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CN-115773374-B - Magnetic fluid seal with sealing gap magnetic field regulation and control capability

CN115773374BCN 115773374 BCN115773374 BCN 115773374BCN-115773374-B

Abstract

The invention relates to a magnetic fluid seal with a sealing gap magnetic field regulation capability, which comprises a shell, a pole shoe ring, a permanent magnet and a winding. The invention provides a novel magnetic fluid seal, a winding which is provided with controllable current is additionally arranged on the permanent magnet ring position so as to achieve the purpose of regulating and controlling the magnetic field at the sealing gap of the magnetic fluid seal, the structure solves the problems that the permanent magnet which is commonly used in the magnetic fluid seal is difficult to magnetize, difficult to process, easy to demagnetize and uncontrollable in magnetic field, and simultaneously realizes the regulation of the magnetic fluid state at the sealing gap through the regulation and control of the current in the winding, the magnetic fluid sealing device has the advantages that the purposes of high pressure resistance, low temperature starting and long-term preservation of magnetic fluid can be achieved through the reinforcing current, the weakening current and the variable frequency current, so that the problems of high pressure resistance, low temperature starting and long-term preservation existing in engineering are solved well, and one magnetic fluid sealing piece has three functions of high pressure resistance, low temperature starting and long-term preservation.

Inventors

  • LIU JIAWEI
  • LI DECAI

Assignees

  • 北京交通大学
  • 清华大学

Dates

Publication Date
20260512
Application Date
20221116

Claims (6)

  1. 1. A magnetic fluid seal with a sealing gap magnetic field regulation capability comprises a shell (2), a pole shoe ring (3), a permanent magnet (4) and a winding (5); the permanent magnet type aviation power supply is characterized in that a pole shoe ring (3) is arranged on the inner wall of a shell (2), a permanent magnet (4) and a winding (5) are arranged between the two pole shoe rings (3), a gap is reserved between the inner circular surface of the pole shoe ring (3) and the outer circular surface of the shaft (1), pole teeth are arranged on the inner circular surface of the pole shoe ring (3) and extend towards the inner circular surface of the pole shoe ring (3) along the radial direction, a gap is reserved between the inner circular surface of the pole shoe ring (3) and the outer circular surface of the shaft (1), magnetic fluid is filled in the gap for sealing, the winding (5) is formed by tightly pressing copper wires, the gap between the inner circular surface of the winding (5) and the outer circular surface of the shaft (1) is larger than the gap between the inner circular surface of the pole shoe ring (3) and the outer circular surface of the shaft (1), the permanent magnet (4) is formed by splicing cylindrical small magnets, the pole teeth are contacted with the outer circular surface of the winding (5), the shell (2) is provided with radial through holes, the through holes are arranged at the through holes, wires of the winding (5) and the wire is led out of the winding and can be connected with a permanent magnet type power supply through a constant current power supply through a simulation power supply, the size of the permanent magnet can be designed, and the permanent magnet type aviation power supply can be connected with a constant current power supply through the power supply, and a voltage power supply plug can be required, the magnetic field intensity generated by the permanent magnet working independently in the sealing gap is equal to the magnetic field intensity generated by the winding working independently in the sealing gap, so that the zero setting of the magnetic field of the sealing gap is realized.
  2. 2. The magnetic fluid seal with the sealing gap magnetic field regulation capability of claim 1 is characterized in that the number of pole teeth arranged on the inner circular surface of the pole shoe ring (3) is 4-10.
  3. 3. The magnetic fluid seal with the sealing gap magnetic field regulation capability of claim 1 is characterized in that the size of a gap between a pole tooth on the inner circular surface of the pole shoe ring (3) and the outer circular surface of the shaft (1) is 0.05-3 mm.
  4. 4. A magnetic fluid seal with sealing gap magnetic field regulation capability as set forth in claim 1, wherein the outer circumferential surface of the pole shoe ring (3) is provided with a ring groove, and an O-shaped sealing ring is arranged in the ring groove to prevent leakage along a path between the housing (2) and the pole shoe ring (3).
  5. 5. A magnetic fluid seal with sealing gap magnetic field regulation capability as claimed in claim 1 further comprising an end cap (7) and a bearing (6), said end cap (7) being adapted to ensure axial positioning of the pole piece ring (3) and the bearing (6) such that the pole piece ring (3) and the bearing (6) have good coaxiality with the shaft (1).
  6. 6. A magnetic fluid seal with sealing gap magnetic field regulation capability as set forth in claim 5, wherein the bearings (6) are respectively sleeved on the shaft (1).

Description

Magnetic fluid seal with sealing gap magnetic field regulation and control capability Technical Field The invention belongs to the field of mechanical engineering sealing, and particularly relates to a magnetic fluid seal with a sealing gap magnetic field regulating and controlling capability. Background The magnetic fluid seal is characterized in that magnetic fluid is firmly fixed in the seal gap by utilizing magnetic force generated by the permanent magnet in the seal gap, and pressure difference at two sides is resisted, so that the seal effect is achieved, and the magnetic fluid seal research using an electromagnet as a magnetic source is blank, and mainly because under the condition of a conventional working condition, the magnetic field of the seal gap is stabilized at a numerical value, so that the seal requirement can be met. In some application occasions of tip weapons, the installed sealing device needs to be placed for a long time in a working or idle state, and meanwhile, the sealing device is ensured to have stable pressure resistance in the working or idle state, wherein when a magnetic fluid without sealing gap magnetic field regulation and control capability is used for sealing, when a shaft and a pole shoe are in a relatively static state, a stable magnetic field can increase the concentration of magnetic particles in the magnetic fluid at the sealing gap, so that the magnetic particles in the magnetic fluid form a columnar structure, the starting torque is obviously increased, the starting of a sealing main shaft is seriously hindered, and due to the tip effect of the magnetic field, a large amount of magnetic particles are accumulated at the tip of a pole tooth, the concentration of the magnetic fluid at other positions is reduced, and the magnetic particles of the magnetic fluid and the base carrier liquid are separated due to long-term accumulation, so that the performance of the magnetic fluid is seriously influenced. Disclosure of Invention The invention provides a novel magnetic fluid seal, wherein a winding which is provided with controllable current is additionally arranged on the permanent magnet position so as to achieve the purpose of regulating and controlling a magnetic field at a magnetic fluid seal clearance, the structure solves the problems that a permanent magnet which is commonly used in magnetic fluid seal is difficult to magnetize, difficult to process, easy to demagnetize and uncontrollable in magnetic field, and simultaneously realizes the regulation of the magnetic fluid state at the seal clearance through regulating and controlling the current in the winding, wherein the purposes of high pressure resistance, low temperature starting and long-term preservation of the magnetic fluid can be achieved through the strengthening current and weakening current respectively, so that the magnetic fluid seal well solves the three problems of high pressure resistance, low temperature starting and long-term preservation in engineering on one hand, and one magnetic fluid sealing piece has three functions of high pressure resistance, low temperature starting and long-term preservation. The method carries out finite element simulation aiming at a large number of magnetic fluid sealing examples, analyzes simulation results, and obtains reasonable design schemes of winding turns and ring width and ring thickness dimensions of the permanent magnet. The magnetic fluid seal with the sealing gap magnetic field regulation capability comprises a shell, a left pole shoe ring, a right pole shoe ring and a permanent magnet, wherein the pole shoe ring is arranged on the inner wall of the shell, the permanent magnet and the winding are arranged between the two pole shoe rings, a gap is reserved between the inner circular surface of the pole shoe ring and the outer circular surface of a shaft, pole teeth are arranged on the inner circular surface of the pole shoe ring and extend radially to the inner circular surface of the pole shoe ring, a gap is reserved between the inner circular surface of the pole shoe ring and the outer circular surface of the shaft, the gap is filled with magnetic fluid for sealing, the winding is a cylindrical ring formed by tightly pressing copper wires, the gap between the inner circular surface of the winding and the outer circular surface of the shaft is larger than the gap between the inner circular surface of the shoe ring and the outer circular surface of the shaft, the permanent magnet is formed by splicing cylindrical small magnets, the radial through holes are formed in the shell, plugs are arranged at the through holes, wires led out of the winding are connected with a power supply through the gap of the permanent magnet and the aviation plugs on the shell, the winding adopts an adjustable power supply, the size is required to be equal to the size of the permanent magnet when the permanent magnet is independently sealed, and the sealing magnetic field streng