Additive manufacturing processes in fluid power - properties and opportunities demonstrated at a flow-optimized fitting

In recent years, additive manufacturing (AM) techniques have gained in significance. For example, geometries can be produced which, years ago, could only be produced economically with original forming processes, for example due to undercuts or their geometrical properties. AM techniques enable a design of component and machine in which the function fulfilment determines the construction and not the manufacturing possibilities. Components manufactured by AM are increasingly being used in series production and, for example in the aerospace sector, are enabling considerable weight reductions. While other industries have already made efforts and progress in the application AM processes, comparatively little progress has been made in the hydraulics industry. For example, enormous increases in power density could be achieved with this novel approach of manufacturing. The aim of this publication is to present additive manufacturing processes for processing metals which are suitable for use in hydraulic applications and to show ways of making them usable. At first, the methods are presented and their properties and special features are dealt with. Subsequently, the achievable properties are also discussed. Following, an overview on the state of the art for the hydraulics industry is presented and classified with regard to the possibilities of additive manufacturing. Finally, an example is used to illustrate the possibilities offered by AM where a rectangular fitting is presented which has a significantly reduced line resistance thanks to AM and flow-optimization. The design is presented as well as results which allow a classification of the achieved loss reduction.