盾构机主驱动VD形密封圈密封性能研究与优化

Research and Optimization of Sealing Performance of VD Ring for Main Drive of Shield Machine

为研究盾构机主驱动密封圈压缩量以及正反面润滑油脂载荷对密封圈密封性能的影响,通过ANSYS有限元软件研究在不同压缩量和密封圈不同正反面加载压力下,丁腈橡胶(NBR)材料的VD形密封圈的密封性能。结果表明:在压缩量3~7 mm区间,随着压缩量的增加,密封圈接触面的最大von Mises应力先不断增加后逐渐趋于稳定,而最大接触压力不断下降;当压差保持一致时,随着密封圈正反面的压力升高,该VD形密封圈接触面最大压力也保持相近幅值的上升;当密封圈正反面压力变化时,该密封圈结构保证了接触压力的裕度,从而保证了密封结构密封效果的稳定性。通过曲面响应法,对设计的一种带反面支撑结构的VD形密封圈进行优化,得出在压缩量7 mm,密封圈正反面压力0.9-0.6 MPa时,其密封效果最好时出现在支撑角度为9.3453°,支撑长度为59.499 mm时,优化后VD形密封圈最大接触压力提高了16%~25%。

In order to study the influence of the compression amount of the main drive seal ring of the shield machine and the load of lubricating grease on the front and back sides of the seal ring on the sealing performance of the seal ring,the sealing performance of VD seal ring made of nitrile rubber(NBR)was studied under different compression amount and different loading pressures of the front and back sides of the seal ring.The results show that in the range compression amount from 3 mm to 7 mm,with the increase of compression amount,the maximum von Mises stress on the contact surface of the sealing ring increases at first and then gradually tends to be stable,while the maximum contact pressure on the contact surface is decreased.When the pressure difference is consistent,with the increase of the pressure on both sides of the seal ring,the maximum contact pressure on the contact surface of the VD sealing ring also maintains a similar amplitude increase.When the pressure on both sides of the sealing ring changes,the sealing ring structure ensures the margin of contact pressure,so as to ensure the stability of the sealing effect of the sealing structure.Through the surface response method,the VD seal ring with reverse support structure was optimized.It is concluded that the best sealing effect is obtained when the support angle is 9.3453°and the support length is 59.499 mm under the compression amount of 7 mm and the pressure of 0.9-0.6 MPa on the front and back sides of the seal ring.After optimization,the maximum contact pressure of VD seal ring is increased by 16%to 25%.