Fiabilitate si Durabilitate – Fiability Durability No 2 201 5 [607408]

Fiabilitate si Durabilitate – Fiability & Durability No 2 / 201 5
Editura “Academica Br âncuși ” , Târgu Jiu, IS SN 1844 – 640X

86 GEAR WHEELS THE PROC ESSED BY ELECTRICAL
EROSION

Prof.univ.dr.ing. MARCEL S.POPA, Technical University of Cluj -Napoca
Drd. Ing. IOAN BADIU, Technical University of Cluj -Napoca
ABSTRACT: 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 industry ar e preferable ferrous alloys: bronze, brass and aluminum alloys, and
where speeds and demands are low gears are made of sheet steel or alloys. Wheel group required less include
some hand -operated mechanisms, such as jacks, some trolls. These wheels are larg er and they are made of
alloy steel, semi -hard and sometimes gray cast iron FC250, FC300.
KEY WORDS : cogwheels, electrical erosion, materials, processing electrical erosion.

1.INTRODUCTION
For gears subject to high variable operating a t low speed and medium (2 -8m/s) are recommended
semi -hard steels and low alloy likely to be improved. These wheels are used in various fields. For
example, some large gear drive found in mills and cement kilns, some lifting and transport machinery,
agricultural machinery, combine mining. The blanks are obtained by casting, cast iron or steel, some
elements are obtained from the laminates.For heavy gear required to run high peripheral speeds (12 –
16m / s) with high loads and shocks tooth in operation, high toughness steels a re used, which applies
superficial hardening by heat treatment and thermochemical. Steels are suitable for manufacturing
these gears are alloy or alloy, and in some cases can be used and tempered steels. In cases where
demand is particularly high, it is ad visable to use high alloyed steels, case hardening steels such as Cr
– Ni, Cr – Ni – Mo, Cr – Ni – Ni steels W. use is recommended as we confer high resistance of these
wheels.
2.TECHNOLOGICAL PROCESSING ELECTRICAL EROSION

FIG.1. WIRE ELECTRICAL DISCH ARGE (WIRE EDM) MACHINE – 725 × 560 × 215 MM | G22F.

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Fig.2. The 3D graphic of the toothed wheel.

Fig.3. The values of toothed wheel.

Fig.4. The form 2D gears processed by electrical erosion.

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Fig.5. The form 2D gears processed by electrical ero sion.

Fig.6. The form 2D gears processed by electrical erosion.

Fig.7. The form 2D gears processed by electrical erosion .

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Fig.8. The form 2D gears processed by electrical erosion.

3.THE EXPERIMENTAL RESULTS PROCESSING ELECTRICAL EROSION

Fig.9. Table containing the values electrical erosion parameters.

Fig.10. Graphic form of electrical erosion parameters.

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Fig.11. The parameters of electrical erosion.

Fig.12. The connection between electrical erosion parameters.

Fig.13. Surface roughness parameter values .

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Fig.14. Graphic form of electrical erosion parameters.

Fig.15. The reporting of electrical erosion Surface roughness parameters.

Fig.16. Table containing the values electrical erosion parameters.

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Fig.17 . The connection between electrical erosion parameters.

Fig.18. The reporting of electrical erosion Surface roughness parameters.

Fig.19. 3D The form parameters of electrical erosion.

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Fig.20. 3D The form parameters of electrical erosion.

Fig.21. 3D The form parameters of electrical erosion.

Fig.22. The electrical erosion parameter values in the form of balls.

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Fig.23. The straight lines and electrical erosion graphical form parameters.

Fig.24. Form 2D electrical erosion paramete rs and parametric equations.

Fig.25. 2D electrical erosion parameters.

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Fig.26. 3D the form parameters of electrical erosion.

Fig.27. Points that determine erosion parameters electrical lines.

Fig.28. The straight lines electrical parameters and equations erosion graphs.

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Fig.29. The straight lines electrical parameters and equations erosion graphs.

Fig.30. The straight lines electrical parameters and equations erosion graphs.

Fig.31. The straight lines electrical parameters and eq uations erosion graphs.

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Fig.32. The straight lines electrical parameters and equations erosion graphs.

Fig.33. 3D the form parameter intensity.

Fig.34. 3D the form parameter intensity.

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Fig.35. 3D the form parameter intensity.

4.CONCLUSIONS
A range of thermal and thermo -chemical treatments are applied in order to increase the workability
(annealing, tempering), increased durability and reliability in operation (carburizing, hardening,
tempering) or for the purpose of hardening surfaces as sp ecial treatment (cianizarea, surfiza rea,
feroxarea, phosphating, iono -nitrurarea). So to influence and improve the machinability of steels and
cast irons for making gears is necessary to act by heat treatments on materials to improve machining
conditions. If obtained from semi forged gears recommended forging temperature to be 1000 -1250oC,
to avoid fissures and cracks -them. If some small gears and pinions are processed cold (cold extrusion
or stamping) have applied annealing. Nitriding steels are used for g ears subjected to heavy wear, so
heavily loaded. Alloying elements form nitrides hard and stable. Can be nitrided steels and
39MoCA06 38MoCA09 required to wear wheel (gears, sprockets, chain wheels, snails, racks). These
steels are subjected to heat treatm ents for improvement: double quenching and tempering. The
hardness of the nitrided layer depth decreases. Nitriding is done at a temperature of about 500 -600o C
depending on steel co mposition, thickness reaching 0, 8 mm in a time of about 40 -60 hours in two
successive stages
5. 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 n econventionale, Editura Tehnica -Info, Chisinau,
2012.
[4] Buzdugan, Gh., ș.a. – Vibrații mecanice, Editura Didactică și Pedagogică, București, 1979.
[5] Constantinescu, V., ș.a. – Lagăre cu alunecare, Editura Tehnică, București 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] Gafițanu, M. ș.a. – Organe de mașini, vol. 2. Editura Tehnică, Buc urești, 2002.
[9] Ghimisi,S. -An elastic -plastic adhesion model for fretting,15th.Symposium “DanubiaAdria”,
Bertinoro, Italia, 181 -183.

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Editura “Academica Br âncuși ” , Târgu Jiu, IS SN 1844 – 640X

99 [10] Nichici, A.: Prelucrarea prin eroziune electrica in constructia de masini, Editura Facla,
Timisoara, 1983.
[11] Olaru, D.N. – Tribologie. Elemente de bază asupra frecării, uzării și ungerii, Litografia
Institutului Politehnic „Gheorghe Asachi”, Iași, 1995.
[12] Popa,M.S.:Masini, tehnologii neconventionale si de mecanica fina -Editie Bilingva, Romana –
Germana, Ed itura U.T.PRESS, Cluj -Napoca, 2003.
[13] Popa, M.S.: Tehnologii si masini neconventionale, pentru mecanica fina si microtehnica,
Editura U.T.PRESS, Cluj -Napoca, 2005.
[14] Popa, M.S.:Tehnologii inovative si procese de productie, Editura U.T.PRESS, Cl uj-
Napoca,2009.
[15] Rădulescu, Gh., Ilea, M. – Fizico -chimia și tehnologia uleiurilor lubrifiante, Editura
Tehnică, București, 1982,
[16] Sofroni, L.: Fonta cu grafit nodular,Editura Tehnica, Bucuresti, 1978.
[17] Trusculescu, M.: Studiul metal elor, Editura Didactica si Pedagogica ,Bucuresti ,,1978.