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1
Basic Mechanical Drives and Power Transmission Training
December 2007
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Mechanical Drives/Power Transmission Training
The purpose of this presentation is to
provide a overview of industrial drives and their maintenance.
Gear Drives Belt Drives V-Belt Maintenance Chain Drives Sprocket and Roller Chain Maintenance
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Gear Drives
December 2007
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Mechanical Drives/Power Transmission Training
Gear Boxes
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Mechanical Drives/Power Transmission Training
Types Types
Automotive transmissions Auxiliary transmissions Transfer cases Power takeoffs Marine gears Hydraulic drives Industrial transmissions Differentials
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Mechanical Drives/Power Transmission Training
Gear Boxes
Series trains Planetary gearing Speed reducers
Base mountedShaft mounted
Speed increasers
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Mechanical Drives/Power Transmission Training
Gears and Gear Boxes
A gear is a form of disc, or wheel, that has teeth around its periphery for the purpose of providing a positive drive by meshing the teeth with similar teeth on another gear or rack.
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Mechanical Drives/Power Transmission Training
Right Angle Gear Drive
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Mechanical Drives/Power Transmission Training
Spur Gears
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Mechanical Drives/Power Transmission Training
Involute Curve
Cord
Base Circle
Circle involute
Circle
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Mechanical Drives/Power Transmission Training
Pressure Angle
Pressure Angle
Pressure angle
Pressure angle
RotationLine of action
14 ½ ° 20°
Direction of tooth to
tooth push
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Mechanical Drives/Power Transmission Training
Pitch Diameter and Center Distance
221 DDC
221 DCD
Center Distance C
Pitch Diameter D1
Pitch Diameter D2
122 DCD
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Mechanical Drives/Power Transmission Training
Circular/Diametrical Pitch
Circular Pitch
3.1416”
1 2 3 4 5 6 7 8 9 10
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Mechanical Drives/Power Transmission Training
Names of Gear Parts
Clearance
Pitch Circle
Addendum
Pitch Circle
DedendumWhole depth
Working depth
ThicknessCircular
pitchPitch Line
Addendum
Dedendum Whole depth
Thickness
Circular pitch
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Mechanical Drives/Power Transmission Training
BacklashBacklash
Pitch Line
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Mechanical Drives/Power Transmission Training
Other Gear Types
Bevel and Miter Helical Worm Herringbone
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Mechanical Drives/Power Transmission Training
Bevel and Miter Gear
Shaft Angle
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Mechanical Drives/Power Transmission Training
Helical
Helix angle
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Mechanical Drives/Power Transmission Training
Worm Gear
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Mechanical Drives/Power Transmission Training
Herringbone Gear
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Mechanical Drives/Power Transmission Training
Gear Damage
Vibration Frequency Component – gear mesh Normal profile
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Mechanical Drives/Power Transmission Training
Troubleshooting
Inappropriate bidirectional operation Gear overload Misalignment Poor maintenance Induced misalignment Visual inspection
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Mechanical Drives/Power Transmission Training
Wear patterns
Normal
Abrasives in lubricating oil
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Mechanical Drives/Power Transmission Training
Pattern caused by corrosive attack on gear teeth
Pitting caused by gear overloading
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December 2007 Belt Drives
Belt Drives
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Mechanical Drives/Power Transmission Training
Introduction
DescriptionBasic Components
Load carrying sectionRubber compression sectionCover
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Mechanical Drives/Power Transmission Training
Belt Drives Belt drives are used to transmit power
between a drive unit and a driven unit
Drive Motor
Driven Unit
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Mechanical Drives/Power Transmission Training
Belts
The size of the belt must match the sheave size. if they do not match, then the belt will not make proper contact with the sheave and will decrease the amount of load it can transmit.
A
AB
B
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Mechanical Drives/Power Transmission Training
Belt Selection
Standard V-Belt Cogged Belt
Joined V-Belt Positive Drive Belt
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Mechanical Drives/Power Transmission Training
Sheaves
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Mechanical Drives/Power Transmission Training
Shaft Speed
erave_diametDriven_she_rpmdriveshaftncheseDiameterIDriveSheavt_rpmDrivenShaf
12 inch dia.
6 in dia.
1800 rpm
DriveDriven
rpm
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Mechanical Drives/Power Transmission Training
Driven Sheave Diameter
ft_rpmDriven_sha_rpmdriveshaftncheseDiameterIDriveSheavveDiameterDrivenShea
___ inch dia.
6 in dia.
1800 rpm
DriveDriven
900 rpm
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Mechanical Drives/Power Transmission Training
Belt Length
12 inch dia.
6 in dia.
DriveDriven
35 inches
2centercenter_to_23.14meterdriven_dia
23.14eterdrive_diamhBelt_lengt
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Mechanical Drives/Power Transmission Training
Belt Speed
1214.3 rpmdiameterFPM
12 inch dia.
6 in dia.
1800 rpm
DriveDriven
900 rpm
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December 2007
V-Belt Maintenance
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Mechanical Drives/Power Transmission Training
Belt Maintenance
Routine maintenance is essential if a belt drive is to operate properly
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Mechanical Drives/Power Transmission Training
Belt Maintenance
Never force belt onto sheave Belt should not ride on bottom of sheave. Check belt condition Belt alignment Tension Inspect sheaves and shafts Belt stretch
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Mechanical Drives/Power Transmission Training
How to Read V-belt Numbers
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Mechanical Drives/Power Transmission Training
Classic Cog V-belts AX-BX-CX-DX
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Mechanical Drives/Power Transmission Training
D-V Wedge Belts 3VX-5VX-8V
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Mechanical Drives/Power Transmission Training
Classic V-belts A-B-C-D-E
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Mechanical Drives/Power Transmission Training
V-belt Inspection
Slapping Squealing Check belt
condition Tightness Tension
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Mechanical Drives/Power Transmission Training
V-belt Sidewall Wear
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Mechanical Drives/Power Transmission Training
V-belt Worn Cover/soft or Swollen
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Mechanical Drives/Power Transmission Training
V-belt Slips, Squeals (Spin Burn)
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Mechanical Drives/Power Transmission Training
V-belt Underside Cracked
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Mechanical Drives/Power Transmission Training
V-Belt Cover Split / Missing Cogs Belts pried upon
Foreign objects Excessive heat Sheave too small Sheave misaligned Improper storage
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Mechanical Drives/Power Transmission Training
Sheave InspectionSheave groves
must be
like this
not this
Dished out
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Mechanical Drives/Power Transmission Training
Sheave Inspection
5V
10.01-16.0O.D.
40 deg
Under 10.0O.D.
38 deg
Over 16.0O.D.42
deg
Example sheave gauge
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Mechanical Drives/Power Transmission Training
Alignment
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Mechanical Drives/Power Transmission Training
Types of Misalignment Angular
Misalignment
Parallel Misalignment
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Mechanical Drives/Power Transmission Training
Shaft Alignment
Cord tied to shaft
Cord touching sheaves at points indicated by arrows
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Mechanical Drives/Power Transmission Training
Tensioning V-belts Drives
Too tight
Too loose
Slight bow
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Mechanical Drives/Power Transmission Training
Check Tension
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Mechanical Drives/Power Transmission Training
Preventative Maintenance
Check belt condition Check belt tension Identify sources of contamination Check sheave alignment Check sheave wear
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December 2007
Chain Drives
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Mechanical Drives/Power Transmission Training
Introduction
DescriptionTypes of links
Self forming teethExtended Pin
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Mechanical Drives/Power Transmission Training
Introduction
DRIVEN ROLL
DRIVE GEAR BOX
Chain Pitch
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Mechanical Drives/Power Transmission Training
Chain Drive
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Mechanical Drives/Power Transmission Training
Advantages No slippage More compact than belt Good for slow speeds Easier to install Not subject to deterioration Operates under wet conditions Less adjustment required Can drive several shafts Less costly than gear drives
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Mechanical Drives/Power Transmission Training
Disadvantages Cannot be used where drive must slip Cannot except misalignment Noisy Causes vibration Needs frequent lubrication Small load capacity Shorter Service Live
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Mechanical Drives/Power Transmission Training
Chain Drive Principles Drive chain
Drive Sprocket
Sprocket
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Mechanical Drives/Power Transmission Training
Shaft Speed
teethcket_#DrivenSpro_rpmdriveshaftteethket_#DriveSproct_rpmDrivenShaf
12 T 6 T
1800 rpm
DriveDriven
rpm
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Mechanical Drives/Power Transmission Training
Chain Length Calculation
2nterCenterToCe2
PitchcketTeethDrivenSpro2
PitchketTeethDriveSprochChainLengt
12 T 6 T
DriveDriven
35 inches
40 Chain
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Mechanical Drives/Power Transmission Training
Chain Speed
12rpmpitchteethFPM
12 T 6 T
1800 rpm
DriveDriven
900 rpm
40 Chain
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Mechanical Drives/Power Transmission Training
Some Chain Drive Examples
Fork Lift Roller Conveyor
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December 2007
Sprocket and Roller Chain Maintenance
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Mechanical Drives/Power Transmission Training
Roller Chain
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Mechanical Drives/Power Transmission Training
Pitch
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Mechanical Drives/Power Transmission Training
Large Pitch Conveyor Chain
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Mechanical Drives/Power Transmission Training
Chain Part Friction Areas
Major friction areas in red
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Mechanical Drives/Power Transmission Training
Lubrication Methods
Hand Oiling Drop Lubrication Oil Bath Rotating Plate Forced Circulation
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Mechanical Drives/Power Transmission Training
Example Application Large Roller Chain Multi-strand conveyor
Large Roller Chain
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Mechanical Drives/Power Transmission Training
Sprockets
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Mechanical Drives/Power Transmission Training
Sprocket Classifications
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Mechanical Drives/Power Transmission Training
Chain Drive Factors Location of slack Chain wrap Vertical arrangement
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Mechanical Drives/Power Transmission Training
Installation – Parallel Shafts
Level
Level
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Mechanical Drives/Power Transmission Training
Installation
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Mechanical Drives/Power Transmission Training
Installation - Sprockets
Straight edge or Straight string
Gap
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Mechanical Drives/Power Transmission Training
Installation
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Mechanical Drives/Power Transmission Training
Chain LengthThe following information is needed for an equation to find the chain length:
1. Number of teeth on the drive sprocket. 2. Number of teeth on the driven sprocket. 3. Center-to-center distance between the shafts. 4. The chain pitch in inches.
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Mechanical Drives/Power Transmission Training
Chain Inspection Cleanliness Lubrication Signs of wear Flexibility Check chain stretch Physical damage
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Mechanical Drives/Power Transmission Training
Chain Wear
WORN CHAINNEW CHAIN
SPROCKET
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Mechanical Drives/Power Transmission Training
Sprocket Tooth Wear SPROCKETS INDICATE
WEAR HERE
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Mechanical Drives/Power Transmission Training
Preventive Maintenance
Inspect for wear Lubricate Check chain sag Set tension Inspect sprockets
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Mechanical Drives/Power Transmission Training
Summary and Quiz
Review Objectives Question and Answer Session