Pillow block bearings, sometimes referred to as plummer block bearings, are mounted bearings that are used to provide load support for a rotating shaft. Their mounting surface is on a plane parallel and offset to the axis of the shaft. Mounting holes or slots in the base or feet of pillow block bearings permit adjustment and easy mounting.

    Pillow block bearings are constructed of a housing and a bearing. Many pillow blocks have a replaceable bearing, referred to as an insert bearing. Bearings used with pillow block housings usually are self- aligning to compensate for angular misalignments. 

    Adjustment of a misaligned shaft can occur in any direction and allows centering and alignment without distorting seals. Pillow block bearing units include a hollow set screw for easy and firm attachment on a shaft and a one-piece housing for structural strength.