b'Ball Bearing ComponentsNCH IOperatingConditionsSelecting the ProperOperating ConditionsType I Type IIaContinuous Preload Preload Partially RelievedType I is recommended for At top stroke, some ballhigh speed, high production bearings have left preload.dies. Throughout the press On the down stroke theystroke, all ball bearings reengage the guide pin andremain in preloaded contact bushing, producing a smallwith the guide pin and upward force which helpsbushing. counteract the natural Please note that a Type I tendency of the ball cage todesign may be run on a creep downward.shorter stroke press, but not ona press whose stroke is longerthan originally chosen.Type IIb Type IIIPreload Relieved DisengagedType IIb is recommended if Type III permits an unlimitedcreeping is a problem. As stroke. Also, if shortersoon as the last ball leaves bushings and cages can bepreload on the up stroke, the used, Type III is economical. cage repositions itself. Thisfeature can eliminate a However, a pinch point is nagging maintenance chore. created when the componentsdisengage, so Type III shouldnot be selected if it compromises safety.16'