Which statement correctly distinguishes ball bearings from roller bearings?

Which statement correctly distinguishes ball bearings from roller bearings?

• A. Ball bearings support radial and axial loads, while roller bearings absorb radial loads only
• B. Roller bearings support both radial and axial loads
• C. Ball bearings absorb radial loads only
• D. Roller bearings absorb only axial loads

Answer: (A)

Understanding how load directions are carried by different bearing types is the key. Ball bearings, with their point contact between the balls and raceways, can handle forces in both the radial direction (perpendicular to the shaft) and the axial direction (along the shaft). This is because the balls can transmit thrust as well as radial load through the race surfaces. Roller bearings, on the other hand, use line contact with cylindrical or similar rollers, which makes them very good at carrying heavy radial loads, but their ability to take axial (thrust) loads is limited unless the design is specialized (such as tapered or angular-contact rollers). So, in typical, straightforward comparison, ball bearings support both radial and axial loads, while roller bearings primarily support radial loads. That’s why this statement is the best distinction among them.

Understanding how load directions are carried by different bearing types is the key. Ball bearings, with their point contact between the balls and raceways, can handle forces in both the radial direction (perpendicular to the shaft) and the axial direction (along the shaft). This is because the balls can transmit thrust as well as radial load through the race surfaces. Roller bearings, on the other hand, use line contact with cylindrical or similar rollers, which makes them very good at carrying heavy radial loads, but their ability to take axial (thrust) loads is limited unless the design is specialized (such as tapered or angular-contact rollers). So, in typical, straightforward comparison, ball bearings support both radial and axial loads, while roller bearings primarily support radial loads. That’s why this statement is the best distinction among them.