Snakelike labyrinth magnetic coupling two-stage sealing device

Abstract

The utility model discloses a snakelike labyrinth magnetic coupling two-stage sealing device which comprises a pump shaft product, a second-stage magnetic compensation sealing assembly is installed on the pump shaft product, the second-stage magnetic compensation sealing assembly comprises a movable ring and a static ring, and a first-stage labyrinth sealing assembly is arranged between the movable ring and the static ring. When the double-stage sealing device is used, the first-stage labyrinth sealing assembly and the second-stage magnetic compensation sealing assembly are utilized, so that the device combines a fluid dynamic pressure effect and a double-stage sealing effect of magnetic compensation, the advantages of low friction and zero leakage are considered, and the problem of high leakage defect at low speed of a traditional single labyrinth sealing structure is solved; and the contradiction that a traditional single magnetic sealing structure is insufficient in magnetic force at a high speed is avoided, the advantage of low leakage of the first-stage labyrinth sealing assembly at the high speed and the sealing effect of reliable contact of the second-stage magnetic compensation sealing assembly at the low speed are fully utilized, the sealing effect is guaranteed, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to non - contact type mechanical seal technical field, concretely is a kind of serpentine labyrinth magnetic coupling two-stage sealing device. BACKGROUND

[0002] Such as nuclear power plant main coolant pump, aviation fuel pump and these need to transport high speed, low viscosity medium equipment, the requirement of higher sealing leakproofness, sealing device can directly affect the safety of nuclear power plant main coolant pump, aviation fuel pump and other pump products.

[0003] The existing nuclear power plant main coolant pump, aviation fuel pump and the like often use labyrinth seal or magnetic seal for protection, however, traditional labyrinth seal relies on small gap to form flow resistance, but for low viscosity medium with viscosity less than 10 centipoise, sealing efficiency can be sharply reduced, and leakage is high, and full magnetic seal needs to maintain contact with continuous magnetic force, and at high speed, sealing surface separation problem caused by magnetic force attenuation can easily occur, therefore, a novel serpentine labyrinth magnetic coupling two-stage sealing device is provided, which can balance low friction and zero leakage. SUMMARY

[0004] The utility model discloses a serpentine labyrinth magnetic coupling two-stage sealing device to solve the problem in the background art.

[0005] To achieve the above object, the utility model provides the following technical scheme: a serpentine labyrinth magnetic coupling two-stage sealing device, comprising a pump shaft product, a two-stage magnetic force compensation sealing assembly is installed on the pump shaft product, the two-stage magnetic force compensation sealing assembly comprises a dynamic ring and a static ring, a primary labyrinth sealing assembly is arranged between the dynamic ring and the static ring, a reverse serpentine groove is arranged on the surface of the dynamic ring, an annular converging gap is arranged on the surface of the static ring, a gas-liquid mixed film is formed between the reverse serpentine groove and the annular converging gap, a Halbach permanent magnet array type magnet is embedded on the static ring, N poles and S poles are uniformly arranged on the Halbach permanent magnet array type magnet, and a soft magnetic alloy layer covers the end face of the dynamic ring.

[0006] The thickness of the soft magnetic alloy layer is 2mm, the saturation magnetic induction intensity of the soft magnetic alloy layer is 1.8T, the static ring is provided with a positioning embedding cavity matched with the Halbach permanent magnet array type magnet, the Halbach permanent magnet array type magnet is provided with a corrosion-resistant caulking layer, the material of the corrosion-resistant caulking layer is epoxy resin, so that the effect of resisting medium corrosion of the Halbach permanent magnet array type magnet is improved, and the N poles and the S poles are alternately arranged on the Halbach permanent magnet array type magnet.

[0007] Preferably, the N pole and S pole are made of neodymium iron boron magnets, and both the N pole and S pole are bonded to the Halbach permanent magnet array at a 45° tilt angle. The magnetization direction of both the N pole and S pole is parallel to the circumferential tangent.

[0008] Preferably, the depth of the reverse serpentine groove is 0.5 mm, the width of the reverse serpentine groove is 1.2 mm, and the helix angle of the reverse serpentine groove is 45°.

[0009] Preferably, the thickness of the gas-liquid mixing membrane is 3-5 μm.

[0010] Preferably, the inlet gap of the annular convergent gap is 0.15 mm, and the outlet gap of the annular convergent gap is 0.05 mm.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] This serpentine labyrinth magnetic coupling dual-stage sealing device optimizes its structure by incorporating a primary labyrinth sealing assembly and a secondary magnetic compensation sealing assembly. On the one hand, when the pump shaft is at a low speed (n < 2000 rpm), the reverse serpentine groove does not generate sufficient dynamic pressure, and the primary labyrinth sealing assembly does not provide adequate leakage protection for the medium. However, the magnetic attraction on the secondary magnetic compensation sealing assembly causes the soft magnetic alloy layer to contact the stationary ring, achieving a zero-leakage seal. On the other hand, when the pump shaft is in the high-speed stage, i.e., n≥2000rpm, the reverse serpentine groove and annular convergent gap on the secondary magnetic compensation sealing component work together to generate a hydrodynamic pressure effect, forming a gas-liquid mixture film with a thickness of 3-5μm for sealing protection. At this time, the gas-liquid mixture film pushes the sealing surface on the moving ring to a non-contact state, and the magnetic force only plays an auxiliary correction role, achieving a low friction effect. This solves the problem of magnetic force attenuation of Halbach permanent magnet array magnets that easily occurs at high speeds. In this way, the device combines the hydrodynamic pressure effect and the dual-stage sealing effect of magnetic compensation, taking into account the advantages of low friction and zero leakage. It solves the problem of high leakage at low speeds in the traditional single labyrinth seal structure, as well as the contradiction of insufficient magnetic force at high speeds in the traditional single magnetic seal structure. It makes full use of the low leakage advantage of the primary labyrinth seal component at high speeds and the reliable contact sealing effect of the secondary magnetic compensation sealing component at low speeds, ensuring both sealing effect and service life. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a partial cross-sectional structure of the present invention.

[0014] Figure 2 This is an enlarged front view cross-sectional schematic diagram of the primary labyrinth sealing assembly of this utility model.

[0015] Figure 3 It is the static ring side view sectional structure schematic view of the utility model.

[0016] Figure 4 It is the static ring side view structure schematic view of the utility model.

[0017] Figure 5 It is the enlarged structure schematic view of the utility model one stage labyrinth seal assembly in high speed state.

[0018] In the drawing: 1, static ring;2, soft magnetic alloy layer;3, dynamic ring;4, one stage labyrinth seal assembly;5, two stage magnetic force compensation seal assembly;6, reverse serpentine groove;7, annular convergent gap;8, positioning embedded cavity;9, N pole;10, S pole;11, Halbach permanent magnet array type magnet;12, pump shaft product;13, corrosion resistant caulking layer;14, gas-liquid mixed film. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0020] Please refer to Figures 1-5 The utility model provides an embodiment: a serpentine labyrinth magnetic force coupling two stage seal device, including pump shaft product 12, pump shaft product 12 is installed with two stage magnetic force compensation seal assembly 5, and two stage magnetic force compensation seal assembly 5 includes dynamic ring 3 and static ring 1. One stage labyrinth seal assembly 4 is arranged between dynamic ring 3 and static ring 1, and the surface of dynamic ring 3 is provided with reverse serpentine groove 6.

[0021] The surface of static ring 1 is provided with annular convergent gap 7, and gas-liquid mixed film 14 is formed between reverse serpentine groove 6 and annular convergent gap 7;When pump shaft product 12 is in high speed stage, that is, n is equal to or greater than 2000rpm, reverse serpentine groove 6 on two stage magnetic force compensation seal assembly 5 and annular convergent gap 7 cooperate to produce fluid dynamic pressure effect, and gas-liquid mixed film 14 with film thickness of 3-5 μm is formed to seal protection.

[0022] Halbach permanent magnet array type magnet 11 is embedded on static ring 1, N pole 9 and S pole 10 are uniformly arranged on Halbach permanent magnet array type magnet 11, and the end face of dynamic ring 3 is covered with soft magnetic alloy layer 2. The thickness of soft magnetic alloy layer 2 is 2mm, and the saturation magnetic induction intensity of soft magnetic alloy layer 2 is 1.8T. Positioning embedding cavity 8 matched with Halbach permanent magnet array type magnet 11 is arranged on static ring 1, and corrosion-resistant caulking layer 13 is arranged on Halbach permanent magnet array type magnet 11 as a whole, and the material of corrosion-resistant caulking layer 13 is epoxy resin, so that the effect of Halbach permanent magnet array type magnet 11 resisting medium corrosion is improved.

[0023] N pole 9 and S pole 10 are arranged alternately on Halbach permanent magnet array type magnet 11. The material of N pole 9 and S pole 10 is neodymium iron boron magnetic block, N pole 9 and S pole 10 are adhered to Halbach permanent magnet array type magnet 11 at an inclination angle of 45°, and the magnetization direction of N pole 9 and S pole 10 is parallel to the circumferential tangent; when the pump shaft product 12 is in the low speed stage, that is, n<2000rpm, the reverse serpentine groove 6 does not form enough dynamic pressure, and the first labyrinth seal assembly 4 is not enough for the leakage protection of the medium, but the magnetic force adsorption on the second magnetic force compensation sealing assembly 5 makes the soft magnetic alloy layer 2 contact with the static ring 1, which can realize zero leakage sealing.

[0024] The groove depth of reverse serpentine groove 6 is 0.5mm, the groove width of reverse serpentine groove 6 is 1.2mm, and the spiral angle of reverse serpentine groove 6 is 45°. The film thickness of gas-liquid mixed film 14 is 3-5μm. The inlet gap of annular converging gap 7 is 0.15mm, and the outlet gap of annular converging gap 7 is 0.05mm.

[0025] When the device needs to work: first, install the device on the appropriate pump shaft product 12, and when the pump shaft product 12 is in the low speed stage, that is, n<2000rpm, the reverse serpentine groove 6 does not form enough dynamic pressure, and the first labyrinth seal assembly 4 is not enough for the leakage protection of the medium, but the magnetic force adsorption on the second magnetic force compensation sealing assembly 5 makes the soft magnetic alloy layer 2 contact with the static ring 1, which can realize zero leakage sealing.

[0026] In addition, when the pump shaft product 12 is in a high-speed stage, that is, n≥2000 rpm, the reverse serpentine groove 6 and the annular convergent gap 7 on the secondary magnetic force compensation sealing assembly 5 cooperate to produce a hydrodynamic pressure effect, forming a gas-liquid mixed film 14 with a film thickness of 3-5 μm to seal and protect, at this time, the gas-liquid mixed film 14 pushes the sealing surface on the dynamic ring 3 to a non-contact state, the magnetic force only plays an auxiliary correction role, realizes a low-friction effect, solves the problem of magnetic force attenuation of the Halbach permanent magnet array type magnet 11 at high speed, and further makes the device combine the double-stage sealing effect of the hydrodynamic pressure effect and the magnetic force compensation, takes into account the advantages of low friction and zero leakage, solves the high leakage defect problem of the traditional single labyrinth sealing structure at low speed, and the contradiction that the traditional single magnetic force sealing structure is insufficient in magnetic force at high speed, fully utilizes the low leakage advantage of the primary labyrinth sealing assembly 4 at high speed and the reliable contact sealing effect of the secondary magnetic force compensation sealing assembly 5 at low speed, both ensures the sealing effect and prolongs the service life.

Claims

1. A serpentine labyrinth magnetic coupling two-stage seal device, characterized in that, The pump shaft product (12) is provided with a two-stage magnetic force compensation sealing assembly (5), the two-stage magnetic force compensation sealing assembly (5) comprises a dynamic ring (3) and a static ring (1), a first-stage labyrinth sealing assembly (4) is arranged between the dynamic ring (3) and the static ring (1), the surface of the dynamic ring (3) is provided with a reverse serpentine groove (6), the surface of the static ring (1) is provided with an annular converging gap (7), the reverse serpentine groove (6) and the annular converging gap (7) form a gas-liquid mixed film (14) therebetween, a Halbach permanent magnet array type magnet (11) is embedded on the static ring (1), the Halbach permanent magnet array type magnet (11) is uniformly provided with N poles (9) and S poles (10), and the end surface of the dynamic ring (3) is covered with a soft magnetic alloy layer (2); the thickness of the soft magnetic alloy layer (2) is 2 mm, and the saturation magnetic induction intensity of the soft magnetic alloy layer (2) is 1.8 T; the static ring (1) is provided with a positioning embedding cavity (8) matched with the Halbach permanent magnet array type magnet (11), and the Halbach permanent magnet array type magnet (11) is provided with a corrosion-resistant caulking layer (13) as a whole; and the N poles (9) and the S poles (10) are alternately arranged on the Halbach permanent magnet array type magnet (11).

2. A serpentine labyrinth magnetic coupling dual-stage sealing device according to claim 1, characterized in that: The N poles (9) and the S poles (10) are made of neodymium-iron-boron magnetic blocks, the N poles (9) and the S poles (10) are adhered to the Halbach permanent magnet array type magnet (11) at an inclination angle of 45°, and the magnetization directions of the N poles (9) and the S poles (10) are parallel to the circumferential tangent.

3. A serpentine labyrinth magnetic coupling dual stage seal device as claimed in claim 1, wherein: The groove depth of the reverse serpentine groove (6) is 0.5 mm, the groove width of the reverse serpentine groove (6) is 1.2 mm, and the spiral angle of the reverse serpentine groove (6) is 45°.

4. A serpentine labyrinth magnetic coupling dual seal device according to claim 1, characterized in that: The film thickness of the gas-liquid mixed film (14) is 3-5 μm.

5. A serpentine labyrinth magnetic coupling dual seal device according to claim 1, characterized in that: The inlet gap of the annular converging gap (7) is 0.15 mm, and the outlet gap of the annular converging gap (7) is 0.05 mm.

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