水润滑轴承加载装置动态磁热耦合机理研究

针对水润滑轴承动态试验研究中电磁加载装置发热以及电磁力不稳定等现象，为了给轴承研究提供准确载荷，对电磁加载装置动态下的磁热耦合机理进行研究。首先建立了电磁加载装置能量损耗数学模型，对能量损耗进行理论分析；其次，构建了电磁加载装置物理模型，进行磁热耦合仿真分析，得到了磁感应强度、铜损耗以及铁损耗的变化规律；最后，进行电磁加载装置能量损耗试验。研究结果表明：动态下电磁力不稳定的主要原因是加载装置存在能量损耗，且以铜损耗与铁损耗为主；能量损耗与轴转速、加载装置激励电流以及初始温度有关，在激励电流1～3 A、转速0～1 800 r/min以及温度22～50℃工况下，电磁力试验值与仿真值最大误差为4.7%。

Research on Dynamic Magneto-thermal Coupling Mechanism of Loading Device for Water-lubricated Bearing

In view of the phenomena such as the heating of electromagnetic loading device and the instability of electromagnetic force in dynamic test of water-lubricated bearings, the magneto-thermal coupling mechanism of loading device was studied in order to provide the accurate load for bearing performance research. Firstly, the mathematical model of energy loss for electromagnetic loading device was established, and the energy loss was analyzed theoretically. Secondly, the physical model of electromagnetic loading device was constructed, the magneto-thermal coupling simulation analysis was carried out, and the variation rules of magnetic induction intensity, copper loss and iron loss were obtained. Finally, the energy loss test of electromagnetic loading device was carried out. The results show that the main reason of unstable electromagnetic force under dynamic conditions is the energy loss of loading device, and the main energy loss are copper loss and iron loss. Energy loss is related to the shaft speed, the excitation current of electromagnetic loading device and the initial temperature. Under the working condition of excitation current (1 - 3 A), the rotating speed (0 - 1 800 r/min) and the temperature (22 - 50 ℃), the maximum error of electromagnetic force between the test and the simulation results is 4.7%.