Transactions of Materials Processing (소성∙가공)

The Korean Society for Technology of Plasticity and materials processing (한국소성∙가공학회)
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Properties of a Helical Gear Due to the Manufacturing Process - Forged versus Machined Product

헬리컬기어 제조공정에 따른 특성 비교 -단조품과 기계가공품-

  • 정현철 (한국기계연구원 부설 재료연구소) ;
  • 강범수 (부산대학교 항공우주공학과) ;
  • 이일환 ((주)T.A.K) ;
  • 최석탁 ((주)T.A.K) ;
  • 신상종 (현대자동차 변속기 생기팀) ;
  • 강성훈 (한국기계연구원 부설 재료연구소) ;
  • 이영선 (한국기계연구원 재료연구소 변형제어연구그룹)
  • Received : 2011.09.19
  • Accepted : 2011.12.12
  • Published : 2012.02.01
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Abstract

Although high productivity is possible, cold forged helical gears have not been widely used due to difficulty in achieving mechanical properties as well as dimensional accuracy of the product. Confidence in the gear characteristics also is very important in heavy-duty gear applications. Therefore, the properties of forged gears must be compared to the properties of conventional machined gears. The properties might be different due to the different fabrication processes. In this study, machined and forged products both before and after heat-treated have been compared by measuring the residual stress and involute curve of the tooth. Characteristics of hardness and microstructure were also compared. Additionally, tooth fracture strength was compared for the heat-treated products. Moreover, the tooth strength and the fracture pattern were compared between the machined and forged gears. The forged gear showed decreased changes in residual stress and decreased changes in dimensions when compared to the machined gear before and after heat treatment. The forged gear was over 10% better than the machined gear in tooth strength.

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References

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