阅读说明：本技术 以径向圆周排列圆柱磁铁为磁源的磁流体密封装置 (Magnetic fluid sealing device using cylindrical magnets arranged in radial and circumferential direction as magnetic source ) 是由 刘嘉伟 李德才 于 2021-09-07 设计创作，主要内容包括：本发明涉及一种以径向圆周排列圆柱磁铁为磁源的磁流体密封,包括外壳、隔磁环、导磁环和圆柱磁铁。本发明提出了一种新型磁流体密封,该结构解决了磁性液体密封经典结构存在的极齿因主轴轴向跳动而磕碰损坏的问题、大间隙下密封性能差的问题和极齿结构因尺寸微小而存在的安装困难和加工工艺差的问题；解决了大直径磁环充磁困难和磁环过薄或过厚难以加工的问题,使得该密封技术成功应用于磁性液体密封的多种场合之中。(The invention relates to a magnetic fluid seal taking cylindrical magnets arranged in a radial circumference manner as a magnetic source. The invention provides a novel magnetic fluid seal, which solves the problems of the classic magnetic fluid seal structure that the pole teeth are damaged due to collision caused by the axial runout of a main shaft, the sealing performance under a large gap is poor, and the pole tooth structure is difficult to install and poor in processing technology due to small size; the problems that a large-diameter magnetic ring is difficult to magnetize and the magnetic ring is too thin or too thick to process are solved, so that the sealing technology is successfully applied to various occasions of magnetic liquid sealing.)

1. A magnetic fluid seal taking cylindrical magnets arranged in a radial circumference way as a magnetic source comprises a shell (2), a magnetism isolating ring (3) and a permanent magnet ring (4); the method is characterized in that: the magnetic isolation ring (3) with the groove formed in the end face of one side is arranged on the inner wall of the shell (2) and sleeved on the shaft, the cylindrical magnet (4) is arranged at the groove, the magnetic conduction ring (5) is arranged at the groove formed in the inner circular face of the magnetic isolation ring (3), the magnetic isolation ring, the magnetic conduction ring and the magnetic isolation ring are sequentially sleeved on the shaft at intervals in a sleeved mode, a gap is reserved between the inner circular face of the magnetic isolation ring (3), the inner circular face of the magnetic conduction ring (5) and the outer circular face of the shaft section of the shaft (1), magnetic fluid (10) is filled in the gap for sealing, the magnetic conduction ring can uniformly distribute magnetic lines of force generated by the dispersed cylindrical magnet and then gather in the sealing gap, and the generated magnetic field gradient enables the magnetic fluid to be stressed on the ring face to form an O-shaped sealing ring, so that certain pressure resistance is achieved.

2. A magnetic fluid seal with radially circumferentially arranged cylindrical magnets as the magnetic source as claimed in claim 1, wherein: the size of a gap between the inner circular surfaces of the magnetism isolating ring (3) and the magnetism conducting ring (5) and the outer circular surface of the shaft section of the shaft (1) is 0.05-1 mm.

3. A magnetic fluid seal with radially circumferentially arranged cylindrical magnets as the magnetic source as claimed in claim 1, wherein: the cylindrical magnets (4) are radially arranged in the combination of the magnetism isolating ring (3) and the magnetic conduction ring (5), the installation positions are cuboid grooves, the groove depth is equal to the diameter of the cylindrical magnets, the ring thickness and the ring width of the magnetism isolating ring are at least three times of the groove depth, the placing directions of the cylindrical magnets in each magnetism isolating ring are the same, the placing directions of the cylindrical magnets in the magnetism isolating rings which are axially adjacent are opposite, the number of the combination of the magnetism isolating ring and the magnetic conduction ring is at least 1, the magnetic field distribution at the sealing gap corresponding to the magnets is uneven due to the radial arrangement structure of the cylindrical magnets, even the magnetic liquid cannot form a ring, the magnetic conduction ring at the sealing gap can enable the magnetic field distribution at the sealing gap to be even, and the magnetic liquid is evenly stressed to form an O-shaped sealing ring.

4. A magnetic fluid seal with radially circumferentially arranged cylindrical magnets as the magnetic source as claimed in claim 1, wherein: annular grooves are formed in the outer circular surface of the magnetism isolating ring (3) and the magnet mounting surface, and sealing rings (7) are arranged in the annular grooves.

5. A magnetic fluid seal with radially circumferentially arranged cylindrical magnets as the magnetic source as claimed in claim 1, wherein: the shell (2), the magnetism isolating ring (3) and the end cover (8) are made of 304 stainless steel non-magnetic conductive materials, and the shaft (1) and the magnetism conducting ring (5) are made of 2Cr13 magnetic conductive materials.

6. A magnetic fluid seal with radially circumferentially arranged cylindrical magnets as the magnetic source as claimed in claim 1, wherein: the magnetic-field-isolating shaft is characterized by further comprising a left bearing (8) and a right bearing (6), wherein the left bearing (8) and the right bearing (6) are respectively sleeved on the shaft (1), and the left bearing (8) is arranged on the left sides of the magnetic-field-isolating ring (3) and the magnetic-conducting ring (5) and is in contact with the magnetic-field-isolating ring; the right bearing (6) is arranged on the right sides of the magnetism isolating ring (3) and the magnetic conduction ring (5) and is in contact with the magnetism isolating ring.

Technical Field

The invention belongs to the field of mechanical engineering sealing, and particularly relates to a magnetic fluid seal using an axial magnetizing permanent magnet ring

And (5) sealing the device.

Background

The magnetic fluid seal is characterized in that magnetic field force generated by the permanent magnet in the seal gap is utilized to firmly fix the magnetic fluid in the seal gap, so that the magnetic fluid can resist pressure difference on two sides, and the sealing effect is achieved.

Under the working condition of high-speed rotation, the classic magnetic fluid seal is easy to generate the jumping of a main shaft due to the tolerance of the inner diameter of a bearing, a common pole tooth structure is easy to collide and damage, so that the sealing device is poor in reliability and high in rejection rate, most of the solutions for solving the problem are the improvement of thickening the pole teeth and increasing the sealing gap on the basis of the classic tooth shape, the sealing pressure resistance of magnetic liquid is obviously reduced along with the increase of the sealing gap, in addition, the problems of difficult installation, poor processing technology and the like exist due to the small size of the pole tooth structure, although the radial magnetizing permanent magnet ring can solve the problems, the large-diameter magnetic ring has the problems of difficult magnetizing and difficult processing.

Disclosure of Invention

The invention aims to provide a magnetic fluid sealing device taking cylindrical magnets arranged in a radial circumference manner as a magnetic source, which solves the problems of pole teeth of a magnetic fluid sealing classical structure that the pole teeth are collided and damaged due to axial jumping of a main shaft, the sealing performance is poor under a large gap, the processing technology is poor due to small size of the pole tooth structure, and the large-diameter magnetic ring is difficult to magnetize or is difficult to process due to over-thin or over-thick magnetic ring, so that the sealing technology is successfully applied to occasions with large axial jumping.

The patent carries out finite element simulation aiming at a large number of magnetic liquid sealing examples, analyzes the simulation result and provides a reasonable design scheme of the structure.

The technical scheme of the invention is as follows: the magnetic fluid seal taking cylindrical magnets arranged in a radial circumference as a magnetic source is characterized in that a magnetism isolating ring with a groove formed in one side end face is arranged on the inner wall of a shell and sleeved on a shaft, the cylindrical magnets are arranged in the groove, a magnetic conduction ring is arranged in the groove formed in the inner circular face of the magnetism isolating ring, the sleeving mode is that the magnetism isolating ring, the magnetic conduction ring and the magnetism isolating ring are sequentially sleeved on the shaft at intervals, gaps are reserved among the inner circular faces of the magnetism isolating ring, the magnetic conduction ring and the outer circular face of a shaft section, magnetic fluid is filled in the gaps for sealing, the magnetic conduction ring can evenly distribute magnetic lines of force generated by the dispersed cylindrical magnets and then gather the magnetic lines of force in the sealing gaps, and magnetic field gradients generated on the circular face enable the magnetic fluid to be stressed to form an O-shaped sealing ring as shown in fig. 3, and the magnetic fluid has certain pressure resistance.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the size of a gap between the inner circular surfaces of the magnetism isolating ring and the magnetism conducting ring and the outer circular surface of the shaft section is 0.05-1 mm.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the magnetic force line direction of the cylindrical magnets is radially arranged in the magnetic isolation ring and magnetic conduction ring combination, the installation position is a cuboid-shaped groove, the groove depth is equal to the diameter of the cylindrical magnets, the ring thickness and the ring width of the magnetic isolation ring are at least three times of the groove depth, the placing direction of the cylindrical magnets in each magnetic isolation ring is the same, the placing directions of the cylindrical magnets in the axially adjacent magnetic isolation rings are opposite, and the number of the magnetic isolation ring and magnetic conduction ring combination is at least 1. Because the radial arrangement structure of the cylindrical magnets causes uneven magnetic field distribution at the sealing gap corresponding to the magnets, even the magnetic liquid cannot form a ring, the magnetic conduction ring at the position can make the magnetic field distribution at the sealing gap uniform, and the magnetic liquid is uniformly stressed to form an O-shaped sealing ring.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: annular grooves are arranged on the outer circular surface of the magnetism isolating ring and the magnet mounting surface, and sealing rings are arranged in the annular grooves.

The shell, the magnetism isolating ring and the end cover of the magnetofluid seal which take the cylindrical magnets arranged on the radial circumference as the magnetic source are made of 304 stainless steel non-magnetic conductive materials, and the shaft and the magnetism conducting ring are made of 2Cr13 magnetic conductive materials.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the magnetic-field-isolating shaft is characterized by also comprising a left bearing and a right bearing, wherein the left bearing and the right bearing are respectively sleeved on the shaft, and the left bearing is arranged on the left sides of the magnetic-field-isolating ring and the magnetic-conducting ring and is in contact with the magnetic-field-isolating ring; the right bearing is arranged on the right sides of the magnetism isolating ring and the magnetic conduction ring and is in contact with the magnetism isolating ring.

Drawings

FIG. 1 is a schematic diagram of a magnetic fluid seal for an axially magnetized permanent magnet ring according to an embodiment of the present invention; the serial number designations and corresponding designations in the drawings are as follows: 1-shaft, 2-shell, 3-magnetism isolating ring, 4-cylindrical small magnet, 5-magnetic conducting ring, 6-right bearing, 7-sealing ring, 8-left bearing, 9-end cover and 10-magnetofluid; FIG. 2 is a top view of the cylindrical magnet isolating ring; FIG. 3 is a graph of the magnetic field intensity distribution of the seal gap with a flux ring; FIG. 4 is a magnetic field intensity distribution diagram of a magnetic liquid at a ring-forming position when a magnetic conductive ring is arranged; fig. 5 is a magnetic field intensity distribution diagram of the magnetic liquid at the ring-forming position without the magnetic conductive ring.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, the technical solution of the present invention is as follows: the magnetic fluid seal taking cylindrical magnets arranged in a radial circumference manner as a magnetic source is characterized in that a magnetism isolating ring with a groove formed in one side end face is arranged on the inner wall of a shell and sleeved on a shaft, the cylindrical magnets are arranged in the groove, a magnetic conduction ring is arranged in the groove formed in the inner circular face of the magnetism isolating ring, the magnetic conduction ring and the magnetic isolation ring are sequentially sleeved on the shaft in a spaced mode, a gap is reserved between the inner circular face of the magnetism isolating ring and the magnetic conduction ring and the outer circular face of a shaft section, magnetic fluid is filled in the gap for sealing, the magnetic conduction ring can enable magnetic lines generated by the dispersed cylindrical magnets to be uniformly distributed and then gathered in the sealing gap, and as shown in figure 2, the generated magnetic field gradient enables the magnetic fluid to be stressed on a ring face to form an O-shaped sealing ring and has certain pressure resistance.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the size of a gap between the inner circular surfaces of the magnetism isolating ring and the magnetism conducting ring and the outer circular surface of the shaft section is 0.05-1 mm.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the magnetizing direction of the cylindrical magnets is radially arranged in the magnetic isolation ring and magnetic conduction ring combination, the installation position is a cuboid-shaped groove, the groove depth is equal to the diameter of the cylindrical magnets, the ring thickness and the ring width of the magnetic isolation ring are at least three times of the groove depth, the placing direction of the cylindrical magnets in each magnetic isolation ring is the same, the placing directions of the cylindrical magnets in the axially adjacent magnetic isolation rings are opposite, and the number of the magnetic isolation ring and magnetic conduction ring combination is at least 1. As shown in fig. 3 and 4, the magnetic field distribution at the sealing gap corresponding to the magnet is not uniform due to the radial arrangement structure of the cylindrical magnets, even the magnetic liquid cannot form a ring, and the magnetic ring at this position can make the magnetic field distribution at the sealing gap uniform, so that the magnetic liquid is uniformly stressed to form an "O" shaped sealing ring.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: annular grooves are arranged on the outer circular surface of the magnetism isolating ring and the magnet mounting surface, and sealing rings are arranged in the annular grooves.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the shell, the magnetism isolating ring and the end cover are made of 304 stainless steel non-magnetic conductive materials, and the shaft and the magnetism conducting ring are made of 2Cr13 magnetic conductive materials.

The magnetic fluid seal taking the cylindrical magnets arranged in the radial circumference as the magnetic source is characterized in that: the magnetic-field-isolating shaft is characterized by also comprising a left bearing and a right bearing, wherein the left bearing and the right bearing are respectively sleeved on the shaft, and the left bearing is arranged on the left sides of the magnetic-field-isolating ring and the magnetic-conducting ring and is in contact with the magnetic-field-isolating ring; the right bearing is arranged on the right sides of the magnetism isolating ring and the magnetic conduction ring and is in contact with the magnetism isolating ring. .