The transport transition to electromobility poses new challenges for research: In order to improve air quality, the EU Commission has decided to limit permissible particulate emissions. A large proportion of particulate emissions in traffic are caused by road turbulence and abrasion from brakes and tyres. As recuperation is often not sufficient for electric drive concepts, mechanical friction brakes, which are subject to wear and tear, continue to be used in ground-based vehicles.
This has led to the consideration of using an eddy current brake, as these are capable of wear-free braking. However, due to their operating principle, they cannot brake to a standstill. This is where the hybrid brake concept developed at DLR comes in. The hybrid brake is a modified eddy current brake. It generates a braking torque in the high speed range through electromagnetic action and also brakes mechanically in the low speed range. Unlike conventional eddy current brakes, the hybrid brake can therefore brake to a standstill and thus fulfils the performance requirements of brake systems for ground-based vehicles.
The eddy current brake performs most of the braking action by converting 90% of the braking energy without wear or emissions; only the remaining portion is converted via highly integrated friction elements. This means that the brake lining is only subjected to minimal stress and therefore lasts the entire life cycle of a vehicle.
Compared to conventional eddy current brakes, the hybrid brake presented here has a power density that is up to three times higher. This is made possible by the use of an anisotropic material structure developed at DLR.
Project goals
- Reduction of brake dust emissions
- Development of a hybrid eddy current brake with a power density of 9kW/kg
- Demonstration and measurement on the test bench
Publications
Contact
Dr.-Ing. Frank Rinderknecht