This document summarizes a seminar presentation on gear manufacturing, quality inspection, failures, and remedial measures. It discusses various gear manufacturing methods like casting, sintering, injection molding, extrusion, stamping, forging, rack generation, shaping, and hobbing. Quality inspection techniques covered include red dye penetration testing, ultrasonic testing, and metallurgical testing. Various types of gear failures are explained such as scoring, wear, pitting, crushing, plastic flow, ridging, fatigue breakage, overload, and rim/web failure. Potential causes and remedies are provided for each failure type.

1. GEARS-MANUFACTURING, QULAITY INSPECTION,
FAILURES AND REMEDIAL MEASURES
Seminar topic
by
A. Sabiha khathun (16481D1501)
M. Tech (Machine Design)
Subject : Gear Engineering
Faculty : Kishore Kumar (Assoc. Prof.)
Department of Mechanical Engineering
Gudlavalleru Engineering College

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3. GEAR MANUFACTURING BY CASTING
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5. SINTERING
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6. INJECTION MOULDING
 Injection moulding is used to make nonmetallic gears in
various thermoplastics such as nylon.
Applications: cameras, projectors, speedometer, washing
machines.
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7. Applications : splined hollow and solid shafts sector gears
Extrusion: to form teeth on long gears, machined for bores
and keyways.
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8. STAMPING
A sheet metal can be stamped with tooth shapes
Applications: toys, hand operated machine gears, slow speed
mechanism gears
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9. FORGING
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13. RACK GENERATION
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14. SHAPING
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15. HOBBING
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16. GRINDING
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17. LAPPING
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18. QUALITY INSPECTION
 Red dye penetration test(RDP): It is also called liquid
penetrant inspection, used to locate surface breaking
defects in metals, plastics. For ferrous components
magnetic particle inspection is preferred.
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19.  Ultrasonic testing: It is a non destructive testing in
which ultrasonic waves are launched into materials to
detect the defects. It is performed on alloys.
 Metallurgical lab: specimens are checked for its desired
composition. In this various tests are conducted like
hardness test etc.
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20. GEAR FAILURES AND REMEDIES
 How to recognize them
 What causes them
 How to avoid them
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21. Failure may the reason of one or a combination of any of
the following factors
 Initial stresses
 Poor tooth design
 Use of incorrect material
 Material defect
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23. Scoring: rapid wear results due to over heating of the mesh,
metal to metal contact.
 Frosting
 Initial scoring
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24.  Moderate scoring
 Destructive scoring
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25.  Causes :excessive operating temperatures, excessive
heat in gear mesh, high surface speeds.
 Remedies: uniform heat removal at the mesh, lubricating
oil must be withstand with the temperatures
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26.  Moderate wear
 Excessive wear
cause: wear in progress, inadequate
lubricant film
Remedies: increasing lubricating film
strength, sufficient oil is supplied to
working surfaces.
Wear: A surface phenomenon in which layers of material is
removed or “worn away”
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27.  Abrasive wear
Cause: foreign material in the lubrication
metallic debris from the gear.
 Corrosive wear
Cause: corrosive elements in oil
remedies: use of filter and use high thick
lubricating oil
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28.  Initial pitting
 Destructive pitting
pitting: a surface fatigue failure depends on number of stress
cycles
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29. Causes :surface irregularities misalignment of gears
remedies: smooth gear surfaces, reduce dynamic loading limit,
keeping the load below the endurance limit.
Crushing:
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30.  COLD FLOW
Cause: rolling and peening action of mesh under
heavy loads.
Remedy: by increasing hardness of contact surfaces
and tooth –tooth spacing.
 RIPPLING
Cause: cyclic loads under high contact stresses.
Remedy: case hardening of tooth surface
Plastic flow: cold working of tooth surfaces caused by
high contact stress
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31.  Ridging
Causes: formation of deep ridges by
plastic flow
Remedy: using more viscous lubricant
oil, reducing contact stresses,
increasing hardness of the material.
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32.  FATIGUE BREAKAGE
Cause: extreme tooth loads, notches
Remedy: higher strength material,
load within endurance limit.
 OVERLOAD
Cause: overload which exceeds
tensile strength
Remedy: torque limiting, overload
protection devices.
fracture: fracture is caused by breakage of whole tooth
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33.  RIM AND WEB FAILURE
Cause: flexure stresses, holes in web
section, vibrations.
Remedy: rim and web thickness
increased, redesign of gear.
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34. THANK YOU
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