Chapter 12 - Gear Drives Flashcards
1
Q
What jobs do gears perform?
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2
Q
Describe pitch line of gears or cylinders
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3
Q
Define:
- addendum (ADD)
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4
Q
Define:
- dedendum (DED)
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5
Q
Define:
- clearance (CL)
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6
Q
Define:
- circular pitch (CP)
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7
Q
Define:
- outside diameter (OD)
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8
Q
Define:
- diametral pitch (DP)
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9
Q
Define:
- pitch diameter (PD)
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10
Q
Define:
- working depth (WKD)
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11
Q
Define:
- whole depth (WHD)
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12
Q
Define:
- chordal thickness (T) (or tooth thickness)
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13
Q
What are the conditions for proper gear meshing?
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14
Q
Describe pressure angle and line of action
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15
Q
What does a millwright use to identify a 14.5 degree pressure angle gear?
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16
Q
How does tooth profile affect the meshing action of two gears?
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17
Q
What are the purposes of backlash between gears?
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18
Q
What types of materials are gears made from?
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19
Q
What factors must be considered when choosing gears from the available materials?
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20
Q
What are the merits and limitations of:
- ferrous metal gears?
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21
Q
What are the merits and limitations of:
- non-ferrous metal gears?
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22
Q
What are the merits and limitations of:
- non-metallic material gears?
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23
Q
List four shaft arrangements
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24
Q
Describe the principles of operation of the following:
- external spur gears
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25
Describe the principles of operation of the following:
| - internal for gears
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26
Describe the principles of operation of the following:
| - rack and pinion spur gears
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27
Describe the principles of operation of the following:
| - helical gears
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28
Describe the principles of operation of the following:
| - double helical gears
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29
Describe the principles of operation of the following:
| - herringbone gears
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30
Describe the principles and operation and the terminology associated with bevel gears, spiral bevel gears and hypoid gears
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31
Describe, non-throated contact, throated contact, double-throated contact and how to identify thrust direction for worm and worm gear sets
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32
What are the shaft arrangements for the following gear sets:
| - internal spur?
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33
What are the shaft arrangements for the following gear sets:
| - rack and pinion?
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34
What are the shaft arrangements for the following gear sets:
| - double helical?
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35
What are the shaft arrangements for the following gear sets:
| - spiral bevel?
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36
What are the shaft arrangements for the following gear sets:
| - hypoid?
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37
What are the shaft arrangements for the following gear sets:
| - throated worm and wheel?
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38
Define overdrive
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39
Describe the principles of operation of positively infinitely variable drive (PIV)
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40
How is greater reduction of speed achieved when a single reduction is not sufficient?
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41
What type of gears and gear arrangements are used in gear reduction units?
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42
What parts and materials are used in the construction of work gear reduction units?
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43
Describe how to fit the worm gear to the worm in a reduction unit
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44
With reference to single reduction worm gear unit:
| - what configurations and directions of drive are attainable?
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45
With reference to single reduction worm gear unit:
| - what does hand of drive refer to?
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46
With reference to single reduction worm gear unit:
| - what gear ratio range is available?
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47
With reference to multiple reduction units:
| - how much gear ratio range is available with a primary helical reduction combined with a worm and worm gear reduction?
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48
With reference to multiple reduction units:
| - how much gear ratio range is available with double and triple, worm and worm gear combinations?
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49
With reference to helical and herringbone reduction units:
| - what shaft configurations are available?
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50
With reference to helical and herringbone reduction units:
| - what gear ratio changes are available with single, double, triple and quadruple reductions?
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51
With reference to helical and herringbone reduction units:
| - what type of bearings are used?
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52
Describe the procedure for fitting both helical and herringbone gears in their respective reduction units
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53
What is the applications for bevel gear units?
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54
What gear ratio ranges are available with bevel gear units and mitre gear boxes?
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55
What are the applications for hypoid gear units?
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56
What gear ratio range is available with hypoid gear reduction units?
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57
Describe the setting of bevel and hypoid gears
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58
With reference to planetary gear units:
| - what is the shaft configuration?
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59
With reference to planetary gear units:
| - what gear ratio range is available?
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60
With reference to planetary gear units:
| - what drive members make up these gear units?
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61
Which gear is held to achieve overdrive with a planetary gear set?
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62
What type of base is required for motor and gear units coupled with a flexible coupling?
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63
How are drivers connected to gear reduction units?
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64
Where should gear drive units be positioned?
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65
Describe the merits and limitations of base-mounted and shaft-mounted gear drive units
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66
Describe the placement of torque arms on gear drive units so equipped
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67
Describe the lubricating systems used to lubricate gear drive units
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68
Where does one find the specifications or recommendations for the grade of oil for a gear drive unit?
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69
What symptoms will be present if the gear drive bearings are worn?
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70
What symptoms will appear if the gear drive unit is overloaded?
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71
What repair should be made if he shaft is worn or rough at the point of seal contact?
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72
What checks should be made if the oil level drops but stays clean in the gear drive unit?
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73
What would cause oil to get lighter and or darker in colour with use?
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74
What may cause colour streaks or rings in dirty oil during a pour test?
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75
What are the causes of bearing failure?
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