Rolling bearing, in particular a wheel hub assembly, having an improved service life and related method

A method for increasing the service life of a roller bearing provided in a wheel hub assembly of a vehicle, comprising:

• providing an inner ring having a raceway and an outer ring having a raceway, each of the raceways having a roughness value Ra of from 0.05 to 0.15 microns,
• providing a plurality of rolling elements in an annular space between the inner ring raceway and the outer ring raceway,
• providing a lubricating grease for bearings containing 1-2 wt % of uniformly dispersed graphene nanoparticles and/or graphene nanoplatelets, the graphene nanoparticles or graphene nanoplatelets having an at least substantially circular shape, a diameter of less than 2 microns and a thickness of 2-8 nm, and
• disposing the lubricating grease in the annular space so that the lubricating grease contacts at least parts of the inner ring raceway and the outer ring raceway and the plurality of rolling elements.

A roller bearing comprising:

• an inner ring, an outer ring, a plurality of rolling bodies housed in an annular space defined between the inner ring and the outer ring, the rolling bodies contacting respective raceways defined on the inner and outer rings and partly delimiting the annular space, to which they are facing, so that the inner and outer rings are relatively rotatable, and a lubricating grease disposed in the annular space and at least on the raceways, so that the rolling bodies are at least partly immersed in, and/or in contact with, the lubricating grease that is enriched with 1-2 wt % of graphene nanoparticles;
• wherein:
• the raceways each have roughness value Ra of from 0.05 to 0.15 microns;
• and
• the graphene nanoparticles are present uniformly dispersed in suspension in the lubricating grease and have a substantially circular shape with a diameter of less than 2 and a thickness of 2-8 nm.