水下磁耦合器隔离套涡流损耗及系统传动效率分析

Study on Eddy Current Loss and System Transmission Efficiency in Insulation Shell of the Under-Water Permanent Magnet Shaft Coupling

水下直驱式电力推进器密封系统多采用磁力耦合器结构,水下磁力耦合器与传统结构并不相同,其在工作气隙中安置了高强度合金隔离套,将动密封转化为静密封结构。隔离套的使用带了一系列新的科学问题和工程问题。气隙中的旋转磁场切割静止的隔离套,在其中产生轴向涡流,引起隔离套涡流损耗,降低系统的传动效率。目前,水下磁力耦合器系统的研究水平与我国水下推进器需求相距较远,本文针对隔离套损耗、系统传动效率进行了深入研究。首先,采用解析方法,对气隙合成磁密、电磁转矩、隔离套涡流电密及损耗和系统的传动效率进行了详细推导,得到了气隙合成磁密、转矩过载倍数、涡流损耗、传动效率与转矩角的函数关系。其次,采用了数值计算方法对上述物理量进行了细致地计算,并与解析结果进行横向对比,验证了解析计算的准确性。为后续水下推进器用磁力耦合器的进一步优化设计提供了坚实的理论依据。

The permanent magnet shaft coupling(PMSC) structure is often applied in sealing system of under-water direct driven electric propeller, which is different from the traditional structure. The high strength alloy insulation shell has been arranged in the air gap and then dynamic Seal changes to static sealing。A series of new scientific and engineering problems have been brought by using insulation shell. The air-gap rotating magnetic field cuts the static insulation shell,producing axial eddy current,causing the shell eddy current loss, deducing the system transmission efficiency. Now the research level has a great deal of differences between the under-water PMSC system and the under-water propeller, so the insulation shell loss and transmission efficiency are studied in this paper. At first the air gap flux density, electromagnetic torque, insulation shell eddy current density, eddy current loss and transmission efficiency are derived by using mathematical analysis method,in order to achieve the following function relation: air gap flux density, torque overload capacity, eddy current loss, transmission efficiency, and torque angle. Then the finite element method has been applied to calculate above physical quantities and the accuracy of the mathematical method is verificated. which provide the theoretical foundation to the following optimal design of PMSC of under-water electric propeller.