Final Activity Report Summary - LUBFUNDAMENTS (Transfer of knowledge on lubrication fundamentals in mechanical products)
In this project scientific knowledge was exchanged between researchers from SKF B.V. (SKF, The Netherlands), Lulea University of Technology (LUT, Sweden) and National Institute of Applied Sciences of Lyon (INSA, France). The project focused on lubrication fundamentals in mechanical products, mainly bearings. Research was done by SKF and LUT on the physical aspects of lubricant greases (focusing on seals, grease lubrication and lubricant chemistry) and by SKF and INSA on macro- and micro geometry of rolling bearing systems (focusing on thin film modelling and surface macro- and micro geometry).
With regards to seals, a numerical model has been developed for the micro-flow between rubber and steel. In addition, an easy to use analytical model has been derived from this numerical model. An overview of the lubricating mechanism has been made and test rigs have been developed to measure the tangential deformation of a radial seal. As for grease lubrication a simulation program has been developed to predict the flow of grease using the granular flow concept (discrete elements), as well as a concept for testing grease rheology. Moreover, flow maps have been produced and generated in a rectangular channel. In the field of lubricant chemistry a test method for anti-wear/EP action has been developed and tests have been executed on a 4-ball machine. The focus of the work was on base oils (also major volume fraction of greases). A theory was developed on adsorption and desorption of layers formed by AW/EP action and under high pressure. Yet, no recipes for new greases were developed in the project.
Focusing on thin film modelling, a new modelling direction in lubricating thin films has been given based on solving the EHL problem in a system approach. Convergence is very much improved and thinner films can be modelled. An internal study has been done using the model described above and comparisons with experiments, showing still good agreement with film thickness up to only a few nanometres. With regards to surface macro and micro geometry a model for the transport of solid contaminants into the contact was developed. Also, models based on multi-layers to treat wall-slip and wettability in lubrication, which would enable the study of surface modification effects have been developed. The effect of spinning and macrogeometry on friction were also studied.
A total of 19 researchers have participated in the research project, 21 scientific articles have been published or submitted (including conference papers and internal reports), researchers participated in at least 10 conferences / scientific meetings and 1 patent has been filed.
With regards to seals, a numerical model has been developed for the micro-flow between rubber and steel. In addition, an easy to use analytical model has been derived from this numerical model. An overview of the lubricating mechanism has been made and test rigs have been developed to measure the tangential deformation of a radial seal. As for grease lubrication a simulation program has been developed to predict the flow of grease using the granular flow concept (discrete elements), as well as a concept for testing grease rheology. Moreover, flow maps have been produced and generated in a rectangular channel. In the field of lubricant chemistry a test method for anti-wear/EP action has been developed and tests have been executed on a 4-ball machine. The focus of the work was on base oils (also major volume fraction of greases). A theory was developed on adsorption and desorption of layers formed by AW/EP action and under high pressure. Yet, no recipes for new greases were developed in the project.
Focusing on thin film modelling, a new modelling direction in lubricating thin films has been given based on solving the EHL problem in a system approach. Convergence is very much improved and thinner films can be modelled. An internal study has been done using the model described above and comparisons with experiments, showing still good agreement with film thickness up to only a few nanometres. With regards to surface macro and micro geometry a model for the transport of solid contaminants into the contact was developed. Also, models based on multi-layers to treat wall-slip and wettability in lubrication, which would enable the study of surface modification effects have been developed. The effect of spinning and macrogeometry on friction were also studied.
A total of 19 researchers have participated in the research project, 21 scientific articles have been published or submitted (including conference papers and internal reports), researchers participated in at least 10 conferences / scientific meetings and 1 patent has been filed.