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Millwright Mechanics - 2nd Year: Gearing Fundamentals Exams, Exams of Mechanics

Millwright Mechanics Millwright Mechanics - 2nd Year: Gearing Fundamentals Exams

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2024/2025

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Millwright Mechanics - 2nd Year: Gearing Fundamentals
Exams
1 / 20
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 .
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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
  3. Enclosed gear drives:** What are the two types of gear drives?
  4. Gears that are exposed to the outside environment: What is an open gear drive?
  5. Thick oil or grease: What is typically used to lubricate an open gear drive?
  6. Gears contained in a gearbox with a lubrication supply: What are enclosed gear drives?
  7. oil, grease: Enclosed gear drives can be lubricated with or .
  8. Matched pairs of gears manufactured together and intended to mate with each other: What are gear sets?
  9. made in sets: Hypoid and bevel gears are usually.
  10. When two or more gears mesh or work together as a unit.: What is a gear train?
  11. The gear with fewer teeth between two gears that have different numbers of teeth mesh: What is a pinion?
  12. drive: The pinion is generally the gear.
  13. 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)?
  14. The input gear of the gear train causing the mating gear to turn.: What is the power in drive gear?
  15. The output gear of the gear train that the the drive gear forces to turn: What is the power out driven gear?
  16. When the input speed of the gearbox is the same as the output speed: What is direct drive?
  17. A gear train with a slower output speed than the input speed: What is a speed reducer?
  18. A gear train wiht a faster output speed than the input speed: What is a speed increaser?
  19. 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?
  20. Using a speed reducer increases torque: How is mechanical advantage in- creased in a gear train?
  21. mechanical advantage: The larger the driven gear is compared to the drive gear, the greater the.

Exams

  1. A gear with a support bearing on one side only: What is a overhung gear (overhung load)?
  2. A gear mounted between two bearings: What is a straddle mounted gear?
  3. Gears with teeth on the inside diameter: What are internal gears?
  4. A gear train with 3 or more shafts and 4 or more gears: What is a compound gear train?
  5. all the ratios through the gear train multiplied: In a compound gear train, the final ratio at the output shaft is equal to.
  6. 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?
  7. When the gear or shaft is allowed to move axially: What is end play?
  8. When a bearing has less than zero axial clearance: What is preload?
  9. Excessive removal of metal from the gear tooth faces: What is gear wear?
  10. **1. Inadequate lubrication
  11. Abrasives in the gear train
  12. Incorrect tooth contact
  13. Extended heavy loads:** What causes gear wear?
  14. A gear or shaft that is allowed to move axially in order to achieve its best position: What is a floating gear or shaft?
  15. 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.
  16. 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.
  17. 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?
  18. 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?
  19. 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?
  20. 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?
  21. The centerline around which a gear or parts revolve.: What is the axis of rotation?
  22. The radial distance from the pitch circle to the bottom land of the tooth: - What is the dedendum?

Exams

  1. 3 pitches: If a worm gear has three starts, the worm advances the worm wheel a distance of for each revolution.
  2. When the face of a tooth has a radius across the flank and the face of the tooth.: What is an involute profile?
  3. Quieter and smoother meshing with the gear: What does an involute tooth profile allow?
  4. Pattern of areas that are in full contact when the gears are meshed togeth- er.: What is a contact pattern?
  5. Relative gear position: What does the contact pattern indicate?
  6. Clearance between the gear teeth at the pitch line, approximately half way up the tooth face.: What is backlash?
  7. Keeps the teeth from binding, allows room for thermal expansion, and allows room for a lubricating film: What purpose does backlash serve?
  8. half: Gears are manufactured with the backlash cut into each gear.
  9. 0.040": The average backlash is divided by the diametral pitch.
  10. The ratio between the number of teeth on a gear and the pitch diameter.: - What is diametral pitch (DP)?
  11. Tooth size: What does the diametral pitch indicate?
  12. small: A gear with large teeth will have a diametral pitch number.
  13. large: A gear with small teeth will have a diametral pitch number.
  14. fractional, whole: Standard pitch gears are available in and numbers.
  15. Premature wear and gear train failure: What does binding lead to?
  16. 14.5 degrees, 20 degrees: Gear trains commonly have pressure angles of or.
  17. the same: Meshing gears must have pressure angles.
  18. The dedendum of one gear contact the addendum of another: In the initial stages of gear tooth contact, which parts of the gears make contact?
  19. sliding: Until opposing gear teeth are in contact at their pitch line, the action between the teeth is.
  20. rolling: When gear teeth are in contact at the pitch line, the action between the teeth is.
  21. **1. Straight
  22. Involute:** What two basic profiles can gear teeth have on their faces?
  23. curve: The involute tooth profile has a on the face of the gear teeth.

Exams

  1. straight: Straight-cut teeth have faces and flanks and are very noisy.
  2. opposite: When an even number of gears mesh with one another, the last gear rotates in the direction of the first one.
  3. same: When an odd number of gears mesh with one another, the last gear rotates in the direction of the first one.
  4. same: An internal gear set has both gears rotating in the direction.
  5. direction of rotation: When replacing a gearbox, make sure they both have the same on the output shaft.
  6. A gear between the drive and a driven gear: What is an idler gear?
  7. Idler gears have no effect: What effect do idlers have on the gear ratio of the two gears with which they mesh?
  8. **1. Change the direction of rotation of the driven gear
  9. They can connect two gears with a centre-to-centre distance that is greater than the diameter of the gears
  10. Function as moveable gears, allowing the set of backlash and mesh pat- terns:** What purpose do idler gears serve?
  11. Speed reducer: Is a gearbox with a gear ratio of 20:1 a speed reducer or speed increaser?
  12. 10 rotations: How many rotations does a drive gear make in order to rotate the driven gear when the gear ratio is 10:1?
  13. 1/2 rotation: How many rotations does a drive gear make in order to rotate the driven gear when the gear ratio is 0.5:1?
  14. Speed increaser: Is a gearbox with a gear ratio of 0.05:1 a speed reducer or speed increaser?
  15. overdrives: Speed increaser gearboxes are often called.
  16. 20/10 = 2: 36/60 = 0.6: 0.6 x 2 = 1. 1.2:1: A gear box has 2 sets of gears. One set has an input gear with 10 teeth and an output gear of 20 teeth and the other set has an input gear with 60 teeth and an output gear with 36 teeth. What is the final out put ratio of the gearbox?
  17. Force of rotation between rotating gears and a shaft: What is torque?
  18. By multiplying the applied force on a shaft by the distance from the centre line of the shaft rotation: How is torque calculated?
  19. 100 ft-lbs: If a 2 foot long wrench has 50 lbs of force applied to it, what is the torque being administered?

Exams

  1. **1. Parallel
  2. Intersecting
  3. Crossing over at 90 degrees:** What 3 basic shaft positions are used to allow gears to mesh properly?
  4. **1. Spur gears
  5. Helical gears of opposite hand
  6. Double helical gears
  7. Herringbone gears:** What type of gears can be mounted on parallel shafts?
  8. On the same plane but 90 degrees from each other: How are intersecting shafts mounted?
  9. **1. Bevel gears
  10. Mitre gears:** What type of gears can be mounted on intersecting shafts?
  11. On different planes and 90 degrees from each other: How are shafts that cross over at 90 degrees mounted?
  12. **1. Worm gears
  13. Hypoid gears
  14. Helical gears of the same hand:** What gears can be mounted on a shaft crossing over at 90 degrees?
  15. gears with teeth cut into the gear blank parallel to the shaft axis.: What are spur gears?
  16. parallel: Spur gears are only suitable for shaft that are.
  17. straight: The teeth on a spur gear have a profile.
  18. **1. External
  19. Internal
  20. Rack and pinion:** Spur gears can be used in 3 basic arrangements:
  21. opposite: When external spur gears mesh with one another, the driven gear turns in the direction.
  22. same: When an internal spur gear meshes with another gear, they turn in the direction.
  23. **1. Teeth have more contact area
  24. Shaft distances can be much closer:** What are the advantages of an internal spur gear arrangement?
  25. A linear surface that has gear teeth cut into it.: What is a rack?
  26. linear: A rack and pinion transfers rotational movement into movement.
  27. Half the sum of the pitch diameters of the two gears: What is the correct distance between two spur gears mounted in a gear box housing?
  28. rolling: During the maximum power transfer between spur gears, the gear

Exams

action is.

Exams

  1. symmetrical (in line) or non-symmetrical (staggered): Double helical gears can have teeth on both sides hat are either .
  2. Axial thrust is cancelled by the opposite row of teeth: What is the advan- tage of using a double helical gear?
  3. A gear with teeth that form a point at the centre of the gear: What is a herringbone gear?
  4. axial thrust: The opposite hand helixes of a herringbone gear cancel out any .
  5. relieved: The centre of a herringbone gear is not as in double helical gears.
  6. high, heavy: Herringbone gears are recommended for -speed, -load applications.
  7. parallel: Herringbone gears must be mounted on posi- tioned shafts.
  8. intersecting axes: Bevel gears are used on shafts that have .
  9. 90 degrees: What angle do the most common bevel gears intersect at?
  10. cones: Bevel gears are cut out of blanks shaped like.
  11. axial thrust and radial: Bevel gears develop loads.
  12. **1. Straddle mount
  13. Overhung:** What two positions can bevel gears be mounted in?
  14. straight: Straight bevel gears have a tooth profile.
  15. curved: Spiral and Zerol bevel gears have a tooth profile.
  16. A bevel gear that intersects at 90 degrees: What is a mitre gear?
  17. 1:1: What is the gear ratio of a mitre gear?
  18. direction: Mitre gears only change the of the output shaft.
  19. tapered: Straight bevel gears have straight but to com- pensate for the smaller inside diameter of the teeth.
  20. low: Straight bevel gears have load capacity.
  21. different: Straight bevel gears can be at many different.
  22. oblique: Spiral bevel gears have curved teeth that are to the shaft axis.
  23. **1. Stronger
  24. Smoother transfer of power:** What advantages does a spiral bevel gear have

Exams

over a straight bevel gear?

Exams

3. Lead angle

Exams

**4. Gear material

  1. Gear design
  2. The amount of torque or load on the output shaft:** What does the efficiency of a worm gearbox depend on?
  3. The distance from one tooth to the next tooth on a worm: What is worm pitch?
  4. The distance in which one tooth on the worm advances in one turn: What is worm lead?
  5. Number of starts x pitch = lead: How is the worm lead determined?
  6. Number of teeth / Number of starts: How is the worm gear ratio found?
  7. 40 / 5 = 8 8:1: A worm wheel with 40 teeth has 5 starts, what is the worm gear ratio?
  8. cylinder: A non-throated worm is shaped like a.
  9. **1. Throated
  10. Non-throated:** What variations are worms available in?
  11. hourglass: A throated worm is shaped like a.
  12. **1. Throated
  13. Non-throated:** What variations are worm wheels available in?
  14. flat tops: The teeth of a non-throated worm wheel have .
  15. concave in the middle: The teeth of a throated worm wheel are .
  16. **1. Non-throated
  17. Single throated
  18. Double throated:** What variations of throat are worm gear sets available in?
  19. one point: On non throated worm gear sets, contact occurs along on each gear.
  20. Either the worm or the worm wheel is throated.: What does a single throated worm gear set provide?
  21. Worm wheel: What gear is usually throated in a single throated worm gear set?
  22. Both the worm wheel and the worm are throated: What does a double throated worm gear set provide?
  23. The double throated worm gear set: Which worm gear set configuration gives the most gear tooth contact?
  24. So that the contact between the teeth is slightly toward the leaving side of the worm wheel.: How should a worm wheel be set up to achieve maximum power capacity and life of the gears?

Exams

  1. A specific combination of gears that can produce several speed and torque combinations from one set of gears in a small space: What is a planetary gear set?
  2. **1. Sun gear
  3. Carrier with planet gears mounted to it
  4. Ring gear:** What 3 parts does a simple planetary gearset consists of?
  5. centre: The sun is the of the planetary gear system.
  6. planetary gears (pinions): The surround and mesh with the sun gear.
  7. ring gear: The surrounds all the gears and meshes with the planetary pinions in a planetary gear system.
  8. reaction member: If one gear is in a fixed position in a planetary gear system, it is referred to as the.
  9. The remaining member: If two members are in a fixed position in a planetary gear system, Where does the power output come from?
  10. **1. Forward reduction
  11. Overdrive
  12. Reverse
  13. Neutral
  14. Direct drive:** What output possibilities are available with a planetary gear set?
  15. The entire set rotates as a group and produces direct drive: What happens to a planetary gear set if two members are locked?
  16. reducer or increaser: Most industrial planetary drives function as a speed .
  17. spur or helical: Planetary gear designs can eith er or .
  18. stronger: More planetary pinions can be added to a planetary gear system to make it.
  19. The large number of teeth engaged at one time.: What makes a planetary gear system so strong?
  20. **1. Single reduction gearbox
  21. Double or multiple reduction gearbox:** What are the two gearbox types?
  22. A gearbox that has two shaft and two gears with one gear mounted on each shaft.: What is a single reduction gearbox?
  23. A gearbox with at least three shafts and four gears.: What is a double or multiple reduction gearbox?
  24. 6:1: What is a typical gear ratio in a multiple reduction gearbox?
  25. When the input and output shafts are on different planes: What is an offset

Exams

reducer?

Exams

  1. True: True or false. Helical gears with parallel shafts must use gears of the opposite hand.
  2. True: True or false. Double helical gears are good for high speeds and heavy loads.
  3. False, spur gears are straight cut and do not intersect.: True or false. A spur gear set that intersects at 90° must be of the same hand.
  4. False, herringbone gears are heavy duty drivers.: True or false. Herringbone gears are light duty drivers.
  5. False: True or false. Bevel gears cross over at 90° and can be straight, spiral or Zerol.
  6. True: True or false. Spiral bevel gears look very similar to hypoid gears.
  7. True: True or false. Hypoid gears have high sliding action and require an EP additive in the oil.
  8. False, the heel of a hypoid or spiral bevel gear is near the outer circle: True or false. The heel of a hypoid or spiral bevel gear is near the inner circle.
  9. True: True or false. Worm gears have a lot of sliding action
  10. True: True or false. Worm gears are less efficient than most other types of gears
  11. False: True or false. A worm gear that has 10 starts will be considered a self-locking gear set.
  12. True: True or false. A double-throated worm and worm wheel gear set will have maximum gear tooth contact.
  13. True: True or false. Light-duty open gear drives are often made from synthetic materials like nylon or phenolics.
  14. False: True or false. A planetary gear system has a sun, stars and ring gear as part of the whole planetary system.
  15. False: True or false. If the input power is on the sun gear and the carrier is locked to the sun, the output will be a forward reduction.
  16. False: True or false. A planetary gear system can be considered a single reduction unit.
  17. a) same DP (diametral pitch) b) same pressure angle c) correct hand of gear d) shifts in correct position e) same helix angle: List six circumstances gears must have in order to mesh.
  18. a) have no effect on gear ratio b) span distance c) reverse direction of rotation d) to provide some means to adjust backlash: List four purposes of an idler.

Exams

  1. counter-clockwise (reverse): A certain gear train has 4 shifts and 6 gears, the input gear rotates clockwise, theoutput gear will rotate .
  2. in reverse: The planet gears in a planetary gear set can cause the ring gear (output) to rotate to the sun gear (input).