?
25. all the ratios through the gear train multiplied: In a compound gear train, the
final ratio at the output shaft is equal to .
26. 3 x 4 x 5 = 60
60:1: A compound gear train has 3 sets of gear. The first gear set has a ratio of 3:1,
the second has a ratio of 5:1, and the third has a ratio of 4:1. What is the final ratio
of the gear train?
27. When the gear or shaft is allowed to move axially: What is end play?
28. When a bearing has less than zero axial clearance: What is preload?
29. Excessive removal of metal from the gear tooth faces: What is gear wear?
30. 1. Inadequate lubrication
2. Abrasives in the gear train
3. Incorrect tooth contact
4. Extended heavy loads: What causes gear wear?
31. A gear or shaft that is allowed to move axially in order to achieve its best
position: What is a floating gear or shaft?
32. right handed: A gear that has teeth that point to the right as viewed from the
shaft axis of the mounted gear is a gear.
33. left handed: A gear that has teeth that point to the left as viewed from the shaft
axis of the mounted gear is a gear.
34. A gear consisting of a shaft with a spiral thread that engages with and
drives an externally toothed wheel.: What is a worm and worm wheel gear set?
35. The side of the gear teeth in contact with the other gear while torque is
applied to the gear train.: What is the drive side?
36. The side of the gear teeth that does not make contact with the the gear
while torque is applied.: What is the coast side of a gear tooth?
37. So it can drive on the coast side, increasing its service life: Why is it
common practice to turn the gears around after they have been in service for some
time?
38. The centerline around which a gear or parts revolve.: What is the axis of
rotation?
39. The radial distance from the pitch circle to the bottom land of the tooth: -
What is the dedendum?
, Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
40. The radial distance from the pitch circle to the top land of the tooth: What
is the addendum?
41. Total height of the whole tooth (addendum + dedendum): What is the whole
depth?
42. The depth that the gear tooth extends toward the root of the mating tooth
when both are in full mesh: What is the working depth?
43. The space between the bottom land of one gear and the top land of the
meshing gear: What is gear tooth clearance?
44. The maximum diameter at the top land of the gear teeth: What is outside
gear diameter?
45. The distance from the centre of one tooth to the centre of the next tooth at
the pitch circle.: What is circular pitch (gear pitch)?
46. An imaginary circle approximately in the middle of the gear teeth: What is
pitch circle?
47. The contact part of the tooth on the addendum.: What is the face of the tooth?
48. The contact part of the tooth below the pitch circle, including the fillet: What
is the tooth flank?
49. The distance from one side of the tooth to the opposite side: What is face
width?
50. The thickness of the gear tooth at the pitch circle: What is chordal thickness?
51. Chordal thickness: What part of the gear tooth indicates tooth strength?
52. Cutting a slight curve on the face of the gear tooth from side to side: What
is crowning?
53. Prevent highly concentrated loads on the ends or edges of the gear teeth
that could cause the teeth to fracture: What is the purpose of crowning gear
teeth?
54. The points of contact as the gear turns: What is the line of action on a gear
tooth?
55. The angle between the line of action and the line tangent to the pitch
circles: what is the pressure angle?
56. The angle of the tooth from the shaft axis of the gear: What is the helix angle?
57. 1. Smoother tooth action
2. More sliding friction
3. Greater axial thrust: What are the results from steeper helix angles?
58. The number of thread starts on the worm gear: What is the start of a worm
gear?
59. It increases the speed in which the worm wheel advances in one turn: What
effect does more starts on a worm gear have?
Exams
1. False: True or false. A herringbone gear with a diametral pitch of 20 should have
at least 0.005 inch backlash.
2. 1. Open gear drive
2. Enclosed gear drives: What are the two types of gear drives?
3. Gears that are exposed to the outside environment: What is an open gear
drive?
4. Thick oil or grease: What is typically used to lubricate an open gear drive?
5. Gears contained in a gearbox with a lubrication supply: What are enclosed
gear drives?
6. oil, grease: Enclosed gear drives can be lubricated with or
.
7. Matched pairs of gears manufactured together and intended to mate with
each other: What are gear sets?
8. made in sets: Hypoid and bevel gears are usually .
9. When two or more gears mesh or work together as a unit.: What is a gear
train?
10. The gear with fewer teeth between two gears that have different numbers
of teeth mesh: What is a pinion?
11. drive: The pinion is generally the gear.
12. The larger circular gear of a bevel and hypoid gear set with the teeth
pointing upwards around the ring when the gear lays flat.: What is a crown gear
(ring gear)?
13. The input gear of the gear train causing the mating gear to turn.: What is
the power in drive gear?
14. The output gear of the gear train that the the drive gear forces to turn: What
is the power out driven gear?
15. When the input speed of the gearbox is the same as the output speed: What
is direct drive?
16. A gear train with a slower output speed than the input speed: What is a
speed reducer?
17. A gear train wiht a faster output speed than the input speed: What is a speed
increaser?
18. the ratio of the force produced by a machine to the force applied to it, used
in assessing the performance of a machine: What is mechanical advantage?
19. Using a speed reducer increases torque: How is mechanical advantage in-
creased in a gear train?
20. mechanical advantage: The larger the driven gear is compared to the drive
gear, the greater the .
, Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
21. A gear with a support bearing on one side only: What is a overhung gear
(overhung load)?
22. A gear mounted between two bearings: What is a straddle mounted gear?
23. Gears with teeth on the inside diameter: What are internal gears?
24. A gear train with 3 or more shafts and 4 or more gears: What is a compound
gear train?
25. all the ratios through the gear train multiplied: In a compound gear train, the
final ratio at the output shaft is equal to .
26. 3 x 4 x 5 = 60
60:1: A compound gear train has 3 sets of gear. The first gear set has a ratio of 3:1,
the second has a ratio of 5:1, and the third has a ratio of 4:1. What is the final ratio
of the gear train?
27. When the gear or shaft is allowed to move axially: What is end play?
28. When a bearing has less than zero axial clearance: What is preload?
29. Excessive removal of metal from the gear tooth faces: What is gear wear?
30. 1. Inadequate lubrication
2. Abrasives in the gear train
3. Incorrect tooth contact
4. Extended heavy loads: What causes gear wear?
31. A gear or shaft that is allowed to move axially in order to achieve its best
position: What is a floating gear or shaft?
32. right handed: A gear that has teeth that point to the right as viewed from the
shaft axis of the mounted gear is a gear.
33. left handed: A gear that has teeth that point to the left as viewed from the shaft
axis of the mounted gear is a gear.
34. A gear consisting of a shaft with a spiral thread that engages with and
drives an externally toothed wheel.: What is a worm and worm wheel gear set?
35. The side of the gear teeth in contact with the other gear while torque is
applied to the gear train.: What is the drive side?
36. The side of the gear teeth that does not make contact with the the gear
while torque is applied.: What is the coast side of a gear tooth?
37. So it can drive on the coast side, increasing its service life: Why is it
common practice to turn the gears around after they have been in service for some
time?
38. The centerline around which a gear or parts revolve.: What is the axis of
rotation?
39. The radial distance from the pitch circle to the bottom land of the tooth: -
What is the dedendum?
, Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
40. The radial distance from the pitch circle to the top land of the tooth: What
is the addendum?
41. Total height of the whole tooth (addendum + dedendum): What is the whole
depth?
42. The depth that the gear tooth extends toward the root of the mating tooth
when both are in full mesh: What is the working depth?
43. The space between the bottom land of one gear and the top land of the
meshing gear: What is gear tooth clearance?
44. The maximum diameter at the top land of the gear teeth: What is outside
gear diameter?
45. The distance from the centre of one tooth to the centre of the next tooth at
the pitch circle.: What is circular pitch (gear pitch)?
46. An imaginary circle approximately in the middle of the gear teeth: What is
pitch circle?
47. The contact part of the tooth on the addendum.: What is the face of the tooth?
48. The contact part of the tooth below the pitch circle, including the fillet: What
is the tooth flank?
49. The distance from one side of the tooth to the opposite side: What is face
width?
50. The thickness of the gear tooth at the pitch circle: What is chordal thickness?
51. Chordal thickness: What part of the gear tooth indicates tooth strength?
52. Cutting a slight curve on the face of the gear tooth from side to side: What
is crowning?
53. Prevent highly concentrated loads on the ends or edges of the gear teeth
that could cause the teeth to fracture: What is the purpose of crowning gear
teeth?
54. The points of contact as the gear turns: What is the line of action on a gear
tooth?
55. The angle between the line of action and the line tangent to the pitch
circles: what is the pressure angle?
56. The angle of the tooth from the shaft axis of the gear: What is the helix angle?
57. 1. Smoother tooth action
2. More sliding friction
3. Greater axial thrust: What are the results from steeper helix angles?
58. The number of thread starts on the worm gear: What is the start of a worm
gear?
59. It increases the speed in which the worm wheel advances in one turn: What
effect does more starts on a worm gear have?
