The most important feature of support and idler rollers is the thick-walled outer ring.
Buildup or elements:
1.Inner ring (IR) or axle
2.Rolling elements (cage or full complement double row)
3.Spacer disc
4.Outer ring (roll or roller sleeve)
5.possible variations: for guidance or retaining higher axial loads with axial bearings
sealed variations Supporting roller / guide roller are not standardised!