Long shaft rod magnetofluid sealing structure

Abstract

The utility model discloses a long shaft lever heavy load hollow shaft magnetofluid sealing structure which comprises a structure body, the structure body comprises a shell, and a shaft, a cover plate, a first magnetic isolation ring, a magnetic pole, a magnetic conduction shaft sleeve, a second magnetic isolation ring, a rear bearing, a magnetic liquid groove, a magnet, a magnetic pole sealing groove, a shaft clamp and a front bearing are arranged in the shell. An inner ring on one side of the front bearing is sleeved with a magnetic conductive shaft sleeve, the other side of the magnetic conductive shaft sleeve is positioned by a shaft clamp, and a shaft sealing groove is formed between the magnetic conductive shaft sleeve and the shaft to achieve static sealing; one side of the outer ring of the front bearing is tightly jacked by a cover plate, and the other side is sequentially provided with a first magnetism isolating ring, two magnetic poles, a magnet, a second magnetism isolating ring and a rear bearing; during installation, the coaxiality of the shaft and the sealing assembly is guaranteed, leakage caused by eccentricity is avoided, and magnetic grease and magnetic liquid are injected to be firmly adsorbed between the inner hole of the magnetic pole and the gap of the shaft, so that sealing is achieved.

Description

Technical Field

[0001] This utility model relates to the field of magnetic fluid sealing technology, and in particular to a long shaft magnetic fluid sealing structure. Background Technology

[0002] In recent years, the development of vacuum equipment both domestically and internationally has been rapid. Magnetohydrodynamic (MHD) seals have been widely applied in many rotary sealing devices, such as those used in vacuum equipment like single-crystal silicon furnaces, vacuum brazing furnaces, vacuum melting furnaces, chemical vapor deposition, ion plating, and liquid crystal regeneration equipment, as well as in high-temperature, high-pressure equipment and equipment with stringent environmental requirements. This improves product quality and yields significant economic benefits.

[0003] Magnetofluid sealing technology is developed based on magnetic fluids. When a magnetic fluid is injected into the gap of a magnetic field, it can fill the entire gap, forming a "liquid O-ring". The function of a magnetofluid sealing device is to transmit rotational motion to the sealed container, and it is commonly used for vacuum sealing.

[0004] Currently, in the application of magnetohydrodynamic (MHD) technology, the contact between the outer surface of the magnetic guide shaft or magnetic guide sleeve and the inner surface of the sealing assembly causes sealing failure. This phenomenon is more likely to occur in structures where no bearings are installed within the MHD seal. This is generally due to the failure to align the coaxiality of the rotating shaft and the sealing assembly during the installation of the MHD seal, causing eccentricity and resulting in contact. These issues are resolved by installing bearings of a certain precision. Due to the rapid development of equipment, there are increasing demands on the internal performance of MHDs, such as various dimensional structural requirements during operation, requiring long shafts to penetrate deep into the equipment. To address these problems, we have designed a long-shaft MHD seal structure to solve the above issues. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a long-shaft magnetohydrodynamic sealing structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A long-shaft magnetohydrodynamic sealing structure includes a structural body, which comprises: a housing, a shaft disposed inside the housing, a front bearing disposed on one side of the shaft, a cover plate disposed on one side of the front bearing pressing against the outer ring of the shaft, and the inner ring of the shaft on this side being positioned by a shaft clip; a magnetically conductive sleeve disposed on the inner ring of the other side, positioned by another shaft clip, a shaft sealing groove disposed between the shaft and the magnetically conductive sleeve, a magnetic fluid groove disposed on the magnetically conductive sleeve, the magnetic fluid groove containing magnetic fluid, and the outer ring of the magnetically conductive sleeve being sequentially disposed of as a first magnetic shielding ring, a magnetic pole, a magnet, a second magnetic shielding ring, and a rear bearing.

[0008] Preferably, the housing further includes a flange sealing groove, a flange hole, and a relief groove. The flange sealing groove is located on the outer side of the housing, the flange hole is located on the outer ring of the housing, and the relief groove is located on the other side of the flange corresponding to the external power equipment structure.

[0009] Preferably, there are two magnetic poles distributed on both sides of the magnet, and a certain gap is required between the magnetic poles and the shaft. The magnetic poles and the shaft are supported by front bearings and rear bearings on both sides.

[0010] Preferably, a first magnetic isolation ring and a second magnetic isolation ring are respectively provided on both sides of the magnetic pole.

[0011] Preferably, the magnetic pole has a magnetic pole sealing groove outside, and a sealing ring is installed in the magnetic pole sealing groove for static sealing between the magnetic pole and the housing.

[0012] Preferably, the magnet is either a button-shaped structure or a ring-shaped structure.

[0013] Preferably, the shaft is an extra-long shaft, which requires heat treatment to increase rigidity, and a bracket bearing is installed on the extra-long portion of the shaft at the equipment.

[0014] Preferably, the two ends of the shaft are provided with a first keyway and a second keyway, and the end of the second keyway away from the housing is provided with a shaft retaining groove.

[0015] Compared with related technologies, the long shaft magnetohydrodynamic sealing structure provided by this utility model has the following beneficial effects:

[0016] 1. A magnetic bushing is provided on the shaft because some equipment cannot have magnetic materials inside, so a shaft made of non-magnetic material is used for transmission.

[0017] 2. The shaft is an extra-long shaft to meet the needs of some equipment, and a bearing needs to be installed at the extra-long shaft so that the force on the bearing is not concentrated on the magnetofluid, thus ensuring the smooth operation of the magnetofluid. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a long shaft magnetohydrodynamic sealing structure proposed in this utility model.

[0019] 101: Shaft; 102: Housing; 103: Second magnetic shielding ring; 104: Magnetic pole; 105: Magnetic guide sleeve; 106: First magnetic shielding ring; 107: Cover plate;

[0020] 1: First keyway; 2: Rear bearing; 3: Relief groove; 4: Flange sealing groove; 5: Shaft retainer; 6: Magnetic fluid groove; 7: Magnet; 8: Magnetic pole sealing groove; 9: Shaft sealing groove; 10: Front bearing; 11: Support bearing; 12: Second keyway; 13: Shaft retainer groove; 14: Flange hole. Detailed Implementation

[0021] The technical solution of this utility model patent will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0022] Example:

[0023] Reference Figure 1 A magnetohydrodynamic sealing structure for a long shaft in a vacuum device, comprising:

[0024] The structural body includes: a housing 102, inside which a shaft 101 is disposed, a front bearing 10 is disposed on one side of the shaft 101, and a cover plate 107 is disposed on one side of the front bearing 10, pressing against the outer ring of the shaft 101. The inner ring of the shaft 101 on this side is positioned by a shaft clip; the inner ring on the other side is provided with a magnetic bushing 105, which is positioned by another shaft clip, and a shaft sealing groove 9 is provided between the shaft 101 and the magnetic bushing 105. The magnetic bushing 105 is provided with a magnetic fluid groove 6, which contains magnetic fluid. The outer ring of the magnetic bushing 105 is provided with a first magnetic shielding ring 106, a magnetic pole 104, a magnet 7, a second magnetic shielding ring 103, and a rear bearing 2 in sequence.

[0025] The housing 102 also includes a flange sealing groove 4, a flange hole 14, and a relief groove 3. The flange sealing groove 4 is located on the outer side of the housing 102, and the flange hole 14 is located on the outer ring of the housing 102, connecting to a vacuum device. The relief groove 3 is located on the other side of the flange, corresponding to an external power equipment structure. The flange side of the housing is connected to the vacuum device, and screws are installed in the vacuum device via the flange hole 14. The flange side is a vacuum environment, and the flange sealing groove 4 is equipped with a suitable sealing ring to statically seal between the flange and the vacuum device. The housing is made of non-magnetic stainless steel, and the relief groove 3 is compatible with the power equipment.

[0026] There are two magnetic poles 104, distributed on both sides of the magnet 7. A certain gap needs to be left between the magnetic poles and the shaft. The magnetic poles and the shaft are supported by the front bearings 10 and the rear bearings 2 on both sides to ensure that the magnetic poles and the shaft do not contact each other when the shaft is running, thereby affecting the magnetic fluid seal. The magnetic poles are made of 3cr13 or 2cr13 magnetic conductive material. The magnet 7 is a permanent magnet and the magnet 7 is either a button-shaped structure or a ring-shaped structure.

[0027] The magnetic poles, magnet, shaft, and magnetic fluid form a magnetic field loop, which is a liquid seal and the main sealing part of the magnetic fluid.

[0028] A first magnetic isolation ring 106 and a second magnetic isolation ring 103 are respectively provided on both sides of the magnetic pole 104 to isolate the magnetic field circuit emitted by the magnet. There is a magnetic pole sealing groove 8 outside the magnetic pole 104, and a sealing ring is installed in the magnetic pole sealing groove 8 for static sealing between the magnetic pole 104 and the housing 102.

[0029] Shaft 101 is an extra-long shaft, and the output shaft dimension on the vacuum side is excessively long, which makes it impossible for the front and rear bearings inside the actual magnetofluid to bear the actual radial force. Heat treatment is required to increase rigidity, and bracket bearing 11 is installed on the extra-long part of the shaft at the equipment.

[0030] The shaft 101 has a first keyway 1 and a second keyway 12 at both ends, and a shaft retaining groove 13 is provided at the end of the second keyway 12 away from the housing 102.

[0031] During operation, the power unit drives the first keyway 1 on the shaft to rotate, and the shaft 101 rotates synchronously, driving the magnetic sleeve 106 on the shaft to rotate synchronously. A sealing ring groove 9 is provided between the magnetic sleeve 106 and the shaft 101. After the sealing ring is added to the sealing ring groove, a static seal is achieved between the magnetic sleeve and the shaft. The magnetic sleeve 106 is provided with a magnetic fluid groove 6. After magnetic fluid is added to the magnetic fluid groove, a closed magnetic field circuit is formed between the magnetic sleeve 105, the two magnetic poles 104, the magnet 7, and the magnetic sleeve 105, so that the magnetic fluid forms a barrier, thereby achieving a rotational seal. The long shaft outputs to the vacuum equipment. The output shaft is too long and is supported and stabilized by a bracket bearing. The output device is then installed by the second keyway 12 and the shaft retainer groove 13 to keep the vacuum equipment in a stable vacuum state during operation.

[0032] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A long-shaft magnetohydrodynamic sealing structure, comprising a structural body, characterized in that, The structure body includes: a housing (102), inside which a shaft (101) is provided, a front bearing (10) is provided on one side of the shaft (101), a cover plate (107) is provided on one side of the front bearing (10) to press against the outer ring of the shaft (101), and the inner ring of the shaft (101) on this side is positioned by a shaft clip; the inner ring on the other side is provided with a magnetic bushing (105), which is positioned by another shaft clip, a shaft sealing groove (9) is provided between the shaft (101) and the magnetic bushing (105), a magnetic fluid groove (6) is provided on the magnetic bushing (105), and a magnetic liquid is provided in the magnetic fluid groove (6), and the outer ring of the magnetic bushing (105) is provided with a first magnetic shielding ring (106), a magnetic pole (104), a magnet (7), a second magnetic shielding ring (103), and a rear bearing (2) in sequence.

2. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, The housing (102) also includes a flange sealing groove (4), a flange hole (14) and a relief groove (3). The flange sealing groove (4) is located on the outer side of the housing (102), the flange hole (14) is located on the outer ring of the housing (102), and the relief groove (3) is located on the other side of the flange corresponding to the external power equipment structure.

3. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, There are two magnetic poles (104), which are distributed on both sides of the magnet (7). A certain gap needs to be left between the magnetic poles and the shaft. The magnetic poles and the shaft are supported by the front bearing (10) and the rear bearing (2) on both sides.

4. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, A first magnetic shielding ring (106) and a second magnetic shielding ring (103) are respectively provided on both sides of the magnetic pole (104).

5. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, The magnetic pole (104) has a magnetic pole sealing groove (8) on its outside. A sealing ring is installed in the magnetic pole sealing groove (8) for static sealing between the magnetic pole (104) and the housing (102).

6. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, The magnet (7) is either a button-shaped structure or a ring-shaped structure.

7. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, The shaft (101) is an extra-long shaft, which requires heat treatment to increase rigidity, and a bracket bearing (11) is installed on the extra-long part of the shaft at the equipment.

8. The long shaft magnetohydrodynamic sealing structure according to claim 1, characterized in that, The shaft (101) has a first keyway (1) and a second keyway (12) at both ends. The second keyway (12) has a shaft retaining groove (13) at the end away from the housing (102).

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