TourTourLoad capacity and squeeze of polymer bearing rings

 Piston diameter D 10-3 m
 Ring width L 10-3 m
 Ring thickness s 10-3 m
 Elastic indentation at the center of contact δ/s %
 Radial bearing clearance dR 10-3 m
 Modulus of elasticity E   MPa
 Semi contact axis b/R=2b/D -
 Angle of contact φ  deg.
 Mean bearing pressure pm = F/(2bB) MPa
 Average bearing pressure F/(LD) MPa
 Local max bearing pressure pmax MPa
 Load capacity F N
 Stiffness F/δ 106 N/m
Guide rings or wear rings are resilient, wear resistant thermoplastic bearings designed to support and guide the rod or piston in a cylinder. These guide rings are especially important in applications where heavy side loadings are unavoidable. The clearance between the guide ring and cylinder is kept small to avoid deformation of the piston or rod seals.

The modulus of elasticity E can best be established by measuring the deflection of a piece of a strip compressed between two parallel surfaces. The modulus of elasticity can be calculated with E=p/(δ/s) where p is the bearing pressure.