Plain thrust bearings are used where only which type of loads are present?

• A. Radial loads
• B. Axial loads
• C. Radial and axial loads
• D. Tangential loads

Answer: (B)

Plain thrust bearings are designed to support forces that push along the axis of the shaft. Their flat, face-to-face contact surfaces are optimized to resist axial (thrust) loads, not forces trying to push the bearing sideways. Because the bearing’s geometry and lubrication film are arranged for thrust resistance, they offer little resistance to radial loads, which is why they aren’t suitable when radial forces are present. In applications with only axial forces, this type of bearing works well; when radial or mixed loads are involved, other bearing types or arrangements are used.