An alternating magnetic liquid seal

Abstract

This invention relates to an alternating magnetic liquid sealing device, belonging to the field of mechanical engineering sealing technology. The device includes: a rotating shaft, a housing, a control unit, module I, module II, magnetic liquid, and pole teeth; wherein module I and module II have identical structures, each consisting of a housing I, a left pole shoe, an electromagnet, a control line, a right pole shoe, and a retaining ring, and the sealing structure should contain at least two modules; the control unit controls the magnetization direction of the electromagnet, causing the magnetic liquid in the two modules to alternately fill the sealing gap to perform the sealing function. When not performing the sealing function, the magnetic liquid gathers between the two pole shoes to obtain heat dissipation and cooling time, avoiding continuous shearing of the magnetic liquid and improving the service life and pressure resistance of the sealing device.

Description

Technical Field

[0001] This invention relates to the field of mechanical engineering sealing technology, and is applicable to magnetic liquid sealing devices that are sensitive to temperature rise. Background Technology

[0002] Even if the two sealing surfaces in a magnetic fluid seal are not in direct contact, the temperature of the magnetic fluid filling the sealing gap will still rise due to continuous shearing. In ordinary magnetic fluid seals, the magnetic fluid is always filled in the sealing gap and is continuously sheared as the shaft rotates, resulting in a continuous increase in temperature without time for heat dissipation and cooling. This affects the service life and pressure resistance of the magnetic fluid seal. Therefore, an alternating magnetic fluid seal that provides heat dissipation time for the magnetic fluid is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a sealing device that allows magnetic fluid to escape from the sealing gap and gain cooling and heat dissipation time, thereby improving the pressure resistance and service life of the magnetic fluid sealing device.

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

[0005] An alternating magnetic liquid sealing device, characterized in that the device comprises: a rotating shaft (1), a housing (2), a control unit (3), module I (4), module II (5), a magnetic liquid (6), and pole teeth (7);

[0006] Module I (4) consists of outer shell I (41), left pole shoe I (42), electromagnet I (43), control line I (44), right pole shoe I (45), and snap ring I (46); Module II (5) consists of left pole shoe II (51), control line II (52), electromagnet II (53), right pole shoe II (54), outer shell II (55), and snap ring II (56);

[0007] The connection between the various parts of the device is as follows: sealing rings are installed in the grooves on the outer ring surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54); pole teeth (7) are machined on the inner circular surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54);

[0008] The assembly process of module I (4) is as follows: install the left pole shoe I (42) and electromagnet I (43) into the outer shell I (41), connect the control line I (44) to the electromagnet I (43) through the through hole on the outer shell I (41), and then install the right pole shoe I (45) and snap ring I (46) into the outer shell I (41). The through hole on the outer shell I (41) through which the control line I (44) passes is sealed with sealant.

[0009] The assembly process of module II (5) is as follows: install the left pole shoe II (51) and electromagnet II (53) into the housing II (55), connect the control line II (52) to the electromagnet II (53) through the through hole on the housing II (55), and then install the right pole shoe II (54) and snap ring II (56) into the housing II (55). The through hole on the housing II (55) through which the control line II (52) passes is sealed with sealant.

[0010] Module I (4) is bolted to the housing (2), and control line I (44) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet I (43) radially. Magnetic liquid (6) is injected into the sealed gap between left pole shoe I (42) and right pole shoe I (45) and the outer surface of the rotating shaft (1). Here, magnetic liquid (6) gathers between left pole shoe I (42) and right pole shoe I (45).

[0011] Module II (5) is installed onto module I (4) by bolt connection. Control line II (52) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet II (53) along the axial direction. Magnetic liquid (6) is injected into the sealing gap between the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1). Here, magnetic liquid (6) gathers in the sealing gap between the pole teeth (7) on the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1).

[0012] In order to ensure that the magnetic fluid under the sealing gap has time to cool and dissipate heat, the sealing device should have at least module I (4) and module II (5) at the same time, that is, at least two modules.

[0013] Compared with ordinary magnetic liquid sealing devices, the beneficial effects of the present invention are as follows: 1. Module I (4) and Module II (5) have the same structure. The modular structure makes it easy to replace or add or subtract to suit different sealing occasions; 2. The control unit (3) can control the alternating change of the magnetization direction of electromagnet I (43) and electromagnet II (53). The electromagnet in the module that performs the sealing function is axially magnetized. As the shaft (1) continues to rotate, the magnetic liquid (6) in this module is continuously sheared, causing the temperature to gradually rise. At this time, the magnetization direction of the electromagnet in the other module changes from radial to axial and begins to perform the sealing function. When the sealing gap in this module is filled with enough magnetic liquid (6), the magnetization direction of the electromagnet in the module that originally performed the sealing function changes from axial to radial. The magnetic liquid here leaves the sealing gap and gathers between the two pole shoes. The temperature begins to decrease. This process is continuously cyclical during the rotation of the shaft (1), which avoids the magnetic liquid being continuously sheared, so that the magnetic liquid (6) in each module has time to dissipate heat and ensures that at least one electromagnet in the module is axially magnetized. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a specific embodiment of the present invention;

[0015] Among them: rotating shaft (1), housing (2), control unit (3), module I (4), module II (5), magnetic fluid (6), pole teeth (7);

[0016] In module I (4): outer shell I (41), left pole shoe I (42), electromagnet I (43), control line I (44), right pole shoe I (45), snap ring I (46);

[0017] In module II (5): left pole shoe II (51), control line II (52), electromagnet II (53), right pole shoe II (54), outer shell II (55), snap ring II (56). Detailed Implementation

[0018] The present invention will be further described with reference to the accompanying drawings. However, the following specific embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention in any way.

[0019] like Figure 1 As shown, the device comprises: a rotating shaft (1), a housing (2), a control unit (3), module I (4), module II (5), a magnetic fluid (6), and pole teeth (7).

[0020] Module I (4) consists of outer shell I (41), left pole shoe I (42), electromagnet I (43), control line I (44), right pole shoe I (45), and snap ring I (46); Module II (5) consists of left pole shoe II (51), control line II (52), electromagnet II (53), right pole shoe II (54), outer shell II (55), and snap ring II (56);

[0021] The connection between the various parts of the device is as follows: sealing rings are installed in the grooves on the outer ring surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54); pole teeth (7) are machined on the inner circular surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54);

[0022] The assembly process of module I (4) is as follows: install the left pole shoe I (42) and electromagnet I (43) into the outer shell I (41), connect the control line I (44) to the electromagnet I (43) through the through hole on the outer shell I (41), and then install the right pole shoe I (45) and snap ring I (46) into the outer shell I (41). The through hole on the outer shell I (41) through which the control line I (44) passes is sealed with sealant.

[0023] The assembly process of module II (5) is as follows: install the left pole shoe II (51) and electromagnet II (53) into the housing II (55), connect the control line II (52) to the electromagnet II (53) through the through hole on the housing II (55), and then install the right pole shoe II (54) and snap ring II (56) into the housing II (55). The through hole on the housing II (55) through which the control line II (52) passes is sealed with sealant.

[0024] Module I (4) is bolted to the housing (2), and control line I (44) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet I (43) radially. Magnetic liquid (6) is injected into the sealed gap between left pole shoe I (42) and right pole shoe I (45) and the outer surface of the rotating shaft (1). Here, magnetic liquid (6) gathers between left pole shoe I (42) and right pole shoe I (45).

[0025] Module II (5) is installed onto module I (4) by bolt connection. Control line II (52) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet II (53) along the axial direction. Magnetic liquid (6) is injected into the sealing gap between the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1). Here, magnetic liquid (6) gathers in the sealing gap between the pole teeth (7) on the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1).

[0026] Among them, Module I (4) and Module II (5) have the same structure. The modular structure makes it easy to replace or add or remove to suit different sealing occasions. The control unit (3) can control the alternating magnetization direction of electromagnet I (43) and electromagnet II (53). The electromagnet in the module that plays a sealing role is axially magnetized. As the shaft (1) continues to rotate, the magnetic liquid in this module is continuously sheared, causing the temperature to gradually rise. At this time, the magnetization direction of the electromagnet in the other module changes from radial to axial and begins to play a sealing role. When the sealing gap in this module is filled with enough magnetic liquid, the magnetization direction of the electromagnet in the module that originally played a sealing role changes from axial to radial. The magnetic liquid here leaves the sealing gap and gathers between the two pole shoes. The temperature begins to drop. This process is continuously cyclical during the rotation of the shaft (1), which avoids the magnetic liquid being continuously sheared, so that the magnetic liquid (6) in each module has time to dissipate heat and ensures that at least one electromagnet in the module is axially magnetized.

[0027] The rotating shaft (1), left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54) are all 2Cr13 with good magnetic permeability;

[0028] The box body (2), outer shell I (41) and outer shell II (55) are all made of non-magnetic materials;

[0029] The composition of the magnetic circuit is explained below: When electromagnet I (43) is axially magnetized, the magnetic field starts from the N pole at the left end of electromagnet I (43), passes through the left pole shoe I (42), the magnetic liquid (6), the rotating shaft (1), the magnetic liquid (6) and the right pole shoe I (45) to reach the S pole at the right end of electromagnet I (43); when electromagnet I (43) is radially magnetized, there are two magnetic circuits. One is that the magnetic field starts from the N pole at the upper end of electromagnet I (43), passes through the left pole shoe I (42) and the magnetic liquid (6) to reach the S pole at the lower end of electromagnet I (43), and the other is that the magnetic field starts from the N pole at the upper end of electromagnet I (43), passes through the right pole shoe I (45) and the magnetic liquid (6) to reach the S pole at the lower end of electromagnet I (43); since the construction of module I (4) and module II (5) is the same, the magnetic circuit of the magnetic field generated by electromagnet II (53) will not be described again.

[0030] This embodiment only illustrates the case with the minimum number of modules, that is, only module I (4) and module II (5), and does not mean that the present invention only has module I (4) and module II (5). The number of modules can be increased according to the actual application.

Claims

1. An alternating magnetic liquid sealing device, characterized in that, The device includes: a rotating shaft (1), a housing (2), a control unit (3), module I (4), module II (5), a magnetic fluid (6), and pole teeth (7); Module I (4) consists of outer shell I (41), left pole shoe I (42), electromagnet I (43), control line I (44), right pole shoe I (45), and snap ring I (46); Module II (5) consists of left pole shoe II (51), control line II (52), electromagnet II (53), right pole shoe II (54), outer shell II (55), and snap ring II (56); The connection between the various parts of the device is as follows: sealing rings are installed in the grooves on the outer ring surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54); pole teeth (7) are machined on the inner circular surfaces of the left pole shoe I (42), right pole shoe I (45), left pole shoe II (51) and right pole shoe II (54); The assembly process of module I (4) is as follows: install the left pole shoe I (42) and electromagnet I (43) into the outer shell I (41), connect the control line I (44) to the electromagnet I (43) through the through hole on the outer shell I (41), and then install the right pole shoe I (45) and snap ring I (46) into the outer shell I (41). The through hole on the outer shell I (41) through which the control line I (44) passes is sealed with sealant. The assembly process of module II (5) is as follows: install the left pole shoe II (51) and electromagnet II (53) into the housing II (55), connect the control line II (52) to the electromagnet II (53) through the through hole on the housing II (55), and then install the right pole shoe II (54) and snap ring II (56) into the housing II (55). The through hole on the housing II (55) through which the control line II (52) passes is sealed with sealant. Module I (4) is bolted to the housing (2), and control line I (44) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet I (43) radially. Magnetic liquid (6) is injected into the sealed gap between left pole shoe I (42) and right pole shoe I (45) and the outer surface of the rotating shaft (1). Here, magnetic liquid (6) gathers between left pole shoe I (42) and right pole shoe I (45). Module II (5) is installed onto module I (4) by bolt connection. Control line II (52) is connected to control unit (3). Control unit (3) provides current to magnetize electromagnet II (53) along the axial direction. Magnetic liquid (6) is injected into the sealing gap between the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1). Here, magnetic liquid (6) gathers in the sealing gap between the pole teeth (7) on the left pole shoe II (51) and the right pole shoe II (54) and the outer circular surface of the rotating shaft (1).

2. The alternating magnetic liquid sealing device according to claim 1, characterized in that: Module I (4) and Module II (5) have the same structure. The modular structure makes it easy to replace or add or remove modules to suit different sealing occasions. In order to ensure that the magnetic liquid under the sealing gap has time to cool and dissipate heat, the sealing device should have at least Module I (4) and Module II (5) at the same time, that is, at least two modules.

3. The alternating magnetic liquid sealing device according to claim 1, characterized in that: The control unit (3) can control the alternating magnetization directions of electromagnet I (43) and electromagnet II (53). The electromagnet in the module that performs the sealing function is axially magnetized. As the shaft (1) continues to rotate, the magnetic liquid (6) in this module is continuously sheared, causing the temperature to gradually rise. At this time, the magnetization direction of the electromagnet in the other module changes from radial to axial and begins to perform the sealing function. When the sealing gap in this module is filled with enough magnetic liquid (6), the magnetization direction of the electromagnet in the module that originally performed the sealing function changes from axial to radial. The magnetic liquid (6) leaves the sealing gap and gathers between the two pole shoes, and the temperature begins to decrease. This process is continuously cyclical during the rotation of the shaft (1), which avoids the magnetic liquid being continuously sheared, allows the magnetic liquid (6) in each module to have time to dissipate heat, and ensures that at least one electromagnet in the module is axially magnetized.

Images