Axle box bearing grease for maximum safety and service life
Reliable lubrication for the highest requirements
Whether for regional trains, freight transport or high‑speed trains, axle box bearings form the central interface between the wheelset and the load‑bearing bogie frame of a rail vehicle. They play a critical role in ensuring safe power transmission and reliable operation.
Throughout their service life, they are exposed to extreme loads. The right lubrication is crucial: only a high‑performance grease reliably protects against wear, prevents overheated bearings and enables long maintenance intervals.
Operational challenges for axle box bearings:
- Extreme mechanical loads: High static and dynamic forces, as well as impact loads, require consistently reliable lubrication performance.
- High speeds: Increasing rotational speeds and vehicle speeds place high demands on lubrication performance.
- Temperature and environmental influences: Heat, frost, and changing environmental conditions must not compromise lubrication performance.
- Water and corrosion protection: Moisture and de‑icing saltsrequire reliable protection against corrosion.
- Extended maintenance intervals: Operators expect long service life combined with reduced maintenance effort.
- Low-friction bearings: Efficient lubrication reduces friction and and supports stable temperature control.
RENOLIT LX-AB 2 – High-performance grease for axle box bearings
RENOLIT LX-AB 2 has been specifically developed for use in axle box bearings of regional and high-speed trains.
The high-performance grease is based on a lithium complex thickener and high-quality synthetic base oils. This combination provides outstanding ageing resistance and ensures reliable lubrication even under extreme operating conditions.
RENOLIT LX-AB 2 offers the following technical features:
- Extremely long service life: Running distances of more than 800,000 kilometers per grease fill without relubrication have been demonstrated on the EN 12082 test rig.
- Controlled oil bleed: ensures a stable lubricant supply even at high rotational speeds
- Reduced friction and wear: supports cool, low‑friction operation of tapered roller bearings in axle box bearings
- High mechanical stability: ensures reliable performance even under vibration and shock loads
- Excellent water and corrosion protection: reliably protects bearings in the presence of moisture and corrosive influences
- Compliance with standards: meets the requirements of EN 12081 and EN 12082 and is suitable for applications up to 220 km/h
Benefits for operators
More safety. More availability. More cost efficiency.
Railway operators benefit in multiple ways with RENOLIT LX-AB 2:
- Longer maintenance intervals:
Reduced maintenance effort and lower life-cycle costs - Highest operational safety:
Minimises the risk of hot bearings or bearing failures - Reliable performance under all conditions:
Thermally stable in heat, cold and wet environments
RENOLIT LX-AB 2 stands for what truly matters in railway operations: unconditional reliability – even under extreme conditions. In extensive laboratory and test rig trials, we have demonstrated the performance potential of this technology, with proven running distances of more than 800,000 kilometers without relubrication. The stable temperature behaviour observed indicates additional service life reserves under real operating conditions. For operators, this means maximum operational safety and maintenance intervals they can rely on."
Dennis Labisch
Application Engineer Greases
Questions and answers on axle box bearings
An axle box bearing is the bearing that connects the wheelset (axle with wheels) to the bogie frame of a rail vehicle. It therefore forms the central interface between the rotating wheels and the vehicle structure.
Axle box bearings must carry enormous loads: static loads (the weight of the railcar) as well as dynamic impacts and lateral forces (for example during switch crossings, curves or shunting operations). At the same time, they are constantly exposed to temperature fluctuations and moisture caused by weather and airflow during operation.
In short, axle box bearings allow the wheels to rotate freely with minimal friction while safely transmitting all loads into the vehicle frame – making them a critical component for safe and efficient train operation.
In principle, a distinction is made between plain bearings and rolling bearings. Historically, plain bearings (often oil‑bath axle box bearings) were widely used in railway axles; today, they have almost entirely been replaced by rolling bearings.
Modern axle box bearings are based on rolling bearing designs and use rolling elements to significantly reduce friction. The following bearing types are mainly used in rail transport:
Cylindrical roller bearings (CRB): Cylindrical rolling elements run on raceways. These bearings are commonly used in passenger and freight wagons as pre‑assembled bearing units (often CRUs – Cartridge Roller Units) and are designed to carry very high radial loads.
Tapered roller bearings: These bearings use tapered rollers and can accommodate both radial and high axial loads. Locomotives and high‑speed trains are typically equipped with tapered roller axle box bearings, often as double‑row tapered roller units (TAROL bearings).
Spherical roller bearings represent a special design that allows limited angular misalignment due to their barrel‑shaped rollers. They were used in certain vehicle series in the past but are rare today. Modern axle box bearings are almost exclusively designed as sealed rolling bearing units, containing a defined grease fill and integrated seals. As a result, they are largely maintenance‑free until the next scheduled overhaul.
As FUCHS products demonstrate, our greases are suitable for all axle box bearing designs – from cylindrical and tapered roller bearings to plain bearing applications.
When switching to a new grease, the previously used product should be removed as completely as possible to avoid incompatibilities. Our application experts will be happy to advise you on the optimal procedure and support you in selecting the appropriate product from the FUCHS portfolio.
How about your challenges?
Let us know how we can support you with your lubricant challenges in rail traffic.
Ralf Schlösser (Business Development Manager Railway EMEA) will be happy to advise you on the comprehensive lubricant solutions from FUCHS.