Gear oil pump often chooses mechanical seal to prevent leakage when conveying high temperature and high pressure oil, and mechanical accident caused by leakage accounts for about 50% of the total maintenance of vertical roller mill oil pump. It can be seen that the reliability of mechanical seal is efficient for oil pump operation. And the extension of service life is of vital importance.

Mechanical seals are generally composed of auxiliary components such as a rotating ring, a stationary ring, a seal ring or a gasket, and an elastic compensating element. The working principle is that a pair of end faces perpendicular to the rotation axis are fitted to each other and relatively rotated, and a very thin liquid film is maintained between the end faces. Under the cooperation of the auxiliary seal, the end faces are subjected to the medium fluid pressure and compensate the mechanical elastic force. The role of maintaining a close fit to achieve the purpose of sealing.

Reasonable design is the basis for the mechanical seal to achieve its function, but the overall design optimization of the oil pump, the selection of equipment accessories, and the choice of material of each component directly affect the sealing performance of the vertical roller mill oil pump.

Taking the magnetic separator in the oil pump as an example, the component not only has the disadvantages of being unable to separate and filter non-metallic particles, is bulky, and is difficult to be repaired, but may also cause the rotation of these and non-metallic materials due to the metallic substances in the magnetic adsorption oil. The moving ring or the stationary ring generates friction, which causes the wear of the component. The non-metallic substance produced by the wear and tear enters the system due to the inability to be adsorbed and filtered to increase the wear, and the long-term operation inevitably leads to a decrease in the sealing performance.

Improper construction of the installation can also cause seal damage. If the hexagon socket screw that is axially positioned in the mechanical seal is not tightly installed, the seal will axially move. When the amount of turbulence is too large, the compression spring cannot make the stationary ring close to the rotating ring. Causing leakage; the shaft end face of the ring seal and the sealing gland end face of the static ring seal ring are not clean enough, which may damage the swivel ring and the stationary ring during installation; and the spring compression of the mechanical seal is also the focus of the installation. The error is less than ±2mm, which may increase the end face specific pressure and friction heat due to the excessive compression. The wear and thermal deformation of the end face are intensified, or the specific pressure of the end face of the stationary ring is insufficient due to the small amount of compression, which affects the sealing effect.