Electrical compressor turbo vs. “turbo lag”

Electric compressors promise a solution. They act independently of the available gas quantity and can be turned on whenever they are needed – to supplement the classic exhaust gas turbocharger when the car is setting off or accelerating, for example. Even at low engine rotational speeds, the charging pressure builds up quickly, and the “turbo lag” very nearly becomes a thing of the past.

“The challenge is in protecting the sensitive electronics and the bearing of the electric compressor from water, dirt and oil reliably and over the long term,” said Key Account Manager Michael Schuhmann. The compressor gear wheel shaft turns at up to 80,000 rpm. In view of the resulting heat and abrasion, sealing with contact seals like the classic Simmerring® is impossible. In exhaust gas turbochargers right now, engineers are generally using piston rings to form a labyrinth to reduce leakage, but the sealing effect is incomplete. For an electric compressor, this is not enough to ensure functioning over the entire service life without additional measures or limitations on installation space.

“Together with Pierburg, we are developing a seal concept that prevents the penetration of air and reagents into the compressor’s interior,” Schuhmann said. “Together, we are on the path to the best possible technical solution for electric compressors.” The advantage: The sealing principle targeted here has already been tried and tested in other regular-production applications at a leading German automaker. “So we already have gained practical experience. We are continuing to work on the solution with Pierburg,” Schuhmann said. “We have already provided various prototype designs that have demonstrated their functionality and reliability in tests at Pierburg and various automakers.” The customer agrees. “The cooperation on this important development project with our partner Freudenberg is developing in a very promising way,” said Stefan Rothgang, senior manager, Auxiliaries and Alternative Drives in Advanced Engineering at Pierburg in Neuss. The first regular production models could benefit from this cooperation in just a few years.