What is the main role of a bearing cap?

The main role of a bearing cap is to secure the bearing liner in place. This is crucial because the bearing liner needs to be properly positioned to effectively support the shaft and ensure smooth operation. The bearing cap provides the necessary clamping force to maintain alignment and prevent any movement of the bearing during operation, which could lead to wear, misalignment, or even failure of the bearing system.

In addition to this primary role, the design and material of the bearing cap are also important as they contribute to the overall durability and performance of the bearing assembly. While bearing caps can have other associated functions, like providing some level of protection or housing other components, their fundamental purpose is centered on securing the bearing liner, making option C the most accurate answer.