A static-rotating loading device for a propeller fan mechanism based on electromagnetic force control

Abstract

The present invention relates to a static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, belonging to the field of aero-engine load simulation. The device disclosed by the present invention includes: axial and radial permanent magnet rings, a propeller fan test piece (3), a radial electromagnet ring (4), a soft body ring (5), an axial electromagnet ring (7), a radial pressure sensor (8), a tension and compression sensor (10), a support, a support seat, and a control unit. The axial and radial permanent magnet rings are respectively installed in the side and top wall surface rings of the propeller fan test piece (3). The radial and axial electromagnet rings are respectively installed in non-contact with the radial and axial permanent magnet rings. The radial electromagnet ring (4) has a radial notch and is installed with a radial pressure sensor (8). A plurality of tension and compression sensors (10) are installed at the end of the axial electromagnet ring (7). By using current control to apply non-contact electromagnetic force on the test piece and using the sensor to feedback force, the present invention has the advantages of closed-loop control loading of force, no binding force interference, good load independent loading property, and simple and reliable electromagnetic force loading.

Description

Technical Field

[0001] The present invention relates to a stationary-rotating loading device for a propeller fan mechanism controlled by electromagnetic force, belonging to the field of aero-engine load simulation. Background Art

[0002] Under stationary test conditions, applying simulated centrifugal loads and aerodynamic loads to a propeller fan test piece can simulate, at a relatively low economic cost, the loading process in which a real hub center piece bears the centrifugal force, axial force, and bending moment transmitted from the propeller fan blades, so as to check whether the strength of the hub center piece meets the standard and test the load-bearing capacity and dynamic response level of the variable pitch hydraulic system. Compared with stationary test conditions, the load simulation in rotating test conditions is closer to the actual loading process of the hub center piece and the variable pitch hydraulic system.

[0003] The hub center piece with a variable pitch mechanism is an important load-bearing component. On the one hand, it needs to bear the centrifugal force, axial force, and bending moment transmitted from the propeller fan blades. On the other hand, it also needs to balance the loads from the variable pitch hydraulic system. When conducting a ground load simulation test on the hub center piece, due to the complex load-bearing form and force transmission route of the test piece, a large number of data measurement points, and different loading methods under rotating and stationary conditions, it often becomes the biggest challenge in test loading.

[0004] At present, the loading methods of domestic blades are mostly independent and separate for rotation and stationary loading. For example, the invention patent with the publication number CN113740370A named "A Hot Spot Simulation Device and Method for a Working Blade" proposes a Stationary state below centrifugal force loading scheme for wire drawing at the top of the blade. There will be interference from binding forces when the test piece deforms; for example, the invention patent with the authorization announcement number CN108760260B named "A Fatigue Test Device and Method for Loading Alternating Aerodynamic Loads on a Wind Turbine Blade" proposes a Under the rotating state distributed alternating aerodynamic load can be loaded on the test blade to more realistically simulate the fatigue load suffered by the blade during actual operation. The mean value and amplitude of the alternating aerodynamic load can be realized by adjusting the rotation speed and pitch angle of the blade respectively. This test scheme cannot be loaded under stationary conditions and has a relatively high test cost.

[0005] Using a rotary joint for the conveying oil circuit under stationary-rotating conditions will have technical problems such as oil leakage caused by unqualified seals or overloaded operation, and the service life of the equipment is much shorter than that of a stationary pure electric control system.

[0006] The load-bearing forms and force transmission routes of the propeller fan and the hub central component of the pitch-changing mechanism under static and rotating working conditions are often inconsistent. Moreover, when the propeller fan simulation component bears loads, the actual and theoretical deviations of the loading force and moment are often caused by the strain displacement at the loading point. How to design a loading device that can work stably and reliably under both static test conditions and rotating test conditions, truly and accurately simulate some of the aerodynamic loads and centrifugal loads received by the propeller fan simulation component, meet the requirements of the maximum axial bending moment, maximum axial force, and maximum radial force, and control the independent loading of various loads according to the load spectrum to the greatest extent, as well as better solve the problems of hydraulic oil leakage and low equipment life, there is currently no good technical solution. Summary of the Invention

[0007] The purpose of the present invention is to provide a static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, aiming to provide an electromagnetic force loading device that has no binding force interference on the propeller fan test piece, precise closed-loop control of force, good independent loading performance of axial force and radial force, can meet both static and rotating conditions, and has almost no oil leakage and a long equipment life.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, comprising: an axial permanent magnet ring, a radial permanent magnet ring, a propeller fan test piece, a radial electromagnet ring, a soft body ring, an electromagnet support frame, an axial electromagnet ring, a radial pressure sensor, an axial tension and compression sensor, a first support, a bearing, a second support and a control unit. The propeller fan test piece includes a tensile rotating joint in the lower half and a "C"-shaped fan body in the upper half. A plurality of propeller fan test pieces are closely arranged and have minute radial cracks to eliminate the interference of circumferential strain force under radial loading. The propeller fan test pieces are installed on the propeller fan pitch interface of the propeller fan wheel disc and are driven to rotate by a rotating shaft. The axial permanent magnet ring and the radial permanent magnet ring are arranged with the same magnetic pole directions (the N poles of the axial permanent magnet ring face the positive axial direction or the negative axial direction, and the N poles of the radial permanent magnet ring diverge or converge in the same radial direction), and are respectively installed in the side wall surface ring and the top wall surface ring of the propeller fan test piece. The radial electromagnet ring and the axial electromagnet ring are respectively installed in non-contact with the axial permanent magnet and the radial permanent magnet. The axial ring on the electromagnet support frame serves as a guide rail for the axial electromagnet ring and also serves as a radial force support for the radial electromagnet ring. The radial electromagnet ring has a radial notch, a first notch axial extension part and a second notch axial extension part. The radial pressure sensor is installed between the two notch axial extension parts to sense the magnitude of the radial force and does not hinder the radial deformation of the radial electromagnet ring. The axial tension and compression sensor is installed at the end of the axial electromagnet ring to sense the magnitude of the axial force. The soft body ring is sandwiched between the radial electromagnet ring and the electromagnet support frame to uniformly compensate for the radial displacement of the radial electromagnet ring during radial loading, so that the radial force is applied as evenly as possible to the propeller fan test piece and reacts on the radial electromagnet ring;

[0010] Due to the counteracting effect of the tensile rotating joint, the propeller fan test piece will not rotate around the midpoint of the blade root during the pitch change process of the propeller fan pitch system. The axial electromagnet ring can apply non-contact axial pressure and tension to the propeller fan test piece during the pitch change process. The magnitude of the magnetic force applied by the axial electromagnet ring to the propeller fan test piece is controlled by the coil current. The axial electromagnet ring needs to ensure that there is no additional load on the propeller fan test piece when there is no loading, that is, there is a compensating current to generate a reverse electromagnetic force to resist the suction force of the permanent magnet on the iron core of the axial electromagnet ring, and by changing the direction of the coil current of the axial electromagnet ring, the applied load can be changed to tension or pressure to achieve bidirectional loading. The radial permanent magnet ring applies a radial force to the propeller fan test piece and also has the technical characteristics of the above-mentioned loading force;

[0011] The static-rotating loading device for a propeller fan mechanism based on electromagnetic force control is supported by the first support and the second support. A bearing is installed on the first support and sleeved on the rotating shaft of the propeller fan wheel disc. The second support is fixedly connected to the electromagnet support frame to form a static loading end for resisting the reaction force transmitted from the electromagnet support frame.

[0012] A static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, characterized in that the structures, magnetic field characteristics, and forces of the radial permanent magnet ring and the axial electromagnet ring have the following characteristics:

[0013] The coil of the radial permanent magnet ring is formed by stacking rectangular coils, which are bent circumferentially along the stacking direction, and then the two ends of the coil are in contact to form a circular coil. The circular coil will form a strong magnetic field with magnetic lines radially outward when passing through direct current, which is used to apply a radial force load to the propeller fan test piece. The radial electromagnetic force ring has a radial notch, a first notch axial extension part, and a second notch axial extension part. The radial pressure sensor is installed between the two notch axial extension parts, and the contact part of the two ends of the coil is placed at the radial notch to ensure the uniformity of the magnetic field force outside the radial notch. When the radial permanent magnet ring applies a radial load force F1, the radial pressure sensor will be affected by a pressure F3, simplifying the force application problem of the radial permanent magnet ring into a solution problem of a circular ring with an inner diameter r, an outer diameter R, a thickness L, and a uniformly distributed pressure F1. The following calculation relationship exists between the two:

[0014]

[0015] In the formula, A is the cross-sectional area of the circular ring, ρ is the radius where it is located, and the negative sign indicates compression;

[0016] The coil of the axial electromagnet ring is formed by axially stacking circular coils, and has the characteristic of a strong magnetic field with magnetic lines in the axial direction, which is convenient for applying an axial load. The magnitude of the axial force F2 and the measured force F4 of n axial tension-compression sensors satisfy

[0017] F2 = n × F4 (2)

[0018] Due to their own uniformly distributed radial and axial magnetic fields, the radial permanent magnet ring and the axial electromagnet ring apply a uniformly distributed load force to the propeller fan test piece, and there is no interference problem of load instability caused by periodic torque and periodic circumferential bending moment generated on the propeller fan test piece when a single load force is applied during rotating loading.

[0019] A static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, characterized in that the methods of applying loads under static and rotating conditions are as follows:

[0020] The static-rotating loading device for a propeller fan mechanism based on electromagnetic force control can apply an axial force F2 and a radial force F1 according to the load spectrum obtained by simulation and other methods under static conditions. During loading, electromagnetic force is used for force transmission, avoiding the binding force caused by the top wire drawing loading when the test piece undergoes strain, which interferes with the deviation between the actual and theoretical values of the axial force and the axial bending moment.

[0021] The described static-rotary loading device for a propeller fan mechanism based on electromagnetic force control. Under rotational conditions, due to contactless electromagnetic force transmission, the loading end is stationary, reducing the harsh test conditions and eliminating technical problems related to lubricating oil lubrication and oil circuit sealing, extending the service life of the equipment, and thus enabling loading under rotational conditions. When applying loads under rotational conditions, the additional loads applied by the propeller fan test piece on the hub central part due to rotation need to be deducted from the load spectrum.

[0022] The described static-rotary loading device for a propeller fan mechanism based on electromagnetic force control is characterized in that the control unit has the following features:

[0023] The control unit includes a power supply, a controller, and a human-machine interface. The controller controls the magnitude of the current delivered by the power supply and receives the feedback signal from the sensor. The human-machine interface displays the load application status in real time. When starting the power supply through operation on the human-machine interface, the system automatically gives a compensation current to the radial permanent magnet ring and the axial electromagnet ring, that is, zero calibration of the radial pressure sensor and the axial tension-compression sensor is performed. The controller receives the force command signal of the load spectrum and outputs two currents of a certain magnitude according to the control law to control the radial permanent magnet ring and the axial electromagnet ring to output electromagnetic forces meeting the requirements. Finally, the feedback force signals of the radial pressure sensor and the axial tension-compression sensor are transmitted to the controller, and the controller converts the signals into the magnitude of the applied load according to the conversion formulas (1) and (2), realizing precise closed-loop control of the radial force, axial force + axial bending moment of the propeller fan test piece.

[0024] Compared with the prior art, the advantages of the present invention are as follows: It adopts a contactless electromagnetic force transmission method for the test piece, realizes independent loading of radial force, axial force + axial bending moment. Since the load-bearing form can still transmit force when the propeller fan test piece rotates, the loading schemes under static and rotational conditions are completed. And the loading end uses an electromagnet controlled by current to control the magnitude of the applied load, and uses sensors for force feedback control, which can achieve the advantages of precise and rapid response of bidirectional load transmission. The present invention solves the complex cross-linking problems of the load-bearing form and the force transmission route under static and rotational conditions, and has the advantages of no binding force interference to the propeller fan test piece, good independent loading of radial force, axial force + axial bending moment, simultaneous satisfaction of loading under static-rotational conditions, and the loading end being a stationary part with no oil leakage and the electromagnetic force loading equipment being simple and having a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a static-rotary loading device for a propeller fan mechanism based on electromagnetic force control of the present invention.

[0026] Figure 2 It is an exploded assembly diagram of a static-rotary loading device for a propeller fan mechanism based on electromagnetic force control of the present invention.

[0027] Figure 3 Schematic diagram of the coils and magnetic field structures of the radial electromagnet ring and the axial electromagnet ring of the present invention.

[0028] Figure 4 Schematic diagram of the structure of the radial electromagnet ring and the radial pressure sensor of the present invention.

[0029] In the figure: 1 - axial permanent magnet ring, 2 - radial permanent magnet ring, 3 - propeller fan test piece, 31 - "C"-shaped fan body, 32 - tensile rotary joint, 4 - radial electromagnet ring, 41 - first notch axial extension part, 42 - second notch axial extension part, 43 - radial notch, 44 - radial coil, 5 - soft body ring, 6 - electromagnet support frame, 7 - axial electromagnet ring, 71 - axial coil, 8 - radial pressure sensor, 9 - first support, 91 - bearing, 10 - axial tension and compression sensor, 11 - second support. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figure 1 and Figure 2, in the embodiments of the present invention, a static-rotating loading device for a propeller fan mechanism based on electromagnetic force control includes: an axial permanent magnet ring 1, a radial permanent magnet ring 2, a propeller fan test piece 3, a radial electromagnet ring 4, a soft body ring 5, an electromagnet support frame 6, an axial electromagnet ring 7, a radial pressure sensor 8, an axial tension-compression sensor 10, a first support 9, a bearing 91, a second support 11, and a control unit. The propeller fan test piece 3 includes a tensile rotating joint 32 in the lower half and a "C"-shaped fan body 31 in the upper half. A plurality of propeller fan test pieces 3 are closely arranged and have minute radial cracks to eliminate the interference of circumferential strain force under radial loading. The propeller fan test piece 3 is installed on the propeller fan pitch interface of the propeller fan wheel disc and is driven to rotate by a rotating shaft. The axial permanent magnet ring 1 and the radial permanent magnet ring 2 are arranged with the same magnetic pole directions (the N poles of the axial permanent magnet ring 1 face the positive or negative axial direction in the same orientation, and the N poles of the radial permanent magnet ring 2 diverge or converge in the same radial direction), and are respectively installed in the side wall ring and the top wall ring of the propeller fan test piece 3. The radial electromagnet ring 4 and the axial electromagnet ring 7 are respectively installed in non-contact with the axial permanent magnet 1 and the radial permanent magnet 2. The axial circular ring on the electromagnet support frame 6 serves as a guide rail for the axial electromagnet ring 7 and also serves as a radial force support for the radial electromagnet ring 4. The radial electromagnet ring 4 has a radial notch 43, a first notch axial extension 41, and a second notch axial extension 42. The radial pressure sensor 8 is installed between the two notch axial extensions to sense the magnitude of the radial force. The axial electromagnet ring 7 is provided with an axial tension-compression sensor 10 at its end to sense the magnitude of the axial force and does not hinder the radial deformation of the radial electromagnet ring 4. The soft body ring 5 is sandwiched between the radial electromagnet ring 4 and the electromagnet support frame 6 to uniformly compensate for the radial displacement of the radial electromagnet ring 4 during radial loading, so that the radial force is applied as evenly as possible on the propeller fan test piece 3 and reacts on the radial electromagnet ring 4;

[0032] Due to the counteraction of the tensile rotating joint 32, the propeller fan test piece 3 will not rotate around the midpoint of the blade root during the pitch change process of the propeller fan pitch system. The axial electromagnet ring 7 can apply non-contact axial pressure and tension to the propeller fan test piece during the pitch change process. The magnitude of the magnetic force applied by the axial electromagnet ring 7 to the propeller fan test piece 3 is controlled by the coil current. The axial electromagnet ring 7 needs to ensure that there is no additional load on the propeller fan test piece 3 when there is no loading, that is, there is a compensating current to generate a reverse electromagnetic force to resist the suction force of the permanent magnet on the iron core of the axial electromagnet ring 7, and by changing the direction of the coil current of the axial electromagnet ring 7, the applied load can be changed to tension or pressure to achieve bidirectional loading. The radial permanent magnet ring 2 applies a radial force on the propeller fan test piece 3 and also has the technical characteristics of the above-mentioned loading force;

[0033] The described static-rotary loading device for a propeller fan mechanism based on electromagnetic force control is supported by a first support 9 and a second support 11. A bearing 91 is installed on the first support 9 and sleeved on the rotating shaft of the propeller fan disk. The second support 11 is fixedly connected to the electromagnet support frame 6 to form a static loading end for resisting the reaction force transmitted from the electromagnet support frame 6.

[0034] Please refer to Figure 3 and Figure 4 In the embodiment of the present invention, for the described static-rotary loading device for a propeller fan mechanism based on electromagnetic force control, it is characterized in that the structures, magnetic field characteristics, and forces of the radial permanent magnet ring 2 and the axial electromagnet ring 7 have the following characteristics:

[0035] The coil of the radial permanent magnet ring 2 is composed of stacked rectangular coils. It is bent circumferentially along the stacking direction, and then the two ends of the coil are in contact to form a circular coil. When a direct current is passed through the circular coil, a strong magnetic field with magnetic force lines radially outward will be formed, which is used to apply a radial force load to the propeller fan test piece 3. The radial electromagnetic force ring 4 has a radial notch 43, as well as a first notch axial extension 41 and a second notch axial extension 42. The radial pressure sensor 8 is installed between the two notch axial extensions. The contact part of the two ends of the coil is placed at the radial notch 43 to ensure the uniformity of the magnetic field force outside the radial notch 43. When the radial permanent magnet ring 2 applies a radial load force F1, the radial pressure sensor 8 will be affected by a pressure F3, simplifying the force application problem of the radial permanent magnet ring 2 into a problem of solving a circular ring with an inner diameter r, an outer diameter R, a thickness L, and a uniformly distributed pressure F1. The following calculation relationship exists between the two:

[0036]

[0037] In the formula, A is the cross-sectional area of the circular ring, ρ is the radius, and the negative sign indicates compression;

[0038] The coil of the axial electromagnet ring 7 is formed by axially stacking circular coils, having the characteristic of a strong magnetic field with magnetic force lines in the axial direction, which is convenient for applying an axial load. The magnitude of the axial force F2 and the measured force F4 of n axial tension and compression sensors (10) satisfy

[0039] F2 = n × F4 (2)

[0040] Due to their own uniformly distributed radial and axial magnetic fields, the radial permanent magnet ring 2 and the axial electromagnet ring 7 apply a uniformly distributed load force to the propeller fan test piece 3, and there is no problem of unstable load interference caused by the periodic torque and periodic circumferential bending moment generated on the propeller fan test piece 3 when a single load force is applied during rotary loading.

[0041] Please refer to Figure 1, in the embodiment of the present invention, a static-rotating loading device for a propeller fan mechanism based on electromagnetic force control is characterized in that the ways of applying loads under static and rotating conditions are as follows:

[0042] The described static-rotating loading device for a propeller fan mechanism based on electromagnetic force control can apply an axial force F2 and a radial force F1 according to the load spectrum obtained by means of simulation, etc. under static conditions. During loading, electromagnetic force is used for force transmission, avoiding the binding force caused by the top wire drawing loading when the test piece undergoes strain, which interferes with the actual deviation of the axial force and the axial bending moment.

[0043] The described static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, under rotating conditions, due to non-contact electromagnetic force transmission, the loading ends are all static, reducing the harsh conditions of the test and eliminating technical problems such as lubricating oil lubrication and oil circuit sealing, extending the service life of the equipment, and thus realizing loading under rotating conditions. For loading under rotating conditions, the additional loads applied by the propeller fan test piece 3 on the hub central part due to rotation need to be deducted from the load spectrum.

[0044] The described static-rotating loading device for a propeller fan mechanism based on electromagnetic force control can apply an axial force F2 and a radial force F1 according to the load spectrum obtained by means of simulation, etc. under static conditions. When simulating radial centrifugal force loading, electromagnetic force is used for force transmission, avoiding the binding force caused by the top wire drawing loading when the test piece undergoes strain, which interferes with the actual and theoretical deviations of the axial force and the axial bending moment. When simulating axial aerodynamic loads, by applying the axial force F2 of the axial electromagnet ring 7, while applying an axial bending moment M1 = F2 × L1 (L1 is the radial distance from the axial loading hydraulic cylinder to the blade root O point), the total axial force F2 can be adjusted.

[0045] The described static-rotating loading device for a propeller fan mechanism based on electromagnetic force control, under rotating conditions, due to non-contact magnetic force transmission, the axial electromagnet ring 7, radial permanent magnet ring 2, soft body ring 5, electromagnet support frame 6, etc. at the loading ends are all static, that is, the loading ends are all static, reducing the harsh conditions of the test and eliminating technical problems such as lubricating oil lubrication and oil circuit sealing, extending the service life of the equipment, and thus realizing loading under rotating conditions. For loading under rotating conditions, the centrifugal loads, axial forces, axial bending moments, etc. applied by the propeller fan test piece 3 on the hub central part due to rotation need to be deducted from the load spectrum.

[0046] In the embodiment of the present invention, the described static-rotating loading device for a propeller fan mechanism based on electromagnetic force control is characterized in that the control unit has the following characteristics:

[0047] The described control unit includes a power supply, a controller, and a human-machine interface. The controller controls the magnitude of the current delivered by the power supply to the radial permanent magnet ring 2 and the axial electromagnet ring 7, and receives the feedback signals from the radial pressure sensor 8 and the axial tension-compression sensor 10. The human-machine interface displays the load application status in real time. When starting the power supply through operation on the human-machine interface, the system automatically gives compensation currents to the radial permanent magnet ring 2 and the axial electromagnet ring 7, that is, zero calibration of the radial pressure sensor 8 and the axial tension-compression sensor 10 is performed. The controller receives the force command signal of the load spectrum, and outputs two currents of a certain magnitude according to the control law to control the radial permanent magnet ring 2 and the axial electromagnet ring 7 to output electromagnetic forces meeting the requirements. Finally, the feedback force signals of the radial pressure sensor 8 and the axial tension-compression sensor 10 are transmitted to the controller, and the controller converts the signals into the magnitude of the applied load force according to the conversion formulas (1) and (2), realizing precise closed-loop control of the radial force, axial force + axial bending moment of the propfan test piece 3;

[0048] The present invention is not limited to the above embodiments. Based on the technical solutions disclosed in the present invention, those skilled in the art can make some simple modifications, equivalent changes, and modifications to some of the technical features without creative labor according to the disclosed technical content, and all belong to the scope of the technical solutions of the present invention.

Claims

1. A static-rotating loading device for a paddle fan mechanism based on electromagnetic force control, comprising: Axial permanent magnet ring (1), radial permanent magnet ring (2), propeller fan test piece (3), radial electromagnet ring (4), soft ring (5), electromagnet support frame (6), axial electromagnet ring (7), radial pressure sensor (8), axial tension-compression sensor (10), first support (9), bearing (91), second support (11) and control unit. The propeller fan test piece (3) includes a tensile rotary joint (32) in the lower half and a "C"-shaped fan body (31) in the upper half. A plurality of propeller fan test pieces (3) are closely arranged and have minute radial cracks to eliminate the interference of circumferential strain forces under radial loading. The propeller fan test piece (3) is installed on the propeller fan pitch interface of the propeller fan disk and is driven to rotate by a rotating shaft. The axial permanent magnet ring (1) and the radial permanent magnet ring (2) are arranged with the same magnetic pole direction and are respectively installed in the side wall ring and the top wall ring of the propeller fan test piece (3). The radial electromagnet ring (4) and the axial electromagnet ring (7) are respectively installed in non-contact with the axial permanent magnet (1) and the radial permanent magnet (2). The radial electromagnet ring (4) has a radial notch (43), as well as a first notch axial extension part (41) and a second notch axial extension part (42). The radial pressure sensor (8) is installed between the two notch axial extension parts to sense the magnitude of the radial force. The axial electromagnet ring (7) is provided with an axial tension-compression sensor (10) at its end to sense the magnitude of the axial force. The soft ring (5) is clamped between the radial electromagnet ring (4) and the electromagnet support frame (6) to uniformly compensate for the radial displacement of the radial electromagnet ring (4) during radial loading, so that the radial force is applied as evenly as possible on the propeller fan test piece (3) and reacts on the radial electromagnet ring (4). Due to the cancellation effect of the tensile rotary joint (32), the propeller fan test piece (3) will not rotate around the midpoint of the blade root during the pitch change process of the propeller fan pitch system. The axial electromagnet ring (7) can apply non-contact axial pressure and tension to the propeller fan test piece during the pitch change process. The magnitude of the magnetic force applied by the axial electromagnet ring (7) on the propeller fan test piece (3) is controlled by the coil current. The axial electromagnet ring (7) needs to ensure that there is no additional load on the propeller fan test piece (3) when there is no load, that is, there is a compensating current to generate a reverse electromagnetic force to resist the suction force of the permanent magnet on the iron core of the axial electromagnet ring (7), and by changing the direction of the coil current of the axial electromagnet ring (7), the applied load can be changed to tension or pressure to achieve bidirectional loading. The radial permanent magnet ring (2) applies a radial force on the propeller fan test piece (3) and also has the technical characteristics of the above-mentioned loading force. The propeller fan mechanism static-rotation loading device based on electromagnetic force control is supported by the first support (9) and the second support (11). A bearing (91) is installed on the first support (9) and sleeved on the rotating shaft of the propeller fan disk. The second support (11) and the electromagnet support frame (6) are fixedly connected to form a static loading end for resisting the reaction force transmitted from the electromagnet support frame (6).

2. The static-rotating loading device of a propeller fan mechanism based on electromagnetic force control according to claim 1, wherein The structures, magnetic field characteristics, and forces of the radial permanent magnet ring (2) and the axial electromagnet ring (7) have the following characteristics: The coil of the radial permanent magnet ring (2) is formed by stacking rectangular parallelepiped coils, which are bent circumferentially along the stacking direction, and then the two ends of the coil are brought into contact to form a circular coil. The circular coil will form a strong magnetic field with magnetic lines of force radially outward when passing a direct current, which is used to apply a radial force load to the propeller fan test piece (3). The radial electromagnetic force ring (4) has a radial notch (43), as well as a first notch axial extension part (41) and a second notch axial extension part (42). The radial pressure sensor (8) is installed between the two notch axial extension parts. The two ends of the coil are placed at the radial notch (43). When the radial pressure sensor (8) is subjected to a pressure F3 when applying a radial load force F1 to the radial permanent magnet ring (2), the problem of applying force to the radial permanent magnet ring (2) is simplified to a problem of solving a circular ring with an inner diameter r, an outer diameter R, a thickness L, and a uniformly distributed pressure F1. The following calculation relationship exists between the two: In the formula, A is the cross-sectional area of the circular ring, ρ is the radius at which it is located, and the negative sign indicates compression; The coil of the axial electromagnet ring (7) is formed by axially stacking circular coils, and has the characteristic of a strong magnetic field with magnetic lines of force in the axial direction, which is convenient for applying an axial load. The magnitude of the axial force F2 and the measured force F4 of n axial tension and compression sensors (10) satisfy F2 = n × F4 (2) Due to their own uniformly distributed radial and axial magnetic fields, the radial permanent magnet ring (2) and the axial electromagnet ring (7) apply a uniformly distributed load force to the propeller fan test piece (3), and there is no problem of unstable load interference that generates periodic torque and periodic circumferential bending moment on the propeller fan test piece (3) when a single load force is applied during rotation.

3. A static-rotating loading device for a paddle fan mechanism based on electromagnetic force control as claimed in claim 1, wherein The methods of applying loads under static and rotating conditions are as follows: The described propeller fan mechanism static-rotation loading device based on electromagnetic force control can apply the axial force F2 and the radial force F1 according to the load spectrum obtained by means such as simulation under static conditions. During loading, electromagnetic force is used for force transmission, avoiding the binding force caused by the top wire drawing loading when the test piece undergoes strain, which interferes with the deviation between the actual and theoretical values of the axial force and the axial bending moment. The described propeller fan mechanism static-rotation loading device based on electromagnetic force control, under rotating conditions, due to non-contact electromagnetic force transmission, the loading ends are all stationary, reducing the harsh conditions of the test, and there are no technical problems of lubricating oil lubrication and oil circuit sealing, extending the service life of the equipment, thereby realizing loading under rotating conditions. When applying loads under rotating conditions, the additional loads applied by the propeller fan test piece (3) to the hub central part due to rotation need to be deducted from the load spectrum.

4. The static-rotating loading device of a paddle fan mechanism based on electromagnetic force control according to claim 1, characterized in that, The control unit has the following characteristics: The described control unit includes a power supply, a controller, and a human-machine interface. The controller controls the magnitude of the current delivered by the power supply and receives the feedback signal from the sensor. The human-machine interface displays the load application status in real time. When starting the power supply through operation on the human-machine interface, the system automatically gives a compensation current to the radial permanent magnet ring (2) and the axial electromagnet ring (7), that is, zero calibration of the radial pressure sensor (8) and the axial tension-compression sensor (10) is performed. The controller receives the force command signal of the load spectrum and outputs two currents of a certain magnitude according to the control law to control the radial permanent magnet ring (2) and the axial electromagnet ring (7) to output electromagnetic forces that meet the requirements. Finally, the feedback force signals of the radial pressure sensor (8) and the axial tension-compression sensor (10) are transmitted to the controller, and the controller converts the signals into the magnitude of the applied load force, realizing precise closed-loop control of the radial force, axial force + axial bending moment of the propeller fan test piece (3).

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