Patent ID: 8931960
Filing Date: 2015-01-13
Classification: A61C,F16C

Abstract:
1. A medical, surgical, or dental handpiece bearing assembly comprising: an outer ring defining an outer raceway and an inner ring defining an inner raceway; said inner and outer rings defining a radial distance between said inner and outer rings; a first shield proximate a first axial end of said bearing assembly and extending from one of said inner and outer rings towards the other of said inner and outer rings, wherein said first shield is integral with said outer ring; a second shield proximate a second axial end of said bearing assembly, wherein said second shield comprises a single-piece construction, said second shield elastically deformable to mechanically interlock with, and extend from one of said inner and outer rings towards the other of said inner and outer rings, said second shield composed of an engineering plastic comprised of an amorphous polyetherimide, and wherein said second shield can withstand exposure to temperatures of approximately 134 degrees Centigrade and exposure to steam without degradation of mechanical properties; wherein said first and second shields each have a length equal to at least 50% of the radial distance between said inner and outer rings; a plurality of balls between said inner and outer rings and positioned to contact said inner and outer raceways; a retainer positioned between said first and second rings defining a plurality of pockets which receives said balls, said retainer composed of an engineering plastic having a composition selected from either a poly(amide-imide) (PAI) or a polyetheretherketone (PEEK) to withstand repeated sterilization, autoclaving, and application temperatures without degradation of mechanical properties, said engineering plastic of said retainer includes carbon fillers and fluoropolymer particles, wherein said fluoropolymer is a polytetrafluoroethylene; and a lubricating grease disposed between the first shield and the second shield, adjacent to the plurality of balls, said grease having a viscosity of at least about 110 centistokes at approximately 104 degrees F.