September 15, 2015
Pierburg
New electric compressor for a more enjoyable drive and enhanced engine efficiency
Pierburg GmbH has developed an electric compressor for spontaneously boosting the charge pressure of engines fitted with an exhaust-gas turbocharger. This component allows pressure to be raised irrespective of the exhaust-gas energyavailable. The outcome: a more enjoyable drive and enhanced engine efficiency. The compressor is compatible with both gasoline and diesel engines. The initial prototypes are available and now being tested by various customers.
The electric compressor fits in well and without any constraints with the proven strategy of downsizing. In contrast to the conventional exhaust-gas turbocharger which is powered bythe energy of the exhaust gases, the electric version responds spontaneously thanks to the practically instantaneous build-up of charge pressure. This makes it a suitable alternative to multi-stage exhaust-gas turbochargers, which are often very costly and bulky. What’s more, the electric energy needed to boost thecharge pressure can be sourced completely or in part from recuperated brake energy which, in turn, leads to another efficiency gain.
Long-term expertise fuels development work
The electric compressor has a wear-free, brushless DC motor which is the outcome of Pierburg’s own longstanding experience in the development and manufacture of electric motors. The motor and the electronic components are cooled by a water jacket connected to the engine cooling system.
Other points of emphasis in the development work were to reduce the mass inertia of the rotating parts in order to shorten response time and to comply with set limits for noise emissions and electromagnetic compatibility.
One special challenge was to achieve the required endurance strength for the individual parts. This is especially relevant regarding the configuration of the rollerbearings and the sealing of the motorand electronic compartmentto prevent the ingress of oil and soot. To this end, Pierburg has integrated an efficient sealing system to ensure maximum protection against premature compressor failure due to contamination.
Background information: electrification of auxiliary assemblies
As it proliferates, the electrification of auxiliary assemblies on IC engines poses rising demands on the available electrical energy. In this context, a rise in the onboard system'ssupply voltage from 12 to 48 V is frequently discussed; in fact, in many cases concrete plans are already taking shape. Given the reduction in current accompanying the risein voltage for the same power requirement, it will in future be possible to use very high-power components such as electricmotor driven compressors for boosting charge pressure.