Coeficiente de atrito

Tribology International 39 (2006) 512–521 www.elsevier.com/locate/triboint

Friction coefficient in FZG gears lubricated with industrial gear oils: Biodegradable ester vs. mineral oil
R. Martinsa,*, J. Seabrab, A. Britoc, Ch. Seyfertd, R. Lutherd, A. Igartuae a ˆ ˜ INEGI, Instituto de Engenharia Mecanica e Gestao Industrial, Porto, Portugal b DEMEGI, Faculdade de Engenharia da Universidade do Porto, Portugal c A. Brito, Industria Portuguesa de Engrenagens L.da, Porto, Portugal d FUCHS Petrolub AG, Mannheim, Germany e ´ Fundacion TEKNIKER, Eibar (Gipuzkoa), Spain

Received 16 November 2004; received in revised form 10 March 2005; accepted 17 March 2005 Available online 3 June 2005

Abstract Two industrial gear oils, a reference paraffinic mineral oil with a special additive package for extra protection against micropitting and a biodegradable non-toxic ester, were characterized in terms of their physical properties, wear properties and chemical contents and compared ¨ ¨ in terms of their power dissipation in gear applications [Hohn BR, Michaelis K, Dobereiner R. Load carrying capacity properties of fast ¨ biodegradable gear lubricants. J STLE Lubr Eng 1999; Hohn BR, Michaelis K, Doleschel A. Frictional behavior of synthetic gear lubricants. Tribology research: from model experiment to industrial problem. Elsevier 2001; Martins R, Seabra J, Seyfert Ch, Luther R, Igartua A, Brito A. Power Loss in FZG gears lubricated with industrial gear oils: biodegradable ester vs. mineral oil. Proceedings of the 31th Leeds-Lyon symposium on tribology. Elsevier; to be published; Weck M, Hurasky-Schonwerth O, Bugiel Ch. Service behaviour of PVD-coated gearing lubricated with biodegradable synthetic ester oils. VDI-Berichte Nr.1665 2002.]. The viscosity–temperature behaviors are compared to describe the feasible operating temperature range. Standard tests with the Four-Ball machine and the FZG test rig [Winter H, Michaelis K. FZG gear test rig—desciption and possibilities.