What type of bearing uses the shaft as the inner race?

In a needle bearing, the shaft serves as the inner race, allowing for a compact design that can handle high radial loads while minimizing friction. Needle bearings consist of long, thin cylindrical rollers, which provide a larger surface area for load distribution compared to traditional ball or cylindrical bearings. This design helps reduce the overall size and weight of the bearing while still maintaining strength and performance in applications where space is a constraint.

The other types of bearings listed employ different mechanisms: radial bearings use balls or rollers contained within an inner and outer race to support radial loads, while thrust bearings are primarily designed to handle axial loads rather than radial loads. Conrad bearings, often referred to as full-complement bearings, do not specifically incorporate the shaft as part of the raceway configuration like needle bearings do. Hence, needle bearings are unique in utilizing the shaft as the inner race, making them ideal for particular conditions in power transmission systems.