Housing: The block housing has mounting holes to enable the pillow block bearing to be attached to various surfaces. An "unsplit" pillow block housing supports the base while also wrapping around the bearing ring as one complete piece. "Split" pillow block housings allow the housing cap to be removed from the base of the pillow block. Most housings are comprised of cast iron or steel, although in more stressful environments aluminum may be used.
Outer Ring: The outer ring of the pillow block bearing is circular shaped on the outside and contains the working parts of the bearing.
Grease Nipple and Hole: The grease nipple extends from the outer ring to allow for lubrication. The hole below is where the grease flows in order to keep the inner parts properly lubricated.
Seal: The seal prevents dirt and other foreign substances from contaminating the inner workings of the bearing.
Ball "Runner Cage": This is where the ball bearings are contained in order to protect them while allowing them to freely roll inside of the round cage.
Hex-Shaped Set Screw: For connecting and securing the shaft inside of the bearing, while allowing tension to be applied or diminished.
Inner Ring: This is what the cage rotates on, while also securing the object needing to rotate.