Loss estimation, thermal analysis, and measurement of a large‐scale turbomolecular pump with active magnetic bearings

Abstract

Temperature rise subjected to the copper losses and iron losses is an important issue for a magnetically suspended turbomolecular pump (MSTMP). In this study, the loss estimation, thermal analysis, and temperature rise measurement of a large‐scale MSTMP are investigated. The copper losses and the iron core losses of two radial magnetic bearings, a thrust magnetic bearing, and a brushless direct current motor (BLDCM) are predicted by the analytical models. Based on the predicted loss values, the heat generation rates in the different parts of the large‐scale MSTMP are calculated, then the thermal field of the prototype is analysed by the 3D finite‐element model. The maximum temperatures estimated for the rotor part and stator part are located at the rotor sleeve and the winding end of BLDCM, which are 68.5 and 55.2 °C, respectively. The loss calculation and thermal field prediction is validated by the temperature rise test in a prototype of large‐scale MSTMP with pumping speed of 4100 L/s, ultimate vacuum of 1.8 × 10−7 Pa, and rated speed of 21,000 r/min. The maximum error between the estimated and the measured temperature rise values is <5%.

Real-time application of a dynamic disturbance suppression control approach for an axial active magnetic bearing system

“…Moreover, AMBs enable the rotor to rotate at extremely high speeds. Therefore, AMBs are wellsuited for high-speed motors, [1][2][3][4][5] turbo machinery, [6][7][8][9][10] high-speed compressors, [11][12][13][14][15] Flywheel Energy Storage Systems, [16][17][18][19][20] and aerospace fields. [21][22][23][24] The dynamics of AMBs are inherently unstable.…”

Effects of Imperfect Assembly and Magnetic Properties on the Three-Pole AMB System

“…It can also be applied in extreme environments, such as very high or low pressure, very high or low temperature, vacuum, and zero gravity. Because of these features, AMB has found wide applications, for instance, in turbo-molecular pumps [2], high-speed air compressor [3,4], flywheel energy-storage systems [5,6], control-momentum wheels [7], printed electronics systems [8], and machine tools [9], etc.…”