BDE-Mechanical

Generally, ball bearings are less expensive than roller bearings for small bores and light loads, whereas roller bearings are less expensive in the larger sizes and heavier loads.

Plain bearing design may be simple or complex.

Unlike lip seals and squeeze packings, felt seals require relative little shaft pressure to function effectively.

Bearing deflection or yield is elastic deformation occurring between balls and raceways because of external loads.

Moving an item or conveyor in steps or increments is called indexing.

When a tapered bearing is subject to a load, a force develops between the roller and the cone back-face rib because the load tries to squeeze the rollers out of the bearing.

These seals are quite similar to rod and piston seals, but are adapted to rotary motion.

Most bearings operate with a fluid film -- oil, another liquid, or a gas.

For instrument bearings, certain special considerations should be emphasized.

Large-diameter bearings have no precise definition.

Universal joints, or U-joints, are used to join shafts that must intersect at angles greater than those that can be accommodated by flexible couplings.

Exclusion seals, wipers, and scrapers clean the surface of a retracting rod, removing abrasive particles such as dirt, mud, and ice.

Joining two shafts is done with mechanical couplings.

Cylindrical roller bearings have high radial capacity.

Specialty bearings appear in many shapes and sizes.