37results about How to "Improve sealing pressure resistance" patented technology

The invention provides a method for improving pressure resistance of magnetic liquid seal in a low-temperature working environment, belongs to the technical field of sealing of mechanism engineering, and in particular applies to magnetic liquid seal. The method comprises the steps of selecting a ferromagnetic material with high permeability and large expansion coefficient, and an alloy steel material with small thermal expansion coefficient and high comprehensive mechanical performance; manufacturing a pole shoe with the ferromagnetic material; manufacturing and processing a composite material shaft being 50 to 100mm in diameter by using the ferromagnetic material and the alloy steel material as an outer layer material and an inner layer material, respectively, wherein the radial length ratio of the ferromagnetic material layer to the alloy steel material layer is 1: 3; applying the pole shoe and the composite material shaft into a magnetic liquid seal device of which a gap ranges from 0.1 to 0.25. With the adoption of the method, the shortages of the existing method for magnetic liquid seal under a low temperature can be overcome, the problem of applying to magnetic liquid seal in a low-temperature environment is solved, the applicable scope of magnetic liquid seal is expanded, and the method is of an important significance.

The invention aims to provide an embedded maze type magnetic fluid sealing device. The embedded maze type magnetic fluid sealing device comprises a stepped shaft, a shell, a left first pole shoe ring,a right first pole shoe ring, a middle sleeve and a middle permanent magnet ring; and the stepped shaft comprises a first-stage shaft with the largest diameter and one or more secondary first-stage shafts which are sequentially reduced in diameter, the secondary first-stage shafts are arranged on the two sides of the first-stage shaft in sequence along the side face of the first-stage shaft, andthe secondary first-stage shafts which take the middle radial section of the first-stage shaft as a boundary are symmetric. The invention aims to solve the problem that an existing sealing device is low in pressure resistance, so that the sealing technology is successfully applied to the fields of high-speed heavy load and the like.

The invention discloses a convex arc type magnetic fluid sealing device which comprises a shaft, a shell, pole shoes, magnet fluid and permanent magnets. The convex arc type magnetic fluid sealing device is characterized in that the shaft penetrates and extends out of the two ends of the shell; the part, located in the shell, of the shaft is provided with at least one circular ring; the outer circumferential faces of the circular rings are in a convex arc shape; at least two pole shoes are arranged on the inner surface of the shell; the part between every two adjacent pole shoes is provided with the corresponding annular permanent magnet; the pole hoes are of circular-ring-shaped structures; the inner circumferential faces of the pole shoes located between the circular rings and the shellare in a concave arc shape; and the magnetic fluid is arranged in sealing clearances between pole teeth and the shaft. By means of the convex arc type magnetic fluid sealing device, the sealing pressure-resisting capability of the magnetic fluid is greatly improved, and the problem that an existing sealing device cannot meet the requirement for high sealing performance under special conditions such as high speeds and heavy loads is solved.

The invention relates to a convex step shaft magnetofluid sealing device. The convex step shaft magnetofluid sealing device comprises a shell, a sealing assembly and an end cover. The sealing assemblycomprises a shaft. The shaft is rotationally arranged in the shell through a bearing. The shaft comprises at least one convex step part. The convex step part comprises a plurality of steps sequentially arranged in the axial direction, and the outer walls of the adjacent steps are connected through arc chamfered transition faces. Each transition face is sleeved with a pole shoe matched with the transition face, wherein the pole shoe extends towards one or two sides of the transition face to the position corresponding to the corresponding step on the side portion of the transition face. Gaps are reserved between the inner walls of the pole shoes and the corresponding transition faces and between the inner walls of the pole shoes and the steps. Pole teeth are arranged on the inner walls of the pole shoes and/or the parts, corresponding to the inner walls of the pole shoes, of the shaft. Permanent magnets are arranged between the adjacent pole shoes. The convex step shaft magnetofluid sealing device is high in pressure resisting capability, the secondary pressure bearing capability and the self-repairing capability are high, the pressure resisting capability and the sealing reliability of magnetic fluid seals under the condition of large gaps are high, and the safety work range is wide.

The invention discloses a method for improving the pressure-resistant capacity and the working reliability of a magnetic fluid seal in a high-temperature working environment, belongs to the technical field of mechanical engineering seals, and is particularly applicable to the magnetic fluid seal. An iron-nickel alloy material with the anomalous thermal expansion characteristic and a ferromagnetic material with the larger thermal expansion coefficient and good comprehensive mechanical properties are selected, pole shoes and a sealing shaft which are matched with each other are made of the selected ferromagnetic material, pole shoe sleeves which are in interference fit with outer rings of the two pole shoes are made of the selected iron-nickel alloy material, and the radial width ratio of each alloy sleeve to each pole shoe is 1:2. With the adoption of the method, defects of existing methods for the magnetic fluid seal at the high temperature are overcome, and the method has the important significance in solving usage problems of the magnetic fluid seal in the high-temperature environment and broadening the application range of the magnetic fluid seal.

The invention discloses a stepped shaft type magnetofluid sealing device. The stepped shaft type magnetofluid sealing device comprises a shaft, an outer shell, sealing rings, pole shoes, magnetofluidand permanent magnets. The shaft penetrates the outer shell, extends out of the two ends of the outer shell and comprises a stepped shaft part, wherein the stepped shaft part is located inside the outer shell. The diameter of a middle step of the stepped shaft part is the maximum, and the diameters of steps at the left side and the right side are decreased progressively and sequentially. Every twoadjacent steps are in circular-truncated-cone transition. The stepped shaft part is provided with cylinder side faces and multiple circular-truncated-cone side faces, wherein the cylinder side facesare parallel with the axis of the shaft, and the circular-truncated-cone side faces are symmetrical about the axis. The inner surface of the outer shell is provided with the two or more pole shoes. Each annular permanent magnet is arranged between the corresponding two adjacent pole shoes. Each pole shoe is provided with radial pole teeth and bevel pole teeth, wherein the radial pole teeth protrude toward the cylinder side faces, and the bevel pole teeth protrude toward the circular-truncated-cone side faces. The magnetofluid is arranged between the radial pole teeth and the cylinder side faces as well as between the bevel pole teeth and the circular-truncated-cone side faces. By means of the stepped shaft type magnetofluid sealing device, the sealing capability and pressure endurance capability of the magnetofluid are greatly enhanced; and the problem that existing sealing devices cannot meet the high-sealing-performance requirement under special working conditions such as the high speed and heavy load is solved.

The invention discloses a serial-connected magnetofluid sealing structure. Multiple first pole shoes are arranged in space between the outer surface of a shaft and the inner wall of a shell; axial magnetizing permanent magnet rings are clamped between two adjacent first pole shoes; radial magnetizing permanent magnet rings sleeve the inner circular surfaces of all the first pole shoes; second poleshoes sleeve the inner circular surfaces of all the radial magnetizing permanent magnet rings; pole teeth are arranged on the inner circular surfaces of the second pole shoes; magnetofluid is injected between the pole teeth and the outer surface of the shaft; the polarities of magnetic poles of two adjacent radial magnetizing permanent magnet rings are opposite; each radial magnetizing permanentmagnet ring is positioned in a magnetic loop consisting of the axial magnetizing permanent magnet rings and the first pole shoes on two sides thereof; and the magnetic field directions of the radial magnetizing permanent magnet rings are the same with the magnetic loop directions thereof. The serial-connected magnetofluid sealing structure improves the magnetic field intensity, improves the sealing and pressure resisting capacity, enables magnetofluid seals in all gaps to exert effects through gradual increment of saturated magnetization strength of the magnetofluid in different gaps, and guarantees the sealing and pressure resisting performances.

The invention discloses a magnetic fluid sealing structure of a vapor compressing distillation device of a space station. The magnetic fluid sealing structure is arranged on a rotating shaft and an end face which need to be dynamically sealed, and comprises a shell, a sealing part, an end cover and two bearings, wherein the sealing part, the end cover and the two bearings are located in the shelland arranged the rotating shaft in a sleeving mode, the shell is sleeved on the rotating shaft in a sleeving mode, and the first end of the shell is connected with the end face; the sealing part comprises a pole shoe assembly, a left magnetism isolating ring, a right magnetism isolating ring and permanent magnets, and the left magnetism isolating ring and the right magnetism isolating ring are located on the two sides of the pole shoe assembly; the pole shoe assembly comprises at least two pole shoes, a plurality of pole teeth are arranged on the inner circle face of each pole shoe in a protruding mode, sealing gaps are formed between the pole teeth and the rotating shaft, the sealing gaps are filled with magnetic fluid, and the outer circle faces of the pole shoes are in sealing connection with the inner wall face of the shell; the permanent magnets are arranged between every two adjacent pole shoes, and the magnetic poles of the adjacent sides of every two adjacent permanent magnetsare the same; a step for being attached to the left magnetism isolating ring is arranged on the inner wall face of the shell in an inward protruding mode, and the end cover is installed at the secondend of the shell and used for pressing the sealing part; and the bearings are installed in installation grooves concavely formed in the inner circular faces of the pole shoes.

The invention relates to a multi-magnetic-resource sleeve type magnetofluid sealing device. The device comprises more than one magnetofluid sealing units, wherein each magnetofluid sealing unit comprises a housing, a left pole shoe ring, a right pole shoe ring, a sleeve, a first left permanent magnet ring, a second left permanent magnet ring, an intermediate permanent magnet ring, a first right permanent magnet ring and a second right permanent magnet ring. With the adoption of the device the problem of low pressure resistance of an existing single-magnetic-resource magnetofluid sealing devicecan be solved; in addition, the device is simple to process, and convenient to assemble, so that the sealing technology can be smoothly applied to the fields such as the field of high speed and heavyload.

The invention aims at providing a facing tooth stepped type magnetofluid sealing device. The facing tooth stepped type magnetofluid sealing device comprises a stepped shaft, a shell, a left pole shoering, a right pole shoe ring, a left permanent magnet ring, a middle permanent magnet ring and a right permanent magnet ring. The stepped shaft comprises a first-level shaft with the largest diameter,and two more or sets of secondary first-level shafts with the diameters gradually reduced. The secondary first-level shafts are sequentially arranged to the two sides along the side face of the first-level shaft and are symmetric about the middle radial section of the first-level shaft left and right. The magnetism gathering effect can be improved, thus, the magnetofluid sealing pressure endurance capacity is improved, meanwhile, magnetofluid sealing failure caused by the centrifugal force effect can be effectively avoided, losses of magnetofluid are reduced, the reliability of sealing is improved, and the service life of sealing is prolonged.

The invention discloses a variable-tooth and variable-gap type magnetic fluid reciprocating sealing structure for a hydraulic cylinder. Multiple annular pole shoes are arranged in the space between the outer surface of a piston rod and the inner wall of the shell in the axial direction at intervals, pole teeth are arranged on the inner circumferential face of each pole shoe, an axial magnetizing type permanent magnetic ring is clamped between every two adjacent pole shoes, the polarities of magnetic poles of every two adjacent axial magnetizing type permanent magnetic rings are opposite, gapsare formed between the pole teeth and the outer surface of the piston rod and filled with magnetic fluid, the sizes of the gaps between the pole teeth and the outer surface of the piston rod are sequentially decreased in the direction from the high-pressure side to the low-pressure side, and the sizes of the gaps between all the pole teeth arranged on the same pole shoe and the outer surface of the piston rod are equal. According to the variable-tooth and variable-gap type magnetic fluid reciprocating sealing structure for the hydraulic cylinder, the condition that the pressure endurance capability is gradually enhanced, and the magnetic fluid leakage resistance is gradually increased is formed through the structure change, and then the effect of further improving the sealing pressure resistance is achieved.

The invention discloses a magnetic source mixing type magnetofluid sealing structure. The magnetic source mixing type magnetofluid sealing structure comprises a shell, a shaft and a plurality of poleshoes, wherein the pole shoes are arranged in the axial direction at intervals; an axial magnetizing type permanent magnet ring is sandwiched between each two adjacent pole shoes; the polarities of magnetic poles of each two adjacent axial magnetizing type permanent magnet rings are opposite; a radial magnetizing type permanent magnet ring is inserted in the inner circle surface of each pole shoe;a gap exists between the inner circle surface of each radial magnetizing type permanent magnet ring and the outer surface of the shaft and is injected with magnetofluid; the polarities of magnetic poles of each two adjacent radial magnetizing type permanent magnet rings are opposite; each radial magnetizing type permanent magnet ring is positioned in a magnetic loop formed by the corresponding axial magnetizing type permanent magnet ring and the pole shoes on the two sides of the corresponding axial magnetizing type permanent magnet ring; and the magnetic field direction of each radial magnetizing type permanent magnet ring is the same as the direction of the magnetic loop in which the radial magnetizing type permanent magnet ring is located. The magnetic field intensity is increased, sealing and pressure-resistant pressure are enhanced, magnetofluid seals in all the gaps can play a role, and the sealing pressure resistance is ensured.