NKE Hauptkatalog / General Catalogue 2011

Handling, Mounting andDismounting Rolling BearingsGeneralNKE rolling bearings are high precision machineelements that are produced in modern plants usingthe latest high technology equipment, machiningto close tolerances of some few microns (e.g. 1micron = 1μm = 0.001 mm).Extensive quality assurance procedures andsystems throughout the whole manufacturingprocess combined with continuous inspection ofproduct quality ensuring even the most exactingdemands in operating reliability, running accuracyand bearing service life are met.But, to guarantee the optimum function of abearing arrangement, special care and attentionmust be given to simple basic rules concerningstorage, handling and bearing mounting.Bearing StorageAll NKE rolling bearings supplied are protected bya high quality preservation oil and are optimumpacked either single boxed, bulk or cassettepacked or to customer requirements.The anticorrosion agent applied at the factoryenables an effective function of the products evenfollowing long storage providing correct storage intheir original undamaged packaging is maintained.In principle bearings should always be stored intheir original packaging. They should only beunpacked prior to their fi tting.The storage of bearings should be in a cleanenvironment at normal room temperature, suchtemperatures being 15°C - 25°C (59°F - 77°F).The relative air humidity must not exceed 60%.Under no circumstances should rolling bearingsbe stored in immediate proximity to water, humidityor any other aggressive chemical matters.Also the storage of bearings or associated partsclose to any metal removing or dust producingmachines must be avoided.Bearings also should not be exposed to any longlasting vibrations or shocks during handling or342storage, because in this way the bearings may bemechanically damaged permanently.Bearings in a packed condition must not beexposed to strong temperature variations ordirect sun light because of the danger of watercondensation (i.e. humidity) in the packaging.In principle all bearings, most particularly thelarger ones must be stored flat (i.e. axially).This is necessary because the individual weightof the larger bearings may deform the bearingrings if they are stored vertically (i.e. radially)additionally, storage of bearings directly on the onthe ground or a floor must also be avoided.Gross mishandling must be avoided at all times,particularly, shocks caused by insecure stacking andcarelessness during stock utilisation and rotation. Iffor any reason the original packaging is damagedthe product inside must be closely examined for itscondition.Shelf LifeSome bearing types, especially those having shieldsor seals on both sides, which are supplied greasefilled (suffixes -2RS, -2RSR, -2Z, -2LFS...) a changein grease consistence must be considered during along-term storage.Over long storage periods the grease becomesstiffer and some grease have a tendency to secretsmall amounts of their base oil. In this way theshelf life of such bearings is reduced. The durationof shelf life differs according to the grease used andthe individual storage conditions.In the case of stiffened grease a somewhat highertemperature and running noise is to be expectedduring the starting phase of the bearing.Only careful consideration of all the relevantstated points is the bearing available for mountingin good condition on demand.www.nke.at