What is the primary function of a bearing in mechanical systems?

The primary function of a bearing in mechanical systems is to reduce friction between moving parts. Bearings achieve this by providing a smooth surface for motion, which allows rotating components, such as shafts, to turn with minimal resistance. By minimizing friction, bearings enhance the efficiency of machines, decrease wear on parts, and allow for smoother operation. This reduction in friction contributes significantly to improving the lifespan of mechanical components, reducing energy consumption, and maintaining precision in operations.

While bearings can also function to support the load of machinery, their main role is focused on facilitating movement and reducing friction. The other options do not align with the essential purpose of bearings, as increasing friction would be counterproductive, and while bearings can play a role in motion, they do not directly generate torque.