Power Losses in a Gearbox Lubricated with Axle Gear Oils

  • Maroua HammamiEmail author
  • Mohamed Slim Abbes
  • Ramiro Martins
  • Jorge H. O. Seabra
  • Mohamed Haddar
Conference paper
Part of the Lecture Notes in Mechanical Engineering book series (LNME)


Three axle gear oils (75W90-A, 80W90-A and 75W140-A), available on the market and labeled as “Fuel Efficient”, and two candidate products (75W85-B and 75W90-B) were selected and their physical and chemical properties were measured and compared. The friction torque inside rolling bearings lubricated with the five axle gear oils was measured in a dedicated test rig. The measurements and the corresponding numerical simulations indicate that friction torque inside rolling bearings is strongly dependent on the operating conditions and on the axle oil formulations. The model was then applied with success to predict the torque loss in gearbox rolling bearings, in particular, those used in the FZG machine slave and test gearboxes. Gear power loss tests were realized on the FZG gear test machine, using type A10 gears and severe operating conditions. The torque loss measurements and the corresponding numerical simulations clearly pointed out the influence on the base oil type, of the oil viscosity and of the additive package on gear torque loss promoted by different axle oil formulations. An average coefficient of friction between meshing gears was devised from the experimental results. Several aspects regarding the meshing gears power loss were investigated like gear loss factor, the coefficient of friction and the influence of gear oil formulation (axle gear oils). A gearbox total power loss can be predicted by estimating the several power loss sources dissipated in gears, bearings and seals.


Axle gear oils Physical and chemical properties Friction torque A10 gears Power loss 

Notation and Units


Axis distance [mm]


Gear face width [mm]


Tip diameter [m]


Shaft diameter [m]


Transverse force to tooth flank [N]


Gear loss factor [–]


Local gear loss factor using rigid load distribution [–]


FZG load stage [–]


Gear module [mm]


Rotational speed [rpm]


Input power [W]


Total power loss [W]


Experimental total power loss [W]


Seals power loss [W]


Rolling bearings power loss [W]


Equivalent contact radius on the pitch point [mm]


Gears power loss [W]


Load dependent gears power loss [W]


Average surface roughness [m]


Wheel static torque [Nm]


Addendum modification coefficients [–]

\(v_{{\Sigma c}}\)

Sum of the rolling velocities on the pitch point [m/s]


Friction coefficient lubricant parameter [–]


Number of teeth of pinion or gear [–]


Pressure angle [°]


Gear helix angle [°]


Dynamic viscosity [Pas]


Total contact ratio [–]


Coefficient of friction in boundary film lubrication [–]


Coefficient of friction in full film lubrication [–]


Average friction coefficient along the path of contact [–].



The authors gratefully acknowledge the funding supported by National Funds through projects NORTE-01-0145- FEDER-000022—SciTech—Science and Technology for Competitive and Sustainable Industries, co-financed by Programa Operacional Regional do Norte (NORTE2020), and Fundo Europeu de Desenvolvimento Regional (FEDER) and LAETA under the project UID/EMS/50022/2013.


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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • Maroua Hammami
    • 1
    • 2
    Email author
  • Mohamed Slim Abbes
    • 1
  • Ramiro Martins
    • 3
  • Jorge H. O. Seabra
    • 2
  • Mohamed Haddar
    • 1
  1. 1.Laboratory of Mechanical, Modelling and ManufacturingNational Engineers School of Sfax (ENIS)SfaxTunisia
  2. 2.Faculdade de Engenharia da Universidade do Porto (FEUP)PortoPortugal
  3. 3.Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI)PortoPortugal

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