Non-contacting mechanical seal type sealing clearance control system and non-contacting mechanical seal type sealing clearance control method

Abstract

The invention discloses a non-contacting mechanical seal type sealing clearance control system and a non-contacting mechanical seal type sealing clearance control method. The non-contacting mechanical seal type sealing clearance control system comprises a torque-speed sensor, a displacement sensor, a coil and a control circuit, wherein the torque-speed sensor is mounted on a rotating shaft and is used for detecting a rotating speed of the mechanical seal type rotating shaft, the displacement sensor is mounted on an outer step of a stationary ring and is used for detecting a distance between the stationary ring and a moving ring, the coil winds around the stationary ring, and the control circuit is connected with the torque-speed sensor, the displacement sensor and the coil and is used for controlling the size and the direction of coil current according to the rotating speed of the mechanical seal type rotating shaft and the distance between the stationary ring and the moving ring so as to adjust repulsive force or attraction force between the stationary ring and the moving ring. The non-contacting mechanical seal type sealing clearance control system has the advantages that opening force or closing force of the stationary ring and the moving ring in non-contacting mechanical seal is compensated magnetically, so that the influences of adverse factors on the seal operation quality are avoided or lowered effectively, and zero-leakage non-contacting mechanical seal advantages are given to full play.

Description

technical field [0001] The invention relates to a sealing gap control system and control method of a non-contact mechanical seal controlled by magnetic force, which can realize the controllability of the size of the sealing gap to ensure stable fluid lubrication and zero-leakage performance of the sealing end face. Background technique [0002] With the development of industrial technology, the performance requirements of mechanical seals are getting higher and higher. Under some working conditions such as high pressure, high speed and high temperature, especially in some aerospace, nuclear power plants, petrochemical and other fields, mechanical seals are required to achieve zero leakage, Small deformation and long life. In addition, the higher and higher energy-saving and environmental protection target requirements have also made improving the stability and life of mechanical seals a topic that has attracted much attention and attention in the field of mechanical seal man...

AI Technical Summary

Problems solved by technology

However, none of the above patents has solved the following problems well: the instantaneous opening ability of the mechanical seal when it is started, the wear problem when it is stopped, and the prerequisite for keeping the end face non-contact during operation—the problem of a stable fluid film with a certain thickness

From the above patents, it can be seen that they all have the problems of limited sealing force, serious end face wear, high frictional heat, and short service life.

Korean patent KR20160079568 discloses a magnetic fluid mechanical seal device, which uses the magnetic force generated by the permanent magnets distributed on the shaft to control the magnetic fluid to achieve the purpose of sealing. However, the magnetic fluid is easily diluted by the medium and cannot form a stable sealing surface and can withstand it. The sealing pressure is limited; U.S. Patent US5267007 discloses a magnetic sealing device for preventing axial end leakage, which uses the magnetic force generated by ferromagnetic materials to absorb magnetic particles and prevent leakage, but the magnetic force will weaken with the increase of adsorbed particles, which is easy to cause Leakage; U.S. patents US8474826B2 and US2006244221A1 disclose a magnetic mechanical seal with an end face shape. The magnetic force only plays the role of sealing closing force. A groove is set on the end face, and the dynamic pressure effect of the groove is used to form a fluid film to reduce end face wear. However, the fluid film is prone to instability under vibration or variable working conditions, which may easily cause leakage or wear

[0005] To sum up, the existing non-contact mechanical seal with end face shape can not solve the problem of instantaneous opening ability when starting up and wear when stopping, and the fluid stability in the sealing gap is insufficient; while the magnetic contact mechanical seal, when installing Due to inaccuracy, vibration, etc., the floating compensation of the end face cannot be controlled

It can be seen that the seals proposed in the existing technologies at home and abroad cannot effectively solve the problems of leakage, wear and stability, and the sealing performance has not reached the ideal state.

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