These new bearings will be able to tell when they are in need of service, and even repair themselves, which would provide significant savings to the industry. Rotating components are everywhere and a single faulty bearing can potentially cause downtime in a factory, or the breakdown of a train or wind turbine. In order to produce these modern bearings, and other concepts for controlling and monitoring production, the world's fifth SKF University Technology Centre was created in 2012 - where the choice of partner was LTU.
Harvests energy from the sensor
One of the graduate students working in the Centre is Fredrik Häggström at EISLAB who has an MSc in Electrical Engineering. His research focuses on collecting energy from the ball bearing.
– My research area is energy harvesting in rotating environments and it is about harvesting energy from the bearing to sensors that monitors the status of the ball bearing. I am currently evaluating different methods for this and then I will also look at energy management, how to store the energy.
The SKF Centre in Livingstone, Scotland, is working on similar issues and Fredrik will soon travel there to take part of their results. Being a PhD student in the SFK-LTU Technology Center means that Fredrik and the other doctoral students have to report to both SKF and LTU.
– SKF want reports and see where we are heading, while LTU expect us to produce scientific articles. Every month we have meetings with representatives from SKF to reconcile what has happened and what to do further ahead. We also have internal meetings every week where we discuss ideas and present what we have done. It is positive that there are different competences of those working in the centre. With my background in electronics, I can for example tell whether a particular circuit works or not. My colleague Nick can answer questions related to mechanics. It's easy to exchange information when we sit in the same room, says Fredrik Häggström.
The PhD student Nicholas Dittes from the state of Ohio in the USA, has a BSc in Mechanical Engineering from Wright State University in Dayton, Ohio. He then studied in Germany and Austria to complete a Master's degree in Biomimetics in Energy Systems. He really enjoys working at LTU where besides the SKF-LTU Technology Centre, he belongs to the Division of Machine Elements.
– The people are very nice here and when I have a problem I can always get help from those who work in centre or from those at the division of Machine elements. I really like to discuss and solve various engineering problems. I have always had a lot of projects going on and I am very good at building things. My greatest strength is problem solving, I almost always know what can be done and what cannot, says Nick Dittes.
Monitors the status of the grease
Nick's research is about developing sensors that will communicate the condition of the grease found in bearings.
– The grease will lose its function before the bearing fails; therefore the grease must be in good condition in order for the ball bearing to be and service may be required in order to achieve the longest service time. It is important to know when the grease needs to be replaced, as it for example will extend the service interval of a wind turbine. All bearings have a seal, and if the seal is broken and the grease runs out or becomes contaminated the bearing will fail in short time. My sensor will hopefully be able to discover this type of problem.
– Others in the group are looking at the vibrations of the bearing, which is another way to predict when the bearing is about to fail, says Nick.