针对现有磁脂密封密封能力有限、运行时极靴易与转轴发生刚性磕碰;而刷式密封摩擦生热较大、不能实现零泄漏等问题,综合磁脂密封与刷式密封的特点,提出了新型柔性极靴磁脂密封。利用GAMBIT和FLUENT软件建立柔性极靴磁脂密封的数值分析模型,对比分析了柔性极靴磁脂密封理论上的温度场分布以及磁脂温升规律等传热特性。结果表明:密封的接触线速度、柔性丝的直径、排列倾角和安装过盈量都会对磁脂温度变化产生一定的影响;排列倾角和安装过盈量对磁脂温升的影响有限。由于涂层厚度过小,改变涂层材料,对磁脂温度的影响较小。此外,建立了柔性极靴磁脂密封试验系统,验证了随着转轴转速的增加,柔性极靴密封功耗和磁脂温度会有明显的上升。
With regard to existing problems of current magnetic grease seal and brush seal such as low bearing pressure ability,pole piece bumps against spindle frequently,biggish friction heat and necessary leakage,combining adventages of magnetic grease seal and brush seal,new Magnetic Grease Seal with Flexible Pole Piece( MGS-FPP) is presented. FEM model for MGS-FPP was set up by GAMBIT and thermal field of seal,temperature of magnetic grease and heat transfer characters were relatively studied in theory. The result shows that sealing contact line speed and the diameter of the flexible pole piece have effect on the temperature change,while arrangement angle and installation interference exerts an limited impact on the temperature rise. Due to thin coating,changing coating material has little influence on temperature of magnetic grease. In addition,test system for MGS-FPP was also established and it is verified that with the shaft speed increasing,the power consumption and the temperature of magnetic grease significantly rise.