An integral cooling magnetic liquid seal

Abstract

The application discloses a whole cooling type magnetic liquid sealing device, which comprises a rotating shaft, a flange sleeve, a welded water jacket, a permanent magnet, a first pole shoe and a second pole shoe, the rotating shaft contains an inlet and outlet passage of liquid refrigerant, a circulation chamber of liquid refrigerant is formed between the flange sleeve and the welded water jacket, the first pole shoe comprises a first annular cooling passage which is independently circulated, the second pole shoe comprises a second annular cooling passage which is independently circulated, the pole tooth section of the first pole shoe and the second pole shoe is funnel-shaped, the magnetic field gradient in the sealing gap is ensured, and the heat conduction area of the pole tooth is increased. The whole cooling type magnetic liquid sealing device of the embodiment of the application realizes synchronous cooling of the shaft and the sleeve by high-pressure liquid refrigerant, can comprehensively reduce the temperature of the magnetic liquid, the permanent magnet, the bearing, the first pole shoe and the second pole shoe in the sealing device, and is suitable for high-temperature and high-speed working conditions.

Description

Technical Field

[0001] This invention relates to the field of mechanical engineering sealing technology, specifically to an integrally cooled magnetic liquid sealing device suitable for high-temperature environments. Background Technology

[0002] Magnetic fluid seals are widely used in vacuum and high-pressure applications due to their advantages such as low friction, zero leakage, and long lifespan. However, when magnetic fluid seals are used under high-speed rotation conditions, the viscous friction between the shaft and the magnetic fluid causes a rapid increase in temperature at the sealing point. The high temperature of the external reaction chamber accelerates this process. This temperature rise leads to rapid evaporation of the magnetic fluid-based carrier liquid, ultimately causing the precipitation of magnetic particles within the magnetic fluid and resulting in a decrease in sealing performance. Simultaneously, under high-speed rotation, the friction between the rolling elements and the inner and outer rings of the bearings inside the magnetic fluid seal also intensifies, accelerating bearing wear and potentially causing failure.

[0003] In related technologies, circulating liquid refrigerant is often used to cool the sealing parts of magnetic liquid sealing devices. For example, the patented magnetic liquid sealing device with a cooling system (patent number: 202111592697.2) proposes a method of cooling the magnet and pole shoe by establishing a liquid refrigerant circulation channel at the magnet; the patented water-cooled magnetic liquid sealing device with a rotating joint on the bushing (patent number: 201410380200.4) proposes a method of cooling the sealing parts by connecting an external water-cooling jacket to the rotating shaft; and the patented high-temperature resistant stirrer... A cooling method for a welded water-cooled jacket was proposed using a magnetic liquid sealing device (patent number: 202020240544.6). However, the above cooling method can only provide localized cooling for the sealing gap or the outer jacket. If only the outer jacket is cooled, the inner ring of the bearing will expand due to heat, causing the bearing to seize. At the same time, the sealing gap will not be sufficiently cooled. If only the shaft is cooled, the high temperature at the permanent magnet will cause the permanent magnet to demagnetize, reducing the magnetic field gradient at the sealing gap. All of these factors will accelerate the failure of the magnetic liquid seal under high temperature or high speed conditions. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, this invention proposes an integrally cooled magnetic liquid sealing device to improve the overall cooling effect of the bearings, pole shoes, magnets, and magnetic liquid in the magnetic liquid sealing device, making it suitable for high-temperature and high-speed working environments and extending its service life.

[0006] An embodiment of the present invention provides an integrally cooled magnetic liquid sealing device comprising: a rotating shaft, a locking end cap, a flange outer sleeve, a welded water jacket, a first diaphragm, a second diaphragm, an O-ring, a first bearing, a second bearing, a first snap ring, a second snap ring, a permanent magnet, a first pole shoe, a second pole shoe, a first end face sealing ring, a second end face sealing ring, a third end face sealing ring, a fourth end face sealing ring, a first radial sealing ring, a second radial sealing ring, a third radial sealing ring, a fourth radial sealing ring, and a magnetic liquid.

[0007] The connections between the various parts of the device:

[0008] The flange outer sleeve is welded to the welding water jacket, forming a circulating chamber for liquid refrigerant between them. An O-ring is then fixed in the groove on the right end face of the flange outer sleeve. The second snap ring is fixed in the snap ring groove on the right side of the rotating shaft. Starting from the left end of the rotating shaft, the second bearing, second spacer, and second pole shoe are installed sequentially. Magnetic fluid is injected into the radial gap between the pole shoe teeth and the rotating shaft. Next, the permanent magnet and the first pole shoe 1001 are installed sequentially, and magnetic fluid is injected into the radial gap between the pole shoe teeth and the rotating shaft. The first spacer and the first bearing are then installed sequentially. The first snap ring is used to axially position the components already installed on the rotating shaft. The assembled rotating shaft is inserted from the left end into the hole in the flange outer sleeve up to the bottom right side. Finally, the locking end cap is fixed to the left end of the flange outer sleeve via a threaded connection. At this point, the assembly of an integrally cooled magnetic liquid sealing device is complete. The liquid refrigerant achieves synchronous cooling of the rotating shaft, the inner ring of the first bearing, the inner ring of the second bearing, and the magnetic liquid through the cooling channel of the rotating shaft; and achieves synchronous cooling of the outer ring of the first bearing, the outer ring of the second bearing, the first pole shoe, the second pole shoe, and the permanent magnet 9 through the cooling channels of the flange outer sleeve, the welded water jacket, the first pole shoe, and the second pole shoe.

[0009] The beneficial effects of this invention are:

[0010] An embodiment of the present invention provides an integrally cooled magnetic liquid sealing device that achieves synchronous cooling of the shaft and outer sleeve by a high-pressure liquid refrigerant through a reasonable cooling channel structure design and a pole shoe and pole tooth structure design. This can significantly reduce the temperature of the magnetic liquid in the sealing gap and the temperature of the permanent magnet, while ensuring that the bearing does not seize up under high temperature and high speed conditions. This makes the device suitable for high temperature and high speed operating environments. Attached Figure Description

[0011] Figure 1 This is a cross-sectional structural schematic diagram of an integrally cooled magnetic liquid sealing device according to the present invention.

[0012] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0013] Figure 3 yes Figure 1 Enlarged view of point B in the middle.

[0014] Figure 4 yes Figure 1 Left view of rotation axis 1.

[0015] Figure label:

[0016] An integrally cooled magnetic liquid sealing device 100;

[0017] Rotating shaft 1; First shaft cold inlet 101; First shaft cold outlet 102; Second shaft cold inlet 103; Second shaft cold outlet 104; First through port 105; Second through port 106;

[0018] Locking end cap 2; First locking blind hole 201; Second locking blind hole 202;

[0019] Flange outer 3; First inlet 301; Second inlet 302; First outlet 303; Second outlet 304;

[0020] Welded water jacket 4; cooling inlet 401; cooling outlet 402; first weld joint 403; second weld joint 404;

[0021] First septum 501; Second septum 502;

[0022] O-ring 6;

[0023] First bearing 701; Second bearing 702;

[0024] First snap ring 801; Second snap ring 802;

[0025] Permanent magnet 9;

[0026] First pole shoe 1001; Second pole shoe 1002; Pole shoe tooth 1003;

[0027] First end face sealing ring 1101; Second end face sealing ring 1102; Third end face sealing ring 1103; Fourth end face sealing ring 1104;

[0028] First radial sealing ring 1201; Second radial sealing ring 1202; Third radial sealing ring 1203; Fourth radial sealing ring 1204;

[0029] First annular cooling channel 1301; Second annular cooling channel 1302;

[0030] Magnetic fluid 14;

[0031] Circulation chamber 15. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] The following is a reference to the appendix. Figure 1 To be continued Figure 4 The technical solution of this application will be described in detail below.

[0034] like Figure 1 As shown, an embodiment of the present invention discloses an integrally cooled magnetic liquid sealing device 100, which includes: a rotating shaft 1, a locking end cap 2, a flange outer sleeve 3, a welding water jacket 4, a first diaphragm 501, a second diaphragm 502, an O-ring seal 6, a first bearing 701, a second bearing 702, a first snap ring 801, a second snap ring 802, a permanent magnet 9, a first pole shoe 1001, a second pole shoe 1002, a first end face sealing ring 1101, a second end face sealing ring 1102, a third end face sealing ring 1103, a fourth end face sealing ring 1104, a first radial sealing ring 1201, a second radial sealing ring 1202, a third radial sealing ring 1203, a fourth radial sealing ring 1204, and a magnetic liquid 14.

[0035] The connections between the various parts of the device:

[0036] The flange outer sleeve 3 is welded to the welding water jacket 4 to form a first weld joint 403 and a second weld joint 404, creating a liquid refrigerant circulation chamber 15 between the flange outer sleeve 3 and the welding water jacket 4. An O-ring seal 6 is then fixed in the groove on the right end face of the flange outer sleeve 3. A second retaining ring 802 is fixed in the retaining ring groove on the right side of the rotating shaft 1. The second bearing 702 is installed sequentially from the left end of the rotating shaft 1 to the second retaining ring 802. A second spacer 502 is installed. A third end face seal 1103 is installed on the left end face of the second pole shoe 1002, and a fourth end face seal 1104 is installed on the right end face of the second pole shoe 1002. A third radial seal 1203 is installed on the left side of the cylindrical surface of the second pole shoe 1002, and a fourth radial seal 1204 is installed on the right side of the cylindrical surface of the second pole shoe 1002. Figure 3 As shown, the second pole shoe 1002 is inserted, and magnetic fluid 14 is injected into the radial gap between the pole shoe teeth 1003 and the rotating shaft 1, as follows. Figure 2 As shown, the permanent magnet 9 is then installed. The first end face sealing ring 1101 is installed on the left end face of the first pole shoe 1001, the second end face sealing ring 1102 is installed on the left end face of the first pole shoe 1001, the first radial sealing ring 1201 is installed on the left side of the cylindrical surface of the first pole shoe 1001, and the second radial sealing ring 1202 is installed on the right side of the cylindrical surface of the first pole shoe 1001. Figure 3As shown, the first pole piece 1001 is inserted, and magnetic fluid 14 is injected into the radial gap between the pole piece teeth 1003 and the rotating shaft 1, as follows. Figure 2 As shown, the first spacer 501 is then installed in sequence, followed by the first bearing 701, and the first retaining ring 801 is used to axially position the components already installed on the rotating shaft 1. The assembled rotating shaft 1 is then inserted from the left end into the hole of the flange sleeve 3 to the bottom right side. Finally, the locking end cap 2 is fixed to the left end of the flange sleeve 3 by threaded connection using the first locking blind hole 201 and the second locking blind hole 202.

[0037] The flange jacket 3 includes a first inlet 301 and a second inlet 302 for liquid refrigerant above, and a first outlet 303 and a second outlet 304 for liquid refrigerant below; the welding water jacket 4 includes a cooling inlet 401 for liquid refrigerant above, and a cooling outlet 402 for liquid refrigerant below; the permanent magnet 9 is a ring-shaped permanent magnet; the center of the outer cylindrical surface of the first pole piece 1001 includes a first annular cooling channel 1301; the center of the outer cylindrical surface of the second pole piece 1002 includes a second annular cooling channel 1302; the pole piece teeth 1003 have a funnel-shaped cross-section, such as... Figure 2 As shown, the narrowest part is the portion in contact with the magnetic fluid 14 at the end, which is intended to ensure the magnetic field gradient within the sealed gap between the rotating shaft 1 and the first pole piece 1001 and the second pole piece 1002. The width gradually increases at the root, which is intended to increase the heat conduction area of ​​the pole piece teeth 1003. The left end face of the rotating shaft 1 includes a first shaft cold inlet 101, a first shaft cold outlet 102, a second shaft cold inlet 103, and a second shaft cold outlet 104, as shown. Figure 4 As shown, the right side of the cylindrical surface of the rotating shaft 1 includes a first through port 105 and a second through port 106. The purpose is to ensure that the first shaft cold inlet 101, the first shaft cold outlet 102, the second shaft cold inlet 103, and the second shaft cold outlet 104 are connected during the processing. After the processing is completed, the first through port 105 and the second through port 106 are welded and precision machined to ensure zero leakage of the liquid refrigerant during the circulation process.

[0038] After installation, the first inlet 301 and the first outlet 303 on the flange outer sleeve 3 are connected to the first annular cooling channel 1301 of the first pole shoe 1001, and the second inlet 302 and the second outlet 304 on the flange outer sleeve 3 are connected to the second annular cooling channel 1302 of the second pole shoe 1002. The first radial sealing ring 1201, the second radial sealing ring 1202, the third radial sealing ring 1203, and the fourth radial sealing ring 1204 are compressed radially to achieve radial sealing. The first end face sealing ring 1101, the second end face sealing ring 1102, the third end face sealing ring 1103, and the fourth end face sealing ring 1104 are compressed axially under the action of the locking end cover 2 to achieve end face sealing. Under the combined action of radial sealing and end face sealing, it can ensure that high-pressure liquid refrigerant does not enter the sealing gap, thereby improving the reliability of the device. Under the action of the magnetic circuit formed by the permanent magnet 9, an O-ring of magnetic liquid 14 is formed at the pole teeth 1003 of the pole shoe in the gap between the first pole shoe 1001 and the rotating shaft 1, and in the gap between the second pole shoe 1002 and the rotating shaft 1. The left side of the rotating shaft 1 is the atmospheric end, and the shaft head is connected to the motor through a rotary joint. The right side is the high-temperature working chamber, and the shaft head is connected to the load in the high-temperature working chamber through a coupling. When the rotating shaft 1 rotates at high speed, for example, when the rotating shaft 1 rotates at a linear speed of 25 m / s, the temperature generated by friction between the outer cylindrical surface of the rotating shaft 1 and the magnetic liquid 14 can reach a temperature of 120°C or even higher. In addition, the temperature in the high-temperature working chamber will also cause the temperature at the magnetic liquid 14 to rise further through heat conduction. The temperature rise will accelerate the evaporation rate of the base liquid of the magnetic liquid 14 and reduce the magnetic properties. The heat generated between the rotating shaft 1 and the magnetic fluid 14 is transferred to the first pole shoe 1001 and the second pole shoe 1002, and then to the permanent magnet 9 and the flange outer sleeve 3. The high-speed rotation of the rotating shaft 1 causes the rolling elements and inner and outer rings of the first bearing 701 and the second bearing 702 to heat up rapidly. The inner and outer rings need to be cooled synchronously to prevent the bearings from seizing due to high temperature. Therefore, the magnetic fluid 14 and the first and second bearings 701 and 702 can be cooled synchronously by cooling the rotating shaft 1, the first pole shoe 1001, the second pole shoe 1002 and the flange outer sleeve 3, thereby ensuring the sealing effect under high temperature and high speed environments.

[0039] During operation, the cooling of the integral cooling magnetic liquid sealing device 100 proposed in this invention by the liquid refrigerant mainly consists of two parts: cooling of the rotating shaft 1 and cooling of the flange outer sleeve 3. It should be noted that the liquid refrigerant can be water, inorganic compound refrigerant, Freon, saturated hydrocarbon refrigerant, unsaturated hydrocarbon refrigerant, and azeotropic mixture refrigerant, etc. Liquid refrigerant enters from the first shaft cooling inlet 101 and the second shaft cooling inlet 103 on the left end face of the rotating shaft 1, and flows out from the first shaft cooling outlet 102 and the second shaft cooling outlet 104 after filling the cooling channel, thus achieving synchronous cooling of the rotating shaft 1, the inner ring of the first bearing 701, the inner ring of the second bearing 702, and the magnetic liquid 14. Liquid refrigerant enters from the cooling inlet 401 above the welding water jacket 4, passes through the circulation chamber 15 between the flange outer sleeve 3 and the welding water jacket 4, enters the first inlet 301 and the second inlet 302 on the flange outer sleeve 3, flows through the first annular cooling channel 1301 of the first pole shoe 1001 and the second annular cooling channel 1302 of the second pole shoe 1002, and returns to the circulation chamber 15. Finally, liquid refrigerant flows out from the cooling inlet 402 below the welding water jacket 4, thus achieving synchronous cooling of the outer ring of the first bearing 701, the outer ring of the second bearing 702, the first pole shoe 1001, the second pole shoe 1002, and the permanent magnet 9.

[0040] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A one-piece cooled magnetic liquid sealing device, characterized in that, include: A rotating shaft, with an atmospheric end on the left and a high-temperature working chamber on the right, has a first cooling inlet, a first cooling outlet, a second cooling inlet, and a second cooling outlet on the left end face of the rotating shaft. The first cooling inlet, the first cooling outlet, the second cooling inlet, and the second cooling outlet are connected through a first through-hole and a second through-hole on the right side of the cylindrical surface of the rotating shaft. The first cooling inlet, the first cooling outlet, the second cooling inlet, and the second cooling outlet define a cooling channel for the liquid refrigerant on the rotating shaft. Flange sleeve, which defines a circulation channel for liquid refrigerant; A welded water jacket is formed by welding the water jacket to the flange outer sleeve to create a circulation chamber for liquid refrigerant. A permanent magnet, wherein the permanent magnet is a ring-shaped permanent magnet; A first pole shoe and a second pole shoe, each of which is fitted onto the outside of the rotating shaft, forming a sealed gap with the rotating shaft and filled with magnetic fluid, the center of the outer cylindrical surface of the first pole shoe includes a first annular cooling channel, and the center of the outer cylindrical surface of the second pole shoe includes a second annular cooling channel. The flange sleeve, the welded water jacket, the first pole shoe, and the second pole shoe define a cooling space for the liquid refrigerant for the first pole shoe, the second pole shoe, the permanent magnet, the outer ring of the first bearing, and the outer ring of the second bearing. The circulation chamber formed after the flange sleeve and the welded water jacket are welded together is connected to the first annular cooling channel of the first pole shoe and the second annular cooling channel of the second pole shoe. The first end face sealing ring and the second end face sealing ring are respectively located in the sealing grooves on the left end face and the right end face of the first pole shoe. The third end face sealing ring and the fourth end face sealing ring are respectively located in the sealing grooves on the left end face and the right end face of the second pole shoe; The first radial sealing ring and the second radial sealing ring are located in the outer cylindrical sealing groove of the first pole shoe; The third radial sealing ring and the fourth radial sealing ring are located in the outer cylindrical sealing groove of the second pole shoe; The first septum has a narrow end face on its left side and a wide end face on its right side. The second septum has a wide end face on the left side and a narrow end face on the right side. The first end face sealing ring is axially pressed against the right end face of the first septum, and the second end face sealing ring is axially pressed against the left end face of the permanent magnet, together with the first radial sealing ring and the second radial sealing ring, defining the first annular cooling channel; The third end face sealing ring is axially pressed against the right end face of the permanent magnet, and the fourth end face sealing ring is axially pressed against the left end face of the second spacer, together with the third radial sealing ring and the fourth radial sealing ring, defining the second annular cooling channel.

2. The integrally cooled magnetic liquid sealing device according to claim 1, characterized in that, The inner cylindrical surfaces of the first and second pole shoes contain multiple pole shoe teeth. The cross-section of each pole shoe tooth is funnel-shaped. The width of the part of the pole shoe tooth in contact with the magnetic liquid is small, and the width of the root of the pole shoe tooth is large.

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