Bosch Touts Electrically Conductive Grease Project

Most lubricants are electrical insulators. That becomes a problem with electric motors and alternators, where lubricants can allow electrical fields to build up in their bearings or between the component's shaft and housing.

As the operating voltage goes up, so do the electrical fields. When they discharge, the sparking that results can melt tiny bit of metal, pitting bearings and their raceways. The result is noise and premature wear.

But Bosch Group and seven other German companies and researcher institutes have developed a grease infused with carbon and ionic fluids that prevent electrical charges from developing.

Their project, which is funded by the German Federal Ministry for Education and Research, has been dubbed SchmiRmaL. The acronym is short for the German phrase "switchable intelligent tribological systems with minimal friction losses and maximum lifespan."

The team's new lubricant, whose carbon content makes it black, has an electrical resistance only one ten-millionth that of a standard commercially available industrial lubricant. Tests to date indicate the material can prevent electrical pitting in devices operating at power levels as high as 400 volts.

The group, which expects to complete its work next April, predicts the material will soon be commercialized. Bosch points out that the new lubes will become increasingly useful as the auto industry strives to achieve sustainable electromobility.

Participants in SchmiRmaL in addition to Bosch are the Fraunhofer Institutes for Mechanics of Materials and for Algorithms and Scientific Computing, Inprotec, IoLiTec-Ionic Liquids Technologies, Kluber Lubrication, Schaeffler Technologies and Schunk.