Experimental rigs for testing components of advanced industrial applications

Increasing the power density of new machines as well as reducing energy losses and wear for a minor environmental impact are very important targets today. The design of new machine components able to work at higher speeds and loads than in the past is not possible without deep tribological investigations in order to obtain significant reductions of friction and wear. Tribological studies can be performed both theoretically and experimentally, but, despite the today's availability of advanced computer programmes, experimental investigations are essential for new developments and for software validation. Experimental tests can be performed on basic test rigs or on real machine components. The first ones allow usually deeper investigations of the contacts but some aspects of the actual behaviour of the real pairs can be missed. For a complete manifestation of the involved phenomena, tests on full scale real components should be performed, particularly for the development of the components of new machines. However, it is not simple to realise the necessary complex experimental rigs and to perform the tests; only strong collaborations between the academic and the industrial worlds can produce successful results. Both basic test rigs are used and real components are tested since many years at the University of Pisa. Particularly strong collaborations have been established between the Department of Civil and Industrial Engineering of the University of Pisa, two big companies, GE Oil&Gas - Nuovo Pignone of Florence and GE Avio of Turin, and a small and medium-sized enterprise, AM Testing, in order to perform investigations on real components such as bearings and gears. In the frame of these collaborations, a Research Centre for Mechanics of Turbomachinery has been established. The cooperation between university and industry is fundamental for the design and the realisation of the experimental rigs as well as for managing the tests. The availability of regional and European funding has recently pushed towards the realisation of new and more powerful test rigs with very complex plants necessary for their operation. Due to the big dimensions of the rigs and to the power involved (about 1 MW), a new laboratory has been built in 2015 for hosting the experimental rigs and the related plants. An experimental rig for testing tilting pad journal bearings, a twin disc machine and two gear test rigs are presently used in the Research Centre. Their essential characteristics and potentialities are described in this work.