External spline DIN Driven machine shaft Dimensi B4-CV-10-A Bevel-helical gear Reduction Box B4

Flender/Flender Gear Units/Bevel-helical gear Reduction Box B4

the pinion driving wheel case is better with respect to gear efciency. In the case of hypoid gears with different effectivepressure angles on the drive and coast tooth anks, driving the gear on the drivetooth ank is more favourable [ WECH8 ]. Viscosity, base oil type and additives are the main inuences of the lubricant on gear efciency [ DOLE0 ]. Viscosity decisively affects the load-independent losses4.3 Efciency 1 generated by displacing and squeezing the lubricant during mesh and by dipping of the gear teeth into the oil sump. In this respect, low viscosity is more favourablethan high one. The different chemical structures of the different lubricant types such as mineral oils, polyalphaolens, esters, polyglycols, etc., also affect ef- ciency, especially in EHD lubrication where the tooth anks are predominantlyseparated by lubricant lm under load. Frictional losses can be reduced by asmuch as 4 % by using synthetic lubricants when compared to using mineral oilbased lubricants. At boundary lubrication, the frictional properties of the tribolog-ical protective layer, resulting from the compound of the additives with the toothank material, are of primary interest. The lubricant and hence the bulk tempera-tures also play role here. The properties of lubricant in terms of frictional behavior at no-load, EHD and boundary lubrication can be examined in the FZG efciency test [ FVA3 ]. 4.3.3 Calculation of Gear Efciency Gear efciency VZis calculated from the tooth mesh loss factor Vand the mean coefcient of friction mZaccording to Table 4.7. The tooth mesh loss factor represents the load sharing and the progression of the sliding velocity along the pathof contact (Table 4.. The distribution of the tangential force on the meshing teeth, .., the variation of the normal force along the path of contact from to , Fig. 4.2, depends on the deection of the teeth. This in turn depends on the load. However, according to[WECH8 ], it is possible to obtain good approximation