Prediction of mechanical gear mesh efficiency of hypoid gear pairs

Non-Newtonian mixed elastohydrodynamics of differential hypoid gears at high loads

“…mean losses of 2.1%). The power loss predicted here is within the range of 1-3%, also predicted by Xu and Kahraman [18] and Kolivand and Kahraman [19]. Fig.18 Inefficiency of the differential hypoid gear pair during the meshing cycle…”

“…A more realistic elliptical point contact would exist in practice. A recent work by Kolivand et al [19] provides a regressed equation for friction, based on mixed elastohydrodynamic conditions and non-Newtonian shear of thin lubricant films. However, the line contact assumption was retained.…”

Evaluating the relationship between use phase environmental impacts and manufacturing process precision

“…2 instead of the traditional R q as used in this paper) on gear efficiency for a helical gear pair modeled after the final drive reduction of a standard automotive manual transmission drivetrain. Similar work has shown an even greater dependence on the surface roughness of the mating surfaces for hypoid gear pairs, which are found in automotive differentials [12]. Because the vast majority of environmental impacts of an automobile occur during the use phase [13], the impact of increased manufacturing precision through better surface finish on the final drive reduction of an automotive manual transmission drivetrain presents the ideal case study for this investigation.…”

The Effects of Microdimple Texture on the Friction and Thermal Behavior of a Point Contact

“…The micro-scale surface topography of rolling mechanical elements (bearings and gears for example) plays an important role in the frictional power loss [1][2][3][4], the surface wear [5,6], the rolling contact fatigue (micro and macro scale pitting) failure [7][8][9][10][11][12], and the surface temperature related scuffing failure [13][14][15]. In the heavily loaded contacts of gearing applications, the presence of the significant surface roughness profiles (tool marks) due to the finishing processes, such as shaving and grinding, introduces frequent asperity Contacts within the elastohydrodynamic lubrication (EHL) conjunction.…”

“…Owing to the asperity contacts, the lubrication film breaks down, where not only the surface tractions but also the surface temperature peak, dictating the friction [1][2][3], and the failures of fatigue [11] and scuffing [15]. To improve the rolling contact performances in these aspects, the surface polishing process that eliminates the local roughness peaks has been shown to be a successful method [1,[17][18][19][20][21].…”