MACHINING BY ELECTRICAL EROSION THE GEAR WHEELS Drd. Ing. IOAN BADIU, Technical University of Cluj-Napoca Prof.univ.dr.ing. MARCEL S.POPA, Technical University of Cluj-Napoca ABSTRACT: Gears which can form a gear tooth are transmitted through successive and continuous contact (gear) rotation and torque between two shafts. For low tooth loads and low peripheral speeds between 0.3 and 2 m / s are chosen based alloys and steels, gray cast iron. In measuring instrument industry kinematics great precision is needed. Wheel group required less include some hand-operated mechanisms, such as jacks, some trolls. These wheels are larger and they are made of alloy steel, semi-hard and sometimes gray cast iron FC250, FC300. KEY WORDS : cogwheels, electrical erosion, materials, gears. 1.INTRODUCTION Breaking teeth fatigue is the main form of damage to the gear steel hardness active flanks> 45 HRC and cast iron gear or materials plastics. Breaking bending occurs due to application of the tooth, while stress variations that cause fatigue of the material and the appearance at the base of the tooth of cracks that develop over time, resulting, ultimately, tooth breakage. Fatigue crack appears in the body connecting the tooth wheel on the stretched fibers, which is the maximum bending stress concentration allowable value, by increasing the module, implementation of large connecting rays and positive displacement profile. 2.THE PROCESSING TECHNOLOGY TOOTHED WHEELS. The avoidance of fatigue fracture of the teeth can be achieved by limiting the bending stresses the base of the tooth to the Fig.1. Breaking the teeth by tiredness 39
. Fig.2.Wire electrical discharge (wire EDM) machine- 350 x 250 x 200 mm BSW-325 Fig.3. The form 2D gears with inclined teeth by erosion electrical processing. Fig.5. The form 2D gears with inclined teeth by erosion electrical processing. Fig.4. The form 2D gears Fig.6. Gear wheels assembled. 40
Fig.7. Gear wheels assembled. Fig.8. The form gear units. 3.EXPERIMENTAL RESULTS FROM THE POCESSING OF ELECTRICAL EROSION. Cogwheels may be machined by wire electrical The advantage is that it is very good precision processing. Fig.9.Table containing the values electrical Fig.10.The reporting of parameters electric 41
Fig.11.Table containing the values electrical Fig.15.Table containing the values electrical Fig. 12.The connection between electrical Fig. 16.The connection between electrical Fig.13. Reporting electric erosion productivity parameters. Fig.17. Connection and reporting productivity parameters electrical Fig.14. Connection and reporting productivity parameters electrical Fig.18.Form 3D graphics parameters electrical 42
Fig.19.Table containing the values electrical Fig.23.Form 3D graphics parameters electrical Fig.20.Form 3D graphics parameters electrical Fig.24.Table containing the values electrical Fig.21.Table containing the values electrical erosion parameters Fig.25.Form 3D graphics parameters electrical Fig.22.Form 3D graphics parameters electrical Fig.26.Form 3D graphics parameters electrical 43
Fig.27.Form 2D graphics parameters electrical. Fig.31.Graphical form of electrical erosion parameters. Fig.28.Form 2D graphics and equations of lines electrical Fig.32.Form 2D graphics paarmetrilor electrical Fig.29.Graphical form of electrical erosion parameters. Fig.33.Form 2D and electrical erosion Fig.30.Graphical form of electrical erosion parameters. Fig.34.Form 2D and electrical erosion 44
Fig.35.Form 2D and electrical erosion Fig.39.Form 2D electrical erosion parameters and values. Fig.36.Form 2D and electrical erosion Fig.40.Table containing the values electrical erosion parameters Fig.37.Form 2D and electrical erosion Fig.41.Form 3D graphics parameters electrical Fig.38.Form 2D and electrical erosion Fig.42.3D graphic form paarmetrilor electrical erosion and values. 45
Fig.43.Table containing the values electrical erosion parameters Fig.45.Form 2D electrice.si erosion parameters values. Fig.44.Form 2D electrical 4.CONCLUSIONS Gears are widely used in mechanical transmissions due to the advantages it presents: constant transmission ratio; operational safety; durability; high efficiency; small size; can be used for a wide range of powers, speeds and gear ratios. As disadvantages can be mentioned: high precision manufacturing and assembly; complicated technology; noise and vibration operation. REFERENCES. [1]Ailincai, G.: Studiul metalelor,institutul Politehnic Iasi, 1978. [2]Balc, N.: Tehnologii neconventionale, Editura Dacia Publishing House, Cluj- Npoca, 2001. [3]Bolundut, L.I.: Materiale si tehnologii neconventionale, Editura Tehnica-Info, Chisinau, 2012. [4]Buzdugan, Gh., ş.a. Vibraţii mecanice, Editura Didactică şi Pedagogică, Bucureşti, 1λ7λ. [5]Constantinescu, V., ş.a. Lagăre cu alunecare, Editura Tehnică, Bucureşti 1980. [6]Colan, H.: Studiul metalelor, Editura Didactica si Pedagogica, Bucuresti, 1983. [7]Domsa, A.: Materiale metalice in constructia de masini si instalatii, Editura Dacia, 1981. [8]Dašić, P.: 100.000 Technical and ICT Abbreviations and Acronyms. Vrnjačka Banja: SaTCIP Ltd., 2013. pp. 1200. ISBN 978-86-6075-001-5. [9]Dašić, P.μ Analysis of the journal impact factor in field of mechanical engineering. Plenary and Invitation paper. In: Proceedings of the 11th International in Mechanical Industry 46
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