20 watts instead of 60 — per shaft
In a typical gearbox in a production environment a DIN seal draws around 60 watts of friction power per shaft. A comparable VR seal draws 20. That is one third — and it adds up.
What 40 watts amount to over a year
A single sealing point, three operating patterns. At an electricity price of €0.20 per kWh and a CO₂ factor of 0.512 kg per kWh.
| Operation | Hours per year | Energy | CO₂ | Cost |
|---|---|---|---|---|
| 1 shift, weekdays | 2.000 | 80 kWh | 41 kg | 16 € |
| 2 shifts | 4.000 | 160 kWh | 82 kg | 32 € |
| Continuous operation | 8.760 | 350,4 kWh | 179 kg | 70 € |
Figures per sealing point. A plant with 40 sealing points on two shifts therefore saves around 6,400 kWh, 3.3 tonnes of CO₂ and €1,280 a year. With the savings calculator you can enter your own figures.
What less friction also brings
Less heat
Less heat put into the sealing point relieves both the elastomer and the lubricant — and so extends the service life of both.
Higher speeds
Frictional heat that is never generated does not have to be carried away. That shifts the permissible surface speed upwards.
Longer maintenance intervals
Less thermal load means less wear — and so fewer shutdowns to change the seal.
The VR Low Friction seal reduces friction by a further 50 to 70 per cent compared with the already friction-optimized standard VR sealing lip.
The p-v diagram
Friction is one part of it; the permissible combination of pressure and speed is the other. For each elastomer the diagrams show which speed is still permissible at which pressure — depending on the shaft diameter.
How to read the diagram
- Find your pressure on the horizontal axis — the axis is scaled in MPa, and 1.0 MPa is 10 bar.
- Go vertically up to the curve for your shaft diameter (20 to 160 mm).
- Read off horizontally to the left: the permissible speed in min−1.
- The straight line separates the two support body ranges. If your point lies in range II, you need the smaller annular gap — see Design guidelines.
What the figures apply to
- Measured values, not calculation models.
- Lubricated sealing lip, without additional cooling.
- The pressure figures apply to the quasi-static condition. Under shock pressure loading the pressure values must be reduced.
From the VR Catalog 2024/25. Is your operating point at the edge, or outside it? Then let us work it through together — for special cases there are designs and materials that appear in no diagram.
Every design, material and size in one PDF
60 pages of design know-how: pressure and p-v diagrams, design guidelines, the elastomer overview and the complete size table with 541 sizes. You receive the link by e-mail straight away.
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