Optimisation of a hydraulic housing for a brake-by-wire system for electrical drives by additive manufacturing

Electrical drives in automotive applications require new brake concepts, e.g. to allow recuperation mode. One approach for these are brake-by-wire systems, which are utilized in electrical motorsports. Based on the design freedom of Additive Manufacturing (AM), in particular laser-based powder bed fusion, a function-integrated hydraulic housing for such brake-by-wire systems is developed. The hydraulic housing is a core component of the brake system, as it holds all electric and hydraulic devices and a complex channel system to link the hydraulic devices. Thus, it must fulfil mechanical and hydraulic requirements, as well as a lightweight design in general. Based on a morphological box, which integrates already existing technical approaches and bionic solution principles, two prototypes were developed: One is derived from a current, conventionally manufactured hydraulic housing, and another one, utilizing the AM-capabilities to full extent. Both designs were developed utilizing three CAD tools, in particular Creo Parametric™ for the design itself, Inspire™ for topology optimisation and FEM calculation, and nTopology to generate ripples and lattices, like Voronoi structures. To develop a complex AM-design utilizing different software tools required several manual process steps. Thereby, insufficient software integration was identified as a hindrance to generate complex designs. Finally, both prototypes were manufactured by laser-based powder bed fusion from the aluminum alloy AlSi10Mg. Further optimisation potential exists, but could not be exploited due to insufficient material models for the mechanical design, e.g. fatigue data. Availability of calculation methods for lifetime prediction was identified as another limitation in the design process.