Set-screw, adapter, and eccentric collar type cylindrical cartridge units allow the self-alignment and free movement of bearings. The use of cylindrical cartridge units also allows for the expansion and contraction of the shaft caused by differences in temperature. Metallic cartridges have grade 10 balls, finished ball paths, and a three-piece “R” seal in wide inner-ring bearing inserts. Conductive rubber cylindrical cartridge units have either a straight, beveled, or special profiled outer diameter and an extended inner ring bearing insert. The conductive rubber cartridge units dampen vibration and have quiet running characteristics. Applications for cylindrical cartridge units include heating and air conditioning systems, ventilating equipment, and conveyor systems.