▁can ▁be ▁relatively ▁cheap ▁compared ▁to ▁other ▁bear ings ▁with ▁a ▁similar ▁load ▁rating . ▁ ▁The ▁bearing ▁can ▁be ▁as ▁simple ▁as ▁two ▁smooth ▁surfaces ▁with ▁se als ▁to ▁keep ▁in ▁the ▁working ▁fluid . ▁In ▁contrast , ▁a ▁conventional ▁rolling - element ▁bearing ▁may ▁require ▁many ▁high - prec ision ▁roll ers ▁with ▁complicated ▁shapes . ▁H ydro static ▁and ▁many ▁gas ▁bear ings ▁do ▁have ▁the ▁comp lication ▁and ▁exp ense ▁of ▁external ▁p umps . ▁ ▁Most ▁fluid ▁bear ings ▁require ▁little ▁or ▁no ▁maintenance , ▁and ▁have ▁almost ▁un limited ▁life . ▁Con vent ional ▁rolling - element ▁bear ings ▁usually ▁have ▁shorter ▁life ▁and ▁require ▁regular ▁maintenance . ▁P ump ed ▁hydro static ▁and ▁aer ost atic ▁( gas ) ▁bearing ▁designs ▁retain ▁low ▁fr iction ▁down ▁to ▁zero ▁speed ▁and ▁need ▁not ▁suffer ▁start / stop ▁wear , ▁provided ▁the ▁p ump ▁does ▁not ▁fail . ▁ ▁Fl uid ▁bear ings ▁generally ▁have ▁very ▁low ▁fr iction — far ▁better ▁than ▁mechanical ▁bear ings . ▁ ▁One ▁source ▁of ▁fr iction ▁in ▁a ▁fluid ▁bearing ▁is ▁the ▁vis cos ity ▁of ▁the ▁fluid ▁leading ▁to ▁dynamic ▁fr iction ▁that ▁increases ▁with ▁speed , ▁but ▁static ▁fr iction ▁is ▁typically ▁neg lig ible . ▁H ydro static ▁gas ▁bear ings ▁are ▁among ▁the ▁lowest ▁fr iction ▁bear ings ▁even ▁at ▁very ▁high ▁spe eds . ▁ ▁However , ▁lower ▁fluid ▁vis cos ity ▁also ▁typically ▁means ▁fluid ▁le aks ▁faster ▁from ▁the ▁bearing ▁surfaces , ▁thus ▁requiring