The PNA Series denotes a type of Self-Aligning Needle Roller Bearing. Its most critical feature is a spherically shaped outer ring (spherical outside surface) and a correspondingly designed housing washer. This unique design allows the entire bearing unit to compensate for static angular misalignment between the shaft and the housing bore. The internal structure still utilizes needle rollers and a cage (or a full complement of rollers) to handle high radial loads. The self-aligning capability helps prevent edge stressing, reduces wear, and ensures smooth operation even when minor misalignments are present due to mounting errors or shaft deflection under load. This makes PNA bearings ideal for applications where achieving perfect alignment is difficult or where operational conditions might lead to shaft bending.
