Axial spherical roller bearings are suitable where:
- bearing arrangements are subjected to high and very high axial loads ➤ section
- dynamic or static misalignments of the shaft relative to the housing, or deflections of the shaft, must be compensated by the bearing under axial loads ➤ section
- radial forces occur in addition to axial forces (maximum 55% of Fa ) ➤ section
- a relatively high speed suitability is required in addition to a high load carrying capacity ➤ section
- high shock type loads must be supported
- bearing parts are to be mounted separately (the bearings are not self‑retaining) ➤ section
Axial spherical roller bearing: comparison of load carrying capacity with axial deep groove ball bearing, compensation of misalignments
Fa = axial load
Ca = basic axial dynamic load rating
Axial spherical roller bearings are available in the basic design as:
- an increased capacity design with sheet steel cage or solid brass cage ➤ Figure
The bearings are available in the majority of sizes as X-life bearings ➤ Figure
The bearing design is dependent on the bearing series and the bearing size. It essentially differs in the configuration and guidance of the cage ➤ section.
Bearings of basic design
The raceway in the housing locating washer has a curved form
Axial spherical roller bearings are part of the group of axial roller bearings. These single row, non-self-retaining rolling bearings comprise solid shaft and housing locating washers with raceways for the rolling elements. Cages guide the large number of asymmetrical barrel rollers ➤ section. The cage, roller and cage assembly, and shaft locating washer form a self-retaining unit. The raceways are arranged oblique to the bearing axis, the raceway in the housing locating washer is of a concave design. This design allows these bearings to combine a range of characteristics, which are essential to many applications, in one bearing, such as angular adjustability for example ➤ section.
Roller contact design
The stress distribution at the contact points between the rollers and raceways is determined by the contact surface of the rollers. As a result, the roller geometry is matched to the raceway. This gives a favourable load distribution over the entire length of the roller and thus prevents both edge stresses and stress peaks at the ends of the roller.
Increased capacity design with sheet steel cage or solid brass cage
Bearings with sheet steel cage
Bearings without a cage suffix have coated sheet steel cages, which are guided by rollers ➤ Figure and ➤ section. These designs are available as X-life bearings ➤ link.
Bearings with solid brass cage
Bearings with the cage suffix MB have solid brass cages that are guided on the shaft locating washer or by the rollers ➤ Figure and ➤ section. The MB design is also available in numerous sizes as X-life bearings ➤ link.
Axial spherical roller bearings of basic design
Fr = radial load
Fa = axial load
Increased capacity design, with sheet steel cage
Increased capacity design, with solid brass cage
X-life premium quality
X-life bearings exhibit considerably higher performance than conventional axial spherical roller bearings. This is achieved, for example, through the modified internal construction, the optimised contact geometry between the rollers and raceways, the new cage design, a higher steel quality, better surface quality and optimised roller guidance and lubricant film formation.
Axial spherical roller bearing in X-life design
Housing locating washer
Shaft locating washer
Increased customer benefits due to X-life
These technical enhancements offer a range of advantages, such as:
- a more favourable load distribution in the bearing and thus a higher dynamic load carrying capacity of the bearings
- downsizing possible, increased performance density
- a higher fatigue limit load
- a higher running accuracy and smooth running
- running with reduced friction and greater energy efficiency
- lower heat generation in the bearing
- higher possible speeds
- lower lubricant consumption and therefore longer maintenance intervals if relubrication is carried out
- a measurably longer operating life of the bearings
- high operational security
- compact, environmentally-friendly bearing arrangements
Lower operating costs, higher machine availability
In conclusion, these advantages improve the overall cost-efficiency of the bearing position significantly and thus bring about a sustainable increase in the efficiency of the machine and equipment.
X-life axial spherical roller bearings include the suffix XL in the designation ➤ section and ➤ dimension table.
Areas of application
Wide application range
Due to their special technical features, X-life axial spherical roller bearings are highly suitable for bearing arrangements in:
- refiners and worm extruders in the pulp and paper industry
- drilling rigs and roll pressers in the cement industry, mining and raw material processing
- work rolls and back-up rolls in cold rolling mills
- extruder gearboxes in chemical plant and refineries
- air preheaters in thermal power stations
- POD and azimuth drives in marine propulsion systems
X-life indicates a high product performance density and thus a particularly significant benefit to the customer. Further information on X-life ➤ link.
Designed for very high axial loads and high radial loads
Axial spherical roller bearings can support very high axial loads in one direction and – since the raceways are inclined relative to the bearing axis – radial loads acting simultaneously. They are designed for very high load carrying capacity and, since they have the maximum possible number of large and long barrel rollers, are also suitable for the heaviest loads. As a result of the inclined raceways, the load is transmitted from one raceway to the other oblique to the bearing axis ➤ Figure. Due to the optimised osculation conditions between the rollers and raceways, uniform stress distribution is achieved in the bearing.
The radial load (Fr, F0r) must not exceed 55% of the axial load ➤ Equation and ➤ Equation.
Force flow under axial load
The load is transmitted from one raceway to the other oblique to the bearing axis.
Axial spherical roller bearings compensate dynamic and static angular misalignments
Due to the concave rolling element raceway in the housing locating washer, axial spherical roller bearings are capable of angular adjustment. As a result, they permit skewing between the shaft locating washer and housing locating washer within certain limits, without causing damage to the bearings or impairing their function. In this way, they can compensate misalignment, shaft deflection and housing deformation ➤ Table. The extent to which these table values can be used in practice is, however, essentially dependent on the design of the bearing arrangement, the type of seal and other factors.
Permissible adjustment angle
The adjustment angles given in the table are permissible under the following conditions: