Bearing roughness specification

[clon]

I am designing a customized TRB (Tapered Roller Bearing) and I need to define the roughness of inner and outer rings raceways and the roughness of the rollers. I would like to do it with respect to Ra and Rsk. The latter (Rsk) is particularly important because when it has negative values, the valleys of the roughness profile behave as little "tanks" for the lubricating oil, ensuring a proper lubrication.

Does someone know which Rsk values are typical used for bearings raceways? I cannot find anything in literature

 

[TugboatEng]

Tapered roller bearings are not hydrodynamic bearings. They do not require reservoirs of oil. High and low spots increase contact pressure and shorten the life of the bearing. Smoother is better.

 

[clon]

Many studies in the literature (e.g., https://www.mdpi.com/2075-4442/8/7/76) confirm that even for TRBs negative skewness can be beneficial. The idea is to have a smooth surface and these pits as reservoirs for oil and to reduce contact pressure. The issue is that I couldn't find any stated values of Rsk.