Sliding bearing classification, characteristics and usage

Plain bearings are bearings that operate in areas of liquid, maximum or dry friction. Functionally, the liquid friction region is ideal because of its low friction losses and minimal wear on the sliding surfaces. Liquid lubrication can be achieved by the relative movement of the sliding surfaces (hydrodynamic and gas-dynamic lubrication) or through the lubrication inlet of an external pressure device (hydrostatic and gas-static lubrication).

Friction losses are approximately one degree higher in the region of maximum friction than in the region of liquid friction, and two degrees higher in the region of dry friction than in the region of liquid friction. The wear of the sliding surfaces differs by a few degrees in the respective regions. These are the reasons for choosing lower operating parameters for bearings operating in the maximum or dry friction region for extended periods of time. In addition, limited durability must also be considered.

Hydrostatic, aerostatic and hybrid bearings always operate in the region of liquid friction. Hydrodynamic and gas hydrodynamic bearings mainly operate in this area. Hybrid bearings are lubricated by static pressure or gas static pressure during start-up and runout, and are lubricated by dynamic pressure or gas dynamic pressure during operation.

Bearings with lower lubrication requirements (ie, short-term lubricated bearings) operate in the area of ​​maximum friction. Hydrodynamic and gas hydrodynamic bearings operate in this area during start-up and runout. Dry friction bearings operate in the dry friction zone.

Slide Bearing