1. PTFE: Poly Tetra Fluoro Ethylene
It is a
Linear chain polymer of high molecular
strength
Chemically inert
Low coefficient of friction
Not oxidized easily
Remains stable at extreme atmospheric
temperatures
Resistant to all common solvent.
2. POT END
POT bearing – It take beneficial properties of
confined elastomer behaving like pressurized fluid in
fixed bearings which helps in rotation and safe load
transfer
Rotational movement permitted by shear
deformation of an elastomeric pad
No compressive deflection of elastomer as it is
encased
Sliding component can be added at top.
3. POT - PTFE END
Mostly POT at bottom
PTFE is helpful in design of large expansion
bearings as no rolling action is there
Uses very low coefficient of friction between
stainless steel and PTFE
Lateral movement restrained by guides
– Guides can be on either side or in center as per
design
9. ROTATION OF POT PTFE BEARING
GAP BETWEEN TOP EDGE OF CYLINDER AND BOTTOM
EDGE OF PISTON SHALL BE MORE THAN 5 MM, 926.3.1.4
10.
11.
12.
13.
14.
15.
16.
17. Pot Bearings used for the first time for Steel
Railway Bridge Girders of Indian Railways in
Mandovi and Zuari Bridges under Konkan Rly
18. Inspection
Generally maintenance free
However, they should be visually examined
during the inspection for any breakage in
dust seal and general cleanliness of the
bearing assembly.
Evidence of free movement with temperature
and under loads to be seen
19. Maintenance Issues
Extremely tight tolerance of manufacturing is
required to be maintained. Common issues:
– Leakage of the elastomer.
– Abrasion or wear of the elastomeric pad.
– Cracking of steel POT under transverse loads
Normal maintenance is cleaning of
surrounding areas usually once a year.
BACK