Development of a Plastic 3D Printed Valve for Small-Scale Electrohydrostatic Actuator Applications

Electrohydrostatic actuators (EHA’s) are well-known for their high power densities (ratio of actuator weight to actuator power) and good dynamic performance. While EHA’s dominate in high-power systems, lower-powered systems (< 100W) typically employ electromechanical type actuators, such as screw actuators, due to the unavailability of low-cost hydraulic components on an appropriate scale. Recently, the radio-controlled hobby industry has started producing small- scale hydraulic pumps and cylinders for model construction equipment. These hobby grade pumps and cylinders may be repurposed in an EHA configuration for use in more demanding applications but limiting this is the fact that no appropriate method of handling the unbalanced cylinder flows of a typical single-rod cylinder exist. An inverse shuttle valve is a simple and efficient solution to compensate for this mismatch of cylinder flows, and the recent progression of 3D printed plastics enables such a valve to be produced for a very low cost. This thesis develops the small-scale 3D printed plastic inverse shuttle valve concept and improves upon prototypes developed within the Fluid Power Research Group at the University of Saskatchewan. Presented in this thesis is a wide variety of experiments investigating and improving the performance potential of such a 3D printed inverse shuttle valve in a small-scale EHA application. The sealing capabilities of 3D printed plastic poppets and the effects of print orientation, surface lapping, valve size, fluid pressure and sealing time were experimentally assessed. The pressure drops of the flow paths in a prototype design were measured and reduced by an informed selection of tubing and fittings. Finally, a series of experiments explored the steady state, dynamic response, and thermal performance of an EHA designed with the newly developed inverse shuttle valve. Satisfactory poppet sealing performance was obtained by utilizing a lapping procedure to smooth the sealing surfaces and selecting sealing element geometries insensitive to misalignment. A low- restriction flow path between the pump and valve was identified to improve power efficiency and reduce the potential for pump cavitation. Testing of the EHA revealed impressive performance, with high force and velocity capabilities, good energy efficiency, and very fast dynamic responses. These results satisfied the research objectives, demonstrating that the use of a 3D printed inverse shuttle valve in a small-scale EHA system is a viable concept

NASA Tech Briefs, November 2002

Topics include: a technology focus on engineering materials, electronic components and systems, software, mechanics, machinery/automation, manufacturing, bio-medical, physical sciences, information sciences book and reports, and a special section of Photonics Tech Briefs

Technology 2003: The Fourth National Technology Transfer Conference and Exposition, volume 2

Proceedings from symposia of the Technology 2003 Conference and Exposition, Dec. 7-9, 1993, Anaheim, CA, are presented. Volume 2 features papers on artificial intelligence, CAD&E, computer hardware, computer software, information management, photonics, robotics, test and measurement, video and imaging, and virtual reality/simulation

Biomimetic Based Applications

The interaction between cells, tissues and biomaterial surfaces are the highlights of the book "Biomimetic Based Applications". In this regard the effect of nanostructures and nanotopographies and their effect on the development of a new generation of biomaterials including advanced multifunctional scaffolds for tissue engineering are discussed. The 2 volumes contain articles that cover a wide spectrum of subject matter such as different aspects of the development of scaffolds and coatings with enhanced performance and bioactivity, including investigations of material surface-cell interactions

Technology for large space systems: A bibliography with indexes (supplement 22)

This bibliography lists 1077 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion

Space station systems: A bibliography with indexes (supplement 10)

This bibliography lists 1,422 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included

Space station systems: A bibliography with indexes (supplement 9)

This bibliography lists 1,313 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included