介质压力及O形橡胶圈压缩率对往复运动轴封性能的影响

以液压缸往复密封中的O形橡胶圈为研究对象，建立其二维轴对称模型。在摩擦系数为0.1，不同介质压力和不同预压缩率的情况下，运用有限元软件ANSYS workbench对O形圈的变形情况及应力大小进行分析。结果表明：O形密封圈在缸筒和活塞杆间隙处应力集中最明显，说明在此位置容易被挤进间隙，造成间隙咬伤，导致密封失效。在压缩率小于15%，介质压力小于15MPa的情况下，剪切应力始终小于丁腈橡胶的剪切强度；在压缩率超过15%时，容易造成 O形圈应力松弛，发生压缩变形；介质压力超过15MPa，剪切应力急剧增加，在往复运动下，密封圈会不断地被摩擦磨损，很容易产生积累损伤，导致裂纹的产生或破损。

Influence of Medium Pressure and O-ring Compression Rate on Performance of Reciprocating Shaft Seal

Taking the O-shaped rubber ring in the reciprocating seal of the Hydraulic cylinder as the research object, a two-dimensional axisymmetric model was established. With a friction coefficient of 0.1, different medium pressures and different pre-compression ratios, the finite element software ANSYS workbench is used to analyze the deformation and stress of the O-ring during installation, static pressure and working conditions. The results indicate that: when the compression rate exceeds 15% during reciprocating motion, it is easy to cause O-ring stress relaxation, compression permanent deformation, and loss of sealing ability; and the seal ring has the most obvious stress concentration in the gap between the cylinder and the piston rod. In this position, it is easy to be squeezed into the gap, causing gap bite, resulting in seal failure; in the case of oil pressure less than 15MPa, the shear stress is always less than the shear strength of nitrile rubber, but under the reciprocating movement, the sealing ring will continue to It is easy to accumulate damage by friction and wear, leading to cracks or damage.