Magnetic fluid combined sealing device

Abstract

The utility model discloses a magnetofluid combined sealing device which is installed on a pump body and comprises a sealing shell arranged on a pump shaft in a sleeved mode and a combined magnetofluid sealing assembly fixed in the sealing shell, the sealing shell is connected with a pump cover, a shaft sleeve rotating along with the pump shaft is fixed on the pump shaft, and the combined magnetofluid sealing assembly is connected with the pump cover. The combined type magnetic fluid sealing assembly is located between the sealing shell and the shaft sleeve, the combined type magnetic fluid sealing assembly and the sealing shell are relatively fixed, the combined type magnetic fluid sealing assembly comprises a magnetic fluid sealing assembly body and a rear sealing assembly body, and a grease storage ring used for being filled with sealing grease is arranged between the magnetic fluid sealing assembly body and the rear sealing assembly body. According to the magnetofluid combined sealing device, the combination of clearance sealing and spiral sealing with magnetofluid sealing is replaced by the oil seal or the water-retaining sealing assembly, normal operation of a pump is ensured, the overall structure is simple and economical, the same water-proof sealing effect can be achieved, and therefore the production cost and the installation cost are reduced, and the production efficiency is improved. And the method has more advantages in manufacturability and cost performance.

Description

TECHNICAL FIELD

[0001] The utility model relates to a magnetic fluid combined sealing device and relates to mechanical sealing technical field. BACKGROUND

[0002] The service life of magnetic fluid sealing mainly depends on the durability of the sealing medium - magnetic liquid (or magnetic grease). As long as the magnetic liquid does not volatilize, deteriorate or lose, its service life can fully meet the needs of production practice. When magnetic fluid sealing is applied to a water pump, the contact between the magnetic liquid and the medium (i.e. water) is inevitable. In the absence of magnetic liquid (or magnetic grease) specially used for waterproofing, in order to realize the practical application of magnetic fluid sealing on a water pump, measures must be taken in the structure to isolate the medium water from the magnetic poles. The pump installed vertically is relatively easy to handle due to the action of gravity; while the horizontal installation of the horizontal pump is more difficult. Patent No. ZL 2023 2 1024432.7 proposes an innovative solution, i.e. the combination of gap sealing or spiral sealing, two kinds of non-contact sealing, with magnetic fluid sealing, to isolate the cooling water of the pump from the magnetic poles of the magnetic fluid sealing, thereby realizing complete non-contact sealing. Ideally, this method seems perfect, but reality is full of challenges. Because both methods require manufacturers to increase design and manufacturing costs, thereby reducing the market competitiveness of the magnetic fluid combined sealing. In addition, the installation of the spiral seal has directionality, which increases the difficulty of assembly. Especially on double suction pumps, if the two seals are installed incorrectly, not only can they not play a water isolation role, but they can also accelerate the failure of the magnetic liquid. At the same time, due to the fact that both gap sealing and spiral sealing have a certain axial size, they are limited by the structure of the pump, and these two structures cannot be realized on many pump types. Therefore, other simple and economical structural forms must be used to achieve the same water isolation effect, so that the magnetic fluid combined sealing can be practically applied in the pump industry. CONTENT OF THE UTILITY MODEL

[0003] The technical problem to be solved by the utility model is to provide a magnetic fluid combined sealing device that is easy to purchase, low in cost, convenient to install and effectively improves the sealing and water isolation effect.

[0004] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0005] A kind of magnetic fluid combination sealing device, it is installed on pump body, including the sealing shell of being set on pump shaft, fixed in the combination magnetic fluid sealing assembly of sealing shell, the sealing shell connects pump cover, the shaft sleeve of being fixed with the rotation of pump shaft is on the pump shaft, the combination magnetic fluid sealing assembly is located between sealing shell and shaft sleeve and is relatively fixed between sealing shell, the combination magnetic fluid sealing assembly includes magnetic fluid sealing assembly and rear sealing assembly, the storage ring for filling sealing grease is arranged between magnetic fluid sealing assembly and rear sealing assembly.

[0006] As preferred, the rear sealing assembly is provided as a water seal ring assembly.

[0007] As preferred, the sealing shell includes water seal ring shell and magnetic fluid sealing shell, the water seal ring shell and magnetic fluid sealing shell are fixed by bolt connection, the water seal ring assembly and magnetic fluid sealing assembly are fixed in the cavity between water seal ring shell, magnetic fluid sealing shell and shaft sleeve, the water seal ring assembly includes first oil seal, first water seal ring, second oil seal, second water seal ring, third water seal ring, third oil seal and positioning ring arranged in sequence from front to back, the hot water drainage cavity is formed between the first water seal ring and the shaft sleeve, the cooling cavity is formed between the second water seal ring and the shaft sleeve, the cooling water inlet cavity is formed between the third water seal ring and the shaft sleeve, the mixing water cavity is formed between the positioning ring, the third oil seal, the shaft sleeve and the sealing shell, the cooling water inlet cavity, the hot water drainage cavity, the cooling cavity and the mixing water cavity are communicated with each other through the gap between the water seal ring assembly and the shaft sleeve, the sealing shell is provided with cooling water inlet and hot water outlet, and the cooling water channel and the hot water channel are provided in the sealing shell, the cooling water channel is communicated with the cooling water inlet and the cooling water inlet cavity, and the hot water channel is communicated with the hot water outlet and the hot water drainage cavity.

[0008] As preferred, the water seal ring assembly includes four groups of ring piece assembly arranged in sequence and set on the shaft sleeve, the ring piece assembly is provided as a sealing rubber plate with a support ring, a water seal ring is provided between the middle two groups of ring pieces, and the water seal ring is connected to the water inlet through the opening at the upper end.

[0009] As preferred, the magnetic fluid sealing assembly includes two oppositely arranged magnetic poles, a positioning magnetic shield plate, two magnetic poles are set on the shaft sleeve and have a gap between the shaft sleeve, the gap is filled with magnetic liquid or magnetic grease filler, the outer side of the magnetic fluid assembly is provided with a sealing gland assembly bolted to the magnetic fluid sealing shell, and the positioning magnetic shield plate is arranged between the sealing gland assembly and the magnetic pole.

[0010] As preferred, the magnetic fluid sealing assembly and the shaft sleeve are provided with a magnetic guide shaft sleeve assembly.

[0011] As preferred, two openings are respectively opened on the upper and lower sides of the cavity in the fat storage ring, the upper opening is connected with the through sealing shell and used as the oil inlet hole for supplementing oil, and the lower opening is connected with the through sealing shell and used as the water outlet hole with a water outlet screw plug for draining water.

[0012] As preferred, the rear sealing assembly is arranged as a water blocking assembly, the water blocking assembly comprises a rubber water blocking plate sleeved on the shaft sleeve and a polytetrafluoroethylene double-lip stainless steel oil seal, the rubber water blocking plate is located between the fat storage ring and the polytetrafluoroethylene double-lip stainless steel oil seal, the front side of the magnetic fluid sealing assembly is provided with a bearing fixed in the sealing shell and sleeved on the shaft sleeve, the front side of the bearing is provided with a threaded pressing assembly pressed on the front side of the bearing, located inside the pump cover and sleeved on the shaft sleeve, and the threaded pressing assembly is bolted and fixed between the pump cover.

[0013] Compared with the prior art, the magnetic fluid combined sealing device replaces the combination of the gap sealing, the spiral sealing and the magnetic fluid sealing by the oil seal or the water blocking sealing assembly, ensures the normal operation of the pump, has simple overall structure, is economical and can achieve the same water sealing effect, thereby reducing the production cost and the installation cost, has more advantages in the process and the cost performance, and is suitable for popularization and application in the pump industry. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0015] Figure 1 is a side partial sectional view of the embodiment one of the present application;

[0016] Figure 2 is a side partial sectional view of the embodiment one of the present application; Figure 1

[0017] Figure 3 is a side partial sectional view of the embodiment one of the present application; Figure 1

[0018] Figure 4 is a side partial sectional view of the embodiment two of the present application;

[0019] Figure 5 is a side partial sectional view of the embodiment three of the present application;

[0020] ​​Wherein: 1, pump shaft; 101, shaft sleeve; 2, sealing shell; 201, water seal ring shell; 202, magnetic fluid sealing shell; 3, pump cover; 4, magnetic fluid sealing assembly; 5, grease storage ring; 6, bolt; 7, first oil seal; 8, first water seal ring; 9, second oil seal; 10, second water seal ring; 11, third water seal ring; 12, third oil seal; 13, positioning ring; 14, hot water discharge cavity; 15, cooling cavity; 16, cooling water inlet cavity; 17, mixed water cavity; 18, cooling water inlet; 19, hot water discharge outlet; 20, oil inlet hole; 21, drain hole; 22, magnetic pole; 23, positioning magnetic separation plate; 25, sealing rubber plate; 26, water seal ring; 27, water inlet; 28, compression bearing; 29, rubber water baffle; 30, polytetrafluoroethylene double-lip stainless steel oil seal; 31, bearing; 32, threaded compression assembly; 33, magnetic pole assembly; 34, bearing pad ring; 35, sealing gland assembly. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model:

[0022] As Figures 1 to 5 shown in a kind of magnetic fluid combined sealing device, it is installed on pump body, including the sealing shell 2 of sleeveing on pump shaft 1, fixed in combined magnetic fluid sealing assembly of sealing shell 2, the sealing shell 2 is connected pump cover 3, the pump shaft 1 is fixed with the shaft sleeve 101 that rotates with pump shaft 1 in turn and forms dynamic ring, the combined magnetic fluid sealing assembly is located between sealing shell 2 and shaft sleeve 101 and is relatively fixed between sealing shell 2 and forms fixed ring, the combined magnetic fluid sealing assembly includes magnetic fluid sealing assembly 4 and rear sealing assembly, magnetic fluid sealing assembly 4 and rear sealing assembly between them are equipped with the grease storage ring 5 for filling sealing grease.

[0023] Embodiment one, in the embodiment, as Figures 1 to 3As shown, the rear sealing assembly is provided as a water seal ring assembly, the sealing shell 2 comprises a water seal ring shell 201 and a magnetic fluid sealing shell 202, the water seal ring shell 201 and the magnetic fluid sealing shell 202 are fixedly connected by bolts 6, the magnetic fluid sealing ring shell is fixedly connected with the pump cover 3, the water seal ring assembly and the magnetic fluid sealing assembly 4 are fixed in the cavity between the water seal ring shell 201, the magnetic fluid sealing shell 202 and the shaft sleeve 101, the water seal ring assembly comprises, from front to back, a first oil seal 7, a first water seal ring 8, a second oil seal 9, a second water seal ring 10, a third water seal ring 11, a third oil seal 12 and a positioning ring 13, the first water seal ring 8 and the shaft sleeve 101 form a hot water drainage cavity 14, the second water seal ring 10 and the shaft sleeve 101 form a cooling cavity 15, the third water seal ring 11 and the shaft sleeve 101 form a cooling water inlet cavity 16, the positioning ring 13, the third oil seal 12, the shaft sleeve 101 and the sealing shell 2 form a mixed water cavity 17, the cooling water inlet cavity 16, the hot water drainage cavity 14, the cooling cavity 15 and the mixed water cavity 17 are connected with each other through the gap between the water seal ring assembly and the shaft sleeve 101, the sealing shell 2 is provided with a cooling water inlet 18 and a hot water outlet 19, and the sealing shell 2 is provided with a cooling water channel connecting the cooling water inlet and the cooling water inlet cavity 16, and a hot water channel connecting the hot water outlet 19 and the hot water drainage cavity 14, in addition, the cavity in the grease storage ring 5 is provided with two upper and lower openings, the upper opening is connected with an oil inlet hole 20 penetrating through the sealing shell 2 and used for supplementing grease, so as to facilitate the sealing ring filled with water-resistant grease, the lower opening is connected with a drainage hole 21 penetrating through the sealing shell 2 and used for draining water, and the drainage hole 21 is provided with a water drainage screw plug, so as to facilitate the drainage of seepage water and check whether the first oil seal 7 is invalid.

[0024] Thus, in the present embodiment, since the supply pressure of the cooling water is usually 0.15-0.2 MPa, after the cooling water enters the sealed casing 2 from the inlet, it firstly flows from the cooling water inlet cavity 16 to the cooling cavity 15 to cool the shaft sleeve 101, and then flows from the cooling cavity 15 to the hot water outlet cavity and is discharged from the upper hot water outlet 19 of the sealed casing 2 through the holes in the annular groove of the first water seal ring 8 to complete the cooling of the seal. When the pressure in the pump (left side of the seal) is less than or equal to the inlet pressure (≤0.15-0.2 MPa), the water in the cooling water inlet cavity 16 will flow through the third oil seal 12 into the mixed water cavity 17 to form mixed water with the medium. When the medium contains a large amount of particulate impurities, the supply pressure of the cooling water must be greater than the pressure in the pump by 0.02-0.05 MPa to reduce the wear of the third oil seal 12 by the medium. The first oil seal 7 and the third oil seal 12 should be selected according to the operating parameters such as the nature of the medium, pressure, and temperature, and generally ordinary skeleton oil seals or stainless steel oil seals are selected. In the present embodiment, since the medium has temperature, corrosiveness, and particulate matter, a polytetrafluoroethylene double-lip stainless steel oil seal 30 with good pressure resistance and wear resistance is selected to ensure that the water in the hot water outlet cavity 14 does not leak into the cavity of the grease storage ring 5, thereby effectively preventing the magnetic pole from contacting water.

[0025] In addition, in the present embodiment, the magnetic fluid seal assembly 4 includes two oppositely arranged magnetic poles 22 and a positioning magnetic shield plate 23, the two magnetic pole sleeves are arranged on the shaft sleeve 101 and have a gap between the shaft sleeve 101, the gap is filled with magnetic liquid or magnetic grease filler, the outer side of the magnetic fluid assembly is provided with a sealing gland assembly 35 which is bolted to the magnetic fluid sealing casing 202, and the positioning magnetic shield plate 23 is arranged between the sealing gland assembly 35 and the magnetic pole. In actual application, the gap of the magnetic fluid seal can be determined according to the cooling water pressure and 1.3-2 times the maximum radial swing of the shaft neck of the pump shaft 1, and the magnetic sealing medium is preferably magnetic grease or a combination of magnetic grease + magnetic liquid with good water resistance.

[0026] In the present embodiment, in order to ensure the normal operation of the magnetic fluid seal and achieve the expected sealing effect, a magnetic conducting sleeve assembly is arranged between the magnetic fluid seal assembly 4 and the shaft sleeve 101.

[0027] In Example Two, in the present embodiment, as shown in Figure 4As shown, the rear sealing assembly is provided as a water seal ring assembly, which comprises four groups of ring piece assemblies arranged in sequence on the shaft sleeve 101, and the groups of ring piece assemblies are provided as sealing rubber plates 25 with rings, and a water seal ring 26 that can be filled with water is arranged between the middle two groups of ring piece assemblies, and the upper end of the water seal ring 26 is connected to the water inlet 27 that penetrates the sealing shell 2, and similarly, the cavity in the grease storage ring 5 is provided with two holes on the upper and lower sides, the upper hole is connected to the oil inlet hole 20 that penetrates the sealing shell 2 and is used to supplement the grease, thereby facilitating the sealing ring filled with water-resistant grease, and the lower hole is connected to the water outlet hole 21 that penetrates the sealing shell 2 and is used to drain water and is provided with a water drain screw plug, thereby facilitating the drainage of seepage water; in addition, the magnetic fluid sealing assembly 4 comprises a magnetic pole and a compression bearing 28, the magnetic pole is sleeved on the shaft sleeve 101, and the shaft sleeve 101 between the two is provided with a pole tooth, and the compression bearing 28 is sleeved on the shaft sleeve 101 and located outside the magnetic pole and compresses the magnetic pole through a partition plate, thereby ensuring the stability of the magnetic pole sealing gap, and thus, in actual application, when the water supply pressure is 0.2-0.15 Mpa, the cooling water will only flow to the outside of the sealing shell 2 through the left two groups of sealing rubber plates 25, and will not flow to the grease storage ring 5 from the right two groups of rubber plates of the water seal ring 26. Only when the sealing rubber plates 25 on the right side of the water seal ring 26 are worn or the water inlet pressure exceeds 0.2 Mpa, water will seep into the grease storage ring 5, which will damage the sealing grease in the grease storage ring 5. As long as the water outlet hole at the lower part of the grease storage ring 5 is not blocked, due to the action of gravity, a small amount of water that seeps into this place will only flow out from the lower water outlet hole of the sealing shell 2, and will not affect the magnetic grease on the magnetic pole of the magnetic fluid sealing. Therefore, such a structure can maximize the service life of the entire magnetic fluid combined sealing.

[0028] In this embodiment, as Figure 5As shown, the rear sealing assembly is arranged as a water blocking assembly, which comprises a rubber water blocking plate 29 sleeved on the shaft sleeve 101, and a polytetrafluoroethylene double-lip stainless steel oil seal 30, the rubber water blocking plate 29 is located between the grease storage ring 5 and the polytetrafluoroethylene double-lip stainless steel oil seal 30, the front side of the magnetic fluid sealing assembly 4 is provided with a bearing 31 fixed in the sealing shell 2 and sleeved on the shaft sleeve 101, the front side of the bearing 31 is provided with a threaded pressing assembly 32 pressed on the front side of the bearing 31 and located inside the pump cover 3 and sleeved on the shaft sleeve 101, and the threaded pressing assembly 32 is fixedly connected with the pump cover 3 by bolts. Similarly, the magnetic fluid assembly comprises a magnetic pole assembly 33, and the bearing pad ring 34 is arranged between the magnetic pole assembly 33 and the bearing 31, so that in actual application, the water blocking assembly and the magnetic fluid sealing assembly 4 are both installed in the sealing shell 2 and are pressed by the threaded pressing assembly 32, thereby forming a fixed sealing stationary ring. The outer diameter of the threaded pressing assembly 32 is matched with the pump cover 3, thereby positioning the sealing shell 2. The threaded pressing assembly 32 is provided with three screw holes, and the sealing assembly is fixedly connected with the pump cover 3 by three internal hexagonal screws. In addition, the movable ring of the sealing assembly is the shaft sleeve assembly, which is composed of the shaft sleeve 101 and the bearing 31. The shaft sleeve 101 on which the magnetic pole assembly 33 is located is processed with pole teeth required by the magnetic fluid sealing, and the bearing 31 is in interference fit with the shaft sleeve 101. When the threaded pressing assembly 32 presses the outer shell of the bearing 31, the bearing pad ring 34, the magnetic pole assembly 33, the grease storage ring 5, the rubber water blocking plate 29, the polytetrafluoroethylene double-lip stainless steel oil seal 30 and the sealing shell 2, the shaft sleeve 101 forms a rotatable whole with the sealing shell 2. After being installed on the pump cover 3, the sealing assembly can be assembled with the pump body and the pump shaft 1 very conveniently. As long as the pump cover 3 is in place, the fastening screw on the shaft sleeve 101 is tightened to fix the sealing shaft sleeve with the pump shaft 1, and the assembly of the sealing is completed. This is much more convenient than the assembly of the mechanical sealing, in which the pin on the movable ring is aligned with the pin hole on the impeller nut and the mechanical sealing positioning sleeve.

[0029] It should be emphasized that the above are only the preferred embodiments of the present application, and do not limit the present application in any form, and any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments still belong to the scope of the technical scheme of the present application.

Claims

1. A magneto fluid combination sealing device, characterized by, The application relates to a combined magnetic fluid sealing assembly installed on a pump body, which comprises a sealing shell sleeved on a pump shaft, a combined magnetic fluid sealing assembly fixed in the sealing shell, a pump cover connected with the sealing shell, a shaft sleeve fixed on the pump shaft and rotating with the pump shaft, and the combined magnetic fluid sealing assembly is located between the sealing shell and the shaft sleeve and is oppositely fixed with the sealing shell.

2. A magneto-fluidic combined seal device according to claim 1, wherein: The rear sealing assembly is a water seal ring assembly.

3. A magneto-fluidic assembly seal according to claim 2, wherein: The sealing shell comprises a water seal ring shell and a magnetic fluid sealing shell which are fixed by bolts, the water seal ring assembly and the magnetic fluid sealing assembly are oppositely fixed in the cavity between the water seal ring shell, the magnetic fluid sealing shell and the shaft sleeve, the water seal ring assembly comprises, from front to back, a first oil seal, a first water seal ring, a second oil seal, a second water seal ring, a third water seal ring, a third oil seal and a positioning ring, a hot water discharge cavity is formed between the first water seal ring and the shaft sleeve, a cooling cavity is formed between the second water seal ring and the shaft sleeve, a cooling water inlet cavity is formed between the third water seal ring and the shaft sleeve, a mixed water cavity is formed between the positioning ring, the third oil seal, the shaft sleeve and the sealing shell, the cooling water inlet cavity, the hot water discharge cavity, the cooling cavity and the mixed water cavity are communicated with each other through the gap between the water seal ring assembly and the shaft sleeve, the sealing shell is provided with a cooling water inlet and a hot water outlet, and the sealing shell is provided with a cooling water channel and a hot water channel which penetrate through the shell and are respectively connected with the cooling water inlet and the cooling water inlet cavity and the hot water outlet and the hot water discharge cavity.

4. A magneto-fluidic assembly seal according to claim 2, wherein: The water seal ring assembly comprises four groups of ring piece assemblies which are arranged on the shaft sleeve in sequence, the ring piece assemblies are sealing rubber plates provided with supporting rings, a water seal ring which can be filled with water is arranged between the middle two groups of ring pieces, and the upper end of the water seal ring is connected with a water inlet which penetrates through the sealing shell.

5. A magneto-fluidic assembly seal according to claim 3, wherein: The magnetic fluid sealing assembly comprises two oppositely arranged magnetic poles and a positioning magnetic shielding plate, the two magnetic poles are sleeved on the shaft sleeve and have a gap between the magnetic poles and the shaft sleeve, the gap is filled with magnetic liquid or magnetic grease filler, the outer side of the magnetic fluid sealing assembly is provided with a sealing gland assembly which is bolted with the magnetic fluid sealing shell, and the positioning magnetic shielding plate is arranged between the sealing gland assembly and the magnetic poles.

6. A magneto-fluidic assembly seal according to claim 3, wherein: A magnetic conducting shaft sleeve assembly is arranged between the magnetic fluid sealing assembly and the shaft sleeve.

7. A magneto-fluidic assembly seal according to any one of claims 3 or 4, wherein: Two upper openings and two lower openings are respectively arranged on the cavity in the grease storage ring, the upper openings are connected with oil inlets which penetrate through the sealing shell and are used for supplementing grease, and the lower openings are connected with water discharge holes which penetrate through the sealing shell and are used for discharging water and are provided with water discharge screws.

8. A magneto-fluidic assembly seal according to claim 1, wherein: The rear sealing assembly is arranged as a water blocking assembly, which comprises a rubber water blocking plate sleeved on the shaft sleeve and a polytetrafluoroethylene double-lip stainless steel oil seal, the rubber water blocking plate is located between the grease storage ring and the polytetrafluoroethylene double-lip stainless steel oil seal, the front side of the magnetic fluid sealing assembly is provided with a bearing fixed in the sealing shell and sleeved on the shaft sleeve, the front side of the bearing is provided with a threaded pressing assembly pressed on the front side of the bearing, located in the pump cover and sleeved on the shaft sleeve, and the threaded pressing assembly is bolted and fixed between the pump covers.

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