Abstract
Small-scale (< 100 W), low-pressure (4 MPa), low-cost hydraulic components, such as pumps and cylinders, have recently become more available. These components have potential uses in demanding applications such as in a pump-controlled electrohydrostatic actuators (EHA)s. This is limited by the fact that the unbalanced flows of a single-rod cylinder require a valve to reconcile the imbalance, which is commercially unavailable in this size and price range. We have hypothesized that it would be feasible to produce this component using additive manufactured (3D printed) plastic. Such a system would be relatively low cost with a high specific power, and could have applications in hand tools, prosthetics, robotics, and more.
This paper focuses on some of the challenges in the use of 3D printed plastic for small-scale poppet valves and pressure vessels. The objectives of this research include the investigations of the sealing performance of 3D printed plastic poppet valves and the mechanical strength of 3D printed plastic pressure vessels. Experimental results included in this paper reveal the effects of surface finish and poppet and seat geometry on sealing performance. The influences of print process, material, and orientation on the strength of a 3D printed pressure vessel are examined and the results can inform valve casing design considerations. Mechanical tensile testing of fused deposition modelling (FDM) printed polyethylene terephthalate glycol (PETG) and stereolithography (SLA) printed acrylonitrile butadiene styrene (ABS)-like test specimens provided insight to the corresponding burst strength of that material and print process. The work presented in this paper advances the state-of-the-art of using 3D printed plastic for the construction of small-scale hydraulic components.
