卡箍快开卧式深海模拟舱的径向密封结构及其密封可靠性评价

针对卡箍快开盖结构的卧式深海模拟舱在深海高背压环境下存在密封可靠性不足问题,提出了一种深海模拟舱O形圈径向密封结构,建立了该结构的非线性有限元模型. 通过O形圈的密封面接触应力与内部Von Mises应力评价该结构的密封可靠性,讨论了舱内介质压力、O形圈预压缩率、槽口倒圆、配合间隙对深海模拟舱密封性能的影响. 仿真结果表明:加压过程中接触应力峰区位置显著改变,舱内水压由0 MPa加至25 MPa时,橡胶圈形状及Von Mises应力分布急剧变化,由25 MPa加至45 MPa时,橡胶圈形状及Von Mises应力峰区位置基本不变,该结构能够实现45 MPa压力下的有效密封. 预压缩率的增加会显著增加主接触面密封带宽度,增大槽口倒圆有助于降低Von Mises应力,Von Mises应力峰值随配合间隙的增加先增大后减小,增大配合间隙有助于提高密封带宽度. 试验结果证明:当O形圈的预压缩率为10℅、槽口倒圆为0. 4 mm、配合间隙为0. 7 mm时,利用该密封结构所研制的深海高压舱在40、45、50 MPa水压时均能保证有效密封.

Radially Sealed Structure of Quick-opening Clamping and Horizontal Deep-sea Simulated Cabin and Its Sealing Reliability Evaluation

For sealing reliability problem with quick-opening clamping and horizontal deep-sea simulated cabin, this paper presents an O-ring radial sealing structure of deep-sea simulated cabin, and establishes a nonlinear finite element model for the structure. Its sealing reliability through O-ring's sealing contacted stress and Von Mises stress were evaluated, and the effect of medium pressure, O-ring's pre-compression ratio, and groove chamfering and clearance on the sealing performance were analyzed. Simulation results show that contacted stress peak area significantly changes with increasing pressure, O-ring and Von Mises stress distribution dramatically changes when the pressure increases from 0 MPa to 25 MPa, however, they do not almost change when the pressure increases from 25 MPa to 45 MPa. The main sealing width will raise with increasing pre-compression ratio, and groove chamfer increasing is helpful for Von Mises stress reduction. Von Mises stress peak value first increases and then decreases with increasing clearance, and the increase of clearance is helpful to improve the sealing width. Experiment results show that when the O-ring pre-compression ratio is 10℅, the groove chamfer is 0. 4 mm, clearance is 0. 7 mm, and the sealing structure can ensure high sealing reliability under 40, 45 and 50 MPa.