Which component is typically inside a pillow block housing?

• A. The bearing
• B. The gearbox
• C. The shaft
• D. The lubrication reservoir

Answer: (A)

Inside a pillow block housing sits the bearing. A pillow block is a self-contained mounting that holds a bearing and provides a rigid support for a rotating shaft. The bearing’s inner race fits on the shaft, while the outer race is secured within the housing. Seals in the block keep lubricant near the bearing and keep dirt out, helping the shaft rotate smoothly with minimal friction. The housing itself is there to mount to a frame and maintain precise alignment of the shaft. Gearboxes aren’t housed in pillow blocks, the shaft passes through the bearing rather than being contained inside the block, and a separate lubrication reservoir isn’t a standard feature inside a pillow block—lubrication is typically supplied through fittings to the bearing.