Design and research of torque tube used in HTS motor

Abstract

In order to improve the overall performance of high temperature superconducting (HTS) motor, a radial connection torque tube with high strength and low thermal leakage has been designed. Firstly, fiberglass epoxy composite is chosen as construction material. The structural size of the torque tube is obtained by means of load analysis and theoretical calculation. Secondly, thermal leakage of the torque tube is calculated with both theoretical method and 3D finite-element analysis (FEA). According to the result of the thermal analysis and mechanical loads, the structural stresses of the torque tube are also obtained by FEA method. Lastly, a low temperature test platform is developed to verify the strength and the thermal leakage of the torque tube. The results show that the maximal shear stress of the torque tube is 24.3 MPa and thermal leakage of torque tube is 10.5 W, which satisfy the design requirements of the HTS motor. The torque tube also works in good condition at full-power and full-torque testing of the motor. The design method is also applicable for other similar design of torque tube in other applications.