基于渗透边界的O形组合圈密封特性研究

为准确研究高压柱塞副O形组合密封圈的密封特性,考虑流体向密封接触区渗透对接触压力的影响,基于逐点比较法提出了综合渗透与非接触边界的数值仿真方法,研究高压流体作用下O形组合密封圈的接触压力与von Mises应力分布。进一步讨论不同预压缩量与流体压力下O形组合密封结构参数对其密封性能的影响。分析结果表明:综合渗透边界与非接触边界的分析方法具有较高的可靠性,试验对比误差为2.9%～4.3%;随着O形圈预压缩量增大,主接触压力与密封长度明显增大,而内部von Mises应力与侧接触压力的变化较小;随着流体压力的增大,O形圈von Mises应力与主、侧接触压力均明显增大,但密封长度的变化较小。此外,组合密封挡圈应用于高压柱塞副可有效避免O形圈局部应力集中,挡圈接触压力随流体压力的增大而增大,但明显小于O形圈主接触压力,仅起辅助密封作用。研究结果为高压柱塞副动密封结构设计与优化提供了依据。

Sealing Performance Analysis of O-ring Assembly Based on Permeable Boundary

In order to accurately study the sealing characteristics of O-ring used for high pressure plunger pairs, considered the influence of fluid penetration into the seal contact area on contact pressure, a numerical simulation method for the comprehensive permeability and non contact boundary was proposed based on the point by point comparison method, and the contact pressure and von Mises stress distribution of O-ring assembly under high pressure were investigated. The influence of O-ring assembly structure parameters on the seal performance under different pre compression and fluid pressure was discussed.The results show that the analysis method synthesized permeable boundary and non contact boundary is highly reliable, and the test comparison error is 2.9%~4.3%; with the increase of O-ring pre compression, the main contact pressure and sealing length increase significantly, but the internal von Mises stress and lateral contact pressure change little; with the increase of fluid pressure, the O-ring von Mises stress and primary and lateral contact pressures increase significantly, but the seal length changes little.The combined seal retainer applied to the high pressure plunger pair can effectively avoid the local stress concentration of the O-ring. The contact pressure of the retainer increases with the increase of fluid pressure, but it is significantly less than the main contact pressure of the O-ring, and only plays the role of auxiliary sealing.The research results provide a basis for the design and optimization of dynamic seal structure of high pressure plunger pairs.