A bearing used on the bottom of a motor where the shaft is positioned vertically is called a ____________ bearing.

• A. Sleeve
• B. Ball
• C. Thrust
• D. Bronze

Answer: (C)

The main idea is matching the bearing to the direction of the load. Bearings handle either axial loads (along the shaft) or radial loads (perpendicular to the shaft). When the shaft is vertical, the weight of the rotor and any axial forces push along the shaft’s axis, so you need a bearing designed to carry that axial load. Thrust bearings are built specifically to support axial forces and prevent the shaft from moving along its axis, which is exactly what’s needed at the bottom of a vertically oriented motor.

Radial-bearing types like ball or sleeve bearings mainly resist forces across the shaft and are not optimized for supporting axial load. Bronze isn’t a type of bearing itself but a material often used in bushings and other bearing components, so it doesn’t define the bearing’s load-direction capability.