The relative ease of lubrication of rolling bearings does not mean, that this problem can be ignored. When it comes to bearings placed inside mechanisms, lubrication with small amounts of oil is sufficient – gearbox interiors, drive bridge, truck hubs, in the motor bearing levers and rollers in the timing system, etc.. It is much worse with bearings, that are exposed to external factors. Oil lubrication, due to its liquid consistency, is then impossible. It is necessary to use solid lubricants and special covers, protecting the inside of the bearing from contamination. Rolling bearings placed in the chassis of a car or somewhere in the equipment work at a rapidly changing temperature. Therefore, only special lubricants should be used (resistant to very high unit pressures, rollers or balls in the bearing come into contact with the raceways over a small distance or pointwise, so at the point of contact the pressures are enormous), ensuring proper lubrication in low (maintaining grease fluidity) and high temperatures (grease must not flow out of the bearing housing). Currently, mineral lithium lubricants or less often lithium-calcium lubricants are most often used for this purpose., always supplemented with a rich set of refining additives. Calcium or lithium soap is a thickening additive. As an anti-seizure additive in special cases (np. in sports) molybdenum disulfide is used. In the automotive industry, much more expensive ones are not yet widely used, but much better meeting the requirements of silicone-based lubricants and synthetic oils.
Tapered roller bearings are used in older wheel hub designs and commonly in final drive bearings. Admittedly, they require precise adjustment of the pre-clearance, but in expensive mechanisms, their durability and ability to carry very high loads are important.
In many cases, a disposable expansion sleeve is used to determine the preload of a pair of tapered roller bearings. Such an element or precise selection of adjustment pads allow to extend the tolerance of enclosures, in which the bearings are embedded.
Cylindrical roller bearing carries the greatest radial loads, but requires others, additional shaft bearing arrangements for the transfer of post-axial forces.
