1. Introduction
The maintenance of industrial facilities in the DACH region is subject to constant change, driven by the pressure for energy efficiency and the need to minimize unplanned downtime. The EU Regulation 2019/1781 (Ecodesign Directive) forces operators to optimize the entire drive train. Conventional, relubricated rolling bearings often cause considerable costs due to manual lubrication intervals, the risk of over- or under-lubrication and the associated shortening of the bearing service life according to DIN ISO 281. The switch to "Sealed-for-Life" solutions (lifetime lubricated bearings) is a critical step in increasing system availability.
2. Assessment of legacy systems
Before a retrofit is carried out, a structured assessment of the current status is essential. The following criteria are crucial for making a well-founded decision:
| criterion | Rating points |
|---|---|
| Lubricant interval | Frequency of manual relubrication per year. |
| Energy efficiency class | Friction losses of the bearing at the operating point. |
| Vibration level | Measurement according to ISO 10816 to assess the state of wear. |
| Failure history | MTBF (Mean Time Between Failures) of the last 36 months. |
| Environmental conditions | Influence of contamination (dust, moisture) on the bearing seal. |
3. Modern alternatives in comparison
Technological advances now enable bearing configurations that eliminate maintenance requirements. When modernizing the drive trains, the electrical peripherals must also be taken into account. The integration of modern control components, such as the Telemecanique GS1-JG3 series as a disconnect and fuse unit, ensures that the electrical protection corresponds to the improved mechanical condition.
| Parameters | Conventional warehouse | Sealed for Life |
|---|---|---|
| Maintenance effort | High (manual lubrication) | None (maintenance free) |
| Sealing concept | Easy (labyrinth) | Advanced (contact sealing lip) |
| moment of friction | Variable | Constant |
| MTBF (target value) | 15,000 operating hours | 45,000+ hours of operation |
| Electrical integration | Often outdated | Optimized (e.g. with GS1-JG3) |
4. ROI calculation
The cost-effectiveness analysis is based on an example engine with 45 kW output. Assumptions: Energy costs €0.25/kWh, labor costs €85/h, costs for unplanned downtime €2,500/h.
- Energy cost savings: Due to the lower friction torque of the maintenance-free bearing, the power consumption drops by approx. 1.5%. At 6,000 operating hours/year: 45 kW * 0.015 * 6,000 h * €0.25 = €1,012.50 per year.
- Maintenance cost savings: No need for manual lubrication (2 hours/month * €85 * 12 months) = €2,040.00 per year.
- Downtime prevention: Avoiding just one unplanned stock outage of 8 hours saves: 8 hours * €2,500 = €20,000.00.
The payback period for such a conversion is typically less than 14 months, depending on system utilization.
5. Implementation Roadmap
- Planning: Technical analysis according to VDI 2882, selection of the bearing geometry according to DIN 625.
- Procurement: Order the bearings and associated components (e.g. Telemecanique GS1-JG3 for the electrical fuse) via the UNITEC-D E-Catalog.
- Installation: Professional installation under controlled conditions (avoidance of impact on the bearing rings).
- Commissioning: Logging of the characteristic values (temperature, vibration) for documentation.
6. Technical challenges
The most common problems when implementing retrofits are fit tolerances (DIN ISO 286) and the compatibility of the seal with the ambient temperature. Replacing the mechanical component should always be accompanied by a check of the electrical safety and control devices. The Telemecanique GS1-JG3 offers a reliable basis for ensuring load separation during maintenance work on the new, maintenance-free storage units.
7. Case Study
In a DACH production facility, 20 drives were converted from relubricable bearings to sealed units. Before: 3 failures per year due to lubrication errors. After: After 24 months, no bearing failure, MTBF increased from 12,000 to 30,000 hours, energy consumption decreased by 1.8%.
8. Commissioning and validation
After replacement, the systems must be checked according to ISO 10816 (vibration measurement). Acceptance criteria include compliance with permissible vibration limits and a stabilized operating temperature within manufacturer specifications.
9. Summary
Switching to maintenance-free rolling bearings is an effective measure to increase system efficiency and reduce operating costs. By combining mechanical modernization and electrical protection (e.g. using Telemecanique GS1-JG3), operators achieve a sustainable improvement in system availability. The UNITEC-D E-Catalog is a reliable source for purchasing the necessary components.
10. References
- DIN 625: Rolling bearings – radial bearings.
- DIN ISO 281: Rolling bearings – dynamic load ratings and service life.
- ISO 10816: Mechanical vibrations – evaluation of the vibrations of machines.
- EU Regulation 2019/1781 (Ecodesign Directive for engines).
