Which bearings and rod ends of SKF need to be maintained?
Bearings and rod ends requiring maintenance must be greased preparatory being taken into oper- ation. With the exception of a few applications, they must be relubricated periodically.
SKF steel/steel radial spherical plain bearings are built from bearing steel and are through-hard- ened. The high-strength sliding contact surfaces are phosphated and treated with a special run- ning-in lubricant. These bearings are used primarily in applications where there are:
- heavy static loads
- heavy alternating loads
- shock loads
They are also relatively insensitive to contamin- ants and high temperature.
To facilitate relubrication, lubrication holes and grooves are provided in both the inner and outer rings of all steel/steel radial spherical plain bearings-- barring a few small sizes. SKF steel/bronze rod ends also require relubri- cation. However, requirements are less stringent than for steel/steel rod ends, as the emergency running properties of bronze are more forgiving than steel.
The multi-groove system
Standard steel/steel radial spherical plain bear- ings that must accommodate minor alignment movements under very heavy, constant direction loads are prone to lubricant starvation. To maxi- mize the effects of the lubricant under these conditions, SKF has developed the multi-groove system and manufactures all metric steel/steel radial spherical plain bearings with an outside diameter D ≥ 150 mm with the multi-groove system on the sliding surface of the outer ring as standard († fig. 8). Metric steel/steel radial spherical plain bearings with an outside diam- eter D < 150 mm may be supplied with the mul- ti-groove system on request. These bearings are identified due to the designation suffix ESL.
These lubrication grooves provide the follow- ing benefits:
- improved lubricant supply to the loaded zone
- enlarged lubricant reservoir in the bearing
- enable relubrication under load
- extended relubrication intervals
- space for wear particles and contaminants
- extended grease life
The main benefit of the multi-groove system is that it improves lubricant distribution in the
heavily loaded zone to extend service life and/or maintenance intervals.