Composite magnetic field pressure-resistant enhanced magnetic liquid sealing device

Abstract

The invention discloses a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, and belongs to the technical field of mechanical sealing. Main components comprise a left end cover, a sealing seat, a left bearing, a left shaft sleeve, a left pole shoe, a permanent magnet, a right pole shoe, a right shaft sleeve, a right bearing, a right end cover, a rotating shaft, a left magnet array, a left magnetism isolating ring, a right magnetism isolating ring, a right magnet array, an O-shaped sealing ring and magnetic liquid. A composite magnetic field is formed by the permanent magnet (6) and the magnet array, under the dynamic sealing working condition, the magnetic field force generated by the magnet array is used for resisting the stretching effect of rotating shaft shearing on the magnetic linkage, the mechanical strength of the magnetic linkage is improved, the pressure resistance of the sealing structure is integrally enhanced, and the application range of the magnetic liquid sealing device is widened.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic liquid sealing, in particular to the principle and design method of a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, belonging to the technical field of mechanical sealing. Background Art

[0002] The magnetic liquid sealing device uses magnetic liquid as the sealing medium, and has the advantages of zero leakage, long life, high reliability, etc. It has been widely used in high-end mechanical equipment in various fields of industry. However, under rotating conditions, ordinary magnetic liquid sealing devices only have a single longitudinal section sealing magnetic circuit, and have not considered that the pressure resistance of the magnetic chain in the cross section is weakened due to the shearing effect of the rotating shaft, which limits the improvement of the overall pressure resistance of the sealing system. The magnetic liquid sealing device is prone to sealing failure under high linear speed, and the promotion and application of magnetic liquid dynamic seals in the engineering field have fallen into a certain bottleneck. Therefore, a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device with a sealing magnetic circuit in both the transverse and longitudinal sections is proposed. The main method to achieve the enhancement of the pressure resistance of the magnetic liquid sealing device is to improve the sealing structure. By comparing the magnetic liquid sealing devices described in patent publication numbers CN 113108064 A and CN113090760A, although they both enhance the magnetic field strength of the sealing gap by improving the sealing structure, and improve the sealing performance to a certain extent, they do not consider the weakening of the mechanical properties of the magnetic liquid magnetic chain by the rotating shearing effect of the rotating shaft in the cross section, and the improvement of its sealing performance has certain limitations. Summary of the invention

[0003] In view of the above problems, the present invention discloses a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, which aims to solve the following technical problems: the magnetic flux inside the magnetic liquid in the dynamic seal is stretched and deformed by the rotating shear of the rotating shaft, thereby causing the pressure resistance to be weakened and the sealing to fail.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The invention discloses a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, comprising a left end cover (1), bolts, nuts, a sealing seat (2), a left bearing (3), a rotating shaft (11), a right bearing (9), and a right end cover (10). The left end cover (1) and the right end cover (10) are connected and fixed to the sealing seat (2) by bolts and nuts, and the left bearing (3) and the right bearing (9) on the inner side of the end cover cooperate with the rotating shaft (11), which is an interference connection; the magnetic sealing body comprises a left shaft sleeve (4), a left pole shoe (5), a left magnet array (12), a left magnetic isolation ring (13), a permanent magnet (6), a right magnetic isolation ring (14), an O-ring (15), a right magnet array (16), a right pole shoe (7), and a right A shaft sleeve (8) and a magnetic liquid (17), the left shaft sleeve (4) cooperates with the sealing seat (2) to limit the left pole shoe (5), the right shaft sleeve (8) cooperates with the right bearing (9) to limit the right pole shoe (7), a groove is processed inside one side of the pole shoe for placing the magnet array and the magnetic isolation ring, the magnetic isolation ring can reduce the magnetic field interference between the permanent magnet (6) and the magnet array, the other side of the left pole shoe (5) and the right pole shoe (7) is processed with a boss to limit the position of the permanent magnet (6), the inner ring surface of the left pole shoe (5) and the right pole shoe (7) is processed with rectangular pole teeth, the magnetic liquid (17) is filled between the pole teeth and the rotating shaft (11), the magnetic liquid (17) produces a rheological effect after being excited by the magnetic field, and forms a sealing ring to achieve a sealing effect.

[0006] The left magnet array has the same structure as the right magnet array, and is made by combining and splicing 12 annular magnets with a central angle of 28° and 4 annular magnets with a central angle of 6°. Every three 28° annular magnets and one 6° annular magnet form a magnet unit. The magnetic vector direction of each magnet unit is radially inward - circumferential (counterclockwise) - radially outward - circumferential (clockwise) in sequence. The magnet array as a whole is made of four magnet units connected in series clockwise.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] 1. The present invention discloses a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, which, by designing a Halbach magnet array to set a cross-sectional sealed magnetic circuit, weakens the tensile deformation of the magnetic chain caused by shearing, improves the mechanical strength of the magnetic chain, and greatly enhances the pressure resistance of the sealing structure. Different from the traditional magnetic liquid sealing device, it solves the problem that the mechanical strength of the magnetic chain inside the magnetic liquid is reduced due to the shearing effect of the rotating shaft, the pressure resistance of the magnetic liquid sealing device is insufficient at high linear speed, and the sealing failure is prone to occur.

[0009] 2. The present invention discloses a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, which embeds the magnet array in the pole shoe, reduces the axial length of the sealing structure, solves the problem of insufficient axial installation space for the magnetic liquid sealing device, and expands the application scope of the magnetic liquid sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The figure is a schematic diagram of the overall structure of a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device.

[0011] Wherein: 1-left end cover, 2-sealing seat, 3-left bearing, 4-left shaft sleeve, 5-left pole shoe, 6-permanent magnet, 7-right pole shoe, 8-right shaft sleeve, 9-right bearing, 10-right end cover, 11-rotating shaft, 12-left magnet array, 13-left magnetic isolation ring, 14-right magnetic isolation ring, 15-sealing ring, 16-right magnet array, 17-magnetic liquid.

[0012] Figure 2 It is a diagram of the magnetic vector arrangement inside the magnet array and a schematic diagram of the magnetic field direction inside the array. DETAILED DESCRIPTION

[0013] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0014] Embodiment 1:

[0015] This embodiment is a composite magnetic field pressure-resistant enhanced magnetic liquid sealing device. Figure 1 It is mainly composed of two parts: sealing device structure and magnetic sealing body.

[0016] The sealing device structural parts include a left end cover (1), bolts, nuts, a sealing seat (2), a left bearing (3), a rotating shaft (11), a right bearing (9), and a right end cover (10). The left end cover (1) and the right end cover (10) are connected and fixed to the sealing seat (2) by bolts and nuts. The left bearing (3) and the right bearing (9) on the inner side of the end cover cooperate with the rotating shaft (11) to form an interference connection. The magnetic sealing body includes a left shaft sleeve (4), a left pole shoe (5), a left magnet array (12), a left magnetic isolation ring (13), a permanent magnet (6), a right magnetic isolation ring (14), an O-ring (15), a right magnet array (16), a right pole shoe (7), a right shaft sleeve (8), and a magnetic liquid (1 7), the left shaft sleeve (4) cooperates with the sealing seat (2) to limit the left pole shoe (5), the right shaft sleeve (8) cooperates with the right bearing (9) to limit the right pole shoe (7), a groove is processed inside one side of the pole shoe for placing the magnet array and the magnetic isolation ring, the magnetic isolation ring can reduce the magnetic field interference between the permanent magnet (6) and the magnet array, the other side of the left pole shoe (5) and the right pole shoe (7) are processed with a boss to limit the position of the permanent magnet (6), the inner ring surface of the left pole shoe (5) and the right pole shoe (7) are processed with rectangular pole teeth, and the space between the pole teeth and the rotating shaft (11) is filled with magnetic liquid (17), and the magnetic liquid (17) produces rheological effect after being excited by the magnetic field, forming a sealing ring to achieve a sealing effect.

[0017] A Halbach magnet array is designed, in which the magnetic vector directions of each magnet are as follows: Figure 2 As shown, the magnet array is composed of 4 identical modules arranged in a circle. The module consists of four annular magnets. The first three annular magnets in the clockwise direction correspond to a central angle of 28°, and the fourth annular magnet corresponds to a central angle of 6°. The module corresponds to a central angle of 90°, which can form a unidirectional magnetic field in the inner ring. Combining the four modules can realize a clockwise unidirectional magnetic field.

[0018] Since the mechanical strength of the magnetic chain inside the magnetic liquid is inversely proportional to its own length, under the condition of rotary sealing, the magnetic chain undergoes tensile deformation due to the shear force of the rotating shaft, and its mechanical properties decrease, resulting in reduced sealing ability. A cross-sectional sealed magnetic circuit is provided, which is composed of a pole shoe, a magnet array, a magnetic liquid (17), and a rotating shaft (11). The shear force is offset by the unidirectional magnetic field force formed by the magnet array to ensure the mechanical properties of the magnetic chain. At the same time, a longitudinal cross-sectional sealed magnetic circuit is formed in combination with a permanent magnet (6), so as to achieve the effect of enhancing the pressure resistance of the sealing structure under a composite magnetic field.

[0019] Finally, it should be noted that the specific description described above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail, with the aim of helping to further understand the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite magnetic field pressure-resistant enhanced magnetic liquid sealing device, comprising a left end cover (1), bolts, nuts, a sealing seat (2), a left bearing (3), a rotating shaft (11), a right bearing (9), and a right end cover (10), wherein the left end cover (1) and the right end cover (10) are connected and fixed to the sealing seat (2) by bolts and nuts, and the left bearing (3) and the right bearing (9) on the inner side of the end cover cooperate with the rotating shaft (11), which is an interference connection; characterized in that The magnetic sealing body comprises a left shaft sleeve (4), a left pole shoe (5), a left magnet array (12), a left magnetic isolation ring (13), a permanent magnet (6), a right magnetic isolation ring (14), an O-ring (15), a right magnet array (16), a right pole shoe (7), a right shaft sleeve (8) and a magnetic liquid (17). The left shaft sleeve (4) cooperates with the sealing seat (2) to limit the position of the left pole shoe (5). The right shaft sleeve (8) cooperates with the right bearing (9) to limit the position of the right pole shoe (7). The left pole shoe (5) and the right pole shoe (7) are processed with a groove for placing the magnet array and the magnetic isolation ring, and the magnetic isolation ring can reduce the magnetic field interference between the permanent magnet (6) and the magnet array. The other side of the left pole shoe (5) and the right pole shoe (7) are processed with a boss to limit the position of the permanent magnet (6). The inner ring surface of the left pole shoe (5) and the right pole shoe (7) is processed with a rectangular pole tooth. The space between the pole tooth and the rotating shaft (11) is filled with a magnetic liquid (17). The magnetic liquid (17) produces a rheological effect after being excited by the magnetic field, forming a sealing ring to achieve a sealing effect.

2. A composite magnetic field pressure-resistant enhanced magnetic liquid sealing device according to claim 1, characterized in that: The left magnet array has the same structure as the right magnet array, and is made by combining and splicing 12 annular magnets with a central angle of 28° and 4 annular magnets with a central angle of 6°. Every three 28° annular magnets and one 6° annular magnet form a magnet unit. The magnetic vector direction of each magnet unit is radially inward - circumferential (counterclockwise) - radially outward - circumferential (clockwise) in sequence. The magnet array as a whole is made of four magnet units connected in series clockwise.

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