Magnetic field liquid pressure difference sealing performance-rheological property synchronous measurement system

Abstract

The utility model discloses a magnetic field liquid pressure difference sealing performance-rheological property synchronous measurement system which comprises a rheometer main body, a sealing rotor structure, a pneumatic pressurizing device, a temperature control and measurement device and a computer measurement and control device, the pneumatic pressurizing device comprises a constant pressure pump and a gas storage bottle, and is connected with the sealing rotor structure through a vent hole in the shell; the temperature control and measurement device comprises a temperature controller and a temperature control execution module which is arranged on the side wall of an outer cylinder at one end, close to the magnetic liquid area, of the magnetic function unit; the computer measurement and control device is connected with the optical encoder, the pressure sensor, the temperature controller and the torque control type motor. The system can simulate and test the sealing effect and rheological property of the magnetic liquid in a static state and a dynamic state, explores the actual influence of the magnetic liquid on the sealing property when the magnetic liquid flows, and supports the rheological test under the condition of multi-field coupling of a flow field, a magnetic field and a temperature field.

Description

Technical Field

[0001] This utility model belongs to the technical field of magnetic liquid (magnetic fluid) measurement system, and in particular, relates to a synchronous measurement system for magnetic field liquid pressure difference sealing performance and rheological performance. Background Technology

[0002] With the deepening of industrial applications in my country, magnetic fluid sealing technology has gained increasing attention from the industry due to its unique advantages. This technology has matured in many aspects, possessing advantages such as low leakage rate, long lifespan, corrosion resistance, resistance to high and low temperatures, and wear-free operation, providing reliable sealing solutions for petrochemical, aerospace, energy, and nuclear industries. However, in certain specific fields, such as deep-sea exploration, high-pressure oil and gas extraction, and high-performance pump and valve systems, these operating conditions often present significant pressure differential challenges, placing more stringent requirements on the performance of magnetic fluid seals. Torque control of sealing devices and the stability of the magnetic fluid interface require in-depth research into the rheological properties of magnetic fluids.

[0003] Traditional rheometers cannot test the sealing performance and rheological behavior of magnetic fluids in actual sealing environments. Currently, friction and sealing performance in magnetic fluid seals can be tested separately, but there is little focus on the simultaneous measurement of pressure differential sealing performance and rheological performance of magnetic fluids under specific operating conditions. The coupling effect of pressure differential sealing performance and rheological performance is lacking, and there is no research on the microscopic mechanism.

[0004] As described in the paper "Theoretical Analysis and Experimental Studies on Torque Friction in Magnetic Fluid Seals," an experimental setup was designed to study torque friction in magnetorheological fluid seals. The setup consisted of a torque sensor 1 driven by an electric motor and a test chamber 2. A sealing bushing 16 was mounted on shaft 17, along with four sealing stages 18 and a magnetic fluid 19. The seal was also composed of poles 9 and 14, which were made of ferromagnetic material. The magnetic field source was an axially polarized permanent magnet 11. Thermal stability during the test was ensured by fluid flow through channels 10 and 15. Channels 7, 8, 12, and 13 were made of paramagnetic material. During measurement, the entire test chamber 2 moved towards the sealing bushing. Shaft 6 moved along a guide rail, mounted in bracket 4. Screws 3 were used to accurately adjust the final distance. The torque sensor measured the frictional force generated by the ferromagnetic fluid. However, the magnetic fluid was placed in the gap between sealing stages 18 and poles 9, and did not directly form a magnetic circuit with the shaft, which differed from the actual operating environment. Furthermore, the operating environment of differential pressure seals was not simulated.

[0005] Existing patent publication number CN113532707A discloses a precise measurement system for radial sealing torque of magnetic liquids, including a rheometer electromagnet module, a base, a set screw, an internal hex bolt, a housing, a rotating shaft, a stationary ring of a through-hole air slip ring, a moving ring of a through-hole air slip ring, a rheometer rotating shaft, a rigid coupling, an air nozzle, and an air pipe. A magnetic circuit is formed between the rheometer electromagnet module, the housing, and the rotating shaft. The magnetic field strength can be adjusted by changing the power supply current to the electromagnet. However, this patent focuses on optimizing the magnetic field strength and mechanical structure, without addressing the research on the coupling effects of multiple physical fields such as temperature and flow fields, and therefore cannot comprehensively reflect the sealing performance under complex actual working conditions; it also does not involve simulating and testing the sealing effect and rheological properties of magnetic liquids under static and dynamic conditions. Utility Model Content

[0006] This invention primarily addresses the problem that traditional rheometers cannot test the sealing performance and rheological behavior of magnetic fluids in actual sealed environments. Currently, tests are conducted on friction and sealing performance in magnetic fluid seals, but little attention is paid to the simultaneous measurement of differential pressure sealing performance and rheological performance of magnetic fluids under specific operating conditions. There is a lack of research on the coupling effect of differential pressure sealing performance and rheological performance, and no research on the microscopic mechanisms involved. Therefore, this invention proposes a system for the simultaneous measurement of differential pressure sealing performance and rheological performance of magnetic fluids.

[0007] A synchronous measurement system for magnetic field-liquid pressure difference sealing performance and rheological performance includes a rheometer body, a sealed rotor structure, a pneumatic pressurization device, a temperature control and measurement device, and a computer control system. The rheometer body includes a motor mounting base, a torque-controlled motor, an optical encoder, a coupling, bearings, a shaft, and a rotor. The sealed rotor structure includes a magnetic functional unit, a non-magnetic fixed assembly, and a housing, with seals provided on the mating surfaces of each part. The pneumatic pressurization device includes a constant pressure pump and a gas storage cylinder, connected to the sealed rotor structure through a vent hole on the housing. The temperature control and measurement device includes a temperature controller and a temperature control execution module disposed on the outer cylindrical sidewall of the magnetic functional unit near the magnetic liquid region. The computer control system connects the optical encoder, pressure sensor, temperature controller, and torque-controlled motor to achieve synchronous data acquisition and dynamic control.

[0008] Furthermore, the housing is a concentric cylindrical structure, and the internal sealing structure consists of a magnetic functional unit and a non-magnetic fixing assembly, with a magnetic fluid inside the housing. The magnetic functional unit is a permanent magnet, and the non-magnetic fixing assembly includes an upper constraint component and a lower support platform. A pressure sensor is installed on the inner wall of the upper constraint component near the magnetic fluid. The permanent magnet achieves bidirectional positioning through the non-magnetic fixing assembly, which includes the upper constraint component and the lower support platform, both of which are sealed to the housing using rubber sealing rings.

[0009] Furthermore, the magnetic functional unit includes pole shoes and pole teeth; the permanent magnet, pole shoes, pole teeth, magnetic fluid, and rotor constitute a closed magnetic circuit, and the contact surfaces of the components constituting the circuit are provided with sealant.

[0010] Furthermore, each of the pole shoes is equipped with a temperature control module on the outer cylindrical sidewall near the magnetic liquid region for measuring and adjusting the temperature of the magnetic liquid; and each of the pole teeth is equipped with a pressure sensor on the cavity wall.

[0011] Furthermore, the pole teeth of the pole shoe are rectangular, single-sided beveled, or double-sided beveled to adapt to different sealing gap requirements.

[0012] Furthermore, the temperature control execution module includes a temperature measuring element and a temperature adjusting element. The output end of the temperature measuring element is externally connected to the input end of the temperature controller to realize data acquisition, which is used to feed back the actual temperature of the magnetic liquid to the temperature controller. The temperature adjusting element is driven by the output end of the temperature controller to perform temperature adjustment.

[0013] Furthermore, the temperature control execution module is fixed to the outer cylindrical surface of the permanent magnet pole using a high thermal conductivity epoxy resin bonding process. It is also connected to the temperature controller to receive control signals, adjust the current magnitude, and construct a closed-loop temperature control system.

[0014] Furthermore, the motor mounting base is fixed to the motor frame on the shaft end face of the housing by screws and spring washers. The motor frame is vertically mounted on the shaft end flange face of the housing using an L-shaped support structure and is axially constrained by locating pins.

[0015] Furthermore, the torque-controlled motor is a coreless motor used to control torque.

[0016] Furthermore, the central part of the rotating shaft is radially and axially positioned using angular contact bearings, air bearings, or magnetic levitation bearings. This reduces resistance and ensures a uniform and consistent gap between the rotor and the pole teeth, thereby guaranteeing a uniform distribution of the magnetic fluid within this gap.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] 1. This utility model includes a rheometer body, a sealed rotor structure, a pneumatic pressurization device, a temperature control and measurement device, and a computer measurement and control system. The rheometer body includes a motor mounting base, a torque-controlled rotary motor, a high-rigidity coupling, bearings, a rotating shaft, an optical encoder, and a rotor. This utility model, using a rheometer body and a pneumatic pressurization device, can simultaneously test the differential pressure sealing performance and rheological behavior of magnetic liquids under simulated actual sealing environments (non-uniform magnetic field, narrow annular gap), revealing the coupling mechanism between the two and providing direct data support for the optimization of sealing materials. It can simulate and test the sealing effect and rheological performance of magnetic liquids under static and dynamic conditions, exploring the actual impact of magnetic liquid flow on sealing performance. It supports rheological testing under multi-field coupling conditions of flow field, magnetic field, and temperature field. Furthermore, the entire measurement system has a simpler structure, is more compact, and is easier to operate.

[0019] 2. This invention utilizes a closed magnetic circuit composed of a magnetic functional unit, a rotor, and a magnetic fluid, combined with a rotating shaft design, to realistically reproduce the magnetic field distribution and stress state of the magnetic fluid in an actual sealed structure. A constant-pressure pump is employed to precisely regulate the air pressure, supporting continuous simulation of static and dynamic pressure environments, covering complex operating conditions from low to high pressure, and improving the engineering applicability of the test results.

[0020] 3. This invention utilizes a closed-loop temperature control system (temperature sensing element + temperature regulating element) to precisely control the temperature of magnetic fluids, study the influence of temperature on sealing performance and rheological behavior, and expand the testing dimensions. Combined with a computer-based measurement and control system, it achieves synchronous data acquisition and dynamic regulation under multi-field coupling conditions, comprehensively evaluating the overall performance of the magnetic fluids. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the synchronous measurement system of this utility model;

[0022] Figure 2 This is a schematic diagram of the sealed rotor structure of this utility model;

[0023] Figure 3 This is a schematic diagram of the sealed rotor structure of this utility model, including pole shoes and pole teeth;

[0024] Figure 4 This is a partial enlarged view of the pole teeth of this utility model;

[0025] Figure 5 This is a connection diagram of the computer measurement and control system of this utility model;

[0026] Figure 6 This is a schematic diagram of the pole tooth structure of the pole shoe of this utility model;

[0027] Figure 7 This is a schematic diagram of the camera of this utility model.

[0028] In the above diagram, 1. Optical encoder; 2. Torque-controlled motor; 3. Shaft; 4. High-rigidity coupling; 5. Upper bearing end cover; 6. Bearing; 7. Bearing mounting sleeve; 8. Bearing positioning sleeve; 9. Lower bearing end cover; 10. Coupling; 11. Rotor; 12. Motor mounting base; 13. Screws and spring washers; 14. Motor frame; 15. Housing; 16. Upper constraint assembly; 17. Rubber seal ring; 18. Permanent magnet; 19. Lower support platform; 20. Pressure sensor; 21. Temperature control actuator module; 22. Magnetic fluid; 23. Temperature controller; 24. Gas storage cylinder; 25. Constant pressure pump; 26. Computer; 27. Pole shoe; 28. Pole gear; 29. ​​Data acquisition card; 30. High-magnification camera; 31. Bracket. Detailed Implementation

[0029] To clearly illustrate the technical features of this utility model application, the present utility model will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0031] Furthermore, in the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," 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 communication connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] In this utility model, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0034] Example 1

[0035] like Figure 1 As shown, a synchronous measurement system for sealing performance and rheological properties of magnetic field liquid pressure difference includes a rheometer body, a sealed rotor structure, a pneumatic pressurization device, a temperature control and measurement device, and a computer control system. The rheometer body includes a motor mounting base 12, an optical encoder 1, a torque-controlled motor 2, a high-rigidity coupling 4, a bearing 6, a bearing positioning cylinder 8, a bearing mounting sleeve 7, a rotating shaft 3, and a rotor 11. The sealed rotor structure includes a permanent magnet 18, an upper constraint assembly 16, a lower support platform 19, a rotor 11, and a housing 15, with seals provided on the mating surfaces between each part. The pneumatic pressurization device includes a constant pressure pump 25 and a gas storage cylinder 24, which are connected to the sealed rotor structure through vent holes on the housing 15. The temperature control and measurement device includes a temperature controller 23 and a temperature control execution module 21 disposed on the outer cylindrical sidewall of the permanent magnet 18 near the magnetic liquid 22 region. Figure 7 As shown, the computer measurement and control device is connected to the optical encoder 1, pressure sensor 20, temperature controller 23 and torque control motor 2 to realize synchronous data acquisition and dynamic control.

[0036] In this embodiment, as Figure 1 , Figure 5As shown, the rheometer body is used to simulate the rheological conditions under sealed magnetic liquid application conditions, and to study the rheological behavior of magnetic liquids under non-uniform magnetic fields and narrow annular gaps. The rheometer body includes a motor mounting base 12, an optical encoder 1, a torque-controlled motor 2, a coupling 10, a bearing 6, a bearing positioning sleeve 8, a bearing mounting sleeve 7, a rotor 11, and a rotating shaft 3. Specifically, the optical encoder 1 is connected to the analog input interface B2 of the data acquisition card 29 via cable A1. The torque-controlled motor 2 is a coreless motor to reduce inertia and achieve direct torque control. One end of the high-rigidity coupling 4 is connected to the torque-controlled motor 2 via a spline, and the other end is connected to the input end of the rotating shaft 3 via a flat key, thus realizing torque transmission. The shaft 3 is precisely radially positioned using angular contact bearings or air bearings 6 in the middle, ensuring a uniform and consistent clearance between the rotor 11, permanent magnet 18, upper constraint assembly 16, and lower support platform 19. This guarantees the uniform distribution of magnetic fluid 22 within the clearance. Axially, the bearing 6 is securely fixed together with the upper bearing end caps 5 and lower bearing end caps 9, stepped shaft shoulders, and bearing positioning cylinders 8, ensuring the stability of the shaft 3 during operation. The output end of the shaft 3 is connected to the rotor 11 via a high-rigidity coupling 10. Within the sealed structure, the rotor 11, permanent magnet 18, and magnetic fluid 19 form a magnetic circuit, realistically replicating the magnetic field distribution and stress state of the magnetic fluid in the actual sealed structure.

[0037] like Figure 2 As shown, in this embodiment, the sealed rotor structure consists of a permanent magnet 18, an upper constraint assembly 16, a lower support platform 19, a rotor 11, and a housing 15. After the magnetic fluid 22 is injected, the permanent magnet 18, the magnetic fluid 22, and the rotor 11 form a closed magnetic circuit, realistically replicating the magnetic field distribution and stress state of the magnetic fluid in the actual sealed structure. To prevent leakage, sealant is provided at the contact surfaces between the parts constituting the magnetic circuit, and rubber sealing rings 17 are used to seal the permanent magnet 18, the upper constraint assembly 16, the lower support platform 19, and the housing 15. The housing 15, as a container, has a concentric cylindrical structure and is used to fix and install sealing components and bearings. The motor mounting base 12 is fixedly mounted on the motor frame 14 on the shaft end face of the housing 15 by screws and spring washers 13. The motor frame 14 adopts an "L-shaped" support structure and is vertically installed on the shaft end flange face of the housing 15, and axial constraint is achieved by locating pins.

[0038] like Figure 1 and Figure 5As shown, a pressure sensor 20 is installed on the inner wall of the end face near the magnetic liquid on the upper constraint assembly 16 and is connected to the analog input interface B3 of the data acquisition card 29 via cable A2. A temperature control execution module 21 is installed on the outer cylindrical side wall of the permanent magnet 18 near the magnetic liquid 22 region. The temperature control execution module 21 includes a temperature measuring element and a temperature adjusting element, and is connected to the temperature controller B1 via cable A3 to acquire data and feed back the actual temperature of the magnetic liquid 22 to the temperature controller 23. The temperature adjusting element is driven by the output of the temperature controller to achieve temperature measurement and adjustment of the magnetic liquid 22. The temperature control execution module 21 is fixed to the outer cylindrical side of the permanent magnet 18 using a high thermal conductivity epoxy resin bonding process, and is connected to the temperature controller 23 to receive control signals and adjust the current magnitude, thereby constructing a closed-loop temperature control system to achieve temperature control. Through the closed-loop temperature control system (temperature measuring element + temperature adjusting element), the temperature of the magnetic liquid 22 is precisely controlled, and the influence of temperature on sealing performance and rheological behavior is studied, expanding the testing dimensions.

[0039] Example 2

[0040] like Figure 3 As shown, a synchronous measurement system for magnetic field liquid pressure difference sealing performance and rheological performance includes a rheometer body, a sealed rotor structure, a pneumatic pressurization device, a temperature control and measurement device, and a computer measurement and control system. The rheometer body includes a motor mounting base 12, an optical encoder 1, a torque-controlled motor 2, a high-rigidity coupling 4, a bearing 6, a bearing positioning cylinder 8, a bearing mounting sleeve 7, a rotor 11, and a rotating shaft 3. The sealed rotor structure includes pole teeth 28, pole shoes 27, a permanent magnet 18, a rotor 11, and a housing 15, with seals provided on the mating surfaces between each part. The pneumatic pressurization device includes a constant pressure pump 25 and a gas storage cylinder 24, and is vented through the housing 15. The structure includes a sealed rotor with a hole connection; the temperature control and measurement device includes a temperature controller 23 and a temperature control execution module 21 located on the outer cylindrical sidewall of the pole shoe 27 near the magnetic liquid region. This module includes a temperature measuring element and a temperature adjusting element, connected to the temperature controller via cable A4 (denoted as B1). It acquires data and feeds back the actual temperature of the magnetic liquid 22 to the temperature controller 23. The temperature adjusting element is driven by the output of the temperature controller for temperature regulation, thus achieving temperature measurement and adjustment of the magnetic liquid 22. The computer control device connects to the optical encoder 1, pressure sensor 20, temperature control execution module 21, and hollow cup motor 2 to achieve synchronous data acquisition and dynamic control. Figure 6 As shown, the shape of the pole tooth 28 can be rectangular, single-sided oblique, or double-sided oblique, etc. In this embodiment, a rectangular pole tooth 28 is used to fit a uniform gap.

[0041] like Figure 4 and Figure 5As shown, this embodiment focuses on simulating the sealing performance under high pressure differential conditions. The sealing rotor structure adopts rectangular pole teeth 28, and pressure sensors 20 are installed in the cavity walls between the pole teeth 28. The pressure sensors 20 are connected to the data acquisition card 29 via cables, as shown below. Figure 4 Cables A5 through A8 are connected to analog input interfaces B4 through B7 of data acquisition card 29. Data acquisition card 29 transmits data to computer 26 via USB data cable. The middle of shaft 3 uses an air bearing for radial positioning to ensure uniform gap between rotor 11 and pole teeth 28.

[0042] The computer-controlled measurement and control system includes a computer 26 and a data acquisition card 29, connected to an optical encoder 1, a pressure sensor 20, a temperature controller 23, and a coreless motor. The computer 26 dynamically controls the rotational speed of the coreless motor and applies stress to generate a constant shear rate. When the shear flow reaches a steady state, the torque is measured. Using known parameters such as the clearance and rotor 11 geometry, the computer 26 can calculate fluid performance parameters under different shear rate conditions, such as viscosity, strain, storage modulus, and loss modulus. An external pneumatic pressurization device has a threaded through-hole on the housing 15. An external gas cylinder 24 is connected to the vent as a gas source. The gas pressure is controlled by a constant-pressure pump 25. Different pressure gases are input through the vent of the housing 15 to simulate deep-sea or high-pressure oil and gas extraction environments.

[0043] During testing, a constant pressure pump 25 applies a constant air pressure, and a coreless motor drives the rotor 11 to generate shear flow. A computer-controlled measurement and control system (computer 26 + data acquisition card 29) simultaneously collects temperature, torque, and pressure data, analyzes the rheological behavior (such as viscosity temperature dependence) and static and dynamic sealing performance of the magnetic liquid 22 at different temperatures, and provides experimental basis for the selection of sealing materials under extreme temperature environments.

[0044] Example 3

[0045] In this embodiment, the housing 15 is made of pressure-resistant transparent material and is equipped with a high-magnification camera 30 to facilitate real-time observation of the flow pattern and rheological behavior of the magnetic liquid 19 in the sealed gap.

[0046] As shown in Figure 7, a high-magnification camera 30 is mounted on a bracket 31. The high-magnification camera 30 can magnify up to 100 times. It focuses on the magnetic liquid 22 at the sealing gap in the main sealing area of ​​the magnetic liquid 22, and transmits the changes in real time through the computer on the left.

[0047] Obviously, the above-described embodiments of this utility model are merely examples for clearly illustrating this utility model and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system, characterized in that, The device comprises a rheometer body, a sealed rotor structure, a pneumatic pressurization device, a temperature control and measurement device, and a computer-controlled measurement and control system. The rheometer body includes a motor mounting base, a torque-controlled motor, an optical encoder, a coupling, bearings, a shaft, and a rotor. The sealed rotor structure includes a magnetic functional unit, a non-magnetic fixed assembly, and a housing, with seals provided on the mating surfaces of each part. The pneumatic pressurization device includes a constant pressure pump and a gas storage cylinder, connected to the sealed rotor structure through a vent hole on the housing. The temperature control and measurement device includes a temperature controller and a temperature control execution module located on the outer cylindrical sidewall of the magnetic functional unit near the magnetic liquid region. The computer-controlled measurement and control system connects the optical encoder, pressure sensor, temperature controller, and torque-controlled motor to achieve synchronous data acquisition and dynamic control.

2. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 1, characterized in that, The housing is a concentric cylindrical structure. The internal sealing structure of the housing consists of a magnetic functional unit and a non-magnetic fixing assembly, and the housing contains a magnetic liquid. The magnetic functional unit is a permanent magnet, and the non-magnetic fixing assembly includes an upper constraint component and a lower support platform. A pressure sensor is provided on the inner wall of the end face of the upper constraint component near the magnetic liquid.

3. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 2, characterized in that, The magnetic functional unit includes pole shoes and pole teeth. The permanent magnet, pole shoes, pole teeth, magnetic fluid, and rotor form a closed magnetic circuit, and the contact surfaces of the components forming the circuit are provided with sealant.

4. The synchronous measurement system for magnetic field liquid pressure difference sealing performance and rheological performance according to claim 3, characterized in that, Each of the pole shoes has a temperature control module installed on the outer cylindrical sidewall near the magnetic liquid region for measuring and adjusting the temperature of the magnetic liquid; each of the pole teeth has a pressure sensor installed on the cavity wall.

5. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 4, characterized in that, The pole teeth of the pole shoe are rectangular, single-sided beveled, or double-sided beveled to adapt to different sealing gap requirements.

6. The synchronous measurement system for magnetic field liquid pressure difference sealing performance and rheological performance according to claim 1, characterized in that, The temperature control execution module includes a temperature measuring element and a temperature adjusting element. The output of the temperature measuring element is externally connected to the input of the temperature controller to realize data acquisition, which is used to feed back the actual temperature of the magnetic liquid to the temperature controller. The temperature adjusting element is driven by the output of the temperature controller to perform temperature adjustment.

7. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 6, characterized in that, The temperature control execution module is fixed to the outer cylindrical surface of the permanent magnet pole using a high thermal conductivity epoxy resin bonding process.

8. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 1, characterized in that, The motor mounting base is fixed to the motor frame on the shaft end face of the housing by screws and spring washers. The motor frame is vertically installed on the shaft end flange face of the housing using an L-shaped support structure and is axially constrained by locating pins.

9. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 1, characterized in that, The torque-controlled motor is a coreless motor used to control torque.

10. The magnetic field liquid differential pressure seal performance-rheological property synchronous measurement system according to claim 1, characterized in that, The central part of the rotating shaft is positioned radially and axially using angular contact bearings, air bearings, or magnetic levitation bearings.

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