logging in or signing up helical gear presentation srieg Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 553 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: October 22, 2012 This Presentation is Public Favorites: 0 Presentation Description helical gear presentation- a case study Comments Posting comment... Premium member Presentation Transcript PowerPoint Presentation: A SEMINAR REPORT ON FATIGUE GAILURE OF HELICAL GEARS DEPARTMENT OF MECHANICAL ENGINEERING 2010-11Contents: Contents 1. Introduction 2. Case study 3. Experimental procedure 4. Results and discussion 5. ConclusionIntroduction : Introduction Failure analysis of helical gear used in a bus gearbox History-Gear has been in use for 3 years Material-AISI 8620 Steel Evaluation methods-Visual inspection, photo documentation, chemical analysis, micro hardness measurement, metallographic examinationTYPES OF GEAR FAILURES : TYPES OF GEAR FAILURES Fatigue Impact Fracture Wear Stress Rupture Surface contact fatigue- pitting, spallingCAUSES: CAUSES Poor design of gear set Misalignment of gears Overloads Subsurface defects in internal areas Use of incorrect materials and heat treatmentCASE STUDY : CASE STUDY Bus with problem with its transmission gearbox Gearbox running hot with excessive vibrations Problem was with the fourth speed drive gearGeneral appearance of failed helical gear: General appearance of failed helical gearPowerPoint Presentation: Parameters Value Number of teeth helical gear 36 Helix angle 15 0 Module, normal (mm) 4 Pitch circle diameter (mm) 150 Outer diameter (mm) 158 Face width (mm) 42Spectrum analysis and micro hardness measurement: Spectrum analysis and micro hardness measurement Result revealed that material was AISI8620 carburized steel Core hardness =439HV Surface hardness=550Hv Case depth=0.63mm Microstructure consist of martensite and retained austeniteMicrostructure: MicrostructureVisual inspection: Visual inspection No. of adjacent teeth failed due to fatigue A triangular piece of the teeth had broken off Crack initiation and bench marks can be seen by necked eyes Origin of crack was at the pitch line No corrosion media were found on fractured surfacePhotograph of failed gear tooth: Photograph of failed gear toothPitting : Pitting Destructive pitting and spalling were also noted on loaded side of each tooth Destructive pitting appears as much larger pits than initial pitting In spalling pits are large in diameter and quite shallow Spalling is caused by excessively high contact stressPhotograph of Pitted gear teeth: Photograph of Pitted gear teethSEM and EDX Examination: SEM and EDX Examination SEM inspection to identify cause of fatigue crack initiation and propagation River-like pattern could be seen in propagation zone EDX attached to fractured surface to determine gear chemistry To verify presence of any other associated componentsCrack initiation and propagation: Crack initiation and propagationConclusion: Conclusion Composition, microstructure, hardness and case depth found satisfactory Fractographic features indicated that fatigue was the main failure cause Misalignment was observed which has caused failure Formation of destructive pitting and spalling at one end was due to load concentration at that areaTHANK YOU!: THANK YOU! You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.