Analysis of Leakage and Leakage Caused by Installation and Assembly Accuracy Issues of Circular Arc Oil Pump

[1] Leakage caused by installation and assembly accuracy issues of gear pumps

(1) Installation problems of pumps

The vibration of gear pumps has a particularly serious impact on mechanical seals, so the installation of pump couplings is an important factor. In addition, the dimensions of the shaft string, the perpendicularity of the sealing box end face and shaft, the gap between the gland and the sealing box, the gap between the pump cover and the pump body, the shaft sleeve and radial runout exceed the standard, which will affect the sealing performance

(2) Mechanical seal assembly accuracy problem

The unscientific assembly accuracy of mechanical seals in gear pumps is also a factor that causes seal damage, such as insufficient concentricity in the installation of dynamic and static rings, and inappropriate compression during mechanical seal installation.

. When the compression amount is too large, it will cause the dynamic and static ring end faces to fit too tightly, and cannot open normally to form a liquid film during operation, leading to severe wear and failure. If the compression amount is too small, the end face will have a lower specific pressure, which is easily affected by pressure fluctuations, pump vibration and other factors during operation, and the sealing surface will open and fail

[2] Analysis of mechanical seal leakage during trial operation of circular arc pump

When a static trial circular arc pump is running, the centrifugal force caused by rapid rotation will greatly affect the medium inside the pump, so it is impossible for the leakage of the mechanical seal of the circular arc pump to be caused by the medium.

During the trial operation, the mechanical seal leakage of the circular arc pump is mostly caused by the damage to the friction pairs of the dynamic and static rings. The common reasons why friction pairs cannot function are as follows:

① During operation, due to various reasons, the axial force separates from the contact surface between the dynamic and static rings in the mechanical seal device of the circular arc pump, resulting in leakage of the mechanical seal device

② Excessive compression during the installation of mechanical seals leads to severe wear and scratches on the friction pair end face

③ The sealing ring of the moving ring is too tight, and the spring cannot adjust the axial floating amount of the moving ring

④ The sealing ring of the static ring is too loose, and when the dynamic ring floats axially, the static ring detaches from the static ring seat

⑤ There are granular substances in the working medium, which enter the friction pair during operation and damage the sealing end faces of the dynamic and static rings