What component helps reduce the load on the cylinder's rod bearing and prevent bearing wear?

The correct component that helps reduce the load on the cylinder's rod bearing and prevent bearing wear is the cushioning system. Cushioning systems are designed to slow down the motion of the cylinder's piston as it approaches the end of its stroke. This gradual deceleration helps minimize the impact forces that can otherwise create strain on the cylinder rod and its bearings. By managing these forces, the cushioning system reduces wear and tear on the bearing surfaces, thereby extending their lifespan and maintaining optimal performance of the pneumatic system.

A sealing ring primarily functions to prevent air leakage from the cylinder, while a guide block helps to maintain alignment and provide support to the moving piston rod, which is important but does not specifically address the load or wear on the bearing. The stop tube serves to limit the travel of the piston rod and prevent it from exceeding its designed stroke length, but it does not mitigate the forces acting on the bearing during operation. Thus, among the options, the cushioning system directly contributes to reducing loads and wear on the rod bearing.