Which type of bearing is considered a sliding type?

Journal bearings are classified as sliding-type bearings due to their design and function. In a journal bearing, a shaft or other rotating element slides over a layer of lubricating oil within the bearing. This sliding action is contrasted with rolling bearings, where one component rolls over another, reducing friction through rolling motion.

In journal bearings, the surfaces of the shaft and the bearing shell come into direct contact with the lubricant acting as a film that separates them, reducing wear and friction. This type of bearing is particularly efficient in applications where smooth motion is essential and where loads are primarily axial or radial.

Ball bearings, needle bearings, and roller bearings, on the other hand, are rolling-type bearings. These bearings use rolling elements to maintain the separation between the moving parts, thereby minimizing friction through rolling rather than sliding. Each of these rolling bearings has specific applications based on their load capacities and directional load handling.