Can we lubricate gearboxes with water?

Tommy Brandt, System Engineer at CEVT.

The short answer is of course no. You can’t replace the oil with pure water. But just like you can buy water-based paint for the house, there are water-based lubricants under development that potentially can be used with a positive effect on efficiency and product lifetime of the gearbox in electric vehicles. 

“The main benefit with a water-based lubricant is the substantial reduction in friction losses and better thermal properties compared to a traditional oil. To realize a potential industrialization of water-based lubricants in our transmissions there are areas ranging from micro geometries to system level design that needs to be understood and developed” says Tommy Brandt, System Engineer at CEVT. 

To harvest the improvements and address the challenges the Swedish Energy Agency has just granted CEVT resources to lead a joint project together with SKF and Luleå Technical University to explore how water-based lubricants can improve the already high efficiency of electric vehicles.

“Energy efficiency will always be a high focus area in CEVT. It must be. Our customers expect nothing less. This project enables a close collaboration with strategic industry partners as well as with the academia. The likelihood that this will be implemented in future industrialization projects is great. It will be a win not only for the partners in the project but for the environment”, says Tommy Brandt.

The name of the new research project is Longer Driving Range by Efficient Transmissions. The project will focus on enhanced understanding of water-based lubrication of bearings, tribological effects on gears and transmission level requirements for the use of water-based lubricants. 

“The electric vehicles of the future place new demands on materials and technologies. Through this collaboration we will expand our knowledge of water-based lubricants, giving us great insight into the future needs of sustainable vehicles,” says Gregory Zimmerman, SKF Director Product Line Electric Vehicles.

"With this grant from the Swedish Energy Agency, we will be able to take important steps to realize water-based lubrication in future transmissions. The project is a win, win, win that will deepen our knowledge on system level design of transmissions for the use of water-based lubricants. It will expand our cooperation with the academic expertise in the field of tribology at Luleå University of Technology and through the partnership with SKF we secure the knowledge build up in one of the most critical areas of our transmissions. We have managed to form a strong project line-up! We need the supplier’s expertise and the suppliers need our system level know-how for water-based lubrication to happen. This is true also for the suppliers of the actual lubricants who will now benefit from a strong development partner”, says Tommy Brandt. 

“We look forward to continue our work on water-based lubricants since it is a way to reduce the use of oils with fossil origin. It is very exciting to start optimizing the tribological system for a completely new type of lubricants. Oil lubricants have been developed over more than a hundred years. Now we must learn how surfaces and materials must be chosen to maximise performance for this lubricant as well. This project is perfectly in line with the research strategy of Luleå University of Technology. It will be a part of the research platform Creaternity which aims at finding sustainable and circular engineering solutions, says Roland Larsson, professor and scientific leader at Luleå University of Technology. “

The project has been granted 6.2 MSEK in this project. The process to start up the project will now commence.