Innovations on tribology test rigs

Based on several expert reports the costs due to friction losses and wear causes about 2 to 7 % of the national products. In Austria the losses are about 5.5 to 8 billion Euro, whereas 1.1 to 1.9 billion Euro could be saved due to additional research and consequent industrial application of the obtained research results. Tribology aspects of friction, wear and lubrication are commonly investigated by testing materials under simulated conditions using special test rigs. Essential preconditions for the improvement of industrial applications concerning friction losses are on the one hand the availability of results from tribological investigations and on the other hand their high accuracy. The quality of a tribological test rig is essentially determined by the fact, that the measured friction force is identical with the real friction force caused by a defined displacement of two specimens under given test conditions (contact and/or specimen form, presence of additional substances, normal load, temperature, test frequency, etc.). Investigations carried out by state of the art test rigs show a very strong influence due to their dynamical response on the test parameters them self (e.g. modulation of the normal load and/or the displacement characteristics), and the measuring arrangement and therefore the accuracy of the measurement results. Within this proposed project a new test rig for tribological investigations shall be developed which eliminates systematical errors of test conditions, and avoids misinterpretations due to false measuring results. This shall be obtained by the following innovations: Non-contacting application of the normal load (using specially developed active magnetic bearings), tangential force measurement with a very stiff arrangement, leading to high eigenfrequencies (allowing active filtering of the measured signal without a noticeable influence in a wide operating frequency range). To obtain the acceptance for industrial applications of this new tribological test rig technology comparative test series at low test frequencies, small displacements and noncritical normal loads with conventional test rig technology and the new concept, will be accomplished to debilitate tribology specialist reservations, such as presence and/or influence of magnetic stray fields, possibility of additional displacements as a result of using active magnetic bearings.