High-speed magnetic liquid sealing device

Abstract

The invention belongs to the technical field of mechanical engineering sealing and is particularly suitable for the field of high-speed rotating sealing. The invention discloses a high-speed magnetic liquid sealing device, and belongs to the field of mechanical engineering sealing. The sealing device comprises a water inlet (1), magnetic liquid (2), a magnetic conductive rotating shaft (3), a non-magnetic conductive end cover (4), a sealing ring I (5), a non-magnetic conductive shell (6), a magnetic conductive sleeve (7), a cylindrical permanent magnet (8), a cooling water tank (9), a water outlet (10) and a sealing ring II (11). In the device, the magnetic conductive sleeve is a whole, so that the use of a sealing ring and the machining of a groove are reduced, the machining difficulty is reduced, and the precision of the axial size is ensured. After the sleeves of the magnetic liquid sealing device are integrated, the problems that the two sleeves are difficult to be coaxial due to the fact that the permanent magnets attract the sleeves and the sleeves collide with the permanent magnets due to magnetic force can be solved, meanwhile, the sleeves can be installed only by overcoming the friction force of one sealing ring, heating installation is not needed any more, and the installation difficulty is reduced.

Description

Technical Field

[0001] This invention belongs to the field of mechanical engineering sealing technology, and is particularly applicable to the field of high-speed rotary sealing. Specifically, it relates to a high-speed magnetic liquid sealing device. Background Technology

[0002] Mechanical seals are widely used rotary shaft dynamic seals, achieving good results in many high-pressure, high-temperature, medium-to-low-speed, and corrosive media conditions. However, mechanical seals suffer from significant drawbacks at high speeds, including high heat generation, short lifespan, and the need for an oil lubrication system. Magnetic fluid seals achieve sealing through a magnetic fluid within the sealing gap, avoiding direct contact between the two sealing surfaces and the resulting friction and wear. Compared to mechanical seals, they can adapt to higher shaft speeds. However, traditional magnetic fluid seal devices face challenges at even higher speeds, such as viscous frictional heat generation from the magnetic fluid and centrifugal force causing the magnetic fluid to be flung away. These are two reasons why the development of magnetic fluid seal devices in the field of ultra-high-speed dynamic seals has been hindered. Currently, there are few structural improvements for high-speed magnetic fluid seal devices; therefore, a high-speed magnetic fluid seal device is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a magnetic liquid sealing device that is simple in structure, easy to assemble, and resistant to high speeds.

[0004] The technical solution adopted in this invention is:

[0005] A high-speed magnetic liquid sealing device includes: an inlet (1), a magnetic liquid (2), a magnetic shaft (3), a non-magnetic end cap (4), a sealing ring I (5), a non-magnetic outer shell (6), a magnetic sleeve (7), a cylindrical permanent magnet (8), a cooling water tank (9), an outlet (10), and a sealing ring II (11).

[0006] The connection between the various parts of the device is as follows: the sealing ring I (5) is installed in the groove on the outer circular surface of the magnetic sleeve (7); the sealing ring II (11) is installed in the groove on the end face of the magnetic sleeve (7) that contacts the non-magnetic outer shell (6);

[0007] A cylindrical permanent magnet (8) is installed in the annular groove in the middle of the magnetic sleeve (7). Several cylindrical permanent magnets (8) are arranged in a ring in the groove to form a magnetic source assembly for the sealing device. The right end face of the magnetic sleeve (7) is in contact with the right inner end face of the non-magnetic shell (6). The outer circular surface of the magnetic sleeve (7) is in contact with the inner circular surface of the non-magnetic shell (6). The non-magnetic end cap (4) is connected to the non-magnetic shell (6) by screws. The right end face of the non-magnetic end cap (4) is in contact with the left end face of the magnetic sleeve (7) to complete the positioning of the magnetic sleeve (7).

[0008] The magnetic shaft (3) is coaxial with the magnetic sleeve (7) through the bearing outside the device. The teeth on the shaft are symmetrically distributed on both sides of the permanent magnet. Sufficient magnetic liquid (2) is injected into the device to form a magnetic liquid sealing ring between the teeth of the magnetic shaft (3) and the magnetic sleeve (7).

[0009] Due to the close contact between the non-magnetic outer shell (6) and the magnetic sleeve (7), the sealing ring I (5) and sealing ring II (11) are pressed together to form a seal; the empty groove between the non-magnetic outer shell (6) and the magnetic sleeve (7) forms a cooling water tank (9), and the cooling water enters the cooling water tank (9) through the inlet (1) and finally leaves the cooling water tank through the outlet (10).

[0010] Compared with mechanical seals and conventional magnetic fluid sealing devices, the advantages of this invention are:

[0011] 1. It avoids the friction and wear problems of mechanical seals at high speeds, reduces heat generation, and improves service life; 2. Compared with traditional magnetic liquid sealing devices, in this device, the sleeve is no longer divided into multiple sleeves installed on both sides of the permanent magnet, but is processed as a whole, reducing the use of sealing rings and groove processing, reducing processing difficulty, and better ensuring the accuracy of axial dimensions; 3. After the sleeve of the magnetic liquid sealing device is integrated, it can avoid the problem of the two sleeves being unable to be coaxial due to the permanent magnet attracting the sleeve, and the problem of the sleeve and permanent magnet colliding due to magnetic force. At the same time, the installation of the sleeve only needs to overcome the friction of one sealing ring, eliminating the need for heating installation and reducing installation difficulty; 4. In order to improve the magnetic liquid sealing device... To increase the pressure resistance, the number of sleeves needs to be increased to increase the number of magnetic liquid sealing rings. Each sleeve requires a cooling water tank for cooling, so the number of cooling water tanks in the magnetic liquid sealing device is large and unnecessary. In this invention, in addition to the sleeves becoming a whole, the cooling water tanks also become a whole. The device has only one inlet and one outlet, which reduces the processing difficulty and increases the heat exchange area to obtain better heat dissipation effect to improve the pressure resistance. 5. Compared with the traditional magnetic liquid sealing device, in order to improve the pressure resistance to cope with high speed, this invention only needs to increase the length of the sleeve and the number of cylindrical permanent magnets, rather than increasing the number of sleeves and inlet / outlet ports, which reduces the assembly difficulty and processing difficulty. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the high-speed magnetic liquid sealing device of the present invention;

[0013] Figure 1 In the middle: water inlet (1), magnetic liquid (2), magnetic shaft (3), non-magnetic end cap (4), sealing ring I (5), non-magnetic outer shell (6), magnetic sleeve (7), cylindrical permanent magnet (8), cooling water tank (9), water outlet (10), sealing ring II (11). Detailed Implementation

[0014] The present invention will be further described with reference to the accompanying drawings as specific embodiments. For ease of description, the words "left" and "right" appearing below only indicate that they are consistent with the left and right directions of the accompanying drawings themselves, and do not limit the structure.

[0015] A high-speed magnetic liquid sealing device includes: an inlet (1), a magnetic liquid (2), a magnetic shaft (3), a non-magnetic end cap (4), a sealing ring I (5), a non-magnetic outer shell (6), a magnetic sleeve (7), a cylindrical permanent magnet (8), a cooling water tank (9), an outlet (10), and a sealing ring II (11).

[0016] The connection between the various parts of the device is as follows: the sealing ring I (5) is installed in the groove on the outer circular surface of the magnetic sleeve (7); the sealing ring II (11) is installed in the groove on the end face of the magnetic sleeve (7) that contacts the non-magnetic outer shell (6);

[0017] A cylindrical permanent magnet (8) is installed in the annular groove in the middle of the magnetic sleeve (7). Several cylindrical permanent magnets (8) are arranged in a ring in the groove to form a magnetic source assembly for the sealing device. The right end face of the magnetic sleeve (7) is in contact with the right inner end face of the non-magnetic shell (6). The outer circular surface of the magnetic sleeve (7) is in contact with the inner circular surface of the non-magnetic shell (6). The non-magnetic end cap (4) is connected to the non-magnetic shell (6) by screws. The right end face of the non-magnetic end cap (4) is in contact with the left end face of the magnetic sleeve (7) to complete the positioning of the magnetic sleeve (7).

[0018] The magnetic shaft (3) is coaxial with the magnetic sleeve (7) through the bearing outside the device. The teeth on the shaft are symmetrically distributed on both sides of the permanent magnet. Sufficient magnetic liquid (2) is injected into the device to form a magnetic liquid sealing ring between the teeth of the magnetic shaft (3) and the magnetic sleeve (7).

[0019] Due to the close contact between the non-magnetic outer shell (6) and the magnetic sleeve (7), the sealing ring I (5) and sealing ring II (11) are pressed together to form a seal; the empty groove between the non-magnetic outer shell (6) and the magnetic sleeve (7) forms a cooling water tank (9), and the cooling water enters the cooling water tank (9) through the inlet (1) and finally leaves the cooling water tank through the outlet (10).

[0020] The composition of the magnetic circuit is explained below: the magnetic field lines emitted from the N pole of the cylindrical permanent magnet (8) pass through the magnetic sleeve (7), the magnetic liquid (2), the magnetic shaft (3), and then return to the S pole of the cylindrical permanent magnet (8) through the magnetic liquid (2) and the magnetic sleeve (7) on the other side; when the magnetic field lines pass through the teeth on the magnetic shaft (7), they form a magnetic field gradient, which binds the magnetic liquid in the sealed gap.

[0021] The non-magnetic end cap (4), sealing ring I (5), non-magnetic outer shell (6), and sealing ring II (11) are made of non-magnetic materials, while the magnetic liquid (2), magnetic shaft (3), and magnetic sleeve (7) are made of magnetic materials.

[0022] The number of teeth on the magnetic shaft (3) is determined by the actual working conditions. It can be designed as a single-stage seal at the very least, and the position of the teeth can also be on the inner circle of the magnetic sleeve (7). Whether the teeth are on the shaft or the sleeve does not affect the working principle of the magnetic liquid seal.

[0023] The length of the magnetic sleeve (7) is related to the actual pressure resistance requirement. The higher the pressure resistance requirement, the longer the magnetic sleeve (7) is. However, the dimensions of the water tank and permanent magnet mounting slot on the magnetic sleeve (7) remain unchanged. When the length of the magnetic sleeve (7) is increased, the number of water tanks and permanent magnet mounting slots is increased accordingly. They are increased in the order of water tank, permanent magnet mounting slot, water tank, permanent magnet mounting slot, etc., forming a symmetrical structure. The permanent magnets are installed with their magnetic poles facing each other. As the length of the magnetic sleeve (7) increases, the lengths of the non-magnetic outer shell (6) and the magnetic shaft (3) also increase accordingly.

[0024] The coaxiality between the magnetic shaft (3) and the magnetic sleeve (7) is ensured by bearings outside the device.

[0025] The inlet (1) and outlet (10) are equipped with quick-connect fittings for connecting to cooling water. The cooling water is low-temperature pure water, and a suitable cooling water can be selected according to the required cooling temperature. The overall structure consists of only one inlet, one outlet, and one cooling water tank.

[0026] The cooling water tank (9) allows cooling water to flow evenly through the groove of the sleeve, carrying away the heat generated by the rotation of the shaft.

[0027] The cylindrical permanent magnet (8) is made of neodymium iron boron with good magnetic properties.

[0028] The type of magnetic fluid is selected according to the different usage environments and sealing media.

[0029] In the above specific embodiments, the material selected for the cylindrical permanent magnet (8), the form of installing the permanent magnet on the magnetic sleeve (7) to form a permanent magnet ring, the axial length of the sleeve in the figure and the corresponding number of water tanks and permanent magnet mounting slots, and the interface form of the inlet and outlet are only preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A high speed magnetic liquid seal apparatus, characterized by, The sealing device comprises: a water inlet (1), a magnetic liquid (2), a magnetic conducting shaft (3), a non-magnetic conducting end cover (4), a sealing ring I (5), a non-magnetic conducting shell (6), a magnetic conducting sleeve (7), a cylindrical permanent magnet (8), a cooling water tank (9), a water outlet (10), and a sealing ring II (11). The connection between the parts of the device is as follows: the sealing ring I (5) is installed in the groove on the outer surface of the magnetic conducting sleeve (7); the sealing ring II (11) is installed in the groove on the end surface of the magnetic conducting sleeve (7) in contact with the non-magnetic conducting shell (6); The cylindrical permanent magnet (8) is installed in the annular groove in the middle of the magnetic conducting sleeve (7), and several cylindrical permanent magnets (8) are arranged in a ring in the groove, forming a magnetic source assembly of the sealing device; the right end surface of the magnetic conducting sleeve (7) is in contact with the right inner end surface of the non-magnetic conducting shell (6), the outer surface of the magnetic conducting sleeve (7) is in contact with the inner surface of the non-magnetic conducting shell (6), the non-magnetic conducting end cover (4) is connected with the non-magnetic conducting shell (6) by screws, and the right end surface of the non-magnetic conducting end cover (4) is in contact with the left end surface of the magnetic conducting sleeve (7), thereby positioning the magnetic conducting sleeve (7); The coaxiality between the magnetic conducting shaft (3) and the magnetic conducting sleeve (7) is ensured by bearings outside the device; the teeth on the shaft are symmetrically distributed on both sides of the permanent magnet; a sufficient amount of magnetic liquid (2) is injected into the device, and a magnetic liquid sealing ring is formed between the teeth of the magnetic conducting shaft (3) and the gap of the magnetic conducting sleeve (7); The sealing ring I (5) and the sealing ring II (11) are compressed to form a seal due to the close contact between the non-magnetic conducting shell (6) and the magnetic conducting sleeve (7); the air gap between the non-magnetic conducting shell (6) and the magnetic conducting sleeve (7) forms a cooling water tank (9); cooling water enters the cooling water tank (9) through the water inlet (1) and finally exits the cooling water tank through the water outlet (10).

2. The high-speed magnetic liquid sealing device according to claim 1, wherein: the non-magnetic conducting end cover (4), the sealing ring I (5), the non-magnetic conducting shell (6), and the sealing ring II (11) are made of non-magnetic conducting materials, and the magnetic liquid (2), the magnetic conducting shaft (3), and the magnetic conducting sleeve (7) are made of magnetic conducting materials.

3. The high-speed magnetic liquid sealing device according to claim 1, wherein: the length of the magnetic conducting sleeve (7) is related to the actual pressure resistance requirement; the higher the pressure resistance requirement, the longer the magnetic conducting sleeve (7); however, the size of the water tank and the permanent magnet installation groove on the magnetic conducting sleeve (7) remains unchanged; when the length of the magnetic conducting sleeve (7) is increased, the number of water tanks and permanent magnet installation grooves is also increased; the arrangement order is water tank, permanent magnet installation groove, water tank, permanent magnet installation groove, and so on; the permanent magnets are installed in a manner that the magnetic poles are opposite to each other; when the length of the magnetic conducting sleeve (7) is increased, the length of the non-magnetic conducting shell (6) and the magnetic conducting shaft (3) is also increased accordingly.

4. The high-speed magnetic liquid sealing device according to claim 1, wherein: the coaxiality between the magnetic conducting shaft (3) and the magnetic conducting sleeve (7) is ensured by bearings outside the device.

5. The high-speed magnetic liquid seal device of claim 1, wherein: The overall structure has only one water inlet, one water outlet and one cooling water tank.

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