Influence of load on Schaeffler bearing type and bearing size
The load determines the type and size of the bearing.
The bearing size is normally determined by the external load. In selection of Schaeffler bearing, it must be noted that roller bearings can be subjected to higher loads due to the line contact than ball bearings of the same size.
Schaeffler bearings for predominantly radial loads
In the case of radial loads, the forces act perpendicular to the bearing axis.
If radial loads (so-called transverse forces) are present - these are forces perpendicular to the longitudinal axis of the shaft - bearings are used that support exclusively or predominantly radial forces, which are therefore radial ball bearings and radial roller bearings.
FAG cylindrical roller bearings N and NU, INA needle roller and cage assemblies, drawn cup needle roller bearings with open ends, needle roller bearings and FAG toroidal roller bearings can support radial forces only.
Schaeffler bearings for predominantly axial loads
If mainly axial forces are present - these are forces in the direction of the longitudinal axis of the shaft - bearings are used that support exclusively or predominantly axial forces.
Low to moderate axial loads
If low to moderate pure axial loads are present, suitable bearings are FAG axial deep groove ball bearings and four point contact bearings. If axial load in one direction is present, single direction axial deep groove ball bearings can be used.
If moderate to high axial loads in one direction are present, the Schaeffler bearings available are INA axial needle roller bearings, axial cylindrical roller bearings, axial tapered roller bearings and FAG axial spherical roller bearings. Axial cylindrical roller bearings or axial spherical roller bearings arranged adjacent to each other in pairs are suitable for high axial loads of alternating direction.
Schaeffler bearings for combined loads
Certain rolling bearings can be subjected to combined loads (radial and axial).
The axial load carrying capacity of a bearing is determined by the nominal contact angle α. The greater this angle, the higher the axial load carrying capacity of the bearing. An indication of its axial load carrying capacity is also provided by the bearing-specific axial load factor Y in the product tables; the smaller this factor, the higher the axial load capacity.
Suitable bearings for combined load
Suitable bearings are FAG deep groove ball bearings, four point contact bearings, single and double row angular contact ball bearings, spherical roller bearings and single row tapered roller bearings. FAG Self-aligning ball bearings and cylindrical roller bearings NJ (semi-locating bearing) and NU (locating bearing) + L-section ring HJ (= semi-locating bearing unit) can also be used.
Axial loads present in one direction only can be supported by FAG single row angular contact ball bearings and tapered roller bearings, cylindrical roller bearings NJ as well as NU + HJ and FAG axial spherical roller bearings. For alternating load directions, these bearings must always be mounted with a second bearing (the second bearing must provide support in the opposing direction). For mounting in sets, single row angular contact ball bearings as universal bearings and matched tapered roller bearing sets comprising two single bearings are available.
The axial load can also be supported by means of a separate bearing.
If the axial load component is too high, the axial load can also be supported by means of a separate bearing. In addition to a pure axial bearing, radial bearings - e.g. FAG deep groove ball bearings and FAG cylindrical roller bearings or four point contact bearings capable of supporting axial forces in both directions - can be used.
If FAG four point contact bearing is to be used as an axial bearing only, the outer ring must have radial clearance in the housing.
Schaeffler bearings for supporting tilting moments
If a load acts eccentrically, the bearing is subjected to tilting moments. In addition to FAG double row deep groove ball bearings and angular contact ball bearings, suitable bearings in this case are in particular the FAG single row angular contact ball bearings or tapered roller bearings matched in and X or O arrangement.
The tilting moment produced by the eccentrically acting force F is supported by a double row deep groove ball bearing.
M = tilting moment
F = eccentrically acting radial force