What faults can occur due to an inclined static ring end face?

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The so-called inclination of the static ring’s end face refers to the situation where the deviation between the sealing end face of the static ring and the axis centerline exceeds the allowable value; the dynamic ring presses tightly against the end face of the static ring under the force of the spring. The swing value of the rotating ring’s end face during operation depends on the aforementioned perpendicularity error. If the perpendicularity error between the end face of the stationary ring and the shaft is too large, the vibration of the end face of the rotating ring will also be significant, which inevitably causes the sealing ring of the rotating ring to move back and forth rapidly on the shaft. The result of this back-and-forth movement is wear of the moving ring seal, and it also accelerates the wear of the shaft sleeve, causing pitting on its surface. Ultimately, this leads to an increase in leakage and a shorter seal lifespan. Calculations show that for conventional mechanical seals, the axial natural frequency of the moving ring assembly under spring force is always lower than the rotation frequency of the pump (referring to a pump with a speed of 2950 r/min); in other words, the sealing mechanism has poor follow-up capability. This phenomenon worsens as the pump’s rotation speed increases, and it can be described as \"poor follow-up performance\". The leakage amount of a seal is related to its followability; the better the followability, the less the leakage. Since the pump speed remains constant (with a few exceptions), the follow-up ability for a given sealing structure also remains constant. To reduce the leakage amount, it is difficult to focus on improving followability; the only option is to reduce the swing amplitude of the moving ring. If the end face of the stationary ring is tilted significantly, it will push the moving ring a considerable distance away at the \"higher point\" of the stationary ring. Due to poor follow-up capability, the moving ring does not have time to fit against the end face of the stationary ring before the second and third rotations occur; as a result, the end faces of the moving and stationary rings cannot come into contact with each other, creating a large gap between them. Naturally, this leads to increased leakage. If the inclination of the static ring’s end face is very small, the gap between the end faces of the static and dynamic rings will also be small, resulting in minimal leakage. When the thickness of the liquid film between the end faces of the stationary and rotating rings is large, the pressure of this liquid film also exceeds normal levels. Combined with factors such as pump vibration, this can easily cause the sealing surfaces to be pushed apart, resulting in unstable sealing performance and reduced reliability.