Analysis of hydraulic units manufactured by powder bed fusion

This work provides collecting, analyzing and discussing the published information in the field of additive manufacturing of hydraulic units, hydrodynamic characteristics, hydraulic and mass-dimensional characteristics, sealing of hydraulic units [1], [2], [3]. The goal of the research consists of producing hydraulic units with increased energy efficiency manufactured by the SLM method. To do this, the authors have provided an overview of the current state of the hydraulic units manufactured by the powder bed fusion technologies. Groups of units and their parts, most frequently produced by powder bed fusion technologies have been placed special emphasis on. In the examined units, the pressure and flow rates remained the same as in the original manufacturing method. The use of optimal design programs led to a reduction in the mass and dimensions of the casing parts by 95% and 75% respectively, and also to obtaining 60% less pressure loss at a given flow rate. The SLM method has been identified as the most optimal for producing sealing surfaces. From the point of view of surface quality, we have come to conclusion that the roughness of the valves channels, manifolds and valve blocks within Ra 2-40 μ m can be obtained by powder bed fusion technologies. For spool valves and valve-saddle surfaces obtained by powder bed fusion technologies, post-processing is required because of the requirement for lower durability for long- term performance. Further research will be focused on the development of a methodology for designing energy-efficient hydraulic units with reduced mass and hydrodynamic characteristics.