▁( iii ) ▁the ▁natural ▁res ili ence ▁of ▁rub ber ▁gives ▁the ▁bearing ▁good ▁properties ▁for ▁shock ▁and ▁v ibration ▁absor ption ▁and ▁wear ▁resistance . ▁Water ▁lub ric ated ▁rub ber ▁bear ings ▁operate ▁under ▁the ▁condition ▁of ▁mixed - lub ric ation . ▁ ▁Air ▁bear ings ▁ ▁Un like ▁contact - roller ▁bear ings , ▁an ▁air ▁bearing ▁( or ▁air ▁c aster ) ▁util ises ▁a ▁thin ▁film ▁of ▁press ur ized ▁air ▁to ▁provide ▁an ▁exceed ingly ▁low ▁fr iction ▁load - b ear ing ▁interface ▁between ▁surfaces . ▁The ▁two ▁surfaces ▁don ' t ▁touch . ▁Being ▁non - contact , ▁air ▁bear ings ▁avoid ▁the ▁traditional ▁bearing - related ▁problems ▁of ▁fr iction , ▁wear , ▁particul ates , ▁and ▁lub ric ant ▁handling , ▁and ▁offer ▁distinct ▁advantages ▁in ▁precision ▁position ing , ▁such ▁as ▁lack ing ▁back l ash ▁and ▁st iction , ▁as ▁well ▁as ▁in ▁high - speed ▁applications . ▁ ▁The ▁fluid ▁film ▁of ▁the ▁bearing ▁is ▁air ▁that ▁flows ▁through ▁the ▁bearing ▁itself ▁to ▁the ▁bearing ▁surface . ▁The ▁design ▁of ▁the ▁air ▁bearing ▁is ▁such ▁that , ▁although ▁the ▁air ▁constantly ▁esc apes ▁from ▁the ▁bearing ▁gap , ▁the ▁pressure ▁between ▁the ▁faces ▁of ▁the ▁bearing ▁is ▁enough ▁to ▁support ▁the ▁working ▁loads . ▁This ▁pressure ▁may ▁be ▁generated ▁extern ally ▁( a er ost atic ) ▁or ▁internally ▁( a er od ynamic ). ▁ ▁Aer od ynamic ▁bear ings ▁can ▁only ▁be ▁operated ▁in ▁high -