Weight reduction of high performance helicopter lubrication pumps by PM aluminium alloys R. Gradinger 1, H. Kilian 1, M. Schuller 2, M. Tauscher 2, P. Schäffler 3 1 LKR Leichtmetallkompetenzzentrum Ranshofen GmbH, AIT Austrian Institute of Technology 2 TEST-FUCHS GmbH 3 Alulight International GmbH 5th International Conference Supply on the wings 2-4. Nov. 2010, AIRTEC fair, Frankfurt / Main, Germany
Outline Introduction of LKR Greening of aircraft Weight saving in general Weight reduction of high performance helicopter lubrication pumps by PM aluminium alloys Concept PM aluminium alloy selection Prototyping Experimental results Outlook Summary AIRTEC 2010 2
LKR is a buiness unit of AIT s MOBILITY department AIT is one of Europe s leading mobility research centres through efficient, safe and green mobilty solutions through extensive expertise in simulation coupled with a highly- developed d research infrastructure t through networking with science and industry on a national and international level * LKR Leichtmetallkompetenzzentrum Ranshofen GmbH LKR Leichtmetallkompetenzzentrum Ranshofen GmbH
Most important research topics Materials development Development and optimisation of alloys Optimisation of heat treatment parameter Improvment of mechanic and dynamic characteristics Optimisation of the microstructures of alloys Process development and optimisation i Development and improvment of casting processes Evaluation and optimisation of metal forming processes Simulation of process technologies Evaluation and optimisation of processes in external production lines Validation and prototyping Materials based design Design of light weight structures Crash simulation of vehicle components and structures t Optimisation of topology and structure Joining technologies Demonstration of prototyping LKR Leichtmetallkompetenzzentrum Ranshofen GmbH
Greening of aircraft The greening of aircraft is in the focus of European research activities e.g. the Joint Technology Initiative Clean Sky: large industrial players and EC committed themselves to big efforts concerning airframe, engines and systems. In the R&D focus are configuration, materials, weights, aerodynamics, energy efficiency, bio fuels et cetera. 5
Weight saving in general One main factor to increase environmental friendliness of aircrafts is mainly the reduction of their weight. But battle of materials is not only daily business in large airframe structures (e.g. CFRP for A350WXB) or engines (γ-tial for low pressure turbine application), also in smaller components. To an increasing i amount, material mix concepts with the best materials at the right place are chosen in aerospace as well as in other sectors like automotive or mechanical engineering. 6
Weight reduction of helicopter lubrication pumps In aircrafts, fuel pumps are used for the continuous supply of the engines with fuel. Lube oil pumps p are used for provisioning of lube oil circuits of engines and gearboxes. In the field of aviation fuel and lube oil pumps there were few of innovations done during the last years and decades. The need of lightweight construction, typically limited space in aircrafts and therefore high specific power, respectively, lead to high rotational speed of the pump wheels, which causes a principal disadvantage of low efficiency by concept. The increasing importance of low emissions (CO2, noise) leads to an high potential of improvement of fuel and lube oil pumps as a contribution towards the environmental goals to be achieved. 7
Weight reduction concept The main concept for the weight reduction of high performance helicopter lubrication pumps p p was to substitute the standard steel material of the inner and outer pump wheel by innovative powder metallurgical (PM) y in order to demonstrate a aluminium alloys reference for a weight saving of 25 % (of the typical mass of 2.2 kg of the basic lube pump). 8
Selection of proven powder metallurgically produced alloys Evaluation of PM alloys which are in industrial use, providing positive experience from automotive series parts: - AA 4041 : - AA 6082 - AA 7020 9
General advantage of PM alloys 10
Prototyping of pump wheels PM alloying Cold isostatic pressing Extrusion Cutting Heat treatment Wire-electro discharge machining Sizing* * series production option 11
Experimental results After evaluating samples with mechanical and tribo-chemical tests as well as with pump-related test equipment the material AA 4041 is principally feasible for the usage in inner and outer pump wheels. Due to the unchanged geometry of the wheels (base: steel) an increased wear at the outer wheel can be observed due to the higher coefficient of thermal expansion (CTE) of aluminium alloys. Without optimizing the geometry, a weight saving potential of 12% is feasible by combining outer wheels made of steel with inner wheels out of AA 4041. Through the change of the pump geometry it will be possible to use the innovative materials for the outer and the inner pump p wheel and would result in a saving of weight of 24-25 %. Different coatings proved to be useful, too. 12
Outlook Next R&D steps are being made in joint activities with different R&D and industrial partners, e.g. in Austria in the context of components for a range extender in hybrid cars. The additional results for the PM materials under harsh internal combustion engine application will be used for the design of high performance helicopter lubrication pumps which will then take account of all material specific boundary conditions incl. ΔCTE. 13
Summary A weight reduction potential of high performance helicopter lubrication pumps was identified. Different PM aluminium i alloys were chosen in order to be evaluated as an substitute for steel in pump wheels. Suitable materials and coatings were selected and evaluated, production technologies were defined and parts for the qualification were produced. Further R&D is currently being done and these results will be added d to the experiences made so far in order to find the best future series design. AIRTEC 2010 14
Acknowledgement The funding granted by the Federal Ministry for Transport, Innovation and Technology via the Austrian Research Promotion Agency (FFG) for this research project HPP is gratefully acknowledged as well as the support of involved project partners. AIRTEC 2010 15
AIT Austrian Institute of Technology your ingenious partner Rudolf Gradinger LKR Leichtmetallkompetenzzentrum Ranshofen GmbH rudolf.gradinger@ait.ac.at