Rullalaakereita

Rullalaakereita is the Finnish term for rolling bearings, a family of bearing assemblies that reduce friction between moving parts by placing rolling elements between inner and outer races. They are designed to support radial loads and, in many configurations, axial loads as well, enabling smooth rotation in machinery and vehicles.

Construction and variants: typical rolling bearings consist of an inner race, an outer race, rolling elements such as balls or rollers, and a cage to space the elements. Seals or shields may be fitted to retain lubricant and exclude contaminants. The rolling contact lowers friction and wear compared with sliding bearings. Major variants include ball bearings (with spherical rolling elements) and roller bearings (with cylindrical, needle, or tapered elements), each designed for specific radial, thrust, or combined loads.

Materials and lubrication: most bearings are made from high-strength alloy steels or surface-treated variants; surfaces are hardened to resist wear. Lubrication with grease or oil is essential to reduce friction, carry away heat, and protect against corrosion. Maintenance also involves proper mounting, alignment, and sealing to prevent contamination.

Applications and reliability: rolling bearings are ubiquitous in automotive drivetrains, industrial gearboxes, electric motors, machinery, aerospace components, and consumer appliances. Bearing life is commonly described by reliability metrics under specified load, speed, and lubrication conditions. Their performance depends on cleanliness, lubrication, installation accuracy, and temperature management.

See also: bearing, tribology, ball bearing, roller bearing.