Shear Stress Analysis of EHL Oil Films Based on Thermal EHL Theory - In the Case of Elliptical Contact Condition -

Abstract

Under the elliptical contact conditions with an ellipticity parameter of Ke=1.4, a non-Newtonian thermal EHL analysis was carried out. The lubricating oil was assumed to behave as a Maxwell fluid. Lubricating oil is the automotive traction oil with the viscosity grade of ISO VG32. Input parameters are maximum Hertzian pressure PH=1.5 GPa, entrainment velocity ue=10 m/s, slide-roll ratio Σ=0%∼4.0% and inlet oil temperature t0=413 K. The shear stress distribution under elliptical contact conditions showed a similar tendency to that obtained in point contact conditions, and it was found that the traction coefficients at maximum Hertzian pressure of PH=1.5 GPa are scarcely affected by the shape of contact area. Furthermore, although both the pressure distributions and the temperature distributions hardly changed up to the slide-roll ratio of Σ=1.0%, the considerable variation in the shear stress distributions was recognized.

Keywords

• shear stress
• traction oil
• thermal ehl
• maxwell model
• elliptical contact
• slide-roll ratio