140 Beats per Second

© Atlas Copco Rock Drills AB

In a workshop initiated by Freudenberg Sealing Technologies, the developers found the precise cause of the wear: The seals were not just stressed by the piston’s longitudinal movement – the piston was simultaneously setting the seals into a rotational motion as well. This analysis showed that one of the radial shaft seal rings moves relatively constantly at 300 to 400 revolutions per minute, for which it was not designed. Therefore, Freudenberg engineers developed a special solution for the COP MD20, incorporating a changed design and a new mix of materials. Subsequently, trials on the test stand and with six test vehicles – which had to prove themselves underground in Australia, Sweden, Spain and Portugal – provided the evidence: The lifespan of the crucial seal could be extended significantly.

Since early 2017, Atlas Copco has been producing the new rock drill COP MD20 from in Örebro (Sweden). Freudenberg Sealing Technologies is the sole supplier of all 30 seals used in the new machine generation. Besides numerous components in the hydraulic system, the equipment also incorporates housing seals, which ensure that neither drilling dust nor moisture can penetrate the equipment.

Freudenberg experts from Hamburg, Schwalmstadt and Weinheim (all Germany), as well as Sweden, were involved in the development of the COP MD20 sealing system. The whole project followed the innovation management process of Freudenberg Sealing Technologies. It began with a joint customer–supplier workshop and walked through a five step process starting in R&D and ending up with the production of a break through innovation.