Load
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
p_{m} = F/(2bB) 
MPa 
Average bearing pressure
F/(LD) 
MPa 
Local max bearing pressure p_{max} 
MPa 
Load capacity
F 
N 
Stiffness F/δ 
10^{6} 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. 

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