A rotating flow diverter has a lubricated sealed bearing assembly for isolating bearing elements from wellbore fluids under pressure. The sealed bearing assembly is supported between an outer bearing housing and an axially rotatable quill. The bearing assembly further has bearing elements with a bearing lubricant under pressure and a seal assembly. The seal assembly has at least one sealing element which comprises a body, the body having an outer peripheral wall, an inner sealing surface having a plurality of sealing lips and an annular cavity, and a loading ring for compressionally fitting within the annular cavity to urge the sealing surface radially inwardly for sealing engagement with tubulars.