多孔扇形分布端面机械密封的结构优化

以微型多孔扇形分布光滑端面机械密封为对象,建立了表征密封端面运行状态的物理方程,并采用有限单元法求解了端面流体膜压力的控制方程,即二维稳态Reynolds方程;给出了流体膜刚度、端面开启力、泄漏率和流体膜刚漏比等主要密封性能参数的计算表达式;在给定操作参数条件下,分析研究了这些密封性能参数受微型多孔端面扇形区的数量k,周向开孔比α与径向开孔比β,以及微孔半径rp与深径比ε等微孔几何参数影响的规律,提出了获得优良密封性能的几何参数优选原则和优选范围.结果表明,在给定操作参数和密封介质性质的条件下,扇形区块数和微孔径一定时,微孔深径比对机械密封性能的影响最明显,其次是周向开孔比和径向开孔比,且当ε=0.003~0.007,α=0.3~0.5,β=0.45~0.85时,多孔端面密封可获得最佳综合性能.

Geometric optimization of mechanical seals with porous sector sealing face

A two dimensional steady state Reynolds equation was solved by finite element method,which controls the fluid film pressure distributions between the faces of a mechanical seal with a porous sector sealing face.The expressions for the major sealing performance parameters such as fluid film stiffness,opening force,leakage rate and stiffness to leakage rate ratio were presented.The effects of the textured geometric parameters on the sealing performance were analyzed under the given operation conditions and for a given sealed media,which mainly referred to porous sector number,the textured length ratios both in the circumferential direction and in the radial direction,the micropore radius and the micropore depth to diameter ratio.The geometric-optimization principle was presented for getting excellent sealing performance.The results show that the most important geometric parameter is the micropore depth to diameter ratio,and the textured length ratios both in the circumferential direction and in the radial direction are the next important ones when the textured geometric parameters and the micropore diameter are given.When the depth to diameter ratio is 0.003～0.007,and the textured length ratios both in the circumferential direction and in the radial direction are 0.3～0.5 and 0.45～0.85,respectively,such mechanical seals will offer excellent performance.