Modelling and Test of an Integrated Magnetic Spring-Eddy Current Damper for Space Applications

This article belongs to the Special Issue Actuators and Dampers for Vibration Control: Damping and Isolation Applications.We present the design, manufacturing, and dynamical characterization of a mechanical suspension made by a passive magnetic spring and an eddy current damper integrated into a single device. Three configurations with 2, 3, and 4 permanent magnets axially distributed with opposite polarizations are designed, simulated, manufactured, and tested. Stiffness of 2410, 2050, 2090 N/m and damping coefficient of 5.45, 10.52 and 17.25 Ns/m are measured for the 2-, 3-, and 4-magnets configurations, respectively. The magnetic suspension provides good mechanical properties combined with excellent cleanness and high reliability, which is very desirable in mechanical systems for space applications.The research leading to these results has received funding from the Spanish Ministerio de Economía y Competitividad under the Plan Estatal de I+D+I 2013-2016, grant agreement no ESP2015-72458-EXP

Design and test of cryogenic cold plate for thermal-vacuum testing of space components

This paper proposes a novel cryogenic fluid cold plate designed for the testing of cryogenic space components. The cold plate is able to achieve cryogenic temperature operation down to -196 °C with a low liquid nitrogen (LN2) consumption. A good tradeoff between high rigidity and low thermal conduction is achieved thanks to a hexapod configuration, which is formed by six hinge-axle-hole articulations in which each linking rod bears only axial loads. Thus, there is not any stress concentration, which reduces the diameter of rod sections and reduces the rods' thermal conduction. This novel design has a unique set of the following properties: Simple construction, low thermal conduction, high thermal inertia, lack of vibrational noise when cooling, isostatic structural behavior, high natural frequency response, adjustable position, vacuum-suitability, reliability, and non-magnetic. Additionally, the presented cold plate design is low-cost and can be easily replicated. Experimental tests showed that a temperature of at least -190 °C can be reached on the top surface of the cold plate with an LN2 consumption of 10 liters and a minimum vibration frequency of 115 Hz, which is high enough for most vibration tests of space components.The research leading to these results received funding from the Spanish Ministerio de Economía y Competitividad inside the Plan Estatal de I+D+I 2013-2016 under grant agreement n° ESP2015-72458-EXP. The authors wish to recognize the work of Alba Martínez Pérez in the preparation of figures, the work of Miguel Fernández Muñoz in 3D model preparation, and the assistance of Hector Cruz Rosco during thermal and dynamic tests. The authors especially wish to recognize the work of Jorge Serena de Olano in CNC manufacturing