Walzenlager

Walzenlager, also written Wälzlager in German, is a mechanical bearing that reduces friction between moving parts by using rolling elements. A Walzenlager typically consists of an inner ring, an outer ring with raceways, rolling elements (balls or rollers), and a cage that keeps the elements evenly spaced. The rolling elements convert sliding contact into rolling contact, enabling smooth rotation and the ability to carry loads with low friction.

The most common types are ball bearings (Kugellager) and roller bearings. Ball bearings use spherical balls and are well suited for high-speed operation and mixed radial and axial loads. Roller bearings use cylindrical or needle rollers that handle higher radial loads; there are many subtypes, including cylindrical roller bearings, needle roller bearings, spherical roller bearings, and tapered roller bearings, each with different load and stiffness characteristics. Some designs provide seals or shields and various preload options.

Materials are typically hardened steel, though high-performance versions may use ceramic rolling elements. Lubrication is essential and provided by grease or mineral oil; seals protect against contamination, and relubrication intervals depend on load and speed.

Applications span automotive, industrial gearboxes, machine tools, electric motors, conveyors, and aerospace. The choice of bearing type depends on load direction, speed, misalignment tolerance, and the required rigidity.

Maintenance involves monitoring lubrication, contamination control, and proper installation with correct clearance and preload. Improper mounting, contamination, or inadequate lubrication are common failure modes.

Walzenlager are standardized by international and national bodies (ISO, DIN) and are manufactured by many firms such as SKF, Timken, FAG, and NSK.