A pillow block bearing is a type of housed mounted bearing used to support rotating shafts and couplings in power transmission systems. It is comprised of a housing (mounted block) and an insert bearing that is typically self-aligning. The housing of the bearing is perpendicular to the shaft, featuring bolt holes that enable users to secure the pillow block bearing in place. In addition, this type of mounted bearing is sealed and shielded to create a clean, contained environment.

Pillow block bearings are versatile and suitable for a wide variety of applications including rolling mills, ventilation systems, paper machines, conveyor belt rollers, and long shafts connecting motors and industrial gearboxes.

It is important to note that pillow block bearings are similar but not the same as plummer blocks. They differ in application. Plummer blocks are suitable for applications that need to transmit high power and handle heavy loads. Pillow block bearings, on the other hand, are typically used for lightweight applications.

Pillow block bearings that feature a set screw locking system use screws to secure the inner ring to the shaft. This type of shaft locking mechanism is easy to use and does not require a collar. In addition, they are suitable for reversing direction applications.