Page 137 - 摩擦学学报2025年第5期

第 5 期 许华林, 等: 阶梯螺旋槽端面密封摩擦学性能数值研究 771

In order to further improve the load capacity, opening capacity and wear suppression ability of the logarithmic
spiral groove during the start-stop period while keeping the original groove type, a new stepped spiral groove with a step
along the circumferential direction was proposed. The analytical lubrication model of stepped spiral groove seal was
established, combined with the Jakobsson-Floberg-Olsson (JFO) cavitation boundary condition to solve the cavitation
problem that always occurred in the spiral groove, and the finite volume method was used to calculate the tribological
properties with different geometrical parameters and operating conditions.
The traditional flat-bottomed spiral grooves with primary groove depth d 1 =1, 3 and 5 μm and their corresponding
stepped spiral grooves were systematically analyzed and compared under different working conditions, in which
secondary groove-to-land ratio β=0.3, and the secondary groove depth d 2 =2d 1 . The load capacity, stiffness, cavitation
rate and opening speed were obtained for a fixed film thickness, as well as the film thickness and friction torque at a
fixed load. The results showed that the load capacity and film stiffness of the stepped spiral groove were much greater
than that of the corresponding flat-bottomed one, while the opening speed and cavitation rate were smaller than that of
the traditional flat-bottomed one under the same conditions.
Based on the results, the principle of load capacity enhancement of the stepped spiral groove was analyzed
intensively. It could be found that, the circumferential variable depth stepped spiral groove introduced an additional
Rayleigh bearing effect on the original flat-bottomed one. The additional hydrodynamic pressure enhanced the load
capacity at the step, significantly reduced the area of the cavitation region that did not provide an effective load capacity,
and provided an enhancement of the load capacity in the pressure peak area at the termination line of the groove. From
the numerical comparison, under the working condition of film thickness H 0 =1 μm and rotational speed ω=50 r/min, the
peak pressure of the stepped spiral groove was increased by 7.14%, the cavitation rate was reduced by 93.42%, and the
total load capacity was further increased by 19.83% on the basis of the optimized flat-bottomed spiral groove. It could be
concluded that the additional Rayleigh bearing effect due to the introduction of a step at the bottom of the spiral groove
was the main mechanism for the stepped spiral groove to effectively improve the load capacity and opening capacity.
Key words: face seal; stepped spiral groove; cavitation; tribological performance; Rayleigh bearing

机械密封是航空发动机重要基础轴封装置，由动 未提升；王衍等 [17-18] 在螺旋槽的基础上设计了特斯拉
[19]
环、静环以及补偿机构等组成，依靠流体动压效应在 阀型槽；宗聪等 在螺旋排布的基础上设计了似叠罗
密封面间形成稳定油膜以提高摩擦学性能. 但启停阶 汉型槽，均可以提升承载力，但是设计复杂. 目前对螺
[20]
[21]
段转速较低，流体动压效应弱，液膜承载能力低，无法形 旋槽底部深度的设计较少，Wang等 和张伟政等 分
成有效油膜，处于混合润滑状态，导致摩擦磨损严重，显 别设计了径向不等深阶梯槽和径向双槽螺旋槽，可以
著影响密封环使用寿命. 表面织构技术可以有效提升密 有效减少泄漏，但均未提升承载力.
封环承载力和减磨效果，多采用微孔和微槽2种织构. 目前研究者对螺旋槽进行了有效探索，但保持原
织构形状和分布对摩擦学性能有显著影响 [1-2] ，针 有槽型的优化多为减少泄漏方面，而非增加承载力、
对微孔型织构，研究者开展了大量的工作，除了早期 减小磨损，形状改变的新槽型研究中对承载能力进行
[4]
[3]
[8]
的圆形孔 ，还有椭圆形 、三角形 [5-7] 和菱形 等多种 了优化但失去了螺旋槽结构简单易加工的优势. 本文
微孔类型. 对于微槽型织构，研究发现螺旋槽效果较 中提出1种保持原有螺旋线型的周向变深度新型阶梯
[10]
[9]
好，应用较为广泛且便于优化 . 李振涛等 探究了螺 螺旋槽，在圆周方向进行变深度设计增强了流体动压
旋槽密封中各种参数对空化的影响，明确了螺旋槽空 效应，有效降低空化率，同时实现提高承载能力、液膜
[11]
化机理及液膜特性. 孟祥铠等 和赵一民等 [12-13] 对螺 刚度及开启能力.

旋槽密封环进行了研究，发现其在高PV值工况下可以
产生良好的流体动压效应，实现全膜润滑，并给出了 1 计算模型
平底螺旋槽的优化设计规律. 近年来在传统平底螺旋 螺旋槽是密封和推力轴承端面常用的织构形式，
[14]
槽的基础上又提出了多种衍生槽的设计，李英等 和 有效改善了密封等的摩擦学性能. 为进一步提升密封
李京泽等 分别设计了径向反向双列螺旋槽和径向 环承载能力、降低开启速度，考虑到Rayleigh轴承良好
[15]
同向双列螺旋槽；左松奇等 设计了长短螺旋槽叠加 的承载能力，本文中以设计有阶梯螺旋槽的油润滑端
[16]
的组合螺旋槽，均实现了泄漏量的减少，但承载能力 面密封为对象. 密封模型如图1(a)所示，沿旋转方向螺