GEAR WHEELS THE PROCESSED BY ELECTRICAL EROSION...Fiabilitate si Durabilitate - Fiability & Durability No 2/ 2015 Editura “Academica Brâncuşi” , Târgu Jiu, ISSN 1844 – 640X

Fiabilitate si Durabilitate - Fiability & Durability No 2/ 2015 Editura “Academica Brâncuşi” , Târgu Jiu, ISSN 1844 – 640X

86

GEAR WHEELS THE PROCESSED 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 are 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 larger 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 at 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 are 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 advisable 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 DISCHARGE (WIRE EDM) MACHINE- 725 × 560 × 215 MM | G22F.


87

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.


88

Fig.5. The form 2D gears processed by electrical erosion.




89


3.THE EXPERIMENTAL RESULTS PROCESSING ELECTRICAL EROSION

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

Fig.10. Graphic form of electrical erosion parameters.


90

Fig.11. The parameters of electrical erosion.

Fig.12. The connection between electrical erosion parameters.

Fig.13. Surface roughness parameter values.


91

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.


92

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.


93



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


94

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

Fig.24. Form 2D electrical erosion parameters and parametric equations.

Fig.25. 2D electrical erosion parameters.


95

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.


96





97


Fig.33. 3D the form parameter intensity.



98


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 special treatment (cianizarea, surfizarea,

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 gears 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 treatments 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 composition, 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 neconventionale, Editura Tehnica-Info, Chisinau,

2012.

[4] Buzdugan, Gh., ş.a. – Vibraţii mecanice, Editura Didactică şi Pedagogică, Bucureşti, 1979.

[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] Gafiţanu, M. ş.a. – Organe de maşini, vol. 2. Editura Tehnică, Bucureşti, 2002.

[9] Ghimisi,S. -An elastic-plastic adhesion model for fretting,15th.Symposium “DanubiaAdria”,

Bertinoro, Italia, 181-183.


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 şi ungerii, Litografia

Institutului Politehnic „Gheorghe Asachi”, Iaşi, 1995.

[12] Popa,M.S.:Masini, tehnologii neconventionale si de mecanica fina-Editie Bilingva, Romana-

Germana, Editura 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, Cluj-

Napoca,2009.

[15] Rădulescu, Gh., Ilea, M. – Fizico-chimia şi tehnologia uleiurilor lubrifiante, Editura

Tehnică, Bucureşti, 1982,

[16] Sofroni, L.: Fonta cu grafit nodular,Editura Tehnica, Bucuresti, 1978.

[17] Trusculescu, M.: Studiul metalelor, Editura Didactica si Pedagogica ,Bucuresti ,,1978.

Documents

GEAR WHEELS THE PROCESSED BY ELECTRICAL EROSION...Fiabilitate si Durabilitate - Fiability & Durability No 2/ 2015 Editura “Academica Brâncuşi” , Târgu Jiu, ISSN 1844 – 640X