Fraunhofer Institute for Mechanics of Materials IWMA significant portion of the energy consumption in pumps is attributable to friction losses in plain bearings and mechanical seals. Although energy consumption has been significantly reduced in recent years through friction optimization, there is still a need for new solutions to minimize friction and thus improve the efficiency of pumps. As part of the EWARP joint project, so-called hard/soft pairings were considered, in which a DLC-coated sliding component is combined with a carbon graphite counterpart as a thrust bearing, radial bearing, or mechanical seal.
EWARP: Increasing the energy efficiency of water-lubricated friction pairs in pumps
Completed research project
Project description
The reliability and operational safety of pumps is largely determined by the bearings and mechanical seals. Energy efficiency can be improved by significantly reducing friction in plain bearings and dynamic seals and stabilizing it at a low level.
The overall goal of the EWARP joint project was to develop a technology for reliable and energy-efficient pumps in which friction and wear losses in water-lubricated systems are reduced with the help of a material-optimized sliding pair of DLC coatings and carbon graphite-based components.
Fraunhofer IWM subproject: Development and tribological qualification of DLC coatings in water-lubricated bearings
The objectives of the subproject included the development of coatings for media-lubricated plain bearings and mechanical seals based on PE-CVD carbon layers, the optimization of the layers with regard to graphite sliding partners, tribological investigations to clarify the tribological mechanisms and improve running properties, the development of measures for improved corrosion protection, and the verification of increased performance, load-bearing capacity, and reliability with reduced friction losses.
As part of the project, both DLC coatings and graphite materials were developed and tribologically evaluated for use under typical operating conditions in pumps (for predominantly aqueous media at elevated temperatures). This made it possible to identify DLC coating variants and carbon graphite materials that show an improvement in friction properties compared to the state of the art.
Transfer of project results to the following Fraunhofer IWM R&D services for companies:
- Development and tribological qualification of DLC coatings in water-lubricated bearings
