What type of bearings includes journal bearings, plane bearings, and Babbitt shells?

Friction bearings encompass a variety of bearing types, including journal bearings, plane bearings, and Babbitt shells. These bearings operate on the principle of providing a supportive surface for rotating shafts while allowing for relative motion between surfaces. The defining feature of friction bearings is that they rely on the contact between the bearing surfaces to support loads.

Journal bearings, for instance, consist of a shaft rotating within a cylindrical casing, while plane bearings are typically flat surfaces that allow for linear motion. Babbitt shells involve a soft metal alloy that coats a bearing surface, providing a wear-resistant layer. All these primarily function based on the sliding contact and the generation of friction, which they aim to minimize through lubrication.

Other types of bearings, such as magnetic bearings and hydrodynamic bearings, operate on different principles. Magnetic bearings use magnetic fields to suspend the shaft and eliminate physical contact, while hydrodynamic bearings rely specifically on the motion of the lubricant to create a film that supports the load. Thus, the focus on sliding and load-supporting characteristics firmly places journal bearings, plane bearings, and Babbitt shells within the category of friction bearings.