Magnetofluid sealing structure

Abstract

The invention discloses a magnetofluid sealing structure. The magnetofluid sealing structure comprises a hollow shell and a rotating shaft; the rotating shaft and the shell are connected through a bearing in an assembled mode, multistage of steps are arranged on the outer surface of the rotating shaft, and at least one second permanent magnet is arranged in the radial direction between the outer surface of the rotating shaft and the inner wall of the shell; pole shoes are arranged on the two sides of each second permanent magnet, and each pole shoe is arranged to directly face one of the steps; gaps exist between the pole shoes and the outer surface of the rotating shaft, and magnetofluid is injected to the gaps; the rotating shaft is provided with a cavity, first permanent magnets are mounted in the cavity, and each first permanent magnet is correspondingly arranged in a magnetic circuit formed by the corresponding second permanent magnet and the pole shoes on the two sides of the corresponding second permanent magnet; and the field directions of the first permanent magnets are the same as that of the magnetic circuits where the first permanent magnets are located. According to the magnetofluid sealing structure, by additionally provided with the first permanent magnets, sealing performance of the magnetofluid is improved, the anti-pressure capability of magnetofluid sealing is increased, and the rotating shaft is designed by adopting a stepped shaft form, so that loss of the magnetofluid during sealing failure is reduced.

Description

technical field [0001] The invention specifically relates to a magnetic fluid sealing structure. Background technique [0002] The magnetic fluid seal has the advantages of no solid friction between the seals, long service life of the seals, and zero leakage. Among them, one of the applications is for the sealing of rotating shafts, such as vacuum sealing (ion implanters, x-ray diffractometers, etc.), gas sealing (x-ray tubes, etc.), liquid sealing (deep water pumps, ship screw propeller shafts, etc.) ) and dust-proof seals (textile machinery, computer hard drives, etc.). [0003] One of the methods to improve the pressure resistance of magnetic fluid seals in large gaps is to improve the structure of magnetic fluid seals, such as the sealing devices described in Chinese patents CN206320304U and CN203348559U. Although the sealing performance of the two sealing devices described in the above patent documents has been greatly improved compared with ordinary magnetic fluids, ...

AI Technical Summary

Problems solved by technology

[0006] 1. On the outer surface of the rotating shaft, the area where the magnetic fluid is sealed is the optical axis section. Once the magnetic fluid leaks, it will cause complete leakage and seal failure

[0007] 2. If a single-stage seal is used, the magnetic supply capacity is weak, the magnetic sealing performance is poor, and it is difficult to meet the requirements of vacuum sealing; if a multi-stage seal is used, the sealing performance can be improved, but multiple sets of pole pieces and permanent magnets are required, occupying The space is large, resulting in a bulky structure, which is also not conducive to the lightweight of the sealed structure

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