CN106950062B - Test experiment table for anti-drop performance of magnetic suspension bearing - Google Patents

Abstract

The invention discloses a test bench for the anti-drop performance of magnetic suspension bearings, which includes: a shell; a radial bearing stator, an axial bearing stator, a motor stator and two protective bearings, the radial bearing stator, the axial bearing stator and the motor stator. Both are installed in the casing, and the two protective bearings are installed outside the casing and located at the left and right ends of the casing; the magnetic levitation shaft system is located in the casing and the left and right ends respectively extend out of the casing; two contact force measurement platforms , two contact force measurement platforms are set outside the shell and located at the left and right ends of the shell respectively. The protective bearing is installed on the contact force measurement platform. Each contact force measurement platform includes four piezoelectric sensors. The test bench for testing the anti-drop performance of the magnetic suspension bearing according to the present invention is suitable for evaluating the reliability and service life of the protective bearing, studying the anti-drop performance of the protective bearing, and has high measurement accuracy.

Description

Test bench for magnetic bearing drop resistance

Technical field

The present invention relates to the technical field of magnetic suspension bearings, and specifically to a test bench for testing the anti-drop performance of magnetic suspension bearings.

Background technique

Magnetic bearings use electromagnetic force to make the shaft system and bearings rotate in relative suspension. They have the advantages of no friction resistance, high operating accuracy, adjustable stiffness and damping, and are especially suitable for use in high-speed, low-loss, and low-noise situations. Protective bearings (for example, rolling bearings) are auxiliary support structures for magnetic suspension bearings. One of its main functions is that when the magnetic suspension bearing fails (for example, the magnetic suspension shaft system falls), the protective bearing can temporarily support the high-speed rotating shaft system to allow it to re- Hover or safely slow down.

When the high-speed rotating magnetic levitation shaft system falls, violent collision and friction will occur between the shaft system and the inner ring protecting the bearing. Since there is a small gap between the shafting and the inner ring that protects the bearing, the trajectory response of the shafting during a drop is very complex, including pendulum vibration, mixed friction, bounce, and full circumferential friction. The contact force between the shaft system and the protective bearing has high amplitude and high frequency characteristics. Huge vibration and impact are likely to cause the protective bearing to fail, or even cause the magnetic bearing and rotor to be severely burned.

At present, there is still a lack of effective technical means for testing the anti-drop performance of protective bearings, so there is still a lot of work to be done to predict the service life of protective bearings. Bench experiments are an important means to study the anti-drop performance of magnetic suspension bearings. That is, high-speed drop experiments of magnetic suspension shafts are carried out by simulating the actual operating conditions of magnetic suspension bearings. However, bench experiments are usually only used to study the impact of different parameters on the axis. The influence of trajectory and vibration does not involve the life evaluation and anti-drop performance research of the protective bearing.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a test bench for the anti-drop performance of magnetic levitation bearings. The test bench for the anti-drop performance of magnetic levitation bearings is suitable for evaluating the reliability and service life of protective bearings, and studying the anti-drop performance of protective bearings, and The measurement accuracy is high.

A test bench for testing the anti-drop performance of magnetic suspension bearings according to an embodiment of the present invention includes: a shell; a radial bearing stator, an axial bearing stator, a motor stator and two protection bearings, the radial bearing stator, the axial bearing The stator and the motor stator are both installed in the housing, and the two protective bearings are installed outside the housing and located at the left and right ends of the housing respectively; a magnetic levitation shaft system, the magnetic levitation shaft system is located at the The magnetic levitation shaft system passes through the radial bearing stator, the axial bearing stator, the motor stator and the protective bearing respectively; two contact forces Measuring platform, the two contact force measuring platforms are arranged outside the housing and are located at the left and right ends of the housing respectively. The protective bearing is installed on the contact force measuring platform. Each contact force measuring platform includes Four piezoelectric sensors used to measure the contact force between the protective bearing and the magnetic suspension shaft system.

The test bench for the anti-drop performance of the magnetic levitation bearing according to the embodiment of the present invention can simulate actual working conditions, evaluate the reliability and service life of the protective bearing, study the anti-drop performance of the protective bearing, and conduct research on the relationship between the magnetic levitation shaft system and the protective bearing. The measurement accuracy of contact force is relatively high.

In addition, the test bench for testing the anti-drop performance of magnetic suspension bearings according to embodiments of the present invention also has the following additional technical features:

According to some embodiments of the present invention, the housing is fixed on the support by a spring steel pressure band, the contact force measurement platform further includes a frame, and the frame and the support are both installed on the base.

According to some embodiments of the present invention, there are two radial bearing stators and they are respectively located at the left and right ends of the housing. Each of the radial bearing stators has a clearance fit with the housing and is fixed by a housing end cover. In the housing, the housing end cover is threadedly connected to the housing.

According to some embodiments of the present invention, the axial bearing stator is clearance-fitted with the housing and includes: two sub-bearing stators; stator spacers, the two sub-bearing stators are spaced apart by the stator spacers, two The sub-bearing stator and the stator gasket are threadedly connected to the housing.

According to some embodiments of the present invention, the magnetic suspension shaft system includes: a main shaft, the left and right ends of the main shaft both extend out of the housing; a radial bearing rotor, a thrust plate, a motor rotor and a protective sleeve. The radial bearing rotor , the thrust plate, the motor rotor and the protective sleeve respectively correspond to the positions of the radial bearing stator, the axial bearing stator, the motor stator and the protective bearing, and the radial bearing The rotor, the thrust plate and the motor rotor all have an interference fit with the main shaft, the protective sleeve has a clearance fit with the main shaft, and the protective sleeve is fixed on the main shaft through a round nut.

According to some embodiments of the present invention, the test bench for the anti-drop performance of the magnetic suspension bearing also includes a motor water jacket for cooling the motor stator and the housing, and the motor water jacket has an interference fit with the motor stator. And in clearance fit with the housing, the housing is provided with a water inlet and a water outlet respectively connected with the gap between the housing and the motor water jacket.

Advantageously, the water inlet is located at the bottom of the housing and the water outlet is located at the top of the housing.

In some embodiments of the present invention, the left and right ends of the motor water jacket are equipped with first-level sealing rings and second-level sealing rings, and the second-level sealing ring at the left end of the motor water jacket is opposite to The first-stage sealing ring is adjacent to the left end surface of the motor water jacket, and the second-stage sealing ring at the right end of the motor water jacket is adjacent to the right end surface of the motor water jacket relative to the first-stage sealing ring.

Furthermore, the housing is also provided with a leakage port, and the leakage port is located between the adjacent first-level sealing ring and the second-level sealing ring.

Optionally, a zinc rod is provided between the motor water jacket and the casing to prevent corrosion of the motor water jacket and the casing, and the zinc rod is installed on the casing through a plug.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of the drawings

Figure 1 is a cross-sectional view of a test bench for testing the anti-drop performance of a magnetic suspension bearing according to an embodiment of the present invention;

Figure 2 is a perspective view of the shell of a test bench for testing the anti-drop performance of magnetic suspension bearings according to an embodiment of the present invention;

Figure 3 is a perspective view of a radial bearing stator of a test bench for testing the anti-drop performance of magnetic suspension bearings according to an embodiment of the present invention;

Figure 4 is a perspective view of the sub-bearing stator of the test bench for testing the anti-drop performance of the magnetic suspension bearing according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of the main shaft of a test bench for testing the anti-drop performance of magnetic suspension bearings according to an embodiment of the present invention.

Reference signs:

Magnetic bearing drop resistance test bench 100,

Base 1, piezoelectric sensor 2, contact force measurement platform 3, radial displacement sensor 4, housing end cover 5, motor gland 6, housing 7, water outlet 8, motor water jacket 9, motor stator 10, hanging hole 11 , spring steel pressure belt 12, thrust plate 13, radial bearing stator 14, radial bearing rotor 15, protective bearing 16, round nut 17, axial displacement sensor 18, sensor support 19, frame 20, protective sleeve 21 , axial bearing stator 22, stator gasket 23, support 24, leakage port 25, water inlet 26, motor rotor 27, zinc rod 28, plug 29, first-stage sealing ring 30, second-stage sealing ring 31, Spindle 32.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention.

The test bench 100 for testing the anti-drop performance of a magnetic suspension bearing according to an embodiment of the present invention is described below with reference to the accompanying drawings.

As shown in Figures 1 to 5, a test bench 100 for testing the anti-drop performance of a magnetic suspension bearing according to an embodiment of the present invention includes a housing 7, a radial bearing stator 14, an axial bearing stator 22, a motor water jacket 9, and a motor stator 10 , two protective bearings 16, magnetic suspension shafting and two contact force measurement platforms 3.

Specifically, the housing 7 is fixed on the support 24 by a spring steel pressure band 12 through a threaded connection, and the support 24 is connected to the base 1 through bolts. The housing 7 is provided with a lifting hole 11, and the lifting ring is threadedly connected to the lifting hole 11 to facilitate the movement of the housing 7. The radial bearing stator 14, the axial bearing stator 22 and the motor water jacket 9 are all assembled in the housing 7 through clearance fit to ensure coaxiality between the three.

As shown in Figure 1, two radial bearing stators 14 are located at the left and right ends of the housing 7 respectively. The housing end cover 5 is fixed on the housing 7 through threaded connection to fix the radial bearing stator 14. In this way, both the two radial bearing stators 14 can be ensured. The coaxiality between the radial bearing stators 14 makes it easy to disassemble and install multiple times. A rubber gasket is arranged between the housing end cover 5 and the radial bearing stator 14 to evenly distribute the pressure on the radial bearing stator 14 . As shown in Figure 3, the radial bearing stator 14 adopts an octupole structure, and the radial bearing stator 14 is made of laminated silicon steel sheets.

As shown in Figure 4, the axial bearing stator 22 is composed of two sub-bearing stators. The two sub-bearing stators are separated by stator gaskets 23. The stator gaskets 23 ensure the spacing and parallelism between the working surfaces of the two sub-bearing stators. . In the axial direction of the axial bearing stator 22 (that is, the left and right direction shown in the figure), the two sub-bearing stators and the stator gasket 23 are connected in the housing 7 through threaded fasteners; in the radial direction of the axial bearing stator 22 (i.e., the up and down direction shown in the figure), the two sub-bearing stators and the stator gaskets 23 are clearance-fitted with the housing 7 respectively. In this way, the coaxiality between the two sub-bearing stators can be ensured, and it is easy to disassemble and install for multiple times. Install.

The motor stator 10 is connected to the motor water jacket 9 through an interference fit, and the motor gland 6 is threadedly connected to the housing 7 to fix the motor water jacket 9 . The bottom of the housing 7 is provided with a water inlet 26 and the top is provided with a water outlet 8. The water inlet 26 and the water outlet 8 are respectively connected with the gap between the housing 7 and the motor water jacket 9. At the same time, the water inlet 26 is connected to the water pump through a rubber tube. The water outlet is connected, the water outlet 8 is connected to the water tank through a rubber tube, and the water inlet of the water pump is connected to the water tank. In this way, when the motor is running, circulating cooling water can be passed between the motor water jacket 9 and the housing 7 to cool the motor stator 10 and shell 7.

The left and right ends of the motor water jacket 9 are both equipped with a first-stage sealing ring 30 and a second-stage sealing ring 31. The second-stage sealing ring 31 at the left end of the motor water jacket 9 is adjacent to the first-stage sealing ring 30 of the motor water jacket. 9, the second-stage sealing ring 31 on the right end of the motor water jacket 9 is adjacent to the right end surface of the motor water jacket 9 relative to the first-stage sealing ring 30. In this way, the first-stage sealing ring 30 and the second-stage sealing ring 31 To seal the role of circulating cooling water. Further, a leakage port 25 is arranged on the housing 7, and the leakage port 25 is located between the adjacent first-level sealing ring 30 and the second-level sealing ring 31, so that the water leaking between the two-level sealing rings can be promptly removed. discharge.

Preferably, a zinc rod 28 used as a sacrificial anode is provided between the motor water jacket 9 and the casing 7 to prevent corrosion of the motor water jacket 9 and the casing 7 . The zinc rod 28 is installed on the shell 7 through the plug 29, and the plug 29 is threadedly connected to the shell 7, so that the zinc rod 28 can be quickly disassembled and replaced.

The magnetic levitation shaft system includes a main shaft 32, a radial bearing rotor 15, a thrust plate 13, a motor rotor 27 and a protective sleeve 21. The radial bearing rotor 15, the thrust plate 13 and the motor rotor 27 are all connected to the main shaft 32 through interference fit. The radial bearing rotor 15 is made of laminated silicon steel sheets. The protective sleeve 21 is connected to the main shaft 32 through a clearance fit. The round nut 17 used in conjunction with the protective sleeve 21 is fixed on the main shaft 32 through a threaded connection to lock the protective sleeve 21, and the protective sleeve 21 is easy to disassemble and replace. .

There is a measuring point at each of the left and right ends of the main shaft 32, and four radial displacement sensors 4 are arranged at each measuring point, that is, eight radial displacement sensors 4 are arranged at both ends of the main shaft 32 to measure the magnetic levitation axis. The radial displacement of the system is the displacement of the magnetic levitation shaft system along its radial direction, that is, the displacement of the magnetic levitation shaft system in the up and down direction. Among them, each radial displacement sensor 4 is connected to the housing end cover 5 through threads and is located outside the housing 7. The four radial displacement sensors 4 at each measurement point are installed on the housing end cover in a differential installation manner. 5 on. Specifically, two radial displacement sensors 4 are installed on the opposite sides of each measuring point in each direction. For example, each measuring point is provided with one radial displacement sensor in the four directions of up, down, front and back. Sensor 4, thereby eliminating the mechanical coupling component in the dynamic signal.

The axial displacement sensor 18 is used to measure the axial displacement of the main shaft 32 (that is, the displacement of the main shaft 32 along its axial direction, that is, the displacement of the main shaft 32 in the left and right directions). The axial displacement sensor 18 is fixed on the sensor through a threaded connection. On the support 19, the sensor support 19 is connected to the base 1 through bolts. Optionally, both the radial displacement sensor 4 and the axial displacement sensor 18 are eddy current sensors.

Two contact force measurement platforms 3 are respectively arranged on the left and right sides of the housing 7. Each contact force measurement platform 3 includes a frame 20, and the frame 20 is connected to the base 1 through bolts. Each contact force measurement platform 3 is equipped with a protective bearing 16 and four piezoelectric sensors 2. The protective bearing 16 consists of a pair of angular contact ball bearings installed face to face. The piezoelectric sensors 2 are piezoelectric quartz force sensors. Contact force measurement The platform 3 uses the piezoelectric sensor 2 to measure the amplitude and vibration frequency of the contact force between the magnetic suspension shaft system and the protective bearing 16 during the fall process.

Specifically, the four piezoelectric sensors 2 on each contact force measurement platform 3 are respectively arranged in the horizontal direction (i.e., the front and rear direction) and the vertical direction (i.e., the up and down direction shown in the figure). In this way, the magnetic levitation shaft system and protection The contact force between the bearings 16 is transmitted to the piezoelectric sensors 2 arranged along the above four directions respectively in the horizontal and vertical directions. The contact force between the magnetic suspension shaft system and the protective bearing 16 is the contact force in the above four directions. The vector sum of .

The following describes the working principle of the test bench 100 for testing the anti-drop performance of magnetic suspension bearings according to the embodiment of the present invention with reference to the accompanying drawings.

When working, first turn on the water pump, the circulating cooling water enters the motor water jacket 9 from the water inlet 26, the circulating cooling water leaves the motor water jacket 9 from the water outlet 8, the circulating cooling water leaking from the first-stage sealing ring 30 can escape from the leakage port 25 is discharged; then, turn on the power of the radial displacement sensor 4 and the axial displacement sensor 18, and the eddy current sensor outputs the position signal of the magnetic suspension shaft system on the five degrees of freedom to the controller; secondly, turn on the power of the controller, The controller starts to calculate the program and outputs the current command signal; then, the power amplifier is turned on to change the current command signal of the controller into the current in the coil, so that the spindle 32 can float in the radial and axial directions of the spindle 32, thereby achieving Closed-loop feedback control of magnetic bearings; then turn on the asynchronous motor, and the motor stator 10 of the asynchronous motor is connected to the frequency converter. By changing the frequency of the frequency converter, the stepless speed change of the asynchronous motor between 0-18000rpm can be achieved.

Among them, by turning off the frequency converter and the power amplifier at a given speed at the same time, the free fall experiment of the magnetic levitation shaft system at this speed can be carried out. In the drop experiment of the magnetic levitation shaft system, the measurement data of the eddy current sensor is collected through the controller, and the collected measurement data is transmitted to the host computer; each piezoelectric sensor 2 communicates with the signal conditioner, and the signal conditioner transmits the piezoelectric The contact force signal transmitted by sensor 2 is amplified, and then the amplified contact force signal is connected to the high-speed acquisition card, and the high-speed acquisition card then transmits the amplified contact force signal to the host computer. As a result, the host computer completes the display and storage of real-time signals from the eddy current sensor and piezoelectric sensor 2 for post-processing use.

To sum up, according to the test bench 100 for the anti-drop performance of magnetic levitation bearings according to the embodiment of the present invention, it is possible to complete the drop experiment of the magnetic levitation shafting system at the initial rotation speed of 0-18000 rpm (that is, different initial rotation speeds), and record the drop process of the magnetic levitation shafting system. The trajectory of the shafting in the system as well as the amplitude and vibration frequency of the contact force between the magnetic suspension shafting and the protective bearing 16; at the same time, through multiple drop experiments, the life experiments of the protective shaft sleeve 21 and the protective bearing 16 can be carried out to analyze the performance of the protective bearing 16 Anti-drop performance; and by using protective sleeves 21 of different materials or surface treatments, drop experiments and life experiments of sleeves made of different materials or surface treatments can be performed to analyze the anti-drop performance of the protected bearings.

In addition, the test bench 100 uses two contact force measurement platforms 3 to perform drop experiments on two protective bearings 16 at the same time. The two contact force measurement platforms 3 and the main body of the magnetic suspension bearing adopt a split structure, which reduces the contact between the main components of the magnetic suspension bearing. The force measurement platform 3 interferes with the force measurement platform 3, and the piezoelectric sensor 2 can be used to measure the change pattern of the contact force between the magnetic suspension shaft system and the protective bearing 16.

In short, according to the magnetic suspension bearing anti-drop performance test bench 100 according to the embodiment of the present invention, the reliability and anti-drop performance of the protective bearing 16 can be evaluated under simulated actual working conditions; four piezoelectric sensors 2 can be used to measure The amplitude and vibration frequency of the contact force in each direction experienced by the protective bearing 16. The contact force between the magnetic suspension shaft system and the protective bearing 16 is the vector sum of the contact forces measured by the piezoelectric sensors 2 in the above four directions; Moreover, by fixing the housing 7 and the two contact force measurement platforms 3 separately on the base 1, the interference of the support of the housing 7 on measuring the contact force between the magnetic suspension shaft system and the protective bearing 16 is reduced, and the contact force during the fall is improved. Measurement accuracy of force and vibration frequency.

In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "up and down", "left and right", " The orientations or positional relationships indicated by "front and rear", "inner", "outer", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing this document. The invention and simplified description are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore are not to be construed as limitations of the invention. In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "specific embodiments," "preferred embodiments," "examples," or "some examples" or the like is intended to be in conjunction with the description of the embodiment. or examples describe specific features, structures, materials, or characteristics that are included in at least one embodiment or example of the invention. In this specification, schematic representations 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 any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the invention. The scope of the invention is defined by the claims and their equivalents.

Claims (9)

1. The utility model provides a test experiment table of magnetic suspension bearing anti-drop performance which characterized in that includes:

a housing;

the radial bearing stator, the axial bearing stator and the motor stator are all arranged in the shell, and the two protection bearings are all arranged outside the shell and are respectively positioned at the left end and the right end of the shell;

the magnetic suspension shafting is arranged in the shell, the left end and the right end of the magnetic suspension shafting extend out of the shell respectively, and the magnetic suspension shafting passes through the radial bearing stator, the axial bearing stator, the motor stator and the protection bearing respectively;

the two contact force measuring platforms are arranged outside the shell and are respectively positioned at the left end and the right end of the shell, the protection bearing is arranged on the contact force measuring platforms, and each contact force measuring platform comprises four piezoelectric sensors for measuring the contact force between the protection bearing and the magnetic suspension shafting;

the axial bearing stator is in clearance fit with the housing and includes:

two sub-bearing stators;

a stator shim, by which two of the sub-bearing stators are spaced apart;

in the axial direction of the axial bearing stator, the two sub-bearing stators and the stator gasket are connected in the shell through threaded fasteners; the two sub-bearing stators and the stator gasket are respectively in clearance fit with the housing in a radial direction of the axial bearing stator.

2. The test bench for the anti-falling performance of the magnetic suspension bearing according to claim 1, wherein the shell is fixed on a support by a spring steel press belt, and the contact force measurement platform further comprises a frame, and the frame and the support are both installed on a base.

3. The test bench of claim 1, wherein the radial bearing stators are two and are respectively positioned at left and right ends of the housing, each radial bearing stator is in clearance fit with the housing and is fixed in the housing by a housing end cover, and the housing end cover is in threaded connection with the housing.

4. The test bench for anti-drop performance of a magnetic suspension bearing according to claim 1, wherein the magnetic suspension shafting comprises:

the left end and the right end of the main shaft extend out of the shell;

radial bearing rotor, thrust disk, motor rotor and protection axle sleeve, radial bearing rotor thrust disk motor rotor with the protection axle sleeve respectively with radial bearing stator axial bearing stator motor stator with protection bearing position corresponds, just radial bearing rotor thrust disk motor rotor all with main shaft interference fit, the protection axle sleeve with main shaft clearance fit, the protection axle sleeve passes through round nut to be fixed on the main shaft.

5. The test bench of any of claims 1-4, further comprising a motor water jacket for cooling the motor stator and the housing, the motor water jacket being in interference fit with the motor stator and in clearance fit with the housing, the housing being provided with a water inlet and a water outlet in communication with the gap between the housing and the motor water jacket, respectively.

6. The test bench for the anti-drop performance of a magnetic suspension bearing according to claim 5, wherein the water inlet is positioned at the bottom of the housing and the water outlet is positioned at the top of the housing.

7. The test bench for anti-drop performance of a magnetic suspension bearing according to claim 5, wherein a first-stage sealing ring and a second-stage sealing ring are sleeved at the left end and the right end of the motor water jacket, the second-stage sealing ring at the left end of the motor water jacket is adjacent to the left end face of the motor water jacket relative to the first-stage sealing ring, and the second-stage sealing ring at the right end of the motor water jacket is adjacent to the right end face of the motor water jacket relative to the first-stage sealing ring.

8. The test bench of claim 7, wherein a leak is further provided on the housing, the leak being located between the adjacent first and second seal rings.

9. The test bench for the anti-falling performance of the magnetic suspension bearing according to claim 5, wherein a zinc rod for preventing the motor water jacket and the shell from being corroded is arranged between the motor water jacket and the shell, and the zinc rod is installed on the shell through a blocking wire.