A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS ...A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.展开更多
The viscoelastic properties of the normal PTFE plastic and strengthened PTFEplastic for bearing pad are measured. The mechanical properties of the composite material forbearing pad, which is made of the aforementioned...The viscoelastic properties of the normal PTFE plastic and strengthened PTFEplastic for bearing pad are measured. The mechanical properties of the composite material forbearing pad, which is made of the aforementioned plastics as matrix reinforced by fine bronzeelastic springs, are modeled and relaxation modulus of the material are presented. The differencebetween these two kinds of PTFE is studied. The results show that the complex modulus of PTFEplastics for bearing pad is higher than that of normal PTFE plastics.展开更多
文摘A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.
基金This project is supported by National Natural Science Foundation of China(No.19990510)Selected from Proceedings of 2000 the First International Conference on Mechanical Engineering
文摘The viscoelastic properties of the normal PTFE plastic and strengthened PTFEplastic for bearing pad are measured. The mechanical properties of the composite material forbearing pad, which is made of the aforementioned plastics as matrix reinforced by fine bronzeelastic springs, are modeled and relaxation modulus of the material are presented. The differencebetween these two kinds of PTFE is studied. The results show that the complex modulus of PTFEplastics for bearing pad is higher than that of normal PTFE plastics.
