高压往复动密封柱塞微扰摆动的稳定性分析

Stability analysis of a slightly swung reciprocating plunger under high pressure

在高压往复单元中 ,滑动副之间经常会出现滑动不灵或卡死的现象。为了探讨问题的本质 ,本文针对柱塞、缸筒滑动副推导了非定常工况下的 Reynolds方程 ,并用数值法进行了求解 ,得到了柱塞受微扰摆动时描述油膜动态特征的刚性力矩及阻尼力矩的关系曲线 ,分析了系统的稳定性。结果表明 :柱塞受微扰摆动时系统是极不稳定的 ,油膜侧向力随柱塞表角的增大而增大 ,滑动副之间会因摩擦、磨损最终导致密封失效。在高压密封结构设计中 。

Locking sometimes occurs between moving parts in high pressure reciprocating compressors. Such systems are analyzed by deriving a dynamic Reynolds equation for a system having a plunger and a cylinder. Curves describing the relationship between the rigidity torque, the damping torque of the oil film and the obliquity of the plunger under high pressure are obtained numerically. The stability of the system is then analyzed. The results show that a system with a slightly swung plunger is rather unstable. The sealing between the moving parts often fails because of friction, wear or even locking. The ability to center the system and the side force of the oil film should be taken into account during the design of high pressure sealing systems.